Foals Flashcards
What are the main diarrheal diseases in a foal? (6)
- Foal heat diarrhea
- Viral Enteritis
- Salmonella
- Clostridia
- Rhodococcus equi diarrhea
- Equine proliferative enteritis ( Lawsonia intracellularis)
Which diarrheal disease in foals tend to affect them in their first 1-2 weeks of age?
- Foal heat diarrhea
- Viral enteritis
- Clostridia
What diseases cause diarrhea more commonly in foals that are at least a month old?
- Salmonella
2. Rhodococcus equi diarrrhea
What is the common age of a foal that equine proliferative enteritis affects?
5-6 month weanlings..so not actually a foal anymore
Which causes of foal diarrhea can be prevented with a vaccine?
- Viral enteritis
- Salmonella
- Equine proliferative enteritis
Which cause of foal diarrhea has a 10 day mark for when foals show clinical signs, what does this 10 day mark mean?
Foal heat diarrhea and it coincides with the first postpartum estrus of the mare
Why do foals, even orphan foals, get foal heat diarrhea?
It is a physiologic change in the GI tract of the foal, so it is self limiting in usually less than 7 days
How would you treat foal heat diarrhea?
It is not necessary, but best to keep them clean to prevent fly strike and scalding, with other basic nursing care
What is the etiology of viral enteritis in foals?
Caused by rotavirus, so adults do not get it. It invades the small intestinal absorptive cells leading to proliferation of crypts cells causing malabsorption and maldigestive diarrhea
What is the most common cause of infectious diarrhea in the neonate foal?
Viral enteritis- rotavirus
Why do foals die from viral enteritis?
Hypovolemic shock due to the profuse watery diarrhea that causes dehydration, electrolyte disturbances and acid/base disturbances
What foal diarrheal disease can be diagnosed with PCR?
- Viral enteritis
2. Equine proliferative enteritis
How would you diagnose foal diarrhea in foals suffering from salmonella?
Blood culture
How would you diagnose foal diarrhea in foals suffering from clostridia?
You must detect the genetics for the toxins released by the clostridia species, and these are very labile, so the manure needs to be frozen before it is cultured
Why can you not diagnose rhodococcus equi diarrhea in foals with a fecal culture?
It can be found in normal flora
List three important ways in which you can support a diagnosis of lawsonia intracellularis -equine proliferative enteritis in a foal.
- Ultrasound detection of thickened SI
- CBC showing hyperfibrinogenemia and hypoproteinemia
- Chem profile showing hypoalbuminemia
T/F: The rotavirus that causes viral enteritis survives well in the environment and animals can shed it for months; therefore, overcrowding and poor hygiene/biosecurity needs to be avoided.
TRUE
Which compound is most effective of killing rotavirus?
Phenolic
How would you treat a foal with viral enteritis?
- Feed live cultured yogurt
- Administer human lactate tablets to counteract SI damage
- Nutritional support
- Other supportive care like fluids
Is is more common for a foal to die of viral enteritis or improve? How long does it take them to improve?
More common to improve within 2-5 days, but can take up to 2 weeks
If you can diagnose viral enteritis in a foal with PCR, what sample would you need and what does it detect? What are other test syou can do other than PCR?
Fecal sample and the ELISA can detect serotypes H1 and H2
Latex agglutination test
EM
A month old foal presents to you with profuse water diarrhea, appears to be in sever abdominal pain and is obtunded. You notice there are pigeons roosting in the roof of the stall and the mare is dirty , what disease are you thinking about?
Salmonellosis
What clin path findings would you find in a foal with salmonella?
- Acidemia
- Neutropenia
- Leukopenia
- Hypovolemia
Which disease that causes diarrhea in foals can cause them to be in septic shock before diarrhea develops?
Salmonella
How would you treat a foal suffering from salmonellosis?
- Isotonic Fluids
- Plasma
- Antibiotics not the first choice..very resistant to most
- Nutrition
- Prevention is the KEY..keep stall clean so foal doesn’t get feces in mouth
What type of clostridia strains tend to cause foal diarrhea?
C. Perfringens type A, B and C is most common
C. Difficile
A foal born in the last 24 hours presents to you with hemorrhagic diarrhea and severe gas distention..what is your top differential?
