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Don’t let pinkeye make you see red

As we approach the hot summer months, more and more producers are dealing with the nuisance of pinkeye. Pinkeye is a highly infectious bacterial disease. Although pinkeye is nonfatal, it costs cattle producers over $150 million per year. These expenses result from decreased weight gain, reduced milk production and treatment costs. Additionally, infected animals are worth less at sale time. Pinkeye is second only to scours/diarrhea in terms of diseases affecting calves.

Causes of Pinkeye

While the bacteria Moraxella bovis is one of the main causative agents, other microorganisms such as Chlamydia, Mycoplasma and Acholeplasma or viruses such as the IBR virus can either predispose the eye to pinkeye or make the disease more severe.

Irritants to the eye make it more susceptible to development of pinkeye. Plants irritate though release of pollen and chaff and also physically through poking, especially in the seedhead stage. Dust is usually not a major factor for pastured cattle and is more relevant in confinement. Several species of flies (face flies, stable flies and house flies) also provide irritation and can actively carry infective agents from animal to animal. Face flies have been shown to remain infected with M. bovis for up to 3 days after feeding on infected secretions. Pinkeye can also spread via physical animal to animal contact, especially in close quarters.

If left untreated, ulcerations can occur and can result in loss of the eye. This is particularly troubling for bull calves, as bulls rely on visual cues for detecting cows in heat. Research has shown that weaning weights can be reduced as much as 60 lbs per calf. Additionally, cattle with pinkeye are discounted an average of $11.75 per CWT at the sale barn.


M. bovis is susceptible to many antibiotics including oxytetracycline, penicillin and sulfonamides. Treatment involves handling cattle and either delivering an IM or SubQ injection or other direct eye treatments. As always, consult with your veterinarian prior to treatment. It bears mentioning that the new FSMA regulations will require a veterinary prescription for these drugs in the not so distant future. These drugs are available over-the-counter as it stands today.


Given that treatment is expensive, prevention becomes even more important. The first means of prevention is to never bring infected animals to your farm in the first place through careful inspection prior to purchase. Also, a standard quarantine for new animals will help identify carriers and allow them to be treated prior to introduction into the main herd. Commercial vaccines are available, (Consult with your veterinarian before embarking on a vaccination program.) but even vaccine manufacturers recommend environmental management and fly control in addition to vaccination. Proper mineral and vitamin nutrition including adequate levels of zinc and vitamin A (both critical for eye integrity) will also aid in the prevention of pinkeye. Additionally, regular clipping of pastures will not only remove seedheads from irritating animals’ eyes, but will also increase the relative nutritional value of your pastures by increasing vegetative growth. And finally, fly control will go a long way to keep pinkeye from spreading throughout your herd.

Feed Through Fly Control

Rabon® Oral Larvicide is a nontoxic feed-through larvicide. Rabon® interrupts the lifecycle of the target flies by preventing larvae from developing into adults. Rabon® is not absorbed by the animal and safely passes through the digestive tract. There is no slaughter withdrawal and Rabon® can be safely fed to lactating and pregnant cows. Rabon® remains in the manure where it kills developing larvae on contact. Rabon® is the only feed-through fly control product to control horn flies, face flies, stable flies and house flies. As mentioned earlier, face flies, house flies and stable flies are known to transmit pinkeye from cow to cow. Reducing the number of these flies will cut transmission, especially in a pasture situation. Another advantage of Rabon® is that it can be utilized for fly control for horses as well as cattle. Rabon® is environmentally safe and has no adverse effect on the dung beetle or other beneficial insects.

CRYSTALYX® ROLyx® Max and CRYSTALYX® ROLyx® Pro-Mag both contain Rabon® and are available in variety of sizes and packaging to fit any need. From the convenient, single-trip, Bio-Barrel® CRYSTALYX® ROLyx® Max to the economical CRYSTALYX® ROLyx® Pro-Mag in returnable steel barrels, we have a product to fit any size operation and any production scenario. Additionally, both CRYSTALYX® ROLyx® Max and CRYSTALYX® ROLyx® Pro-Mag deliver organic, chelated sources of trace minerals, including zinc along with vitamin A which both so important for eye integrity.


In summary, pinkeye is a costly bacterial disease for the cow-calf producer. Anything that irritates or damages the eye makes it more susceptible to infection. Treatment involves costly antibiotics and stressful cattle handling, thus prevention is preferred. Prevention of pinkeye can be achieved through a combination of vaccination, management and fly control. CRYSTALYX® products containing Rabon® offer the superior fly control of Rabon® along with the proven intake and superior nutrition of CRYSTALYX®. To learn more, visit www.crystalyx.com to find the self-fed fly control supplement that works best for you.

Rabon® is a registered trademark of Bayer HealthCare, LLC

CRYSTALYX®, ROLyx® and Bio-Barrel® are registered trademarks of Ridley Block Operations