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