Clostridia infection
Why can clostridial infections in foals be so damaging?
The anaerobes produce gas that distends the intestinal lumen which can lead to bowel perforation and peritonitis ; in addition to the clostridial toxins damaging enterocytes causing villus atrophy
What is the best way to prevent a clostridial or salmonella infection from causing diarrhea in a foal?
Pre-foaling hygiene
How would you treat a clostridial infection in a foal?
Treatment is unrewarding, but can consider:
- Giving an antitoxin
- Probiotics
- Low dose metronidazole
- Fecal transplants
A 3 month old foal presents to you with lung/respiratory signs in addition to uveitis, joint effusion and diarrhea, what foal diarrheal disease is at the top of your differential list?
Rhodococcus equi
How would you treat rhodococcus equi diarrhea in a foal?
Administer for 3-4 weeks:
- Macrolides
- Riframprin
Which foal diarrheal disease also affects pigs and can cause anorexia, edema, lethargy, weight loss and sometimes a fever/diarrhea?
Lawsonia intracullularis-equine proliferative enteritis
Why are foals mostly affected by lawsonia intracelularis in the fall and winter months? How is it transmitted?
They are weaned between August and Feb.
Feco-oral transmission from pigs, wild animals or other horses
How would you treat a weanling foal with equine proliferative enteritis?
- Oxytetracycline
- Crystalloid fluids and plasma
- Nutritional support with increased protein
How can equine proliferative enteritis be prevented? How is the prognosis?
- Vaccine ( for swine)
- Decrease stress
- Parasite control
Good prognosis
How can passive transfer of immunoglobulins between the mare and the foal fail?
- Lack of ingestion of colostrum
- Ingestion of poor quality colostrum
- Failure to absorb colostral antibodies
What is the most common cause for neonatal foal morbidity/mortality?
Septicemia
What microbes are usually responsible for septicemia in foals? (5)
Gram negative bacteria:
- Actinobacillus equuli
- Klebsiella pneumonia
- Escherichia coli
- Salmonella
- Pseudomonas
Why is diagnosing septicemia in a foal difficult?
It is difficult to identify high risk neonates early, as they are the most at risk.
What are some important predisposing factors with the mare that can lead to septicemia in a foal?
- Chronic illness like laminitis
- Prepartum colostrum loss
- Induced births
- Dystocia
- Premature placental separation
- Death
- Older mare with poor colostrum
What are some important predisposing factors with the foal that can lead to septicemia?
- Failure of passive transfer
- Low birth weight
- Premature
- Meconium staining/aspiration
- Abnormal behavior like a lack of suckle
How can a foal and mare be managed correctly in order to prevent septicemia in the foal?
- Don’t overcrowd
- Sanitize
- Ventilate
- Don’t use the wrong antimicrobials or use too mch
- Dilute umbilical cord with dilute chlorhexidine, not 2% iodine
In what ways can gram negative bacteria enter the body to cause septicemia in the foal?
- Inhalation
- Ingestion
- Umbilical contamination
What is different in a foal versus a mare that predisposed them to septicemia?
They are not immunocompetent
What are the PE findings of a septicemic foal? (12)
- Subnormal temperature
- Toxic MM
- Increased CRT
- Petechiation of the pinnae
- Apnea
- Tachycardic
- Diarrhea
- Seizures
- Uveitis
- Hypopyon
- Lame
What is the definitive diagnosis for septicemia in a foal?
Positive blood culture or tissue culture from two or more organs/tissue
What is the diagnostic tool of choice for septicemia foals when they are still alive?
Sepsis score sheet
How does a septicemic foal present?
Lethargic with a decreased appetite and suckle response, sleeping all the time
How would you treat a foal that is septic?
- Bactericidal antimicrobial
- Plasma
- Isotonic fluids
- Correct hypoglycemia and acidemia
- Nutritional support
How can a septic foal be prevented?
- Identify high risk neonates prepartum or postpartum
2. Prevent failure of passive transfer
What is meconium?
Glandular secretions and swallowed amniotic fluids/cellular debri by the foal
Where do meconium impactions in foals usually occurs?
