The REST Of Equine II UPDATED
ACTUAL EXAM Questions And Answers
You suspect that an 18 year old Quarter Horse mare has recurrent airway obstruction (RAO; also known
as chronic obstructive pulmonary disease) based on clinical signs of increased respiratory rate and effort,
expiratory wheezes on auscultation, and the age of the horse. What cytologic finding of bronchoalveolar
lavage (BAL) fluid would be supportive of RAO?
Neutrophilic inflammation
Mononuclear inflammation
Eosinophilic inflammation
Mixed inflammatory response (neutrophils, macrophages, and eosinophils) - CORRECT
ANSWERS In health, BAL fluid primarily consists of macrophages. However, in RAO, neutrophils
are the predominant cellular finding. RAO typically affects older horses and is a response to
environmental allergens. The classic case is the horse that is stalled in the winter and possibly housed in
the vicinity of the hay storage. When the horse is exposed to hay allergens (via inhalation),
bronchoconstriction and neutrophilic inflammation occur resulting in clinical signs.
What structure is not likely to be affected with a guttural pouch infection of a horse?
CN VI
CN VII
Carotid artery
CN IX
Cranial sympathetic trunk - CORRECT ANSWERS The correct answer is CN VI. This nerve does
not run along the guttural pouch in contrast to the others listed. Both the internal and external carotids
may be affected during a guttural pouch infection. In case you don't remember, the guttural pouch in a
horse is the air-filled diverticula of the auditory tube which communicates between the middle ear and the
pharynx. Sometimes foreign material will get trapped there and result in infection.
You are examining a 7 year old Thoroughbred gelding for severe bilateral epistaxis. After the epistaxis
has decreased, endoscopy of the pharynx reveals blood from the left guttural pouch opening (see image).
What is the most appropriate treatment for hemorrhage from guttural pouch mycosis?
Tie off the left common carotid artery
Surgical occlusion of involved arteries (i.e. internal or external carotid artery) under general anesthesia
,Lavage guttural pouch with antifungals
Pass endoscope into affected guttural pouch and cauterize involved vasculature - CORRECT
ANSWERS Guttural pouch mycosis has several different clinical presentations. In some horses,
epistaxis is observed, while in others, cranial nerve deficits such as dysphagia may be observed. When
hemorrhage is present, the disease is advanced and more aggressive therapy must be pursued. In this case,
surgical occlusion of the involved arteries is necessary (i.e. embolization coils or balloons). If you lavaged
the guttural pouch in this case, you may exacerbate the bleeding. Passage of the endoscope may also
disrupt the clot and cause further hemorrhage. Furthermore, cauterization of the vessels involved using an
endoscope is not possible. Tying off the left common carotid artery seems like a good idea, but because of
the circular blood flow in the brain, hemorrhage will continue.
What is the most frequently observed side effect associated with acepromazine use in horses?
Arrhythmias
Hypotension
Seizures
Paraphimosis - CORRECT ANSWERS The correct answer is hypotension. Acepromazine will
reliably cause hypotension. Acepromazine may cause paraphimosis in male horses, but this is not very
common. However, because of this, many veterinarians will not use acepromazine on stallions.
Acepromazine actually has anti-arrhythmogenic properties. Acepromazine does reduce the seizure
threshold, but seizures are not as common as hypotension.
Several horses are suspected to be infected with equine infectious anemia as a result of having a history of
weight loss, anemia, and intermittent fevers. What is the test of choice for confirming infection?
Identification of organism in white blood cells
Immunodiffusion
ELISA for antibody
Paired antibody titers
ELISA for antigen - CORRECT ANSWERS The correct answer is immunodiffusion. This is more
commonly known as the Coggin's test. There are ELISA tests available but if the result is positive, you
always need to confirm this with a Coggin's test, as there is the possibility of a false positive. EIA is
caused by a virus that is related to the human immunodeficiency virus, and there is no way to visualize it
in the blood on a smear. Treatment of EIA usually involves isolation and supportive care. The main modes
of transmission are via blood-sucking flies that act as vectors and contaminated instruments.
