Pink Eye in Cattle - Signs, Stages and Treatment
Pink eye in cattle can be caused by many different things and having excellent management practices play a vital role in controlling pink eye. A lot of people think that pink eye is only caused by flies, but this is not true. Pink eye can also be caused by long pasture grasses and dusty feed bunks. Treating pink eye in the early stages is a critical step to ensure that your animal will not have permanent eye damage that could possibly lead to blindness.
What is Pink Eye?
Pink eye is a bacterial infection of the eye that causes inflammation and sometimes temporary or permanent blindness.
What causes Pink Eye?
• Primary infectious agent is the bacterium Moraxella bovis.
• Eye irritation must be present for the disease to develop.
• Flies feed around the eyes and nostrils of cattle causing irritation of that eye and spreading the disease to other animals. Bacteria can survive on flies for up to 4 days.
• Irritation from tall weeds and grass or feed and dust from bunks can cause pink eye.
• Exposure to excessive UV rays can also cause the disease to occur.
Who is likely to get Pink Eye?
• Calves are more likely to get pink eye than adult cattle. Adult cattle develop protective antibodies on the eyes surface that protect them from getting pink eye.
• Bull calves are more likely to get the disease than heifer calves.
The four stages of pink eye in cattle:
Excessive watering of the eye and sensitivity to light. Blinking the infected eye more frequently and redness along the eyelid. Desire to stay in the shade to get out of the sun. Decreases in appetite due to pain. Will develop a small ulcer in the center of the cornea. Looks like a small white spot. Cornea becomes slightly cloudy grey color.
Signs in stage 1 continue but now the ulcer spreads across the cornea. More inflammation occurs and the cornea becomes cloudier. Blood vessels outside of the cornea begin to grow across the cornea. This makes the cornea look pink.
At this stage the ulcer ends up covering most of the cornea. Inflammation spreads to the inner part of the eye. This causes the eye to fill with fibrin, this is a pus-like substance and makes the eye look yellow.
The ulcer goes completely through the cornea. The iris may protrude through the ulcer. May lead to glaucoma or persistent swelling. This will lead to the eye being partially or completely blind. The eye could completely rupture and causing permanent blindness.
Treatment for pink eye in cattle:
Treatment for pink eye varies depending on the stage that the pink eye is at and it is important to catch pink eye at a early stage and treat it. Pink eye is very contagious, so this is important to stop the spreading of the disease to other animals.
Treatments for the different stages:
Stage 1: Use of a long-acting tetracycline is effective for treating this stage. Another treatment for this stage is putting a small amount of penicillin and dexamethasone, this is known as a bulbar conjunctiva, in the eye a couple times will treat this stage also.
Stage 2: At this stage it is recommended to use long-acting tetracycline and bulbar conjunctiva.
Stage 3: Tetracycline and a bulbar conjunctival injection are used together with an eye patch, suturing the third eye lid over the eye, or suturing the eyelids shut. This causes for a reduction in further irritation of the eye to occur.
Stage 4: This has the same treatment as stage 3.
Preventing pink eye:
• Keep grasses and weeds cut
• Fly control
Pink eye can be a major problem in the cattle industry. If it is not treated right away it can lead to permanent blindness. Some sprays and ointments can be used if caught early on, Vetericyn Bovine Eye Wash can be used to help kill bacteria in the eye.