Small colon and rectum
How soon should meconium pass from a foal?
24 hours, but usually sooner
T/F: Fillies are more likely to suffer from meconium impactions.
False, colts are
What might predispose a foal to a meconium impaction?
- Delayed nursing ( nursing has a laxative effect)
- Dehydration
- Premature foal
- Dystocia
A foal presents to you constantly posturing to defecate with straining, abdominal distention, tachycardic, is not nursing, and is in respiratory distress. What is on your differential list?
- Meconium impaction
2. Strangulating colonic lesion
How can you diagnose a meconium impaction in a foal?
- Rule out other causes such as intususception and atresia coli
- Digital rectal
- Ultrasound
- Radiographs
T/F: In order to treat a meconium impaction, you would administer oral laxatives like milk of magnesia.
FALSE: you would treat with a fleet soapy water or a acetylcysteine enema
A 4 day old male foal presents to you obtunded with a loss of suckle. He walks around constantly trying to urinate, but nothing is occuring. You do blood work and find that he is hyperkalemic, hyponatremic, and hypocalcemic. What is your top differential?
Uroabdomen
How would you treat a uroabdomen in a foal?
- IV fluids with NaCL and no potassium
- Insulin
- Dextrose
- Decompress abdomen and do a surgical correction
T/F: Uroabdomen in a foal is not an immediate emergency.
True
What can cause uroabdomen in foals?
- Ruptured/torn bladder
- Urachal ruptures
- Omphaloateritis
- Urachitis
What is the most important treatment when you are presented with a seizuring foal?
Find the underlying cause and in the meantime, treat with midazolam or diazepam to control the seizures.
What is potassium bromides role in the treatment of a seizuring foal? What other treatment is similar
A long term maintenance drug
Phenobarbital
What are some potential causes of seizures in a foal? (10)
- Birth related asphyxia or hypoxic ischemic injury
- Metabolic issues
- Bacterial/viral miningoencephalitis
- Tyzzers disease
- Botulism
- Trauma
- Prematurity
- Liver disease
- Heat stroke
- Hydrocephalus and other developmental congenital diseases
T/F: Tonic clinic grand mal seizures are more common in foals than in adults.
FALSE, foals can have this presentation, but is is more common to have repeated behavior that can change in the frequency or severity.
What phase of seizuring is the most challenging to recognize in a foal, which is more common to recognize?
Most challenging is prodromal and most common is the postictal
What are the two forms of Hypoxic ischemic encephalopathy?
- Birth related asphyxia or hypoxic cerebral ischemic injury
- Neonatal maladjustment syndrome
What occurs during pregnancy that can cause hypoxic ischemic encephalopathy?
Pregnenolone is normally high at birth and decreases rapidly after birth, but sometimes it doesn’t and since it acts like an anesthetic and tonically inhibits the CNS of the foal, it can lead to dummy foals aka neonatal maladjustment syndrome.
What is a treatment frequently used for foals experiencing neonatal maladjustment syndrome? Why?
Madigan squeeze to imitate birth canal compression triggering the pituitary-hypothalmic axis to prepare for the extrauterine environment
What are some possible causes of birth related asphyxia or hypoxic cerebral ischemic injury in a foal that can lead to hypoxic ischemic encephalopathy?
- Red bag syndrome
2. Dystocia
what are the typical clinical signs of a foal suffering from hypoxic ischemic encephalopathy?
- Loses suckle response after a few hours or days
- Lose affinity for the mare
- Aimless wandering and vocalization
- Blind
- Dog sitting
- Seizures
- Stupor/Coma
You suspect a foal is has hypoxic ischemic encephalopathy, how would you know for sure?
There is no definitive test as the lab results and CSF fluid may be normal. The best you can do is rule out other causes with the history and PE.
How would you treat hypoxic ischemic encephalopathy in a foal?
Depends on the cause, whether is is caused by pregnane levels, red bag, or another ischemic event. You would want to control the clinical signs with electrolytes, acid/base , fluids, seizure medications , anti-inflammatories, keep warm as they can become hypothermic, and give nutritional support.
What are a few complications that can later arise from a foal that was suffering from septicemia?