,A 4-year old horse has been losing weight over the last 4 weeks, is yawning frequently, and appears
disinterested in and unaware of its surroundings, as shown in the photo. The horse has been vaccinated
properly each year against West Nile, WEE/EEE, tetanus, flu, strangles, and EHV-1. The TPR is normal,
but the horse can be positioned close to a wall and will remain there. You suspect what condition as most
likely?
Western equine encephalomyelitis
Rabies
West Nile virus encephalomyelitis
Equine protozoal myeloencephalitis
Hepatoencephalopathy - CORRECT ANSWERS Regardless of the cause of hepatic disease, when
enough liver function is lost, hepatoencephalopathy can result. Increases in ammonia, aromatic amino
acids, and mercaptans may play a role in developing CNS signs. The duration of 4 weeks and the normal
TPR make an infectious disease less likely. The clinical signs do not fit rabies or protozoal
myeloencephalitis.
A 1-year old Appaloosa gelding presents for generalized crusting lesions around the mucocutaneous
junctions of its head and along its ventrum. A biopsy of the lesions shows acantholytic cells and a
diagnosis of Pemphigus foliaceus. What is the treatment for this disease?
Penicillin
Systemic anti-fungals
Immune suppressive doses of corticosteroids
Topical anti-fungals
Anti-inflammatory doses of corticosteroids - CORRECT ANSWERS The correct answer is immune
suppressive doses of corticosteroids. Pemphigus foliaceus is an autoimmune disease in which antibodies
are formed against the intercellular adhesin proteins. In horses, this disease causes crusting lesions of the
head, limbs, and ventrum. Definitive diagnosis is found on biopsy of the skin showing acantholysis. There
are two forms of the disease in horses. The juvenile form may result in spontaneous remission and carries
a good prognosis. The adult form of the disease carries a worse prognosis.
A 16-year old pregnant Standardbred mare presents with an acute onset of colic. On presentation, she has
a heart rate of 64, respiratory rate of 32, and is pawing. CRT is approximately 3.0 seconds, and mucous
membranes are red. Her rectal temperature is 101.3F. Gastrointestinal sounds are completely absent, and
gastric reflux yielded 16L of brown- to yellow-colored fluid. Which of the following is a possible
diagnosis?
Left dorsal colon displacement
, Nephrosplenic entrapment
Right dorsal colon displacement
Mesenteric rent
Cecal impaction - CORRECT ANSWERS The correct answer is a mesenteric rent. A mesenteric
rent can result in a strangulating intestinal obstruction. Other causes of strangulating intestinal
obstructions include intussusceptions, hernias, epiploic foramen incarceration, volvulus, and strangulating
lipomas. Left dorsal colon displacement is the same thing as splenic entrapment and will typically not
result in a colic presentation this severe.
Which of the following tapeworms is not found in horses?
Anoplocephala perfoliata
Dipylidium spp.
Anoplocephala magna
Paranoplocephala mamillana - CORRECT ANSWERS The correct answer is Dipylidium spp.
Dipylidium tapeworms are found in cats and dogs. The other three tapeworm species can occur in horses.
Clinical signs include unthriftiness, anemia, and colic. Infections can be treated with praziquantel.
Pyrantel salts are only effective against Anoplocephala spp., but not P. mamillana.
You are examining a 13-year old Paint mare for a 2-week history of inappetence and mild weight loss. On
closer examination, you observe the following lesions on the white areas of the horse (see image). What
condition should you consider?
Photosensitization secondary to hepatic disease
Dermatitis secondary to renal failure
Primary insect hypersensitivity
Dermal necrosis secondary to NSAID administration - CORRECT ANSWERS Horses may
demonstrate photosensitization from liver disease because the chlorophyll in the diet is usually converted
to phylloerythrin and excreted by the liver. With hepatic disease, the phylloerythrin is deposited in the
skin; UV light reacts with it and results in dermal damage. Skin lesions are not seen with NSAIDs and
renal disease, whereas insect hypersensitivity is usually associated with urticaria.
Calculate the extracellular volume of a 450kg horse.
