ICVA NAVLE Exam 1 Questions with Complete
Solutions.
Fifteen of a group of 200, 7 month old feedlot calves are lame. The calves arrived at the
feedlot approximately one month ago, and one week later, 40 of the animals developed
pneumonia. These calves were treated with oxytetracycline, and the pneumonia
appeared to resolve. On physical examination, the affect calves have swellings in the
carpi, tarsi, and stifles with distension of associated tendon sheaths, and stiff gait. Two
calves are euthanized. Postmortem eamination shows fibrinous pleuritis and papillary
muscle necrosis. Which of the following organisms is the most likely cuase of these signs?
a) arcanobacterium (actinomyces) pyogenes
b) histophilus somni
c ) mannheimia hemolytica
d) pasteurella multocida
e) salmonella thyphimurium - Correct Answer B) histophilus somni
Histophilus somni is a well known cause of systemic disease in feedlot cattle, including
respiratory disease, speticemia, and polyarthritis. In this case, the calves initially
developed pneumonia, and now soe of them show signs of lameness, joint swelling, and
stiff gait, which are consistent with septic arthritis, and polyarthritis that can occur after a
histophilus somni infection
- additionally the post mortem finding of fibrinous pleuritis and papillary muscle necrosis
also strongly suggest histophilus soni as the causative agent.
-Known to cause arthritis, pleuritis, myocarditis, and septicemia in calves
What is hyperkalemic periodic paralysis in a horse - Correct Answer -a genetic disorder
that affects muscles causing episodes of muscle weakness or paralysis.
-It is autosomal dominant
What is the cause of hyperkalemic periodic paralysis - Correct Answer THe disorder is
caused by a mutation in the sodium channel gene, leading to increased potassium levels
in the blood. This affects the electrical activity of muscle cells, causing the muscles to
contract abnormally
,What are symptoms of hyperkalemic periodic paralysis in horses - Correct Answer -
muscle twitching or trembling
-weakness or partial paralysis especially in hindquarters
-episodes of muscle stiffness
-respiratory issues in severe cases
-horse remains alert
what are triggers of hyperkalemic periodic paralysis - Correct Answer -high potassium
intake from feed such as alfalfa, molasses or certain grains
-stress, exercise or fasting
how would you manage hyperkalemic periodic paralysis - Correct Answer -dietary
modification like feeding low potassium diets and aoiding alfala and monitor potassium
intake
-medicate with acetazolamide and hydrochlorothiazide
-consistent exercise and minimize stress
A 3-year old Percheron mare is undergoing routine dental evaluation. Physical
examination shows bilateral prolapse of the nictitating membrane and muscle
fasciculations of the neck, shoulders, and flank. During examination, the mare's hindlimbs
give way, and she leans back in a dog-sitting posture. Rectal temperature is 100.4
degrees F (38.0 degrees C), heart rate is 60 beats/min, and respiratory rate is 30
breaths/min.
Which of the following is the most likely diagnosis?
A) Equine degenerative myeloneuropathy
B) Equine motor neuron disease
C) Exertional rhabdomyolysis
D) Hyperkalemic periodic paralysis
E) Tetanus - Correct Answer D) hyperkalemic periodic paralysis
HYPP leads to episodes of periodic muscle weakness or paralysis.
-Prolapse of the nictitating membrane is characteristic of HYPP due to muscle weakness
in the face
,-Weakness and collapse suggest muscle paralysis or severe weakness, dog sitting
posture strongly supports this
A 3-year old Percheron mare is undergoing routine dental evaluation. Physical
examination shows bilateral prolapse of the nictitating membrane and muscle
fasciculations of the neck, shoulders, and flank. During examination, the mare's hindlimbs
give way, and she leans back in a dog-sitting posture. Rectal temperature is 100.4
degrees F (38.0 degrees C), heart rate is 60 beats/min, and respiratory rate is 30
breaths/min.
