dogs and cats 13 Flashcards
diffusion barriers (sucralfate) when used, what are they, effect, indications and administration
chronic vomiting
- Sulphated sucrose and polyaluminium hydroxide
- In acidic environment cross polymerises to form viscous gel
○ Binds to necrotic tissue like a liquid band-aid
○ Also stimulates prostaglandin production, absorption bile salts and inactivation gastric pepsins
○ Stimulates mucosal defences
- Indications
○ Treatment of gastric ulceration (doesn’t prevent) and reflux oesophagitis
- Administration
○ Apart from food and other drugs (30 minutes except for digoxin, tetracyclines, fluroquinolones, its 2 hours)
histamine H2 receptors anatagnoists when used, action, indications, examples and how often need to give
- Action
○ Competitively inhibits gastric acid secretion by 70-90% (by binding H2 receptors site on parietal cell) - Indications
○ Treatment of gastric ulceration due to NSAID, uraemia and other causes
○ Does not prevent NSAID-ulceration - Examples and how often need to give
○ Cimetidine (tagamet) q 6-8 hours
○ Ranitidine (zantac) q 12 hours
○ Famotidine (pepcid) q 24 hour
○ Nizatidine (tazac) - Reduce dose by 50% if impaired renal function
proton pump inhibitor action, 2 main examples, when used and indications
- Inhibits gastric acid secretion by irreversibly binding proton-transporting enzyme at luminal surface of parietal cell
- Complete inhibition of gastric acid secretion
○ More effective than H2 antagonists
example
1) omeprazole - mast cell tumours
2) pantoprazole - suspected or confirm gastric ulceration - Indications -> ONLY WHEN STRONGLY SUSPECTED GI ULCERATION
prostalgandin E1 analogues main example, effect, wen used and efficacy
○ Misoprostol (cytotect)
○ Synthetic replcaement for PGE1 and therefore promotes gastric mucosal defence mechanisms
○ Used for prophylaxis against NSAID gastric mucosal injury (not effective as treatment)
○ Efficacy not proven in small animals
gastric acid suppression drugs for chronic vomiting what two drugs don’t need to give together and when should use
No need to give proton pump inhibitors AND histamine H2 receptor antagonists
So when should we use these drugs?
- WHEN HAVE - documented/strongly suspected GI ulceration
- NOT just cause vomiting and inappetant and primary have diarrhoea
○ Pancreatitis, cirrhosis, chronic kidney disease, gastritis, NSAID prophylaxis (only effective when 2 x dose and leads to side effects)
○ UNLESS-> these lead to GI ulceration
What are the 6 main GI causes of chronic vomiting and list the 3 main common first
- Inflammatory bowel disease/chronic enteropathy (diarrhoea (dogs), Vomiting (cats))
- Dietary intolerance/sensitivity
- Intestinal lymphoma (cats»_space;dogs)
- Chronic pancreatitis
- Structural (pyloric stenosis)
- Other neoplasia
What are the 6 main non-GI differential diagnosis of chronic vomiting
- Hyperthyroidism (cats)
- Renal failure
- Liver disease
- Heart disease
- Hypercalcaemia
- Hypoadrenocorticism
Haematemesis what is it, is it significant and common cause
- Digested blood = coffee grounds
○ Significant gastric ulceration or bleeding -> not always have melena (can be delayed) - Often concurrent melena but can be delayed
- Significant haematemesis, especially if weight loss is also present, should ALWAYS be investigated
ulcerated disease
what are the GI phyiological protections against ulceration
○ Gastric mucus and bicarbonate to form gel layer
○ High epithelial cell turnover (high energy requirements)
○ Tight junctions and lipoprotein layer of cells
○ Rich vascular supply
○ Protective prostaglandins (PEG and PGI2)
gastric ulceration what caused by and main consequences/clinical signs
- Caused by anything that disrupts mucosal barrier or causes excessive acid secretion
- Signs of melena, haematemesis, weight loss, pain and other associated disease
Consequences of GI ulceration - Hypoproteinaemia
- Anaemia