180L
45L
ACTUAL EXAM Questions And Answers
You suspect that an 18 year old Quarter Horse mare has recurrent airway obstruction (RAO; also known
as chronic obstructive pulmonary disease) based on clinical signs of increased respiratory rate and effort,
expiratory wheezes on auscultation, and the age of the horse. What cytologic finding of bronchoalveolar
lavage (BAL) fluid would be supportive of RAO?
Neutrophilic inflammation
Mononuclear inflammation
Eosinophilic inflammation
Mixed inflammatory response (neutrophils, macrophages, and eosinophils) - CORRECT
ANSWERS In health, BAL fluid primarily consists of macrophages. However, in RAO, neutrophils
are the predominant cellular finding. RAO typically affects older horses and is a response to
environmental allergens. The classic case is the horse that is stalled in the winter and possibly housed in
the vicinity of the hay storage. When the horse is exposed to hay allergens (via inhalation),
bronchoconstriction and neutrophilic inflammation occur resulting in clinical signs.
What structure is not likely to be affected with a guttural pouch infection of a horse?
CN VI
CN VII
Carotid artery
CN IX
Cranial sympathetic trunk - CORRECT ANSWERS The correct answer is CN VI. This nerve does
not run along the guttural pouch in contrast to the others listed. Both the internal and external carotids
may be affected during a guttural pouch infection. In case you don't remember, the guttural pouch in a
horse is the air-filled diverticula of the auditory tube which communicates between the middle ear and the
pharynx. Sometimes foreign material will get trapped there and result in infection.
You are examining a 7 year old Thoroughbred gelding for severe bilateral epistaxis. After the epistaxis
has decreased, endoscopy of the pharynx reveals blood from the left guttural pouch opening (see image).
What is the most appropriate treatment for hemorrhage from guttural pouch mycosis?
Tie off the left common carotid artery
Surgical occlusion of involved arteries (i.e. internal or external carotid artery) under general anesthesia
,Lavage guttural pouch with antifungals
Pass endoscope into affected guttural pouch and cauterize involved vasculature - CORRECT
ANSWERS Guttural pouch mycosis has several different clinical presentations. In some horses,
epistaxis is observed, while in others, cranial nerve deficits such as dysphagia may be observed. When
hemorrhage is present, the disease is advanced and more aggressive therapy must be pursued. In this case,
surgical occlusion of the involved arteries is necessary (i.e. embolization coils or balloons). If you lavaged
the guttural pouch in this case, you may exacerbate the bleeding. Passage of the endoscope may also
disrupt the clot and cause further hemorrhage. Furthermore, cauterization of the vessels involved using an
endoscope is not possible. Tying off the left common carotid artery seems like a good idea, but because of
the circular blood flow in the brain, hemorrhage will continue.
What is the most frequently observed side effect associated with acepromazine use in horses?
Arrhythmias
Hypotension
Seizures
Paraphimosis - CORRECT ANSWERS The correct answer is hypotension. Acepromazine will
reliably cause hypotension. Acepromazine may cause paraphimosis in male horses, but this is not very
common. However, because of this, many veterinarians will not use acepromazine on stallions.
Acepromazine actually has anti-arrhythmogenic properties. Acepromazine does reduce the seizure
threshold, but seizures are not as common as hypotension.
Several horses are suspected to be infected with equine infectious anemia as a result of having a history of
weight loss, anemia, and intermittent fevers. What is the test of choice for confirming infection?
Identification of organism in white blood cells
Immunodiffusion
ELISA for antibody
Paired antibody titers
ELISA for antigen - CORRECT ANSWERS The correct answer is immunodiffusion. This is more
commonly known as the Coggin's test. There are ELISA tests available but if the result is positive, you
always need to confirm this with a Coggin's test, as there is the possibility of a false positive. EIA is
caused by a virus that is related to the human immunodeficiency virus, and there is no way to visualize it
in the blood on a smear. Treatment of EIA usually involves isolation and supportive care. The main modes
of transmission are via blood-sucking flies that act as vectors and contaminated instruments.