This is a case of HYPP, why would Equine Degenerative Myeloneuropathy be incorrect -
Correct Answer EDM is a neurodegenerative disease that causes progresse ataxia (
incoordination) and weakness in young horses, particularly those deficient in vitamin E.
Although it causes weakness, EDM is more associated with ataxia ( uncoordinated
movement) rather than acute muscle fasciculations or prolapse of the nictitating
membrane. It is a chronic, progressive condition, unlike the episodic nature of HYPP
A 3-year old Percheron mare is undergoing routine dental evaluation. Physical
examination shows bilateral prolapse of the nictitating membrane and muscle
fasciculations of the neck, shoulders, and flank. During examination, the mare's hindlimbs
give way, and she leans back in a dog-sitting posture. Rectal temperature is 100.4
degrees F (38.0 degrees C), heart rate is 60 beats/min, and respiratory rate is 30
breaths/min.
This is a case of HYPP, why would Equine Motor Neuron Disease be incorrect - Correct
Answer EMND is a neurodegeneratie disorder and is associated with vitamin E deficiency
-EMND causes muscle atrophy and weakness, primarily affecting posture and gait over
time. However it does not typically cause acute episodes of weakness with fasciculation
and prolapse of the third eyelid like HYPP does. EMND is also more chronic in its
progression, not episodic.
A 3-year old Percheron mare is undergoing routine dental evaluation. Physical
examination shows bilateral prolapse of the nictitating membrane and muscle
fasciculations of the neck, shoulders, and flank. During examination, the mare's hindlimbs
give way, and she leans back in a dog-sitting posture. Rectal temperature is 100.4
degrees F (38.0 degrees C), heart rate is 60 beats/min, and respiratory rate is 30
breaths/min.
, This is a case of HYPP, why would Exertional Rhabdomyolysis be incorrect - Correct
Answer ER is a condition where muscle damage occurs after exercise, resulting in muscle
stiffness, pain and potentially dark urine due to myoglobin release.
-While muscle fasciculations and hind limb weakness could suggest muscle damage, ER
is typically associated with exercise induced pain and stiffness rather than sudden
collapse. Additionally, prolapse of nictitating membranes is not a feature of ER
A 3-year old Percheron mare is undergoing routine dental evaluation. Physical
examination shows bilateral prolapse of the nictitating membrane and muscle
fasciculations of the neck, shoulders, and flank. During examination, the mare's hindlimbs
give way, and she leans back in a dog-sitting posture. Rectal temperature is 100.4
degrees F (38.0 degrees C), heart rate is 60 beats/min, and respiratory rate is 30
breaths/min.
This is a case of HYPP, why would Tetanus be incorrect - Correct Answer _Tetanus is
caused by neurotoxin produced by Clostridium tetani leading to rigid paralysis, muscle
spasms and an exaggerated response to stimuli
-Tetanus causes rigid muscle contraction and spasms rather than muscle weakness seen
in this case. Prolapse of the nictitating membrane can be seen in tetanus, but the muscle
fasciculations and collapse described are ore consistent with HYPP than the rigid
paralysis of tetanus
A 6 year old male cocker spaniel dog has recurrent otitis externa. Microscopic
examination of a smear of purulent discharge from the ear shows large numbers of rod
shaped bacteria. Which of the following is the most likely causative organism?
A) escheria coli
b) klebsiella spp
c) pasteurella multocida
d) pseudomonas aeruginosa
e) staphylococcus intermedius - Correct Answer d) pseudomonas aeruginosa
Pseudomonas aeruginosa is a gram-negative, rod-shaped bacterium commonly
associated with recurrent and chronic otitis externa in dogs, especially when standard
treatment fails. It is known for its resistance to many antibiotics and its ability to form
biofilms, making infections persistent and difficult to treat.
Clinical Relevance: Pseudomonas is often found in moist environments, which makes the
ear canal, especially in breeds prone to ear infections like Cocker Spaniels, a suitable
Solutions.