- Electrolyte loss
- Metabolic alkalosis
- Pain -> due to reflux, oesophagitis, regurgitation
- Anorexia
- Decreased gastric motility -> GO reflux -> oesophagitis -> regurgitation
gastric ulceration what are the main causes
Primary GI disease
- gastritis, neoplasia (gastric carcinoma) - common in dogs, outflow obstruction
drugs - common - NSAIDS, corticosteroids
Systemic disease - liver disease, DIC, pancreatits (not as commo), hypoadrenocorticisim
gastric hyperacidity - gastrinomas, mast cell tumours
if suspect gastric ulceration for chronic vomiting what is the main approach
- Rule out drugs
- Rule out systemic disease
- Rule out inflammatory intestinal disease
- Rule out neoplastic disease (abdomen and elsewhere)
○ Any nodule find need to aspirate (mast cell tumour)
what inital tests to run in a chronic vomiting investigation
- Haematology
- Serum biochemistry and electrolytes
- Urine analysis
- T4 in cats
- Survey abdominal radiographs (thorax if regurgitation)
○ Ultrasound instead for cats as wanting to rule out lymphoma
what is the main reasons cats vomiting and why is diagnosis more difficult in cats
Why would cats vomit?
- Common with concurrent disease due to anatomy
○ Intestine, pancreas and biliary tree are very close leading to disease in one resulting in disease in others
Why is diagnosis more difficult in cats?
- All chronic inflammation in gut will lead to lymphocytic-plasmacytic inflammation
○ Difficult to differentiate inflammation from small cell lymphoma
- Often chronic history
- Diarrhoea not always observed
- Pruritis may be manifested as vomiting of hair balls
○ Owner may think that is normal however for some cats if just start vomiting hairballs when normally don’t then abnormal
- Only severe disease will cause weight loss
What are the 6 main differentials for chronic vomiting in cats
- Metabolic disease - thyroid and kidney - rule out first
- Dietary sensitivity/food intolerance/dietary responsive enteropathy
- Antibiotic responsive enteropathy
- Inflammatory bowel disease (steroid responsive enteropathy)
- Intestinal lymphoma
- Chronic pancreatitis
dietary sensitivity in cats types, other signs related how test and what generally occurs
- True sensitivity is Type I mediated
- Usually concurrent pruritis, young cats
- Protein most antigenic
- GI signs resolve within 1-2 weeks and should recur with rechallenge
- HOWEVER only about 50% of dogs signs recur with rechallenge suggesting other reason for improvement on diet
○ Fibre may alter intestinal microflora -> soluble fibre also increases faecal water contents
○ Insoluble fibre increases faecal dry matter and highly fermentable fibre may increase methane production and worsen motility
○ High fat diets or poorly digestible starches may prolong gastric emptying and cause vomiting
inflammatory bowel disease in cats definition and the 3 types - EXAM
- Definition
○ Chronic (>3 weeks) clinical signs with inflammation within the GI tract and no identifiable cause
○ Usually lymphocytic-plasmacytic
○ Loss of tolerance to antigens - Due to confusing nomenclature, now classified as:
○ Food responsive (not food allergy)
○ Antibiotic responsive (not speicific infection)
○ Immunosuppressive responsive (only true IBD)
Feline lymphoma what generally presents as, what are the 2 types, which good and which bad
present as chronic vomiting
a. Small cell lymphocytic -> one found in the gut, lymphocytes look normal
b. Large cell (lymphoblastic) -> large granular cells - BAD
Small cell lymphocytic lymphoma in cats general presentation, type of cell, diagnosis, predilection site
§ Well, older cat with chronic vomiting
§ Usually T lymphocytes extending up from bottom to top villus
§ Cells small, with minimal features of malignancy
§ Immunohistochemistry and PCR clonality testing to help distinguish from IBD
§ Predilection site: distal ileum
small cell lymphocytic lymphoma diagnostic difficulties and potential causes