,A 4-year old horse has been losing weight over the last 4 weeks, is yawning frequently, and appears
disinterested in and unaware of its surroundings, as shown in the photo. The horse has been vaccinated
properly each year against West Nile, WEE/EEE, tetanus, flu, strangles, and EHV-1. The TPR is normal,
but the horse can be positioned close to a wall and will remain there. You suspect what condition as most
likely?
Western equine encephalomyelitis
Rabies
West Nile virus encephalomyelitis
Equine protozoal myeloencephalitis
Hepatoencephalopathy - CORRECT ANSWERS Regardless of the cause of hepatic disease, when
enough liver function is lost, hepatoencephalopathy can result. Increases in ammonia, aromatic amino
acids, and mercaptans may play a role in developing CNS signs. The duration of 4 weeks and the normal
TPR make an infectious disease less likely. The clinical signs do not fit rabies or protozoal
myeloencephalitis.
A 1-year old Appaloosa gelding presents for generalized crusting lesions around the mucocutaneous
junctions of its head and along its ventrum. A biopsy of the lesions shows acantholytic cells and a
diagnosis of Pemphigus foliaceus. What is the treatment for this disease?
Penicillin
Systemic anti-fungals
Immune suppressive doses of corticosteroids
Topical anti-fungals
Anti-inflammatory doses of corticosteroids - CORRECT ANSWERS The correct answer is immune
suppressive doses of corticosteroids. Pemphigus foliaceus is an autoimmune disease in which antibodies
are formed against the intercellular adhesin proteins. In horses, this disease causes crusting lesions of the
head, limbs, and ventrum. Definitive diagnosis is found on biopsy of the skin showing acantholysis. There
are two forms of the disease in horses. The juvenile form may result in spontaneous remission and carries
a good prognosis. The adult form of the disease carries a worse prognosis.
A 16-year old pregnant Standardbred mare presents with an acute onset of colic. On presentation, she has
a heart rate of 64, respiratory rate of 32, and is pawing. CRT is approximately 3.0 seconds, and mucous
membranes are red. Her rectal temperature is 101.3F. Gastrointestinal sounds are completely absent, and
gastric reflux yielded 16L of brown- to yellow-colored fluid. Which of the following is a possible
diagnosis?
Left dorsal colon displacement
, Nephrosplenic entrapment
Right dorsal colon displacement
Mesenteric rent
Cecal impaction - CORRECT ANSWERS The correct answer is a mesenteric rent. A mesenteric
rent can result in a strangulating intestinal obstruction. Other causes of strangulating intestinal
obstructions include intussusceptions, hernias, epiploic foramen incarceration, volvulus, and strangulating
lipomas. Left dorsal colon displacement is the same thing as splenic entrapment and will typically not
result in a colic presentation this severe.
Which of the following tapeworms is not found in horses?
Anoplocephala perfoliata
Dipylidium spp.
Anoplocephala magna
Paranoplocephala mamillana - CORRECT ANSWERS The correct answer is Dipylidium spp.
Dipylidium tapeworms are found in cats and dogs. The other three tapeworm species can occur in horses.
Clinical signs include unthriftiness, anemia, and colic. Infections can be treated with praziquantel.
Pyrantel salts are only effective against Anoplocephala spp., but not P. mamillana.
You are examining a 13-year old Paint mare for a 2-week history of inappetence and mild weight loss. On
closer examination, you observe the following lesions on the white areas of the horse (see image). What
condition should you consider?
Photosensitization secondary to hepatic disease
Dermatitis secondary to renal failure
Primary insect hypersensitivity
Dermal necrosis secondary to NSAID administration - CORRECT ANSWERS Horses may
demonstrate photosensitization from liver disease because the chlorophyll in the diet is usually converted
to phylloerythrin and excreted by the liver. With hepatic disease, the phylloerythrin is deposited in the
skin; UV light reacts with it and results in dermal damage. Skin lesions are not seen with NSAIDs and
renal disease, whereas insect hypersensitivity is usually associated with urticaria.
Calculate the extracellular volume of a 450kg horse.
180L
45L