- Pneumonia
- Septic arthritis
- Meningitis
- Osteomyelitis
- Peritonitis
- Seizures
- Diarrhea
Which strain of herpes virus can cause diffuse cerebral disease and hypoxia in a foal leading to being born premature or dead?
EHV-1 `
How do foals become infected with equine herpes and how is it treated?
In utero infection and there is no treatment
You are told that you should performJFA test on a foal/mare before the foal consumes the mares colostrum, what does this mean? What are the parameters for a positive test?
You would perform a JFA test on a foal in order to test for neonatal isoerythrolysis. A positive reaction would yield a ratio 1:16 or greater meaning that the colostrum from the dam and the blood from the foal agglutinate.
What is neonatal isoerythrolysis?
Hemolytic anemia induced by anti-red blood cell antibody produced by the dam and transferred to the neonate in the colostrum leading to intravascular RBC destruction.
T/F: Multiparous mares are commonly the culprit when it comes to neonatal isoerythrolysis.
True, the mare most likely became exposed to the blood factor during a previous foaling
How would you diagnose neonatal isoerythrolysis?
Direct coombs test with presence of antibody on the foal’s RBC’s and alloantibodies in the serum or colostrum of the mare
What specific factors can be incompatible between a mare and a foal to cause neonatal isoerythrolysis?
Qa and Aa
What four things must occur in order for neonatal isoerythrolysis to occur?
- Mare lacks either Aa or Qa factor and is bred to a stallion that has one of these factors, becoming sensitized to the factor during pregnancy
- The foal must inherit the factor from the sire
- Alloantibody must be in the colostrum
- Foal must ingest enough colostrum with the alloantibody
What are the biggest clues during a physical exam that points towards neonatal isoerythrolysis?
Born healthy and progressively gets weaker as the days go on, developing pallor or icterus, weakness , loss of sucks and tachypnea/tachycardia with hemoglobinuria and hemoglobinemia.
You perform labwork on a foal you suspect is suffering from neonatal isoerythrolysis, what do you expect to observe?
- Low PCV
2. Decreased total RBC
What are the five main steps you would take to treat a foal suffering from neonatal isoerythrolysis?
- Stall rest
- Diuresis with IV fluids
- Oxygen
- Seizure management
- Transfusion is PCV< 15
What is the best donor plasma for a foal? What must you do to the plasma before giving it to the foal?
The mare, but you must wash the RBC’s with saline to eliminate the antibodies and then do a major and minor crossmatch
A new client is worried about neonatal isoerythrolysis because a mare she just bought who pregnant had the issue with a foal in the past, what can you do to prevent it from occuring again?
- Test the mare’s serum for alloantibody 2-4 weeks before foaling
- JFA test
What is the difference between a premature foal and a dysmature foal?
A premature foal is born at the gestation age of 320 or earlier with signs of immaturity while a dysmature foal is born at term ( 340 days), but developmentally immature.
What is the first step to identifying is a foal is premature or dysmature? Why would you take this first step?
Take radiographs to see if there is incomplete ossification of the carpal and tarsal bones.
A foal presents to you with a low birth weight, soft and silky hair, thin skin, soft and plaint ear, soft and droopy ears and lax flexor tendons..what is going on?
This is a premature foal
What is the prognosis for a dysmature/premature foal?
Less than 10-20% survive, so it is a guarded prognosis
What are significant factors that decrease the viability of a premature/dysmature foal?
- Low body weight
- Low WBC and PMN with higher lymphocyte counts
- Metobolic acidemia
- Elevated fibrinogen
What diagnostic tests can be done for failure of passive transfer? Which is the gold standard?
- ELISA snap test
2. Single radial immunodiffusion (SRID) -GOLD STANDARD
When does a foal need to absorb colostrum for there to be no failure of passive transfer?
Maximum 12 hours, ideal by 6 hours
Why do foals need to ingest colostrum within a certain period of time?
Foals have specialized mucosal cell in their small intestines at birth that absorb colostral antibodies. These are replaced within 24 hours after birth and absorption ceases.
What does failure of passive transfer put foals at risk for?