Fifteen of a group of 200, 7 month old feedlot calves are lame. The calves arrived at the
feedlot approximately one month ago, and one week later, 40 of the animals developed
pneumonia. These calves were treated with oxytetracycline, and the pneumonia
appeared to resolve. On physical examination, the affect calves have swellings in the
carpi, tarsi, and stifles with distension of associated tendon sheaths, and stiff gait. Two
calves are euthanized. Postmortem eamination shows fibrinous pleuritis and papillary
muscle necrosis. Which of the following organisms is the most likely cuase of these signs?
a) arcanobacterium (actinomyces) pyogenes
b) histophilus somni
c ) mannheimia hemolytica
d) pasteurella multocida
e) salmonella thyphimurium - Correct Answer B) histophilus somni
Histophilus somni is a well known cause of systemic disease in feedlot cattle, including
respiratory disease, speticemia, and polyarthritis. In this case, the calves initially
developed pneumonia, and now soe of them show signs of lameness, joint swelling, and
stiff gait, which are consistent with septic arthritis, and polyarthritis that can occur after a
histophilus somni infection
- additionally the post mortem finding of fibrinous pleuritis and papillary muscle necrosis
also strongly suggest histophilus soni as the causative agent.
-Known to cause arthritis, pleuritis, myocarditis, and septicemia in calves
What is hyperkalemic periodic paralysis in a horse - Correct Answer -a genetic disorder
that affects muscles causing episodes of muscle weakness or paralysis.
-It is autosomal dominant
What is the cause of hyperkalemic periodic paralysis - Correct Answer THe disorder is
caused by a mutation in the sodium channel gene, leading to increased potassium levels
in the blood. This affects the electrical activity of muscle cells, causing the muscles to
contract abnormally
,What are symptoms of hyperkalemic periodic paralysis in horses - Correct Answer -
muscle twitching or trembling
-weakness or partial paralysis especially in hindquarters
-episodes of muscle stiffness
-respiratory issues in severe cases
-horse remains alert
what are triggers of hyperkalemic periodic paralysis - Correct Answer -high potassium
intake from feed such as alfalfa, molasses or certain grains
-stress, exercise or fasting
how would you manage hyperkalemic periodic paralysis - Correct Answer -dietary
modification like feeding low potassium diets and aoiding alfala and monitor potassium
intake
-medicate with acetazolamide and hydrochlorothiazide
-consistent exercise and minimize stress
A 3-year old Percheron mare is undergoing routine dental evaluation. Physical
examination shows bilateral prolapse of the nictitating membrane and muscle
fasciculations of the neck, shoulders, and flank. During examination, the mare's hindlimbs
give way, and she leans back in a dog-sitting posture. Rectal temperature is 100.4
degrees F (38.0 degrees C), heart rate is 60 beats/min, and respiratory rate is 30
breaths/min.
Which of the following is the most likely diagnosis?
A) Equine degenerative myeloneuropathy
B) Equine motor neuron disease
C) Exertional rhabdomyolysis
D) Hyperkalemic periodic paralysis
E) Tetanus - Correct Answer D) hyperkalemic periodic paralysis
HYPP leads to episodes of periodic muscle weakness or paralysis.
-Prolapse of the nictitating membrane is characteristic of HYPP due to muscle weakness
in the face
,-Weakness and collapse suggest muscle paralysis or severe weakness, dog sitting
posture strongly supports this
A 3-year old Percheron mare is undergoing routine dental evaluation. Physical
examination shows bilateral prolapse of the nictitating membrane and muscle
fasciculations of the neck, shoulders, and flank. During examination, the mare's hindlimbs
give way, and she leans back in a dog-sitting posture. Rectal temperature is 100.4
degrees F (38.0 degrees C), heart rate is 60 beats/min, and respiratory rate is 30
breaths/min.