§ Diagnostic difficulties
□ Not always changes on ultrasound and if so not pathognomonic (inflammation or neoplasia)
□ Where to biopsy and how
□ How to interpret the biopsy -> PARR testing useful
§ Potential causes
□ Genetic predisposition
□ Any chronic inflammation -> IBD, helicobacter
□ Cigarette smoke exposure
□ FIV
Large cell (lymphoblastic) lymphoma what cells, age, results in/character and prognosis
§ B and T lymphocytes, no effect on prognosis
§ Cats of any age
§ Rapidly progress, and form transmural masses and spreads to lymph nodes
□ Cats are sicker than with small lymphoma, signs of intestinal obstruction
§ Large granular lymphocytes highly malignant and metastasise to other sites
§ Poorer prognosis
Crhonic pancreatitis in cats, what generally reported with, clinical signs and diagnosis
- Up to 100% reported with concurrent disease
○ Hepatomegaly, thickening intestines - Cause or consequence
- Even more vague clinical signs
○ Anorexia, lethargy, vomiting, diarrhoea, weight loss, jaundice - Diagnosis
○ Little to no change bloods (no change lipase and amylase, TLI and PLI not helpful)
○ No real sensitivity in ultrasound
○ Pancreatic biopsy -> only way
What are the 5 main clinical priorities when presented with well but vomiting cat
- Examine to ensure no physical abnormalities
- Obtain full dietary history
- Rule out metabolic disease if indicated
○ Hyperthyroidism
○ Renal disease
○ Cholangiohepatitis/cholescystitis
○ Pancreatitis - Treatment trial (work from top down)
- diet
- antibiotics
- immune suppressive - diagnosic investigation if treatment trial don’t work
treatment diet trail for well but vomiting cat which diet, when should see response and 3 possible outcomes and what to do
§ Which diet
□ Hydrolyzed or novel protein source
□ High soluble fibre content
□ Restrict access to other food
§ Should see response in 1-2 weeks
□ If do, continue diet for 6 months if completely balanced, and then can try other or previous diets
® Approx 50% won’t relapse
□ If partial response
® Can try alternative hydrolyzed or hypoallergenic diet -> may be variable individual response
□ If no/minimal response to diet
® Is cat still well, no loss in weight or dropping albumin
® Is there an increase in liver enzymes (cholangiohepatitis, but ruled out hyperthyroidism)
® OPTIONS -> Antibiotics, alternative diet or diagnostic pathway (if owner wants to know what is going on)
Treatment trail antibiotics for a well but vomiting cat which use, when respond and what if don’t
§ Amoxicillin 20 mg/kg bid for up to 6 weeks
§ Metronidazole 10mg/kg bid for maximum 3 weeks
§ Again should respond within 1-2 weeks and after 3-4 week course may only need dietary management
§ IF STILL NO RESPONSE TO DIET - need to ‘support’ the cat and happy with diagnosis move onto BELOW
Treatment trail with immune suppressive for well but vomiting cat what is the main thing to use, why and options for administration
§ Nutrition, micronutrient and fluids
§ Cobalamin
□ Supplementation improves clinical signs in cats with GI disease
□ This is regardless which diagnosis and treatments
□ Options
® Treat and measure response or
® Treat empirically (250ug injection once weekly for 4-6 weeks)
Diagnostic investigation if treatment trail don’t work or want to find out exactly what is happening on a well but vomiting cat what are the 3 main options, what good and bad about each
- Ultrasound
○ May be normal or show loss of layering with IBD, small cell lymphoma
○ May show masses, lymphadenopathy, focal intestinal thickening or effusion and can get samples - Endoscopy
○ Limitation access to biopsy - good quality biopsy takes experience and training
○ Gastric good
○ Overlap with IBD in intestine
○ Tricky to get ILEUM -> access from the colon - Exploratory laparotomy
§ Increased morbidity
§ Increase yield
§ Can assess disease outside of intestine
§ Can biopsy ileum easily
