Working Ranch Magazine Summer 2025

Keep An Eye Out BY GILDA V. BRYANT

Early-stage pinkeye.

VERONICA WINTERS / SHUTTERSTOCK

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What to look for and how to treat Pinkeye in your herd.

causing blindness. 3. The eye’s anterior (front) chamber fills with white blood cells or fibrin . During this painful stage, the eye is white, appearing full of pus. The animal is blind at this stage. 4. The resulting ulcer is so thin that the iris prolapses out of the ulcer, causing permanent blindness. “I can still treat the eye in stages one, two, and three,” Strickland explains. “When the animal reaches stage four, there’s no treatment other than removing the eye.” Face flies carry Moraxella bovis and Moraxella bovoculi , the bacteria that cause pinkeye. The female fly carries the organisms on her legs and mouth

lthough pinkeye is a non-fa tal condition in livestock, the economic impact on the U.S. cattle industry is substantial. Calves weigh less at weaning, and pinkeye reduces the pro

ductivity and value of animals. Lew Strickland, DVM, Extension Veterinarian at the University of Tennessee, says the four clinical signs of pinkeye are rated by symptoms: 1. The animal squints its infected eye or produces tears. The cow still has open eyes at this stage. The producer may notice a blue haze (edema) on the eye. 2. The animal’s eye is closed due to pain and there is a visible ulcer. The iris will spasm, and close,

40 I SUMMER 2025 WORKING RANCH audited readers run 21 million head of beef cattle.