GI Flashcards

Question

Chronic severe pyloric lesions in horses: 47 cases

Answer 1

-Chronic severe pyloric lesions predominantly presented in younger horses (median age 3 years) with nonspecific signs such as: Poor body condition (87%) Slow eating (83%) Recurrent colic (74%) Selective appetite (64%) Other signs included frequent recumbency (57%), reflux oesophagitis (19%), and grade 4 squamous ulceration in 85% of cases. -Reduced or absent pyloric motility was noted in most cases. -Gastric dilation and delayed gastric emptying were identified in over half of the evaluated cases. -Medical management with omeprazole was the most common approach. -Gastrojejunostomy was performed in 4 cases to address gastric outflow obstruction, with 2 long-term survivors. -Overall, long-term survival (>6 months) was 41%, with younger horses (<3 years) showing significantly lower survival rates compared to older horses (27.8% vs. 72.2%).

Answer 2

-ileal samples only -all IBD cases, irrespective of diaginosis, were characterised by villous atrophy and lymphoid hyperplasia of the mucosa and submucosa. -The EG cases were further characterised by submucosal and sometimes granulomatous eosinophilic infiltrate, which would extend to a varying degree into the muscularis externa. -The GE cases would frequently have granulomatous epithelioid macrophage clusters of the mucosa and/or submucosa and the lymphoid hyperplasia was often nodular. -The percentage of immunolabelling in IBD horses was reduced for both markers of ICC in the MP region but not in the inner circular muscle layer compared with the control horses. No significant reductions in immunolabelling for nerve cell and glial cell markers were detected in the MP region or inner circular muscle layer. Did not differe between EE and GE -ICC markers= CD117 and TMEM16. Neuronal (PGP9.5) and glial cell (GFAP) -Horses with granulomatous enteritis (GE) exhibited greater variability in ICC reduction compared to those with eosinophilic gastroenteritis (EG).

Answer 3

-Not significant when counfounding taken into account (p=0.07) in multivariable analysis. (sex, breed, metabolic disease) - Incisional complication prevalence was 23.7%. -Horses with incisional complications had a higher BMI (median 203.6 kg/m2 IQR = 191.5-217.4) compared with those without (median 199.1 kg/m2 , IQR = 184.7-210.2) (P = .03). - does not appear to be associated with surgical time.

Answer 4

-The mean values for bodyweights decreased by 7.2% from baseline in unfed horses by the end of the 4-day period of feed deprivation and remained constant in fed horses -Feed deprivation immediately and persistently reduced water consumption to ~16% of fed values, During feed deprivation, horses drank 10.3 mL/kg/d over the 4 days, compared with 63.4 mL/kg/d during fed conditions. Constant throughout the 4 days - laboratory evidence of mild dehydration on day 4; TPP was significantly elevated by feed deprivation on day 4, BUN on days 2-4 and creatinine on days 1-4 (but all remained within rr). No physical evidence of dehydration

Answer 5

-1438 horses from 26 participating institutions from 4 continents were included; - An enteropathogen was identified in 16%: Salmonella spp. 13%. ECoV 9%, C. difficile in 5%, 8.3% AAD. 5% sand enterocolitis. - 76% survived to discharge with no differences identified between geographic regions. - Associated with non survival: SIRS, SIRS and creatinine concentrations > 159 μmol/L, SIRS that had an L-lactate concentration > 2.8 mmol/L , laminitis, increases in PCV, L-lactate and creatinine and TPP at admission, presence of altered mentation and a toxic line in the oral mucus membranes on admission, -66% met SIRS criteria-- ROC curve analysis revealed that a creatinine concentration > 159 μmol/L and an L-lactate concentration > 2.9 mmol/L had the highest sensitivity and specificity to predict the outcome of non-survival when combined with meeting SIRS criteria - Total 7% developed laminitis -The proportion of horses that developed laminitis was lower in Europe. -More horses developed laminitis in the summer (46%, 39/85)

Answer 6

-Horses with NSII and inflammatory abdominal diseasehad higher serum and peritoneal fluid concentrations of NGAL than the other groups (p < 0.001). - Peritoneal fluid NGAL concentrations in horses with NSII were higher than in horses with inflammatory abdominal disease (p = 0.03). - Serum NGAL increased with duration of colic (peritoneal trended but no specific interval differences) -seruma and peritoneal NGAL moderately correlated (r=.5). serum NGAL corrleated with inflammatory markers, and peritoneal NGAL correlated with peritoneal WCC (r=.6) - differential expression in peritoneal fluid may differentiate NSII that may need Sx -Rapid rise and fall pattern

Answer 7

-Morbidity rates were not different between mare groups with 56% of pregnant mares and 51% of control mares reporting at least 1 morbidity. -Nonsurvival was higher in pregnant mares (13%) compared to control mares (5%; P = 0.02) -Swelling was the most common complication in both groups (54% in pregnant mares and 50% in controls), followed by drainage, infection, hernia, and dehiscence. -Longer surgical and anesthesia times were significantly associated with increased risks of swelling and drainage. -Abdominal bandage use was strongly linked to the presence of drainage, infection, and hernia, though this may reflect its application as a response to existing complications. --Nonsurvival was higher in pregnant mares (13%) compared to control mares (5%; P = 0.02) - high rate of caesarean (14/42) in pregnant mares. 12 had caesarean at the time of colic surgery (7 foals survived to discharge)

Answer 8

The procedure was well tolerated in all horses. Minor complications observed were a transient facial paralysis, some incisional fluid collection, and abscesses. Ten samples (10/12) were suitable for assessment of neuronal perikarya, thougn only 8 were from the correct location. Only looked at 2 chronic EGS cases (absence of neurones). Targeted foliate papillae

Answer 9

--Miniature horses and ponies were overrepresented and equids ≤ 1 year of age were overrepresented in the fecalith population compared to the colic population. -92% survived to discharge, 6% were euthanized intraoperatively, and 2% were euthanized during hospitalization. -Nonsurvivors showed more severe colic signs on admission, tachycardia on admission, and hyperlipemia. -Equids with postoperative colic (P = .01) and complications (P = .002) were less likely to survive. - As a group, equids with fecalith obstruction presented with a moderately elevated heart rate, elevated respiratory rate, and normal rectal temperature 37.9 ± 0.6 °C. Hematocrit and TP were normal to elevated with hyperlactatemia and hypertriglyceridemia. Peritoneal fluid TNCC were elevated with an elevated TP -Age (greater), heart rate (lower), and peritoneal TNCC (lower) were significantly different (P < .04) between large colon fecalith obstructions and small colon

Answer 10

-Reduced duodenal contractility at Day 1 postoperatively (6–36 hours) was significantly associated with the development of postoperative reflux (POR; p = 0.013). -Horses with increased duodenal contractility had better odds of survival, with an odds ratio of 1.88 per additional contraction per 2 minutes (p = 0.039). -No clear contraction rate cutoff was identified to definitively distinguish between refluxing and non-refluxing horses, or survivors and nonsurvivors. -Contractility measured after Day 1 did not show significant differences between groups. -Excellent agreement between observers (weighted kappa coefficient = 0.871), indicating that ultrasonographic assessment of duodenal contractility is a reliable technique.

