Abstract
Background:
Malignant catarrhal fever (MCF) is a severe infectious disease that can be fatal and infects both domestic and wild animals, including cows, buffalo, deer, bison, exotic ruminants, and even pigs.

Aim:
MCF is suspected in Buffalo, Basrah, Iraq. Therefore, a clinical, hematological, biochemical, and diagnostic study was conducted.

Methods:
The study was conducted on 163 local Iraqi buffalo breeds, aged 2-6 years, of both sexes, showing signs suggestive of MCF. The control group comprised 25 clinically healthy local buffalo breeds. The disease was diagnosed based on clinical manifestations and confirmed by serodiagnosis using an indirect ELISA test.

Results:
The results indicated that 92% (56.44%) of the animals were positive for MCF. Moreover, the infected buffalo showed an acute form of the disease with anorexia and depression, severe congestion of ocular mucus membranes with blepharospasm, profuse bilateral mucus nasal discharge with mouth breathing, excessive rope salivation with mouth lesions and mouth pain, unilateral or bilateral ocular opacity with lacrimation, enlargement of superficial lymph nodes, diarrhea, and low milk yield, in addition to a significant increase in vital signs. Moreover, leukocytosis due to lymphocytosis along with a significant difference in clotting factor indices was encountered. In addition, hypoglycemia, decreased total protein count, and increased Blood urea nitrogen (BUN), creatine kinase (CK), and Alkaline phosphatase (ALP) were encountered in MCF animals compared with controls.

Conclusion:
MCF is endemic and continues to spread among Iraqi animal fields, where the seroprevalence is high (56.44%). Therefore, strict control measures, including regular annual vaccination, are highly recommended.

Key words: Malignant catarrhal fever; Buffalo; ELISA; Iraq