New solutions in controlling

pinkeye in cattle

It can be very disheartening and sometimes downright frustrating to walk into a pasture field of your cows and calves and spot an animal with pinkeye. Cattleman realize instantly when they spot this eye infection that they have two choices: a). ignore what they have seen and hope it magically goes away, or b). get the animal restrained and provide treatment. In reality, choice (b) is the only way to avoid the problem getting worse and hopefully heal the animal.

Pinkeye in cattle is a contagious infection of the eye. It is caused when bacterial organisms (Moraxella bovis) infect the surface of the eye. Multiple strains of Moraxella bovis have been identified, each capable of creating pinkeye in cattle. The surface of the bacteria has hair like structures known as pili, which extend from the main body of the bacteria. The pili allow the bacteria to attach to the eye cornea and colonize, causing inflammation of the tissue lining of the eyelid and the eyeball itself. Ultimately, the cornea may become ulcerated, resulting in pain and possible blindness.

While bacterial organisms are the root cause of pinkeye in cattle, face flies are the primary vector responsible for spreading the bacteria from animal to animal. They feed on the watery tearing from cattle’s eyes. When they do so they spread the bacteria from animal to animal. Since face flies can visit several animals a day they can spread the pinkeye bacteria throughout the herd.

Seed heads, dust, pollen and UV light are environmental factors that can increase trauma to the eyes. These irritants can scratch the cornea of the eye and allow for easier attachment of the Moraxella bovis bacteria. Keeping pasture fields mowed and in a good vegetative height of 10-12 inches can help reduce eye irritants.

Pinkeye in cattle easily costs producers an average of $100 a head due to reduced weight gain, added treatment costs and discounts on sale day. University research has shown that pinkeye can reduce weaning weights in calves as much as 40 to 60 pounds.

Solutions to control pinkeye

In most cases there is not one single preventive measure that can be taken that will guarantee cattle not getting pinkeye. It must be a combination of proper management practices and even then a little good luck doesn’t hurt also.

The first step for all producers should be a good year round mineral program that provides all of the needed essential minerals. Research has proven that Vitamin A levels in free choice minerals should be a minimum of 200,000 units per pound. Vitamin A deficiency in cattle can lead to several eye complications including pinkeye. A chlortetracycline added active drug ingredient that provides a minimum 70 mg. per head per day is also very beneficial in preventing pinkeye.

The next step can include a variety and/or combination of best management practices that are all helpful as preventatives. Pinkeye vaccinations can be given early in the fly season as an aid in protection from many strains of pinkeye causing bacteria. Fly tags, dust bags, back rubbers, fly bullets, and fly sprays can all be helpful when used in combination.

Probably the best news to come along in preventive practices is the newly released SolidBac Pinkeye IR/PR pellet implants from Pfizer Animal Health.

Administration of these pellets requires a special device called the Soliddose gun. The implant gun normally sells for $65-$70. Using the SoliDoser device, two tiny pellets are administered under the skin at the base of the ear or in the neck. The pink Immediate Release (IR) antigen pellet provides the initial dose. The white Programmed Release (PR) antigen pellet provides an automatic booster dose. The pellet combination provides all season protection in a single dose for cattle three months of age or older. The costs of 50 doses (5, 10-pack clips) is around $130 or about $2.50 per dose. Compared to treatment for an infected cow with pinkeye it’s a real bargain.

For more information about prevention and treatment of pinkeye in cattle contact your local veterinarian, Extension office, or attend a local cattle meeting of the Twin Lakes Cattle Association.

Until next time, keep putting on the pounds!

Steve