This is a case of HYPP, why would Equine Degenerative Myeloneuropathy be incorrect -
Correct Answer EDM is a neurodegenerative disease that causes progresse ataxia (
incoordination) and weakness in young horses, particularly those deficient in vitamin E.
Although it causes weakness, EDM is more associated with ataxia ( uncoordinated
movement) rather than acute muscle fasciculations or prolapse of the nictitating
membrane. It is a chronic, progressive condition, unlike the episodic nature of HYPP
A 3-year old Percheron mare is undergoing routine dental evaluation. Physical
examination shows bilateral prolapse of the nictitating membrane and muscle
fasciculations of the neck, shoulders, and flank. During examination, the mare's hindlimbs
give way, and she leans back in a dog-sitting posture. Rectal temperature is 100.4
degrees F (38.0 degrees C), heart rate is 60 beats/min, and respiratory rate is 30
breaths/min.
This is a case of HYPP, why would Equine Motor Neuron Disease be incorrect - Correct
Answer EMND is a neurodegeneratie disorder and is associated with vitamin E deficiency
-EMND causes muscle atrophy and weakness, primarily affecting posture and gait over
time. However it does not typically cause acute episodes of weakness with fasciculation
and prolapse of the third eyelid like HYPP does. EMND is also more chronic in its
progression, not episodic.
A 3-year old Percheron mare is undergoing routine dental evaluation. Physical
examination shows bilateral prolapse of the nictitating membrane and muscle
fasciculations of the neck, shoulders, and flank. During examination, the mare's hindlimbs
give way, and she leans back in a dog-sitting posture. Rectal temperature is 100.4
degrees F (38.0 degrees C), heart rate is 60 beats/min, and respiratory rate is 30
breaths/min.
, This is a case of HYPP, why would Exertional Rhabdomyolysis be incorrect - Correct
Answer ER is a condition where muscle damage occurs after exercise, resulting in muscle
stiffness, pain and potentially dark urine due to myoglobin release.
-While muscle fasciculations and hind limb weakness could suggest muscle damage, ER
is typically associated with exercise induced pain and stiffness rather than sudden
collapse. Additionally, prolapse of nictitating membranes is not a feature of ER
A 3-year old Percheron mare is undergoing routine dental evaluation. Physical
examination shows bilateral prolapse of the nictitating membrane and muscle
fasciculations of the neck, shoulders, and flank. During examination, the mare's hindlimbs
give way, and she leans back in a dog-sitting posture. Rectal temperature is 100.4
degrees F (38.0 degrees C), heart rate is 60 beats/min, and respiratory rate is 30
breaths/min.
This is a case of HYPP, why would Tetanus be incorrect - Correct Answer _Tetanus is
caused by neurotoxin produced by Clostridium tetani leading to rigid paralysis, muscle
spasms and an exaggerated response to stimuli
-Tetanus causes rigid muscle contraction and spasms rather than muscle weakness seen
in this case. Prolapse of the nictitating membrane can be seen in tetanus, but the muscle
fasciculations and collapse described are ore consistent with HYPP than the rigid
paralysis of tetanus
A 6 year old male cocker spaniel dog has recurrent otitis externa. Microscopic
examination of a smear of purulent discharge from the ear shows large numbers of rod
shaped bacteria. Which of the following is the most likely causative organism?
A) escheria coli
b) klebsiella spp
c) pasteurella multocida
d) pseudomonas aeruginosa
e) staphylococcus intermedius - Correct Answer d) pseudomonas aeruginosa
Pseudomonas aeruginosa is a gram-negative, rod-shaped bacterium commonly
associated with recurrent and chronic otitis externa in dogs, especially when standard
treatment fails. It is known for its resistance to many antibiotics and its ability to form
biofilms, making infections persistent and difficult to treat.
Clinical Relevance: Pseudomonas is often found in moist environments, which makes the
ear canal, especially in breeds prone to ear infections like Cocker Spaniels, a suitable
