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In a review of 159 archived bovine autopsy cases submitted to the Georgia Veterinary Diagnostic Laboratory System from 2001 to 2017, we evaluated histologic lesions and other laboratory test results in cases diagnosed with central nervous system (CNS) disease to determine the most common disorders and the rate of definitive morphologic and etiologic diagnosis within the population. The most common breed was Aberdeen Angus or Angus (31%), and female animals comprised 60% of the overall submissions. Gross anatomic changes were described in 33% of cases that had histologic lesions. Suppurative meningoencephalitis was the most common diagnosis (28% of cases overall) and was frequently associated with bacterial sepsis. Lymphocytic meningoencephalitis without an identified etiology was diagnosed in 17% of cases. Polioencephalomalacia was the most commonly identified noninfectious diagnosis (17%). Hydrocephalus was the most common CNS comorbidity and potential congenital defect. Identification of specific agents was sporadic, and infectious disease testing was largely dependent on fluorescent antibody testing, almost all of which were negative. Our findings indicate the common differential diagnoses for cattle with neurologic signs in the southeastern United States, as well the need for a well-defined, methodical diagnostic approach, including autopsy, histology, and appropriate additional laboratory testing.

Listeriosis is a disease of humans and domestic mammals (mainly ruminants) with variable manifestations, primarily encephalitis, septicemia, and abortion. Although Listeria monocytogenes readily causes illness in ruminants, the prevalence among domestic South American camelids (llamas and alpacas) is low and has not been documented in their wild counterparts, the vicuna and guanaco. We describe herein the clinical signs, autopsy findings, and histopathology of septicemia and suppurative meningoencephalitis caused by L. monocytogenes in 2 neonatal llamas ( Llama glama) from the same herd. L. monocytogenes was isolated in pure culture and identified by real-time PCR on fresh and paraffin-embedded tissue samples of the brain from both crias. This presentation of septicemic listeriosis with meningoencephalitis in 2 animals from the same group is unusual, especially among llamas.

An adult-onset generalized canine demodecosis is a life threatening form of demodecosis often seen in immunocompromised dogs. A generalized, adult-onset canine demodecosis with an unusual vascular invasion, thrombi and dissemination to peripheral, and visceral lymph nodes was diagnosed in an adult, female, American Bulldog of unknown age. Organized thrombi with intralesional mites were observed in multiple lymphatic vessels and in a section of blood vessel. Vascular invasion of mites with dissemination of mites into visceral lymph nodes, is an unusual findings not previously recorded in canine generalized demodecosis. Dissemination of mites to visceral lymph nodes through vascular channels may be part of the pathogenesis of chronic, untreated, and disseminated, adult-onset generalized canine demodecosis.

Case Description—A 7-year-old Quarter Horse gelding was hospitalized in Ocala, Fla, because of lethargy, fever, anorexia, and swelling of distal aspects of the limbs. A tentative diagnosis of equine piroplasmosis (EP) was made on the basis of examination of a blood smear. The case was reported to the Florida State Veterinarian, and infection with Babesia equi was confirmed. The subsequent investigation included quarantine and testing of potentially exposed horses for B equi and Babesia caballi infections, tick surveillance, and owner-agent interviews. Clinical Findings—210 horses on 25 premises were tested for infection with EP pathogens. Twenty B equi–infected horses on 7 premises were identified; no horses tested positive for B caballi. Seven horses, including the index case, had clinical findings consistent with EP Dermacentor variabilis was considered the only potential tick vector for B equi collected, and all D variabilis specimens tested negative for Babesia organisms via PCR assay. Results of the epidemiological investigation suggested that B equi was spread by use of shared needles and possibly blood transfusions. All horses that tested positive were involved in nonsanctioned Quarter Horse racing, and management practices were thought to pose substantial risk of transmission of blood-borne pathogens. Treatment and Outcome—Final outcome of B equi–infected horses was euthanasia, death from undetermined causes, or shipment to a US federal research facility. Clinical Relevance—This investigation highlights the importance of collaboration between private veterinary practitioners, state veterinary diagnostic laboratories, and regulatory officials in the recognition, containment, and eradication of foreign animal disease.