Pinkeye Medication for Cattle

Pinkeye in cattle usually appears in the summer, because face flies spread the bacteria that cause it. However, it can occur in any season. Pinkeye often occurs when flies, dust, sunlight or tall grass irritate eyes. Flies carry the bacteria from one animal to another. Pinkeye is highly contagious and can even affect herds living in the surrounding area.

  1. Causes

    • John Kirkpatrick, DVM, Okla., states that the primary cause of pinkeye is a bacterium called M. bovis. Other microorganisms that can cause pinkeye are chlamydia, mycoplasma, acholeplasma or viruses. Substances scratching and irritating the eye, such as weed, forage and grass or flies can open the way for M. bovis to infect the eye.

    Symptoms

    • Cattle with pinkeye will hold their eyes shut, because they are sensitive to light. Their eyes will water and appear red and inflamed. After a day or two, a white spot will appear on the cornea--the front of the eyeball. As the disease worsens, the spot grows larger and the cornea becomes cloudy and blue.

    Treatment

    • Mild cases of pinkeye may clear up without treatment, but serious cases may cause blindness. Pinkeye should be treated promptly with an antibiotic powder or spray. Restrain the steer so you can squirt the medication right into its eye. Because the steer's tears will wash medications out of the eye, administer the treatment at least twice a day. Placing an eye patch over the eye after treatment can aid in healing by protecting the eye from sunlight, flies and irritants. It may also help in reducing the spread of the disease among the herd.

    Antibiotics

    • According to N.C. State University Cooperative Extension, the approved medications to successfully treat pinkeye are "long-acting tetracycline products (for example, LA-200®, Biomycin 200®, etc.) and now tulathromycin (trade name Draxxin®). These products should be delivered according to label directions in terms of dose and route. Slaughter withdrawal rules should be carefully considered when any antibiotic is used." Another antimicrobial sensitivity study by Oklahoma State university found that "M. bovis is most often susceptible to oxytetracycline (LA-200TM IM or SQ, Bio-Mycin 200TM SQ, and AnchorOxy 200TM SQ), ceftiofur (NaxcelTM, for use by or on the order of a licensed veterinarian), penicillin and sulfonamides."

      Long-acting ox tetracycline has had positive results in curing pinkeye within 24 hours of the first treatment. Penicillin has also had similar results; however, it is more labor intensive treating with penicillin. The best results are received when giving "a combination of intramuscular long-acting oxytetracycline followed by feeding 2-g/head/day oxytetracycline in alfalfa pellets," says Dr. Kirkpatrick.

    Prevention

    • Proper barn maintenance to control flies is vital to reduce the spread of pinkeye throughout a herd. Insecticide ear tags, charged back rubbers, dust bags and sprays can all be used to reduce the number of flies in and around the barn and feedlots. It is also important to keep weeds and grasses low in the pasture to prevent these from irritating the eye. The forage fed to the cattle should also be kept below eye level to keep it from scratching their eyes.