Small Ruminant Flashcards
What is the primary factor associated with pregnancy toxemia in ewes and goats?
A - Young age at parturition B - Clostridium perfringens C - Polioencephalomalacia D - Inadequate nutrition E - High sulfur, Low thiamine diet
D
Pregnancy toxemia in ewes and goats is a severe form of ketosis most associated with inadequate nutrition and twins in OLDER animals
Can occur in either thin or fat animals whose dietary intake does not meet the high energy demands of late gestation
Animals present off feed in late gestation often thin
Severe cases show neurologic dysfunction progressing to recumbency, death
High sulfur and low thiamine are associated with polioencephlomalacia on your DDX for neurologic sheep/cattle
Which reportable condition can affect cattle, but mainly causes disease in sheep?
A - Anthrax B - Rinderpest C - Vesicular stomatitis D - Malignant Catarrhal fever E - Bluetongue
E
Which one of the following choices is the best post-mortem diagnostic test for scrapie in sheep?
A - Histopathology of the obex B - IFA test on whole blood C - ELISA antibody test on serum D - Immunohistochemistry of the third eyelid E - Skin biopsy of scraped area
A
Immunohistochemistry on a sample of obex tissue is the post-mortem test of choice for scrapie.
Histopathology alone can identify characteristic changes of prion disease (vacuolation, neuronal loss, astrocytosis, amyloid plaque) but because histologic changes are often lacking, diagnosis is made based on IHC staining of the obex.
Immunohistochemistry of lymph follicles of the nictitating membrane, though NOT 100% sensitive, can detect scrapie in live animals. The problem is there are many unreadable samples due to lack of lymph follicles in the tissue sample in up to 40%–60% of adult sheep.
A rectal mucosa biopsy test was approved by USDA APHIS in 2008 which is less time-consuming to perform and can be repeated. It yields positive diagnoses in roughly 55%–65% of positive sheep.
Immuno-blot testing of biopsied tonsils may detect prion proteins in subclinically-infected sheep less than 1 year old. Antibodies against scrapie/prions are NOT produced
What is the best way to evaluate the body condition of an adult llama?
A - Palpate over the lumbar vertebrae B - Feel the intercostal spaces C - Digital exam of the supraorbital fossa D - Rectal exam to evaluate pelvic fat E - Weight X height at withers X 0.28
A
Assess body condition of llamas and alpacas by palpating the amount of tissue over the lumbar vertebrae. South American camelids are adapted to high mountain environments and diets.
Most adult males (and females through midgestation), maintain appropriate body condition on 10-14% crude protein grass hay with total digestible nutrients (TDN) of 50-60%.
Late gestation and heavily lactating females need a higher percentage of crude protein and TDN of 65-70%.
Excess legumes in the diet are not typically necessary and may cause obesity.
Several sheep are sick at a petting-zoo that has cows, horses, pigs, bison and white-tailed deer. One of the deer is also affected. Affected sheep are listless and off-feed, with serous or mucopurulent nasal discharge and rectal temperatures ranging from 105-107.5°F (40.5-42°C).
Physical exam shows swollen muzzles with edema and congestion of the lips, nose and face with small hemorrhages and ulcers on the mucous membranes. The ulcers appear where the teeth contact the swollen lips and tongue. Two affected sheep are lame.
What is the diagnosis?
A - Bluetongue B - Peste des petits ruminants (PPR) C - Caprine arthritis encephalitis D - Contagious ecthyma (soremouth) E - Foot-and-mouth disease (FMD)
A
Swollen sore muzzles with mucous membrane erosions, high fevers and lameness suggests infection with bluetongue virus. Bluetongue is almost exclusively seen in sheep, though white-tailed deer, pronghorn antelope and desert bighorn sheep in North America can be severely affected. Rare in cows. REPORTABLE.
Bluetongue is indistinguishable from Foot and Mouth disease (FMD), so that is a good second choice. But FMD is unlikely in the scenario above because FMD mainly affects pigs and cattle.
