Foal disease: PAS, sepsis, diarrhea, meconium impaction, Flashcards
(50 cards)
Foal PAS: definition and causes.
Perinatal asphyxia syndrome:
* Syndrome caused by acute or chronic oxygen deprivation during pregnancy or parturition.
* Further damage caused by reperfusion.
* Brain, GIT and kidneys are most commonly affected.
Risk factors:
* Placentitis or placental insufficiency (twins, post-term pregnancy)
* Prolonged phase 2 during parturition (fetal expulsion phase).
* “Red bag” delivery (indicating placental abruption)
* Severe illness or surgery of the mare during the pregnancy
* Energy deprivation in late pregnancy etc.
Soft bedding, change side every 2 hours, keep the foal
sternal etc.
PAS: clinical signs
Perinatal asphyxia syndrome:
* May appear healthy at birth
* CNS abnormalities during first hours or up to 2 days from birth.
Clinical signs variable:
* Foal is just “not right”
* Loses interest in mare and suckling
* Does not get up and/or lay down voluntarily
* Unable to find the udder
* Recumbency
* Mild to severe seizures
* Irregular breathing
* Colic, diarrhea
* Oliguria/anuria
PAS: respiratory problems
Perinatal asphyxia syndrome:
Respiratory compromise:
* Hypoxemia +/- hyperkapnia
* Give oxygen 5L/hour (Needed for prevention and treatment)
Hypoventilation/apneustic breathing pattern so consider Mechanical ventilation.
* Analeptic Caffeine: loading dose 10mg/kg PO, then 2,5-3 mg/kg SID-BID PO
Soft bedding, change side every 2 hours, keep the foal
sternal etc.
PAS: metabolic problems
Perinatal asphyxia syndrome:
causes a Metabolic acidosis
Changes in electrolytes
* ↓ Na, Cl, Ca
* ↓ or ↑ K
* Should be regularly measured and fluid therapy corrected accordingly.
* If can not be measured, give isotonic fluids and hope for the best.
PAS: kidneys
Perinatal asphyxia syndrome:
- Renal compromise is common.
- Decreased renal bloodflow → tubular injury and necrosis → renal failure.
- Fluid overload results in generalized edema (“Jelly baby”).
Dopamine and furosemide:
* Do not protect kidneys or reverse damage
* They Help to manage fluid overload
- Dopamine 2-5 ug/kg/min CRI
- Furosemide 0,25-1mg/kg IV as a bolus or 2mg/kg/h CRI
PAS: and the gastrointestinal tract
Perinatal asphyxia syndrome:
- Ileus, gastric reflux, gas distention
- Usually worsens with feeding
- May be subtle or severe diarrhea, colic
- Parenteral nutrition necessary
PAS: and seizures
Perinatal asphyxia syndrome:
- Can be obvious or subtle (focal tremors, abnormal eye movement, hyperesthesia, excessive stretching,
extensor muscle tone when recumbent)
Treatment:
* Diazepam 0.1 – 0.44 mg/kg IV to effect (Might only have a short-time effect.)
* Midazolam 0,04-0,1 mg/kg IV slowly or Can be used CRI 2-5mg/h.
* Concurrent respiratory depression with both above drugs.
If the seizures cannot be controlled with diazepam/midazolam:
* Phenobarbital, propofol
* IN-CLINIC care!
* Protect the foal from injury
* Measure electrolytes, glucose
Tx of Cerebral edema:
* Mannitol 0,25-1g/kg as 20% solution over 20 min
* Often results in neurologic improvement
* Avoid overhydration though
PAS: other aspects
* General supportive treatment for recumbent foal
* Maintaining perfusion
* Correction of hypothermia
* Maintaining blood pressure
* Provision of nutritional support
* Enteral if tolerates or parenteral
* Prevention and treatment of sepsis
* Measure IgG and give plasma if needed
* Broad spectrum of antimicrobials
* Soft bedding, change side every 2 hours, keep the foal
sternal etc
PAS - prognosis
Perinatal asphyxia syndrome:
Good/excellent
* If recognized early and aggressively treated
* Up to 80% survive and can be used in sports.
Worse prognosis if treatment is delayed or foal is
septic/dysmature.
Sepsis in foals: definitions.
* SIRS =
* Sepsis =
* Severe sepsis =
* Septic shock =
SIRS, systemic inflammatory response syndrome:
* Fever
* Tachycardia
* Tachypnea
* Leukopenia/leukocytocis
Sepsis = SIRS + infection (either suspected or confirmed)
Severe sepsis = sepsis with acute organ dysfunction (including hypoperfusion and hypotension).
Septic shock = septicemia with hypotension that is refractory to fluid resuscitation (aka no longer responding to fluids).
Leading cause of morbidity and mortality in neonatal foals is…
sepsis.
Common reasons for a neonatal foal to present to the clinic.
- Early recognition and starting the treatment fast is essential for a good outcome.
- NB Treatment failure is still common.
SIRS criteria for foals. (6)
SIRS criteria for foals require the presence of at least 3 of the following criteria, 1 of which MUST be abnormal body temp. of leukocyte count.
- abnormal body temp (either fever or hypothermia)
- tachycardica
- tachypnea
- leukocytosis or leukopenia
- elevated blood LAC
- decreased blood GLU
Causes of sepsis in foals, and predisposing factors. (8)
Usually caused by opportunistic bacteria from the environment, foal’s skin or mare’s genital tract.
Portals of entry: GIT, umbilicus, respiratory tract, placenta.