Answer 11

-Foals in Group FA (dewormed at 2 and 5 months) had significantly higher strongylid and ascarid egg counts than foals in Group FB (dewormed monthly with alternating anthelmintics). -No significant differences in strongylid egg counts were observed between the mare groups, regardless of treatment frequency. - significant differences in bodyweight between foal groups were detected, suggesting that reduced deworming in Group FA did not adversely affect growth. -Mares in Group MA (treated twice yearly) had slightly lower bodyweights compared to other groups, but this finding lacked a clear explanation. -Overall, very few health abnormalities were noted across all groups, indicating that the reduced deworming regimens did not negatively impact general health within the study period. -long term effects not investigated, 1 season on 1 farm only. SB and TB

Answer 12

-Strongyle eggs were detected in only 9% of 851 fecal samples from 79 horses across a 7-year study period in an arid environment. -By the study's conclusion, 97% of fecal samples were negative for strongylid parasites, reflecting effective parasite management. -The arid climate, characterized by low moisture and limited pasture, likely contributed to reduced parasite burden, as strongylid eggs and larvae depend on moisture and moderate temperatures for survival. -Frequent manure removal from stables minimized environmental contamination, further reducing infection risks. -Used a qualitative faecal float and gave moxidectin to all positive

Answer 13

-Transportation significantly increased gastric squamous ulcer scores but not glandular -Ulceration developed rapidly within 12 hours, particularly in horses fasted for 12 hours before transport. -Median gastric fluid (GF) pH during transportation increased significantly (median 6.8-7.2, p < 0.001), suggesting reflux of alkaline small intestinal content as a potential cause. -Confinement without transport (12 hours) did not lead to significant changes in gastric ulcer scores or median GF pH (median pH 1.7-2.5). -Horses fasted for 12 hours before transportation exhibited more severe gastric squamous ulceration. -Feeding closer to the time of departure (within 1-6 hours) was associated with higher retained gastric content and less severe ulceration, possibly providing protective effects. -Gastric ulceration appeared associated with contact between the squamous mucosa and alkaline reflux, rather than prolonged acid exposure. -Alkaline reflux may involve duodenal bile salts and short-chain fatty acids, known to impair mucosal integrity. -? effect of pre movement PPIs

Answer 14

Differences in microbial community composition based on time point and health status were not observed on any taxonomic level. Limited differences were seen on linear discriminant analysis effect size analysis. No difference in alpha diversity indices was observed including richness, diversity based on health status, or time point. No effect of health status on microbial community membership structure was observed. Alpha diversity measures the diversity within a single sample, while beta diversity measures the dissimilarity between two samples Small study, underpowered and faecal only, bacteria only

Answer 15

-Peritoneal bile acids concentration (PBAC) was significantly higher in horses with hepatic and gastrointestinal (GI) ischemic-inflammatory disorders compared to healthy horses and those with GI obstructive conditions. Median PBAC: -Hepatic group: 6.8 µmol/L -GI ischemic-inflammatory group: 3.3 µmol/L -GI obstructive group: 1.2 µmol/L -Healthy controls: 1.0 µmol/L -Horses with non-survivable conditions had significantly higher PBAC (median 4.1 µmol/L) than survivors (median 1.3 µmol/L; p < 0.001). -A PBAC threshold of ≥2.28 µmol/L was associated with hepatic or severe abdominal disease. I think this is essentially meaningless as only 11 healthy controls. -A weak correlation (ρ = 0.44, p < 0.001) between plasma and peritoneal bile acid levels was observed, suggesting that PBAC reflects localized abdominal processes rather than systemic bile acid dynamics. -PBAC demonstrated fair specificity (61%) and negative predictive value (94%) for diagnosing hepatic disease. -For severe abdominal disease (hepatic or ischemic-inflammatory), PBAC showed higher specificity (89%) and positive predictive value (84%).

Answer 16

-Geriatric horses (≥20 years old) had significantly lower survival rates compared to younger horses (2-12 years old). Survival decreased by 11.8% per year of age, geriatric horses were 15.2 times less likely to survive than young-adult. -Plasma transfusion was associated with lower survival -IL-6 and TNF-a were significantly higher in geriatric horses at the onset of diarrhea and remained elevated 6 hours later -No significant differences in Th1/Th2 cytokines (e.g., IFN-γ, IL-4, IL-10)- inflammaging rather than immune shift. -clinical and laboratory parameters did not significantly differ between age groups, indicating similar disease severity. -Pituitary pars intermedia dysfunction (PPID) was more common in geriatric horses but was not associated with survival outcomes. No other comorbidities significantly impacted survival. Immunosenescence - age-associated remodeling of the immune system =alterered adaptive immune response with a reduced number of naïve T cells, an accumulation of impaired memory T cells, and a decrease in the type-1 T helper (Th1)/type-2 T helper (Th2) ratio. - an increase in type-2 (humoral immunity) cytokines such as interleukin-4 (IL-4) and interleukin-10 (IL-10) and potential decrease in type-1 (cellular immunity) cytokines such as interferon-γ (IFN-γ) may be observed in aging patients. Inflammaging, a chronic low-grade inflammatory state associated with aging. Sustained antigenic load and immune stress endured throughout life result in chronic macrophage activation and subsequent production of proinflammatory cytokines, especially IL-6, TNF-α, and IL-1. Evidence of inflammaging has been documented in healthy geriatric horses, with increased expression or blood levels of pro-inflammatory cytokines such as TNF-α and IL-6.

Answer 17

- Werid study that overstates conclusions. Really small groups. -EGGD score increased in PBZ (median change 1) compared to PBZ/OME (median change 0). Just reached significance -High rate of complications! Including 2 dead and 5 did not complete -PBZ/OME (6/8) had more intestinal complications than CON (0/6). 2PBZ developed intestinal complications- not significant (p=0.4) -Plasma protein concentrations decreased in PBZ, compared to CON - squamous ulcers not affected

Answer 18

No signinficant increase of SAA with EGUS or type of ulceration. Medians all within rr.

Answer 19

-Overall agreement using the descriptive grading system was poor (Krippendorff's alpha: 0.19). -Agreement was better for individual categories but remained low: Severity: Fair to moderate (α = 0.52). Distribution: Weak (α = 0.44). Appearance: Minimal (α = 0.38). Shape: Minimal (α = 0.32). -Agreement using the Verbal Rating Scale (VRS; 0–2 grading) was weak (α = 0.53), similar to severity agreement in the descriptive system. -Diplomates achieved higher agreement across all categories compared to non-specialists. Familiarity with the descriptive system improved agreement, regardless of specialist status. -Respondents using the descriptive system in practice showed better consistency.

Answer 20

-The overall prevalence of equine glandular gastric disease (EGGD) across all gastroscopies was 67% (95% CI: 51.6–79). -Prevalence was similar to that in sport horse and leisure horse populations, despite the absence of typical risk factors such as intense exercise or NSAID administration. -Disease severity over time varied: 29% of horses showed worsening of EGGD. 24% showed improvement. 10% had complete resolution. 38% showed no change in disease grade. Among horses with no initial EGGD, 44% developed the disease during the study period. -Despite being retired from athletic use, the teaching herd experienced stressors such as frequent handling by multiple students and staff, separation from the herd, and invasive teaching procedures. -Stress and herd dynamics were hypothesized as contributing factors to EGGD in this population. -Most lesions were mild, multifocal, flat, and haemorrhagic, typically located in the antrum and pylorus.

Answer 21

-IAH, defined as ventral intra-abdominal pressure (IAP) ≥32 mmHg, was present in 30.4% of horses with colic. -Horses with large intestine (LI) medical lesions had the highest IAP levels (mean 36.5 mmHg), compared to other colic categories. -Horses with IAH and medically managed lesions were 15 times more likely to survive compared to horses with IAH requiring surgery (p=0.038). -IAH was not independently predictive of the need for surgery but was associated with poorer survival outcomes in surgical cases. -An IAP cutoff of 32 mmHg showed 31% sensitivity and 100% specificity for identifying horses requiring surgical intervention. -IAH's high specificity indicates its utility for confirming severe cases but highlights limitations as a standalone predictive measure for surgical needs.

Answer 22

Xyl/ lido given 70 mins prior to induction of 10% blood flow jejunal ischemia. n=5/group Histomorphological Injury: -Mucosal injury worsened significantly after ischemia in all groups but did not progress further after reperfusion. -Neither lidocaine nor xylazine preconditioning significantly reduced histomorphological injury compared to the control group. Apoptosis and Inflammatory Markers: -Xylazine preconditioning reduced apoptosis, as indicated by a lower count of caspase-3-positive cells after ischemia compared to the control group (227% median reduction; p = 0.01). -After reperfusion, xylazine-treated horses exhibited significantly fewer calprotectin-positive cells in the mucosa and serosa compared to controls, suggesting reduced inflammation. -Lidocaine preconditioning did not significantly affect apoptosis or inflammatory markers. -Xylazine though it did not reduce observable tissue injury. Lidocaine did not exhibit consistent protective effects under the study conditions.