1. Septicemia 2 Chronic septic arthritis 3. Pneumonia 4. Omphalophlebitis 5. Diarrhea
When does the best colostrum form in the mare? Why is this important?
The last few weeks of pregnancy. If a foal is born premature (320 days or sooner), the best colostrum has not formed yet.
What can lead to failure of passive transfer?
- Fescue toxicity-agalactia
- Old/injured or dead mare
- Premature lactation/birth
- Delayed nursing due to a weak/ill foal
When should foal IG levels be measured and what levels are ideal?
18 hours of age
>800 mg/dl
What levels of IG in foals is considered partial failure and complete failure of passive transfer?
Partial: 400-800 mg/dl
Complete: <400mg/dl
Why would you do a Snap ELISA test to diagnose failure of passive transfer or a SRID test, even though the SRID is gold standard?
The SRID takes 24 hours, while the Snap ELISA is easier, rapid, cost effective and accurate with similiar results
What is the most important consideration to have when dealing with failure of passive transfer?
Prevention is key, clients need to be educated and have an alternate source of colostrum available.
What are some alternate sources of colostrum for a foal? When must these be given?
- Bovine colostrum
- Equine plasma
- Lyophilized equine IgG
The first 6 hours of foals life
What are the characteristics of good quality colostrum?
Specific gravity of >1.060
3,000 mg/dl IgG
How would you treat a foal with failure of passive transfer if it has been longer than 6 hours and you can do longer give colostrum orally?
Plasma transfusion, especially if the foal is septic and IgG < 800 mg/dl and give 20-40 ml/kg of plasma to increase the IgG 200-300 mg/dl in the foal
What factors affect the foals response to the plasma transfusion for failure of passive transfer?
- Concentration of IgG
- Level of the FPT
- Vd of the foal ( viability)
- Consumption of Ig by ongoing processes like sepsis
What the normal gestation length for horses?
340 days
Why is it important to know if a mare was bred in the same location as where she is now?
Rhocococcus equi exposure and difference in gut microbiomes
What can cause hypothyroidism in mares?
Excessive iodine supplementation through the feeding of seaweed
When should a foal be sitting up sternal? Standing?
15-30 minutes for sitting up, 1 hour for standing
When should a foal be nursing and how often?
Nurse by 2 hours, 6-7 times an hour as soon as they wake up from sleeping while laying down
What is the normal temp for a foal? HR? RR?
T: 101-102 F
HR: 70-100
RR: 20-40, but 60-80 first hour of life
Where should you palpate for a pulse in a foal?
- Great metatarsal
- Facial
- Carotid
- Brachial
T/F: A jugular pulse is normal in a foal
False, a jugular pulse is abnormal
When evaluating the respiratory system of a foal, what is normal/abnormal?
Normal: Easy to hear lung sounds, periods of apnea or tachypnea, abnormal pattern while sleeping
Abnormal: Can’t hear lung sounds, paradoxical breathing
When should a foal first urinate?
5-10 hours after birth
T/F: A menance response in a foal is absent for the first 14 days
True
How long should it take for a mare to pass the placenta?
3 hours with a max of 6 hours
How much should the placenta weigh? What if it weights more?
10% weight of foal and if it weighs more, could indicated placentitis and a high risk neonate ( use a scale)
When should you consider giving vitamin supplementation to a foal?
If the client lives in a vitamin E and selenium deficient area ( white muscle disease)
How should you begin the physical exam of a foal?
Observe from outside the stall and make sure to observe the mare too
If there is moisture at the umbilicus of a new foal, what could this indicate?
Patent urachus
What prophylactic treatment should you do for the foal? Not do?
You can give vitamins supplementation depending on the region, give a TAT vaccine is the mare wasn’t given one 4 weeks before foaling, and do ONE enema to help with meconium impaction. DO NOT GIVE ANTIBIOTICS OR GIVE MULTIPLE ENEMAS. If it is a high risk neonate, may need to run a CBC and CHEM panel.
What testing should you do in al foals?
IgG levels to assess failure of passive transfer
What should you make sure you look at when you do a physical exam on the mare after she has given birth?
Look at her mammary glands and make sure there is milk, inspect her vulva to make sure it is normal, make sure she is bonding with the foal and check out her placenta.