If pinkeye is affecting cattle in your herd, treatment options depend on the severity of the infection and the number of animals affected. As always, it’s best to consult your veterinarian for treatment options for your particular situation. There are a lot of treatment options, and we’ve done our best to bring together the best sources of information on the topic. This is Part II of our three-part series covering prevention, treatments, and impact of pinkeye on cattle. Read Part I, “Recognizing and Preventing Pinkeye in Cattle”, here.
According to The Cattle Site, a division of the Mississippi State University Extension Service, recognizing and treating pinkeye early is the best thing that farmers can do. Earlier treatment can reduce discomfort and stress on the animals, and reduces the likelihood that the infection will be spread to more cattle in your herd.
When you examine an animal with pinkeye, be sure to use a new pair of disposable gloves for each animal to reduce transmission from animal to animal. Disinfect any equipment, such as halters or nose tongs, that may touch infected secretions.
M. bovis, the bacteria that most commonly causes pinkeye in cattle, responds best to treatments with the antibiotics oxytetracycline and penicillin. Treatment options for pinkeye are administered through ingestion, injection, or topical methods.
If 5 to 10 percent of your herd appears to have pinkeye, you will likely be looking at treating your entire herd. If you’re only treating affected animals, isolate them from the rest of the herd if possible.
Both of our sources agree that topical sprays and ointments can be effective treatments for the early stages of pinkeye. However, a steady stream of antibiotics is necessary to stop the infection- which means administering a topical ointment or spray several times a day. This is impractical for most operations.
Approved sprays and ointments may be quite effective but must be applied several times a day. Spraying from a distance is usually ineffective because the animals will blink or turn when approached.
In addition, spray treatments can cause further eye irritation and more tear production. This can exacerbate the infection and not keep the antibiotic in the eye where it needs to be.
It is important to follow the labeled dose and route of administration of the product you are using. Many of the nitrofuracin sprays and puffers that were used years ago are now illegal to use in cattle.
The most commonly recommended treatment for pinkeye in cattle is antibiotic injection.
Long-acting oxytetracycline injections have been shown to be effective when used early. When large numbers of animals are affected, oxytetracycline injections are often used in combination with medicated tetracycline feeds. Penicillin injections under the conjunctiva, or thin membrane of the eye, have also been shown to be very effective but are more labor intensive and require better restraint.
The University of Illinois Extension published an article by a group of veterinarians from Virginia Tech (W. Dee Whittier D.V.M., Extension Specialist, John Currin D.V.M., Nancy Currin D.V.M) that lays out the different pinkeye injection treatments for all of the stages of the disease. To learn about how to recognize the different stages of pinkeye infection, click here.
Stage I: Long-acting tetracyclines (Biomycin 200®, LA200®, or their generic equivalents) are effective at this stage of infection. The recommended dose is 4.5 cc per 100 pounds of body weight subcutaneously (SQ). A second injection given 48 to 72 hours later may increase the percentage of cattle that responds to treatment. Another option is to inject penicillin and dexamethasone into the bulbar conjunctiva. The bulbar conjunctiva is the thin membrane that covers the white portion (or sclera) of the eye. If the injection is performed correctly, the conjunctiva will swell and a bulge should be seen in this area. A veterinarian, or someone who has been specifically trained by a veterinarian, should perform this procedure. Injections placed in the wrong area are ineffective in treating pinkeye and could damage the eye.
Stage II: Both tetracycline and a bulbar conjunctival injection are administered at the above dosages.
Stage III: Tetracycline and a bulbar conjunctival injection are administered in conjunction with either an eye patch, suturing the third eyelid over the eye, or suturing the eyelids shut. This makes the eye more comfortable, reducing further irritation, and, therefore, reducing tearing and shedding of the bacteria. Suturing the third eyelid over the eye and suturing the eyelid shut also have the advantage of supporting a fragile cornea to help prevent corneal rupture. Again, this procedure should be done by a veterinarian or someone who has been adequately trained.
Stage IV: Same treatment as Stage III.
To keep pinkeye infections at bay in your herd, the best thing that you can do is to try and prevent it before it starts. If it does take hold, recognizing it early is critical. There are many different antibiotic treatments available for pinkeye, and you should consult a veterinarian about your best treatment options. Antibiotic injections seem to be both efficient and effective. Look for Part III in our series next week, where we will cover the potential impacts of pinkeye on cattle operations.
How much is pinkeye costing you? Read Part 3 in our series about Pinkeye titled “The Many Costs of Pinkeye“.
Image courtesy of the Western Producer