Answer 23

Mechanistically, both pre- and post-conditioning activate a common group of survival protein kinases that lead to attenuation of ischaemia-reperfusion injury '-Dexmedetomidine significantly reduced histological evidence of ischemia-reperfusion injury in equine small intestine. Preconditioning showed greater protection than post-conditioning Horses receiving dexmedetomidine pre- or post-conditioning exhibited: -Lower epithelial injury scores. -Reduced villus surface area (VSA) epithelial denudation. -Better preservation of villus height and crypt-villus ratios compared to controls. -Dexmedetomidine pre- and post-conditioning reduced markers of inflammation, including polymorphonuclear cell (PMN) infiltration and necrotic cell debris. -Reduced apoptosis was observed, indicated by lower cleaved caspase-3 and TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling) activity. -Post-conditioning is more clinically applicable since ischemia in natural colic cases is unpredictable. -Protection likely arises from dexmedetomidine’s anti-inflammatory and anti-apoptotic properties, including modulation of lipid peroxidation and oxidative stress. -Its ability to attenuate cytokine-mediated inflammation and stabilize cellular membranes supports improved outcomes during reperfusion.

Answer 24

-Omeprazole significantly increased gastric pH after 7 days of administration (mean increase from 3.7 to 6.1; p = 0.006) -Significant shifts in the gastric glandular microbiota were observed, with a decrease in evenness after omeprazole treatment (p = 0.05). -The abundance of Clostridium sensu strictu_1 increased significantly (p = 0.002), suggesting that reduced gastric acidity allows for the proliferation of certain bacterial populations. -Overall bacterial richness and diversity in the gastric glandular mucosa did not change significantly. -No significant changes were observed in the richness, diversity, or composition of fecal microbiota after omeprazole administration. -The effects of omeprazole on gastric microbiota were highly variable among individuals, with some horses showing greater shifts in specific bacterial populations than others (implications of small sample size)

Answer 25

EGUC -substantial interobserver reliability for squamous (mean AC2 = 0.69) and glandular mucosa (mean AC2 = 0.72). -Intraobserver reliability was excellent for both squamous and glandular mucosa (mean AC2 = 0.80). -Observer experience had minimal impact on reliability for the EGUC system, supporting its robustness across different skill levels. VAS: -moderate interobserver reliability for squamous mucosal grading (mean ICC = 0.64) but poor reliability for glandular mucosa (mean ICC = 0.35). -Intraobserver reliability was good for squamous mucosa (mean ICC = 0.74) but moderate for glandular mucosa (mean ICC = 0.56). -Experience influenced reliability, with specialists outperforming less-experienced observers, particularly for glandular mucosal grading.

Answer 26

-IPoC significantly reduced paracellular permeability and denuded villus surface area after reperfusion compared to controls. -Despite these improvements, IPoC did not influence other variables, such as histological injury scores or electrophysiological measures. -Microperfusion was consistently reduced during all clamping cycles of IPoC. -Significant oxygen desaturation occurred only during the first clamping cycle, possibly due to the short duration of each cycle. -In control horses, reperfusion led to a significant reduction in claudin-1, claudin-2, and occludin levels, indicating tight junction damage. -In the IPoC group, these reductions were not observed, suggesting a protective effect on tight junction integrity. -only a short period (120min) of reperfusion studied.

Answer 27

-The majority of critically ill foals (69%) maintained an intragastric pH >4 for over 80% of the recording period, with 88% achieving pH >4 for at least 50% of the recording period. -Mean intragastric pH across foals was 5.5 ± 1.8, with considerable interindividual variability (range 0.9–11). Factors Affecting pH: -Placentitis: Foals with a history of placentitis had a higher mean pH and spent less time with a pH <4 (p = 0.01). -Diarrhea: Foals presenting with diarrhea had more acidic profiles, with a higher percentage of time spent at pH <4 (p = 0.02). -Respiratory Insufficiency: Alkaline pH profiles were associated with decreased PaO₂ and increased PaCO₂, suggesting impaired gastric acid secretion related to critical illness. -Surviving foals had a lower mean hourly pH compared to nonsurvivors (p = 0.02), suggesting that the ability to secrete gastric acid may be linked to overall health and survival. -No association was found between % time pH <4 and survival, -Intragastric pH did not exhibit diurnal fluctuations, -Findings challenge the routine use of acid-suppressive treatments. Empirical administration of these medications may disrupt protective gastric acidity and increase risks of bacterial colonization or diarrhea

Answer 28

-Detection of at least one potential enteric pathogen (PEP) or toxin (PEP-T) was higher in hospitalized horses (60.7%) compared to fecal samples submitted to IDEXX Laboratories (31.3%). -The most frequently detected pathogens were: Neorickettsia risticii (37.8%) Clostridioides difficile toxins (16.4%) Clostridium perfringens toxins (14.0%). -Horses with only one PEP or PEP-T detected had lower survival rates (76%) compared to horses with no pathogens (88%) or multiple pathogens (89%). -Detection of multiple pathogens was not associated with increased hospitalization duration, treatment costs, or worse outcomes. -Differences in detection rates between IDEXX and Michigan State University Veterinary Diagnostic Laboratory (MSUVDL) were attributed to variations in case selection, geographic locations, and testing methods. -IDEXX used PCR assays, which detect genetic material but do not confirm active infection or toxin production. -MSUVDL used ELISA for toxin detection and enriched culture methods, which provided more specific insights into pathogen viability and activity.

Answer 29

-Laminitis occurred in 20% (17/85) of horses, predominantly in cases with neorickettsiosis (42%), compared to salmonellosis (15%), and none in coronavirus cases. -Horses with elevated admission heart rates, lower total solids, band neutrophilia, and reduced bicarbonate levels were at increased risk for laminitis (area under the curve = 0.95, sensitivity = 86%, specificity = 84%). -Overall survival rate was 74.1% (63/85 horses), with 100% survival in coronavirus cases. -Neorickettsiosis cases had the lowest survival (65.4%), followed by salmonellosis (70%) and unknown etiology cases (69.6%). -Predictors of nonsurvival included higher admission packed cell volume, elevated lactate levels, and the development of laminitis, which carried a sevenfold higher hazard of nonsurvival. -Coronavirus cases had milder clinical presentations, were less likely to develop diarrhea (13%), and were more likely to display colic (81%). -Neorickettsiosis was significantly associated with higher laminitis rates, likely reflecting regional prevalence and disease severity.

Answer 30

-C. difficile was isolated from 25% of all samples: 31% from foals and 19% from mares. -A total of 44% of foals and 31% of mares shed C. difficile at least once during hospitalization. -Shedding was transient and dynamic, with a high turnover of ribotypes and no consistent patterns of long-term colonization. -A total of 23 ribotypes were identified, with ribotype 078 being the most common (56% of isolates). This is toxigenic and associated with community aquired infections in humans. -Mare-foal transmission was rare; only 3% of mare-foal pairs were shedding C. difficile simultaneously, with only one pair sharing the same strain. -Shedding patterns suggested a combination of community and hospital-associated acquisition, though hospital-associated shedding was not definitively linked to nosocomial transmission. -The prevalence of C. difficile increased during hospitalization, particularly in foals by Day 4–6. -No significant association was found between duration of hospitalization and shedding prevalence in mares, suggesting other factors, such as stress and antimicrobial use, may play a role. -High rates of transient C. difficile shedding, particularly in neonatal foals, highlight the need for rigorous infection control practices in neonatal intensive care units. -No clinical correlations described -Positive fecal samples should not automatically be interpreted as indicators of clinical disease without supporting signs

Answer 31

-Pooling five fecal samples into a single 50 g submission proved as effective as individual cultures in detecting Salmonella spp.. -All horses positive in individual samples were also positive in pooled samples, with no false negatives. -A concentration of 10^2 CFU in a single sample within a pooled set was detectable, provided optimal homogenization methods were used. Adding 20 mL of nutrient broth to pooled samples significantly improved sensitivity compared to samples processed without broth. -Homogenization time (1 minute vs. 5 minutes) did not significantly affect detection rates -The study confirmed intermittent shedding of Salmonella spp. in horses, which necessitates multiple samples for accurate detection. -Continuous shedding was more common than intermittent shedding in this study cohort, but the exact prevalence requires further investigation. -The viability of Salmonella spp. in refrigerated or environmental conditions underscores the importance of proper sample handling and processing protocols to ensure reliable results. -The study relied on high-risk horses with known gastrointestinal symptoms; its findings may not extrapolate to asymptomatic populations where Salmonella spp. concentrations might fall below detection limits.

