Case Reports: Clinical features and postmorteum findings of sheep-associated malignant catarrhal fever in a 2-years old bull

Malignant Catarrhal Fever (MCF) is a fatal lymphoproliferative disease of cattle and other ungulates caused by alcelaphine herpesvirus 1 (AlHV-1) and ovine herpesvirus 2 (OvHV-2), the main causative agents of wildebeest-associated MCF (WA-MCF) and sheep-associated MCF (SA-MCF), respectively. The virus is mainly spread by aerosols from pregnant or newborn sheep, goats, and wildebeest to susceptible animals. This case report presents the clinical features and post-mortem findings of an unusual case of malignant catarrhal fever (MCF) in a two-year-old bull brought to the Professor Feseha Gebreab Memorial Veterinary Teaching Hospital in Bishoftu, Ethiopia. The bull was semi-intensively managed, co-housed, and fed with sheep and other domestic animals. The animal was shivering upon arrival, with naso-ocular discharge and clouding of the eyes. The bull was febrile, with a rectal body temperature of 41.4 oC and a respiratory and heart rate of 40 and 48 beats per minute, respectively. On physical examination, the bull was emaciated, with bilateral yellowish mucopurulent naso-ocular discharge, frequent blinking, bilateral corneal opacity, salivation, a foamy mouth, head pressing, and enlargement of superficial lymph nodes. Malignant catarrhal fever was suspected based on the history and clinical signs, and empiric therapy with 10% oxytetracycline, diclofenac, and IV fluid was initiated. The bull died after receiving the third day of treatment. At necropsy, hemorrhages were found in the esophagus, trachea, and small and large intestines. In the kidney, white foci, enlargement, and fatty degeneration were observed. An ulcerated lesion was seen on the abomasum. In the gall bladder, enlargement and vascularization were also noted. The current case report confirms the rare case of clinical SA-MCF based on the history, exhibited clinical pictures, post-mortem findings, and PCR results. Separation of cattle and sheep is strongly advised to prevent SA-MCF, as no vaccine has yet been developed.