what are the 4 main options for treatment of IBD
1) prednisolone
2) other corticoteroids - not as effective - dexamethasone, budesonide
3) other immunosuppressives - chlorambucil
4) other therapies - not properly evaluted - mega-3 fatty acids, probiotics - don’t use
treatment for IBD prednisolone, when taper, what use with and side effects
○ Start to taper every 3-4 weeks until reach minimum effective dose
○ Continue diet and continue antibiotics for first 2 weeks of prednisolone
○ Side effects
§ PU/PD and alopecia (minimal)
§ Development of diabetes is a risk
treatment for IBD otehr corticosteroids what are the 2 main ones when give and main issue
- not as effective as above
○ Dexamethasone
§ Only if cannot give oral medication and not eating well enough to place in food
§ 1/6th to 1/8th the oral pred dosage q 36-48
§ Profound immune suppression
○ Budesonide
§ Not evaluated in cats
Other immunosuppressives for treatment of IBD when use, what are the 2 options and which is better and why
○ Only if histologic diagnosis 1. Chlorambucil § Current choice as add on § Generally well tolerated 2. Ciclosporin § Be careful with latent toxoplasmosis § Not evaluated in feline IBD
treatment for IBD other therapies what are the 2 main options, when use or not
not properly evaluated
1) Omega-3 fatty acids
§ May interfere with palatability of diets, and cause diarrhoea
2) Probiotics - waste - DON’T USE
§ Lack of translational benefits in people
§ Well tolerated in cats
§ Recent abstracts suggests not effective in feline IBD
small cell lymphoma in cats, prognosis in terms of response to therapy and median remission
- This is a ‘good’ tumour
- Response to therapy 75-90%
- Majority of cats alive and in remission at 2 years
○ Median remission 897 days
treatment of small cell lymphoma
- Still support (cobalamin)
- Still antibiotics and diet
- Initial therapy
○ Prednisolone 3mg/kg once daily, reducing to 1-2mg/kg once daily when have clinical remission
○ Chlorambucil 2mg q 48 hours, 15mg/m^2 q 24 x 4 q 3 weeks, 20mg/m^2 q 2 weeks
same as IBD
If treat IBD and small cell lymphoma the same do we need to differentiate?
- DIFFERENTIATE VIA -> Immunohistochemistry and PAR sample
- Important due to prognosis -> IBD better prognosis than small cell lymphoma
what is a common concurrent disease to IBD in cats and treatment
Cholangiohepatitis/cholecystitis - most common
○ Antibiotics
○ Vitamin K if severe
large cell lymphoma prognosis in terms of remission, median time, when good
- Complete remission in 50-75%
- Overal median remission 4-8 months, overall MST 6-8 months
- Have longer survival if initial good response
- Often unwell, so need nutritional support
- Recent study shows bacteraemia in cats with LC lymphoma
large cell lymphoma in cats treatment basics and main options
Treatment basics - Cobalamin - Antibiotics - Nutritional support Treatment options - Palliative prednisolone - Palliative surgery - Multi-agent chemotherapy - Radiation therapy
patient preparation for GIT surgery what are the 4 main considerations
1) Common disturbances:
○ Dehydration
○ Electrolyte imbalances:
§ Hypochloraemia, Hyponatraemi, Hypokalaemia
○ Acid-base disturbances:
2) Treatment/correction of these pre-op problems important to:
○ Optimise outcomes
○ Prevent complications
3) Fasting for elective procedures can minimise risk of spillage but decreases gastric fluid pH
4) If gastro-oesophageal reflux anticipated –consider H2 antagonist or proton pump inhibitor
○ Rapid induction and airway control if vomiting reflux likely (prevent aspiration)
what are the 5 regions of the stomach and why important in surgery
- Cardia - terminal part of oesophagus, gastro-oesophageal sphincter
- Fundus - can be affected during GDV
- Body - largest part
- Pyloric Antrum - funnelling down into smaller cylinder -> WHERE DO GASTROPEXY
Pylorus - outflow of stomach, muscular sphincter into proximal duodenum