Answer 32

-The gastric microbiome in horses with EGGD exhibited modest structural differences compared to horses without the disease. -Dominant bacterial phyla in mucosal biopsies were Proteobacteria (50%), Bacteroidetes (21%), and Firmicutes (20%). -The most abundant genera included Actinobacillus (17%), Moraxella (10%), and Porphyromonas (9%). -Significant differences were observed between microbiomes of healthy glandular mucosa (EGGD 0) and lesions in severe EGGD (EGGD ≥2), with separate clusters in principal coordinate analysis (PCoA). -These differences were detected using the Jaccard similarity index, suggesting presence/absence of specific taxa rather than abundance shifts. -No significant changes in bacterial richness, diversity, or abundance were identified, indicating that EGGD may not be characterized by broad microbiome dysbiosis. -There were no specific taxa uniquely associated with EGGD, limiting the identification of a bacterial "signature" for the disease. -The gastric fluid microbiome differed modestly from the mucosal microbiome in community composition but showed no significant variations between horses with and without EGGD. -Helicobacter species were detected but showed no association with EGGD

Answer 33

-At baseline (D0), 17% of horses had clinically relevant GGD (scores ≥2). The prevalence was consistent with the lower range reported in racehorses and sport horses in training. -The antral and pyloric regions were the most commonly affected, with congestion being the most frequent lesion type. -Substituting 50% of dietary concentrates with dehydrated alfalfa pellets reduced the prevalence of clinically relevant GGD from 33% in the control group to 12% in the alfalfa group at D42. -Horses in the alfalfa group were 47.7 times more likely to achieve clinical success (GGD scores improving from ≥2 to ≤1) compared to controls. -The apparent protective role of simple sugars in nonulcerated horses raises questions about their interaction with gastric microbiota, particularly Lactobacillus species, which may promote mucosal healing and inhibit pathogenic bacteria.

Answer 34

-Twenty-seven horses had LGI (lone), 44 had CGI (concurrent). Large intestinal lesions (32/44) were more common than small intestinal lesions (12/44) in the CGI group. -Concurrent gastric impactions resolved more slowly than LGI (LGI median 2 days, CGI median 4 days) - Short- (63%, CGI 59%) and long-term survival (LGI 3.5 years; CGI 2.3) were not significantly different. - gastric silhouettes, 24% (15/26) were considered enlarged, extending to ≥6 intercostal spaces. poor sensitivity and specificity of 67% and 20%, - Lone gastric impactions were more likely to experience gastric rupture- 7% had gastric rupture on arrival. - Lone gastric impactions were 8.7 times more likely to require dietary changes. -Gastric impactions recurred in 21.7% of affected horses. Not different CGI vs LGI - treatments: carbonated drink, enteral fluids, IV fluids. 5 were treated with metoclopramide -overall survival to discharge 60.6% 50% returned to normal diet/exercise, 50% required modifications.

Answer 35

-84% of cases with known NSAID dosage histories experienced an overdose. Phenylbutazone was the most commonly implicated NSAID, administered in 74% of cases, often in excessive or prolonged doses. -Overdosing typically occurred via high single doses or extended administration exceeding 8 consecutive days at therapeutic doses. -The most frequent signs were diarrhea (69%), colic (61%), and tachycardia (53%), with hypoalbuminemia (83%) and hypocalcemia (79%) as prominent clinicopathological findings. -Ultrasound was useful, showing right dorsal colonic thickening in 77% of cases, with a median wall thickness of 10 mm (normal is ~3 mm for horses). -Survival to discharge was 57%. -Survival odds decreased with increasing heart rate, packed cell volume, and abnormal mucous membranes upon admission. -Horses receiving prolonged hospitalization had better survival outcomes, likely due to early intervention and effective treatment

Answer 36

-Significant alterations in gut microbiota diversity and composition were observed during antimicrobial administration (days 1–6). -Recovery of baseline microbial profiles occurred by day 30 for most groups, suggesting resilience of equine gut microbiota in healthy horses. -Erythromycin: Caused the most pronounced disruptions, including reductions in cellulolytic and butyrate-producing bacteria (e.g., Fibrobacter, Lachnospiraceae) and increased abundance of facultative anaerobes like Escherichia-Shigella and Fusobacterium. -Metronidazole: Associated with a gradual increase in Bacteroidota and Proteobacteria, along with reduced Verrucomicrobiota. -Doxycycline: Induced moderate disruptions, decreasing cellulolytic bacteria and increasing Bacteroidota. -SMZ-TMP: Showed minimal impact on microbial diversity or composition compared to controls. -The shift from obligate anaerobes to facultative anaerobes (e.g., Escherichia-Shigella, Fusobacterium) was identified as a potential marker of antimicrobial-associated dysbiosis. -Depletion of butyrate-producing bacteria was associated with disruptions in gut homeostasis and potential predisposition to colitis or diarrhea.

Answer 37

-30.2% of horses with colic exhibited DGGR-lipase activity above the published reference limit (>21 U/L). -15.6% had hyperlipasaemia (DGGR-lipase activity >42 U/L, defined as 2× the upper reference limit [URL]). -PM was only performed in 10/192-> no gross evidence of pancreatic lesions. Hyperlipasaemia was significantly associated with: -Non-survival (odds ratio [OR]: 2.7). -Strangulating gastrointestinal disease (OR: 3.1). -Requirement for surgical intervention (OR: 7.9). -Large bowel displacement or torsion (OR: 5.8). -Despite these associations, DGGR-lipase activity had limited sensitivity and diagnostic utility for predicting these outcomes. -Area under the receiver operating characteristic (AUROC) for non-survival: 0.65. -AUROC for surgical treatment: 0.79. -Sensitivity was generally low, limiting its use as a standalone screening tool. Underlying Mechanisms: -Increased DGGR-lipase activity likely reflected secondary pancreatic damage rather than primary pancreatitis, often resulting from ischemia or hypoperfusion associated with severe colic. -No gross pancreatic abnormalities were observed in post-mortem examinations, supporting the hypothesis of secondary involvement.

Answer 38

GI disorders accounted for 24% of all equine cases referred to the hospital over a 12-year period (1833/7488 cases). The vast majority (96%) involved the abdominal GI tract, with a small percentage attributable to esophageal problems (1.3%). The leading causes of GI issues were: -Large colon impaction (33.2% of colic cases). -Gastric (17%). -Spasmodic colic (8.5%). -Other notable conditions included enteritis (6.7%), cecal tympany (5.6%), and large colon displacements or volvuli (3%). -Colic incidence was highest in July, October, and November, likely related to environmental factors such as changes in pasture quality, feeding practices, and reduced exercise in colder months. Warmblood horses made up 49% of GI cases, with a higher-than-expected incidence of large colon impactions compared to other breeds. Blood type horses (e.g., Thoroughbreds) exhibited lower-than-expected rates of enteritis, but a higher susceptibility to impactions.

Answer 39

-Endoscopy demonstrated significantly higher sensitivity (79–85%) compared to mirror examination (23–39%) across all pathologies. -Both modalities exhibited high specificity, with the mirror slightly outperforming endoscopy (87–97% vs. 71–89%). -Endoscopy was especially effective in detecting minor pathologies but had a higher false-positive rate than the mirror. -Endoscopy showed substantial agreement for major pathologies (κ = 0.76) and moderate agreement for minor pathologies (κ = 0.54). -The mirror had lower inter-observer agreement, rated as substantial for major pathologies (κ = 0.64) but only fair for minor pathologies (κ = 0.39). -Moderate agreement was observed for repeated evaluations with both modalities (endoscopy κ = 0.52–0.66; mirror κ = 0.48–0.51). Prevalence of Pathologies: -Endoscopy identified pathologies in 58% of teeth, while the mirror identified 39%. -All horses exhibited some pathology under endoscopic examination, whereas one horse was reported as pathology-free using the mirror. Common Pathologies: -Major Pathologies: Diastemata were the most frequently detected major pathology, accounting for 27–57% of cases. The mirror underdiagnosed diastemata compared to endoscopy. -Minor Pathologies: Infundibular caries were the most common minor pathology detected by endoscopy, comprising 40–55% of total findings.

