Malignant catarrhal fever in a Holstein heifer
A 20-month-old, red and white Holstein heifer, 6-7 months pregnant, presented to Cornell University's Farm Animal Hospital in September 2003 with the chief complaints of acute onset of recumbency, blindness, anorexia, and weight loss. One week prior to presentation, the heifer became anorexic, separated herself from her herdmates and developed bilateral corneal opacity with blindness. The heifer was from a local herd and kept on a 20-acre pasture with 9 other animals. In the same group, 2 heifers had died 2-3 weeks prior to disease in the heifer. In June of 2003, two spring lambs (age: 3-6 months) had been brought onto the farm. The lambs shared a barn with the heifers, but were fenced separately from them by a distance of 3 feet. Diagnostic test results for BVD and IBR, performed by the farm veterinarian, were negative. The farm veterinarian made a tentative diagnosis of Malignant Catarrhal Fever (MCF), based upon clinical signs and a history of contact with sheep. The heifer was referred to Cornell for antemortem testing and necropsy. MCF PCR and MCF CIELISA yielded positive results on antemortem blood. Gross necropsy revealed lesions consistent with MCF, including erosions and ulcerations of the GI tract, bilateral corneal edema, and coronitis. Histopathological lesions revealed a severe diffuse lymphocytic vasculitis and severe lymphocytic keratoconjunctivitis , supportive of MCF. Malignant catarrhal fever is a generalized viral disease of ruminants. It is caused by members of an expanding group of Rhandinoviruses in the Gammaherpesvirinae subfamily. These highly cell associated, lymphotrophic viruses exist in nature as inapparent infections in well-adapted ruminants that serve as reservoir hosts. Transmission of the virus from a reservoir host to a clinically-susceptible species results in a disease that is characterized by high fever, profuse nasal discharge, corneal opacity, ophthalmia, generalized lymphadenopathy, leukopenia, and severe inflammation of the conjunctival, oral, and nasal mucosas. CNS signs, diarrhea, skin lesions, and nonsuppurative arthritis can also be seen. Diagnosis of MCF in a clinically-susceptible species is based upon clinical signs, history of contact with a reservoir host, necropsy with histopathology, and PCR. With the expanding amount of new information, the traditional picture of MCF as a highly fatal, sporadic condition associated with lambing season is becoming less accurate. Clinicians should be aware that MCF can manifest acutely or become latent with recrudescence. While most cattle with clinical MCF die, others may partially or completely recover.
Senior seminar paperSeminar SF610.1 2004 D69
Senior seminar (D.V.M.) -- Cornell University, 2004. Includes bibliographical references (leaves (17-18)).
Cattle -- Virus diseases -- Case studies; Cattle -- Diseases -- Case studies