Predisposing factors:
* FPT
* Systemic illness/colic in mare
* Prematurity/dysmaturity
* Premature placental separation (“red bag delivery”)
* Twins
* Meconium staining
* Dystocia
* Poor hygiene
Clinical signs of sepsis in foals. (6)
- Depression, weakness, recumbency
- Decreased suckling activity (sometimes just stands there but not suckling, milk running from the udder indicating no suckling happening)
- Injection or petechias on mm-s
- Fever or hypothermia (but NB Normothermia also possible)
- Cardiovascular collapse: tachypnea, tachycardia,
hypotension, septic shock. - Localized infection sites
Describe localized infections as a part of foal sepsis.
Not infrequent concurrently with sepsis.
Localized infections:
* Septic arthritis
* Joint effusion and lameness
* Arthrocentesis
* Osteomyelitis
* Pneumonia
* Enteritis
* Meningitis
* Omphalophlebitis
* etc.
Diagnosis of sepsis in foals.
Starts with anamnesis and clinical signs.
Do Blood culture (or culture of other body fluids).
Hematology:
* Leukopenia (or leukocytosis)
* Neutropenia with left shift
* NB Differential counts can be more useful than total cell counts. Compare proportions siis.
* Repeat cell counts helpful too. You can follow trends.
* High fibrinogen (acute phase protein), or can be normal so measure SAA – elevates faster (with hours).
* Hemoconcentration
Biochemistry: azotemia, low TP, high bilirubin…
* Hypoglycemia
* Metabolic acidosis
* Electrolyte disturbances
* Low IgG
Utilize sepsis score sheets!
Describe sepsis score sheets for diagnosis of foal sepsis.
Clinical assessment tools that involve anamnesis, physical examination and laboratory values that are used to predict sepsis in a structured manner.
A score above a certain threshold (e.g., >11 in MSS) indicates a high likelihood of sepsis, prompting early treatment with antibiotics and supportive care.
Describe Antimicrobial treatment of foals for common bacteria.
- Usually mixed infections!
- Gram neg. isolated more often than gram pos.
- Anaerobes less common.
Most commonly isolated in septic foals:
* E.coli (most common)
* Enterobacter
* Klebsiella
* Actinobacillus
* Pasteurella
* Streptococcus
* Enterococcus
* Staphylococcus
Treatment of sepsis: describe antimicrobial use.
Start at the suspicion of sepsis!
ASAP: In human medicine even 3h delay is associated with increased morbidity and mortality.
NB use Broad spectrum!
Parenteral route (IV), bactericidal drugs, usually penicillin/ampicillin + gentamicin/amikacin:
* Ampicillin 20mg/kg IV QID + amikacin 25mg/kg IV SID gives the broadest spectrum: effective against 91.5% of isolates from cultured septic foals.
* Penicillin + gentamicin 82%
* Check creatinine! If renal function is unknow, favor drugs safer for kidneys. For example cefotaxime 40mg/kg IV QID.
Take a blood culture:
* Ideally before initiating antimicrobial treatment.
* But do not delay antimicrobials to have a culture result (no more than 45 min).
Treatment of sepsis: describe hemodynamic support.
- Replacement of deficits and maintenance fluids
- Resuscitation: balanced isotonic crystalloid
- Bolus 20ml/kg and then re-assess (1 L for 50kg foal)
- Can be repeated until perfusion parameters improve (monitor urine output, extremity temperature, pulse quality, blood LAC)
- Every new bolus should be given more slowly
If normovolemia is restored, then CRI maintenance fluids:
* 80-100ml/kg/24h
* Avoid fluid overload (risk of pulmonary and peripheral edema) (monitor for changes in respiratory function)
* Fluid overload is more of a problem than mild fluid restriction!
* Weigh the foal regularly (at least once a day) and adjust your rates again.
Check electrolytes regularly. May be nessesary to mix balanced electrolyte solution with sterile water to avoid hyperchloremia. It has to be mixed before entering the vein (otherwise hemolysis).
Treatment of sepsis: describe blood pressure support.
If fluids are not enough to maintain BP:
* Inotropes – to improve cardiac output e.g. dobutamine
* Vasopressors – to improve BP e.g. norepinephrine
Sequence of care: fluids -> inotropes-> vasopressors
Treatment of sepsis:
Plasma use?
Glucose use?
Anti-ulcer prophylaxis?
Managment of recumbency?
Septic foal will benefit from plasma regardless of IgG but if failure of passive transfer, its definitely required.
* Sick foal uses IgG faster even if normal at first
Glucose: target is to keep between 80 to 180 mg/dL
* Both, hypo-and hyperglycemia increase mortality.
Anti-ulcer prophylaxis:
* Increased risk of diarrhea.
* If GI abnormalities present: prophylaxis is indicated cause increased risk of ulcers.
Managment of recumbency:
* Soft bedding
* Care for catheters (urinary, venous etc)
* Ophthalmic care from prolonged prostration.
Prognosis of sepsis in foals.
- Survival 30-80%
- Prognosis better if diagnosed and treatment started early.
- With Septic arthritis: 3 times less likely to be used athletically.
- Foals that have multiple septic joints have guarded prognosis for athletic performance.
- Glucose and lactate can be prognostic indicators.
- Sometimes the limiting factor is not the ability to survive but the cost of the treatment.
How to give IV plasma.
They rarely have a reaction so this can be done on-farm as well.
Indicated if foal is older than 18 hours or colostrum not available.
- Sedate the foal if needed
- Place an IV catheter
- Use an infusion line that has a plasma filter!
- Start with very slow rate, if no reaction, then increase the speed.
- Monitor foal (HR, RR, temp) during plasma administration.
- Usually considered that 1L = 200mg IgG
- Total FPT requires 3L of plasma.
- Check what’s written on commercial plasma products.
Commercial plasma products for foals are harvested and sold rather than synthetic. The plasma is collected, processed, and then frozen for storage and later use.