Answer 40

-Supplements containing turmeric and devil’s claw did not worsen equine gastric ulcer syndrome (EGUS) scores. -Both treatment and control groups showed significant decreases in EGUS scores by Days 14 and 28 (p < 0.05), indicating no adverse effects from the supplements. -Mean gastric juice pH remained consistently low (mean 2.20) across both groups with no significant treatment or time effects, suggesting the supplements did not influence acid production.

Answer 41

-Overall incidence of incisional complications was 72% in the study population, with 42% experiencing incisional drainage. -No significant difference was found between stainless-steel skin staples (SSS) and nylon sutures in terms of overall complications (70% for SSS vs. 75% for nylon sutures). -Pregnant mares and horses with large intestinal lesions were significantly more likely to develop incisional complications, particularly purulent drainage. -Surgeon experience influenced outcomes: a specific surgeon (Surgeon 3) was associated with significantly fewer complications, particularly incisional drainage. -Horses with large colon lesions were 7.7 times more likely to develop incisional complications compared to other cases. -Nylon sutures were associated with a 3.86 times higher risk of purulent drainage than SSS after adjusting for pregnancy and lesion type. -Despite this, no significant differences were found for other outcomes like hernia or dehiscence. -Herniation occurred in 6.9% of cases, without a clear link to other incisional complications. -Longer surgeries and older, heavier horses were associated with increased risk of bloody drainage.

Answer 42

Statistically significant improvements were observed post-extraction in: -Body condition scores (BCS) and weight. -Reduction in dental pain behaviors such as dropping hay, slower eating, headshaking, and resistance to bridling. -Horses were perceived as happier (mean happiness score increased from 5.3 to 8.4 post-surgery). -Over 90% of owners reported improved welfare and would elect for similar treatment for other horses if needed. -78.7% of owners agreed that the surgery extended their horse's lifespan. -50% of owners reported a significant reduction in the equine pain face three months post-surgery, highlighting the alleviation of dental pain. -Riding activity remained relatively unchanged (62.5% ridden pre-surgery vs. 56.3% post-surgery), suggesting functional ability was retained despite radical tooth extraction.

Answer 43

-The effects of doxycycline on equine gut microbiota were consistent with other broad-spectrum antimicrobials, including trimethoprim-sulfamethoxazole (TMS) and metronidazole, but differed in specific taxonomic shifts and recovery patterns. A 5-day course of oral doxycycline hyclate at 10 mg/kg every 12 hours caused significant dysbiosis, characterized by: -Decreased diversity and richness: A notable drop in alpha diversity indices such as OTU richness and Shannon diversity. -Altered microbial composition: Reduction in Verrucomicrobia and an increase in the Firmicutes:Bacteroidetes ratio during treatment. -Microbial diversity gradually improved after doxycycline discontinuation, with alpha diversity returning to baseline by Day 28 (23 days post-treatment). -All channges were subclinical- no colic or diarrhoea observed -NB: no control group and faecal samples only

Answer 44

-Yearlings: Seropositivity increased significantly from 44.1% in August to 88.8% in December, reflecting rapid exposure and spread after entering farms. -Racehorses: A stable seropositivity rate was observed, with 83.7% seropositive in April/May and 78% by the following May. -ECoV infections in racehorses predominantly occurred during colder months (November–May; infection rate 15.5%), while no infections were reported in warmer periods (April–November). -Yearlings exhibited a rapid spread due to close contact, especially during shared grazing from August to October. -39.2% of infected yearlings exhibited fever, but no severe clinical signs were observed and =/ definitive cause -Only 4% of infected racehorses developed fever, all of whom recovered without intensive care. -The infection did not result in severe gastrointestinal or systemic symptoms in either population.

Answer 45

Increased Gastrointestinal Permeability: -Horses subjected to combined trailer transport (1 hour) and moderate exercise (30 minutes) demonstrated significantly increased gastrointestinal (GI) permeability, measured via plasma iohexol levels. Peak plasma iohexol levels were observed immediately post-exercise (P3), remaining elevated until 2 hours post-exercise (P5). CON horses had no significant change in plasma iohexol from P1 at any time point -> most of the impact appears to be exercise rather than transport. -LPS and SAA were significantly higher in EX than CON at P4 and P6 , respectively.

Answer 46

-The faecal microbiota exhibited step-wise compositional changes correlating with increasing levels of human intervention (Low Management [LM], Medium Management [MM], High Management [HM]). -Firmicutes and Bacteroidetes were the dominant phyla across all groups. -Significant clustering by management level was observed in PCoA (beta diversity), with the HM group differing most significantly from LM, and MM showing an intermediate pattern. -No significant differences in alpha diversity metrics (richness, evenness, Shannon diversity) were detected between groups, although MM exhibited the highest inter-individual variation. HM Group: -Higher abundance of Proteobacteria (linked to starch intake and potential gut dysbiosis). -Functional predictions indicated increased amino acid, lipid metabolism, and xenobiotic pathways. LM Group: -Dominance of Methanobrevibacter (associated with high-fiber diets) and bacteria linked to cellulose degradation (Lachnospiraceae, Anaerolinaceae). -Functional pathways related to energy metabolism were enriched. MM Group: -High variability in taxa abundance, with features of both LM and HM groups, reflecting fluctuating management and dietary practices.

Answer 47

-Owners either already implemented emergency colic plans or showed no intention to do so. -Most agreed that plans could improve welfare (68%) and aid decision-making (78%). -Only 20% of respondents were aware of the "REACT Now to Beat Colic" campaign, but campaign awareness was positively associated with implementation of recommendations. -High rates of implementation for actions like annual dental exams (97%) and worm egg counts (57%). -Low uptake for weekly monitoring of temperature, heart rate, and respiratory rate (over 70% had no intention to start). -Owners who believed emergency planning had a point and knew when to seek veterinary help were more likely to act. -Veterinary professionals were seen as the most influential source of advice (93%). Barriers to Adoption: -Owners felt prepared based on their experiences with mild colic cases, potentially underestimating risks in critical cases. -Social pressure negatively impacted willingness to adopt personal preparation recommendations.

Answer 48

-The biomarker Ki67 identifies proliferating cells, SOX9 identifies progenitor cells, and PHH3 identifies cells actively undergoing mitosis -Reduced expression of Ki67+ proliferative cells was observed in both proximal and distal resection margins of horses euthanized postoperatively compared to controls. -Horses that survived to discharge had cell counts closer to control levels, suggesting that ISC (intestinal stem cell) proliferation is linked to regenerative potential and survival. -Horses with higher SOX9+Ki67+ (co-localized) ISC counts in distal resection margins had fewer preoperative risk factors negatively related to outcome. -No significant relationship was found between post-operative complications and ISC biomarker expression, suggesting that preoperative conditions play a more pivotal role. -Histomorphometric evaluations showed no significant differences in crypt depth or villus height between control and resection margins, highlighting that gross tissue appearance might not reflect underlying cellular compromise. Impact of Injury Beyond Grossly Affected Tissue: -Reduced Ki67+ cell numbers in tissue appearing grossly normal suggest that ischemic injury extends beyond the visibly compromised areas. -Horses undergoing jejunocaecostomy, typically performed when distal ileum is non-viable, were associated with poorer outcomes, aligning with prior studies indicating challenges in achieving successful recovery with this surgical method.

Answer 49

- Only 45% of owners could correctly identify normal heart rate (28–44 bpm) and respiratory rate (8–16 breaths per minute). -A higher percentage (67%) identified the correct normal range for rectal temperature (36.5–39.0°C). While 61% of respondents were confident in recognizing colic signs, their ability to accurately identify colic in case scenarios varied: -Surgical colic: 94% recognized the case as colic. -Medical colic: 68% recognized the case. -Pelvic flexure impaction: Only 44% recognized the case. -Confidence was significantly associated with prior experience of colic and equine-specific qualifications. -In the case scenarios, 49% were confident deciding that a surgical case had colic, but 9% were confident deciding an impaction case had colic. -Behavioral signs like rolling repeatedly, thrashing, or extended periods of lying down triggered most participants to call a veterinarian (90%). -Milder or less specific signs, such as flank-watching or inappetence, often prompted monitoring rather than immediate action. -Owners primarily relied on veterinarians (83%) and personal experience (86%) for colic-related knowledge. -Gaps in knowledge were identified in recognizing mild or less obvious signs of colic and understanding its potential severity. -Misconceptions about colic being a single condition rather than a symptom of multiple underlying issues. -Variability in responses to behavioral changes, particularly mild or early signs.

