|JOHNSON G C|
|WOLFF W A|
|RAMOS J A|
Submitted to: Journal of the American Veterinary Medical Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/10/1994
Publication Date: N/A
Interpretive Summary: Infection of goats with Listeria monocytogenes causes abortion of fetuses and sometimes death of the animal if the infection reaches the brain. This causes economic loss for the farmer raising goats. To better understand the spread of the disease in Missouri, 17 cases were examined where Listeriosis was diagnosed. We found that Angora goats were the most susceptible breed, and that goats eating a woody browse were also more susceptible to infection. Being aware of the risk factors for infection, should allow the goat rancher to control the disease more adequately.
Technical Abstract: There are few descriptions of encephalitic listeriosis in goats in the United States. Of 17 caprine listeriosis cases presented to the University of Missouri Veterinary Medical Diagnostic Laboratory between 1986 and 1993, 12 involved Angora goats, resulting in a relative risk of 22.3 for this breed. Surveys of veterinarians and goat producers confirmed that listerial encephalitis was prevalent in this breed. Typically, about 5% of the flock was affected, most often during winter and early spring months. In no instance did silage form part of the affected flocks' diet. Two observations suggest that eating woody browse may have contributed to the goats' susceptibility: 1, non-Angora brush-eating goats were also commonly treated for encephalitic listeriosis, and 2, a survey of Angora goat owners did not reveal cases of listeriosis in animals fed predominantly hay or pasture. L. monocytogenes was recovered from brainstem (7 of 9 attempted cultures), and L. murrayi was isolated from an additional goat. Seven isolates from 3 flocks were serotyped and examined by restriction enzyme analysis. All belonged to serotype 4, but most exhibited a unique DNA restriction pattern, suggesting that they were usually unrelated, sporadic infections arising from varied sources, even within a flock. However, in one flock, 3 isolates had similar restriction patterns, suggesting a common source of infection.