Infectious Bovine Keratoconjunctivitis, also referred to as Pink Eye, is a highly contagious disease that causes inflammation and ulceration of the cornea and conjunctiva of the eye. This report describes a case of lymphocytopenia in a 1 year old heifer. A Red Bororo heifer was presented to the University of Abuja Veterinary Teaching Hospital. She had a history of bumping into an object. Clinical signs included epiphora, conjunctivitis, with varying degrees of keratitis and lacrimation. Rectal temperature was 38.4˚c and respiratory rate was 28 (cycles /minute). Pulse rate was 48 beats/minute. Blood samples and ocular swab were sent to the laboratory. The ocular swab culture and subsequent identification implicated gram negative, oxidase positive rods and gram positive, coagulase positive cocci as causative agents of the infection. The direct blood smear, wet mount and buffy coat technique revealed that the calf was negative for babesiosis and trypanosomosis. Microbiological examination revealed the presence of only Moraxella bovis in the heifer presented while Staphylococcus aureus was isolated from the other four in-contact cattle. The blood picture also indicated moderately low lymphocytopenia. The animal was treated with 2 doses of long acting oxytetracycilne, 4 days apart, and the blood and microbiological tests were repeated post-treatment. Thereafter, the lymphocyte value returned to values within the normal range. It is important to assay the lymphocyte count in cases of bovine pink eye, so as to prevent dangers that may arise with very low levels of lymphocyte count.