Answer 50

-Anthelmintics were used by 97% of respondents, with MLs being the most common class administered to both mares and foals. -Drug rotation was cited as the most important factor for anthelmintic selection (41% of respondents). -Interval dosing regimens were the predominant approach, used by 61% of respondents for mares and 80% for foals, with treatments typically administered every 2 months. -Only 5% of respondents employed targeted dosing regimens based FECs. -Manure removal was undertaken by 60% of respondents, while pasture rotation (82%) and co-grazing with cattle (36%) were also common practices. -Properties implementing manure removal were six times more likely to use longer anthelmintic intervals (≥3 months) in foals. -While 97% of respondents recognized AR as an important issue, only 15% were aware of resistance on their farms, mostly identified through fecal egg count reduction tests (FECRT). -Many respondents believed their anthelmintics were still effective, despite minimal routine testing for efficacy. -Non-chemical methods, such as manure removal and pasture rotation, were inconsistently applied, and quarantine protocols for new arrivals were not universally adopted.

Answer 51

In the treatment group, following closure of the linea alba, medical grade honey gel (L-Mesitran Soft®) was placed in the incision followed by apposition of subcutaneous tissue and skin. Significantly reduced the prevalence of incisional infections: -Treatment group: 8.2% infection rate. -Control group: 32.5% infection rate (p = 0.02). -The protective effect of MGH had an adjusted odds ratio of 0.2 (95% CI: 0.07–0.8; p = 0.03). -No adverse effects were associated with the intraincisional application of MGH. -The number of horses needed to be treated with MGH to prevent one infection (NNEB) was calculated as 4.7. -Incisional hernias were evenly distributed between treatment (4 cases) and control groups (4 cases). Factors Associated with Infection: -Younger horses (odds ratio [OR]: 27, 95% CI: 2.3–306) and those with diarrhea 48 hours postoperatively (OR: 20, 95% CI: 1.5–277) had increased risks of incisional infection. -Multidrug-resistant bacterial infections were prevalent in both groups but not significantly associated with MGH use. Bacteria isolated included MRSA, Escherichia coli, Enterococcus faecalis, and Proteus mirabilis. -All MRSA infections were observed in the control group, although the study did not definitively establish MGH’s preventive effect against multidrug-resistant bacteria. Looked at macroscopic outcomes only

Answer 52

-EOTRH was diagnosed in 72.2% of the studied Icelandic horses aged 15 years and older. -Male horses had a significantly higher prevalence (80.7%) compared to females (61.9%). -Older horses were more likely to develop EOTRH (p = 0.004), with severity correlating with increasing age. Age-related progression complicates distinguishing between pathological changes and normal aging effects on radiographs. Diagnostics were not specific!! Horses tended not to have clinical signs. -Horses bred in Germany were at greater risk for EOTRH (75.2%) compared to imported horses (58.6%), potentially due to differences in husbandry, climate, and diet. Intensive grazing practices and fertilized pastures in Germany were highlighted as potential contributing factors. -Owners did not suspect EOTRH in 60% of affected horses, reflecting its subclinical nature in many cases. Symptoms such as increased salivation, slow eating, and weight loss were occasionally reported but not consistently recognized.

Answer 53

- 73% (167/228) of equids survived to hospital discharge after undergoing large intestinal trocarization. -No fatalities were directly attributed to the trocarization procedure itself, underscoring its relative safety when appropriately indicated. Factors Influencing Nonsurvival: -Increasing numbers of trocarization procedures were significantly associated with higher odds of nonsurvival (Odds Ratio [OR]: 2.7 per additional procedure; p < 0.001). -Diagnoses of large intestinal strangulating lesions (OR: 7.6) and "other" diagnoses (e.g., gastric rupture) were strongly linked to nonsurvival. -Nonstrangulating large colon lesions significantly decreased the odds of nonsurvival (OR: 0.08). -CRP was observed in 12/60 (20%) medically treated equids with cytological and clinical signs of peritonitis, but it was not associated with the number or site of trocarizations. -85% had increased peritoneal fluid cell counts (>10,000 cells/µL), the clinical relevance was limited in most cases. -Transabdominal trocarization was the most common technique (83%), while transrectal trocarization was less frequently performed (7%). -No severe complications (e.g., intestinal rupture) were reported for either method, and the complication rate was low overall. -Administration of systemic or local antimicrobials was not associated with survival or the occurrence of CRP, raising questions about their necessity in routine practice. -Trocarization was primarily performed for gas distension unresponsive to conservative management. -The procedure provided rapid decompression, alleviating pain and improving hemodynamic parameters in selected cases.

Answer 54

-The novel wireless endoscopy capsule enabled high-resolution imaging of the gastrointestinal (GI) tract mucosa in horses, including: Gastric mucosa, pylorus, duodenal papilla, villi, and ileocecal junction. -Large intestinal mucosa visualization was poor. Three protocols were tested: -Protocol 1 (24-hour fasting and controlled water intake) provided the greatest mucosal visibility. -Increasing exercise Protocol 2- increased hand walking to WID -Protocol 3 extending fasting to 48 hours reduced mucosal visualization and capsule recovery rates. -Total transit time to excretion varied between 3 and 8.75 days, with a median of 6.5 days. -Battery life allowed imaging of the stomach, small intestine, and occasionally the cecum, but no recordings from the colon. -Visualized lesions included gastric erosions, ulcerations, thickened mucosa, small intestinal hemorrhages, and evidence of parasitism. -Lesions observed in capsule images correlated with histopathological findings in post-mortem samples. -Of the 15 capsules administered, 3 were not recovered, highlighting variability in excretion and potential for retention.

Answer 55

-modified Heineke–Mikulicz pyloroplasty was performed on three foals with pyloric stenosis caused by gastric outflow obstruction secondary to gastro-duodenal ulcer disease (GDUD). 2/3 foals survived long-term and achieved intended use, including racing and breeding. -The procedure involved a full-thickness longitudinal incision on the ventral aspect of the pylorus and proximal duodenum, sutured transversely to enlarge the pyloric lumen. Maintained normal gastrointestinal flow without bypassing the pylorus -One foal developed intra-abdominal adhesions and small intestinal volvulus unrelated to the pyloroplasty site and was euthanized. Another foal experienced an incisional infection -All foals presented with recurring colic, abnormal gastric emptying (confirmed by barium studies), and pyloric narrowing (confirmed via gastroscopy). -Medical therapy, including gastroprotectants and prokinetics, failed to resolve the condition before surgical intervention. -The surviving foals had complete resolution of gastric ulcers and normal pyloric function at follow-up gastroscopy. -No postoperative reflux or ileus occurred, and rapid return to enteral nutrition was achieved within 24–36 hours post-surgery. -Pyloroplasty demonstrated comparable or better outcomes than bypass procedures, with fewer long-term complications and lower technical demands

Answer 56

-Significant upregulation of IL1β, IL6, CCL2, and TNF was observed in both the mucosa and muscularis externa of horses undergoing small intestinal resection compared to controls. -PTGS2 expression was elevated in the mucosa but not in the muscularis externa. -Higher TNF expression in the mucosa was significantly associated with the development of POR -No significant gene expression differences were found between horses with and without POR in the muscularis externa. -No differences in gene expression were identified between proximal and distal resection margins, suggesting inflammation was generalized across resected intestinal tissue. -Age was inversely correlated with PTGS2 and CCL2 expression in the mucosa, while trends in the muscularis externa indicated increased expression with age, though not statistically significant. -Gene expression was not significantly associated with duration of colic, length of resection, or survival to discharge. -Unlike rodent models, NOS2 (involved in nitric oxide production) was not expressed, indicating species-specific inflammatory pathways in horses. gene expression =/ protein expression. n=12

Answer 57

Minimal Differences in Fermentation: -Despite differences in composition, feed ingredients (beet pulp, maize, dehydrated alfalfa, oats, soybean hulls, wheat middlings) produced minimal differences in caecal fermentation parameters (pH and [VFA] ) when fed at 0.25% body weight/day. -Post-prandial pH shifts and VFA production followed typical patterns, with peak fermentation activity occurring 4–8 hours after feeding. Normalised by 12 hours -Maize, despite its high starch content, did not significantly depress caecal pH or alter fermentation compared to fibrous ingredients, indicating most starch was digested precaecally at the inclusion level used. -Soybean Hulls: Maintained higher pH levels, potentially due to their high neutral detergent fiber (NDF) content and slower fermentation. -Beet Pulp: Rapidly fermented but associated with transient gastrointestinal issues (e.g., choke) in three horses, highlighting the importance of soaking before feeding. -Oats: Showed prolonged fermentation, likely due to high lignin content, with greater acetate-to-propionate ratios observed at later sampling times. -Dehydrated Alfalfa: Exhibited fermentation patterns similar to other fibrous feedstuffs, with no adverse effects. Volatile Fatty Acid (VFA) Dynamics: -Acetate was the predominant VFA across all treatments, consistent with fermentation of high-fiber diets. -No significant differences in total VFA production were observed between treatments, suggesting comparable fermentative efficiency. n=6

Answer 58

-Most horses (88.4%) exhibited a low level of strongyle infection (0-199 EPG). -Parascaris equorum was identified in 5.1% of horses, with higher prevalence in younger horses and males. -High efficacy against strongyles was observed for ivermectin (100%), doramectin (99.7%), and fenbendazole (100%) using fecal egg count reduction tests (FECRT). -Evidence of reduced efficacy against P. equorum for doramectin (mean FECR 64.16%) was noted, suggesting emerging resistance. Factors Influencing Infection: -Horses dewormed in the previous 12 months had a 74% lower risk of strongyle infection. -Management practices, including stall-keeping and lack of grazing access, likely contributed to lower overall infection prevalence compared to grazing equids. -Only 31.6% of owners implemented routine deworming programs, with significant variability in frequency and products used. -Anthelmintic treatments were largely administered without diagnostic fecal egg counts, relying instead on visual assessment or weight estimation. -Strongyle larvae included Oesophagodontus robustus, Strongylus edentatus, and Triodontophorus spp. No small strongyles (cyathostomins) were detected.

Answer 59

Microbiota Changes Over Time: -A significant decrease in species richness and diversity was observed from hospital admission to day 3 or discharge. -Horses with prolonged colic episodes (≥60 hours) showed distinct microbiota patterns, with lower species richness and Shannon diversity compared to those with colic <60 hours. -Horses with large intestinal (LI) lesions exhibited distinct bacterial populations compared to those with small intestinal (SI) lesions. -Differences in microbiota composition were associated with colic type (strangulating vs. nonstrangulating) and duration. Key Bacterial Trends: -Firmicutes: Decreased from admission to day 1, with partial recovery by day 3/discharge. -Bacteroidetes: Increased during hospitalization, particularly in horses with colic lasting ≥60 hours. -Spirochaetes: Declined significantly by day 3/discharge. -Specific genera, such as Bacteroides, showed notable increases, while others like Treponema decreased, indicating shifts in fermentative digestion. Hospital Management Effects: -Withholding feed, refeeding strategies, and antimicrobials influenced microbiota changes. -Horses that were off feed longer showed reduced diversity and altered bacterial populations, potentially delaying recovery. Microbiota Recovery: -Partial recovery of commensal bacteria (e.g., Lachnospiraceae, Ruminococcaceae) was observed by discharge, though complete restoration likely requires extended recovery periods post-hospitalization.

Answer 60

Significant decrease in colic incidence was observed during the period when germinated barley was included in the diet: -Period 1 (Control): 18.1 cases/100 horses at risk-year. -Period 2 (With Germinated Barley): 5.4 cases/100 horses at risk-year. -This reduction was especially notable in stabled horses (Group A), with colic incidence dropping from 23.9 to 5.3 cases/100 horses at risk-year. Effect of Housing Conditions: -Horses kept in pasture all day (Group B) already had low colic incidence (5.7 cases/100 horses at risk-year) during Period 1, which remained unchanged after barley supplementation in Period 2. Role of Germinated Barley: -Germinated barley (Equinocol®) provided oligosaccharides, such as fructo-oligosaccharides (FOS), which act as prebiotics to improve gut health by promoting beneficial bacteria and stabilizing intestinal flora. Consistency Across Study Conditions: -Feed types, housing, care routines, and veterinary practices were standardized across the two study periods to isolate the effect of germinated barley. Other RF not controlled, including medications/ health. Non concurrent study periods.

Answer 61

-Horses with AAD and Salmonella colitis exhibited significant dysbiosis compared to healthy horses. Dysbiosis included: -Increased Proteobacteria and Bacteroidetes in AAD. -Reduced Firmicutes and increased Lentisphaerae and Euryarchaeota in Salmonella colitis. -AAD resulted in more severe microbiome disruption than Salmonella colitis. Healthy Horse Microbiome Variability: -Diet, particularly grain intake, had the most notable effect among healthy horses, with high-concentrate diets (1-2% of body weight/day) altering microbiome composition. -Horses with high grain intake showed reduced Actinobacteria and increased Bacteroidetes, consistent with previous findings linking starch-heavy diets to microbiome shifts. Alpha and Beta Diversity: -Alpha diversity (richness and evenness) was lower in colitis horses compared to healthy controls. Lots of uncontrolled variables, housing, feeding...single time point. -Beta diversity (community composition) demonstrated distinct clustering between colitis and healthy horses, with AAD showing greater separation from healthy horses than Salmonella. Other Factors: -Signalment (age, breed, sex) had minor effects on microbiome diversity. -Time spent on pasture increased diversity in healthy horses, likely due to the microbiota's response to high-fiber forage.

Answer 62

Colitis and Dysbiosis: -Horses with colitis showed significant gastrointestinal dysbiosis, with an enrichment of facultative anaerobes (e.g., Streptococcus, Lactobacillus, Enterococcus, and Enterobacteriaceae). -Healthy horses had feces enriched with obligate anaerobes such as Treponema, Ruminococcaceae, and Lachnospiraceae. Laminitis Association: -Horses with colitis that developed laminitis were enriched in Lactobacillus, Streptococcus, and Enterobacteriaceae, mirroring patterns observed in laminitis induced by carbohydrate overload. -No significant differences in overall community structure or membership were found between laminitic and non-laminitic horses, suggesting minor microbiota alterations. Survival Outcomes: -Nonsurviving horses with colitis had an enrichment of Streptococcus, Lactobacillus, Clostridium sensu stricto, and Carnobacterium, indicating more severe dysbiosis. -Survivors had more Enterococcus, Mogibacterium, and Pseudomonas, though no significant differences in alpha or beta diversity metrics were detected. Predictive Potential of Microbiota: -Machine learning models (e.g., random forest, neural networks) showed excellent predictive value (AUC ROC > 0.9) in distinguishing healthy from colitis horses based on fecal microbiota. -However, these models failed to predict laminitis or survival outcomes effectively (AUC ROC < 0.7). Pathophysiological Insights: -Alterations in microbiota, particularly the shift from obligate to facultative anaerobes, align with increased oxygen and nitrate availability during inflammation ("oxygen hypothesis"). -Dysbiosis likely contributes to intestinal inflammation, mucosal damage, and systemic bacterial translocation, exacerbating colitis and complications such as laminitis and mortality.

Answer 63

Safety of Sodium Chloride Pellets: -Supplementation with NaCl pellets to replace electrolytes lost in 10 L of sweat (600g/d pellets= 30 g Na and 39 g Cl per day) did not worsen existing gastric mucosal lesions or negatively affect gastric mucosa (both squamous and glangular examined). -The prevalence of gastric mucosal lesions (83.3%) at study onset did not change significantly after 19 days of supplementation. Acid-Base and Electrolyte Balance: -Blood pH and bicarbonate levels remained within normal ranges, indicating no metabolic acidosis. -Serum and urinary sodium (Na+) concentrations increased significantly with NaCl supplementation, suggesting effective compensation for electrolyte losses. Water Intake and Urine Specific Gravity (USG): -Water intake remained unchanged with NaCl supplementation, likely influenced by the mode of water provision (bucket vs. automatic dispensers). -USG decreased over time in both treatment groups but was not specifically affected by NaCl supplementation. Effect on Mineral Status: -Serum calcium (Ca2+) levels decreased in both NaCl and placebo groups but remained within physiological limits. -No significant changes in serum or urinary chloride (Cl-) levels were observed. Comparison to Previous Studies: -Unlike earlier studies that linked hypertonic electrolyte solutions to increased gastric lesions, the pellet form and controlled dosage of NaCl used in this study did not exacerbate gastric mucosal damage. In 15 young WB stallions and short term (19d). management factors not controlled for- confounding. Water intake not measured

Answer 64

-Equine Omega Complete (EOC) did not prevent squamous gastric ulcer formation during a 28-day treatment period followed by an ulcer induction protocol. Ulcer grades significantly increased in both the EOC and control groups but remained stable in the omeprazole-treated group. No conclusions drawn re. glandular lesions. -Serum alpha-tocopherol concentrations increased significantly over time in EOC-treated horses; however, this increase was inconsistent across individuals and not significantly different from the control or omeprazole groups. The alpha-tocopherol content in EOC was lower than the label claim, potentially limiting its efficacy. -EOC contained omega-3 (e.g., DHA, EPA), omega-6, and omega-9 fatty acids but failed to demonstrate protective effects against experimentally induced ulcers. -Independent analysis indicated that the product's alpha-tocopherol levels were below expected concentrations, possibly due to degradation over time.

Answer 65

-92% of juvenile Thoroughbreds undergoing surgery for large colon displacement survived to discharge, consistent with survival rates reported in previous studies (91.5%-97%). -The study demonstrated that surgical correction did not significantly impact overall sales price, race earnings, or race starts when compared to control horses. -70% of the horses that underwent surgery raced at least once, comparable to 69% of controls and the 70% average of Thoroughbreds born in the same era. -Although surgically treated horses had fewer starts during their 2-year-old racing year (0.86 starts compared to 2.01 in controls), this difference diminished in subsequent years, and there was no significant difference in overall starts during the 2- to 4-year-old racing years. -No significant differences were found in race earnings for 2-, 3-, or 4-year-old years, nor for cumulative earnings during the 2- to 4-year-old period, between surgically treated horses and controls. -Older horses at the time of surgery had slightly higher average earnings, suggesting that younger horses may require more recovery time before resuming training and racing.

Answer 66

-Oral Extraction: Associated with the lowest rate of complications (20%) among the methods studied. Preferred due to fewer risks, lower costs, and quicker recovery times. Success rates are lower for fractured or ankylosed teeth, often requiring alternative methods. -Repulsion by Sinus Bone Flap: Had the highest complication rate (80%), including significant risks of sinusitis, alveolar bone damage, and orosinus fistula formation. Often used for chronic sinusitis cases, which may have predisposed these horses to higher complication risks. -Trephination (Maxillary or Mandibular): Moderate complication rates (42%-54%), with maxillary trephination linked to a higher likelihood of superficial incisional surgical site infections (SSI). -Lateral Buccotomy: Complication rate of 53%; associated with facial nerve neuropraxia and increased risks of delayed alveolar granulation. -53% of horses returned to normal activity within 2 weeks post-surgery. -95% resumed work within 2 months, demonstrating the overall feasibility of cheek tooth extractions despite complications. -Oral extraction was the most economical method, while repulsion by sinus bone flap was the most expensive due to higher associated complication management and hospital stay durations.

Answer 67

-13.6% of the 428 cheek teeth extractions had post-operative complications, with 7.9% causing longer-term clinical problems. -The most frequent issue was alveolar sequestration (32 cases, 7.5% of extractions), often associated with infection. -Oral extraction had the lowest complication rate (10.8%), compared to Steinmann pin repulsion (24.4%) and minimally invasive transbuccal extraction (MTE) (25.6%).Repulsion and MTE techniques were more prone to complications due to the forces required and potential alveolar damage. -Complication rates were significantly higher for mandibular cheek teeth extractions (18.1%) compared to maxillary teeth (9.7%).Poorer drainage and denser alveolar bone in the mandible likely contributed to higher rates of infection and sequestration. Risk Factors for Complications -Tooth Position and Type: Mandibular premolars (06s, 07s, 08s) had the highest complication rates (up to 25.6%). -Teeth with pre-existing apical infections were more prone to post-operative issues (18.3% complication rate). -Age of Horses: Younger horses (mean age 9.7 years) were more likely to develop complications compared to older horses (mean age 11.9 years). Longer reserve crowns in younger horses may result in more extensive alveolar disruption during extraction. -Extraction Technique: Oral extraction, when possible, is the safest method with the lowest complication rates. Techniques requiring high mechanical force, such as Steinmann pin repulsion or MTE, are associated with greater risks of alveolar damage and infection.

Answer 68

Hay Feeding: -Associated with a microbiota favoring cellulose digestion, indicated by increased Bacteroidales and Fibrobacteria. -Higher urinary hippurate, a marker of healthy microbiota, was consistently observed. Hippurate has been linked to beneficial gut-host metabolic interactions. Haylage Feeding: -The fermentation process during haylage production increases sugar content, which could explain the increased abundance of sugar-associated bacterial groups like Oscillospira. -Higher urinary ethyl glucoside suggests dietary influences specific to haylage. -Higher levels of glucose in urine for haylage-fed ponies in certain months could suggest metabolic implications, such as increased risk of equine metabolic syndrome (EMS). -Bacterial and metabolic profiles fluctuated over the year, likely influenced by seasonal changes in pasture and forage nutritional content. -The study highlighted the need to consider environmental and management factors when evaluating forage effects. Microbiota and Obesity-Related Diseases: -Differences in microbiota composition suggest forage type may influence risks for obesity and associated conditions like EMS and laminitis. -Hay-fed ponies exhibited characteristics aligned with healthier gut microbiota and lower metabolic disease risk. -Three cases of laminitis occurred during the study, all in the haylage-fed group. This aligns with concerns about the impact of high-sugar diets on metabolic health.

Answer 69

'Contributing Factors: -Poor pasture hygiene (overstocking, lack of faecal removal, and rotational grazing) and inconsistent anthelmintic regimes. -Many horses were in good condition but had been previously neglected, which predisposed them to high parasite burdens. -Resistance was noted as a potential driver of increased larval cyathostominosis incidence. Inflammatory Markers: -Clinically affected horses showed systemic inflammatory markers, including hyperfibrinogenemia, neutrophilia, and a reversed albumin-to-globulin (A:G) ratio. -Severe cases presented with endotoxemia, likely due to compromised intestinal barriers and bacterial translocation. -Post-treatment inflammatory markers persisted in several horses, indicating ongoing subclinical inflammation despite resolution of overt clinical signs. Diversity Loss in Affected Horses: -Alpha-diversity (richness and evenness of gut microbiota) was significantly reduced in clinically affected horses compared to their healthy pasture mates. -Beta-diversity analysis revealed distinct shifts in microbial community composition in affected horses. -Increased abundance of pathogenic or opportunistic bacteria: Streptococcus (family Streptococcaceae), which has been associated with colic and carbohydrate overload in horses. Prevotella, a commensal with potential pathobiontic properties. -Decreased abundance of fibrolytic bacteria (e.g., Fibrobacter, Ruminococcus), crucial for cellulose breakdown and hindgut fermentation, reflecting disruption of digestive efficiency. The "perfect storm" hypothesis suggests that acute larval cyathostominosis arises from: -Massive larval emergence causing direct mucosal damage and inflammation. -Microbial dysbiosis exacerbating structural and functional gut damage, leading to systemic inflammation and endotoxemia. -Helminth removal through anthelmintic treatment may disturb the delicate balance between the parasite, host immune response, and gut microbiota, triggering an inflammatory cascade. Treatment Regimen: -Corticosteroids combined with moxidectin were effective for most clinically affected horses, reducing inflammation and controlling parasitic burdens. -Broad-spectrum antibiotics were used in cases with clinical signs of endotoxemia and appeared beneficial in mitigating secondary bacterial complications.

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