One of my favorite things to do in the summer months is to ride through the pastures to look over our cow-calf pairs. There’s something peaceful about ending the day with my husband and seeing the results of our breeding decisions come to fruition as calves grow and start to really show their potential.
Of course, these pasture rides also include paying attention to details that often require extra labor on our part. There seems to always be a fence to fix, thistles to chop and mineral and creep feeders to fill. However, probably the most dreaded chore of all is discovering a cow or calf that needs medical attention.
Lumps, cuts or down ears are one thing to address, but pinkeye is another beast entirely. This costly disease is not only frustrating, but it’s labor intensive to take care of and can spread quickly if not addressed in a timely fashion.
What’s worse, a calf plagued with pinkeye will have a lower weaning weight, and white scars on the eye will result in a discount on sale day.
It would make economic sense for producers to address pinkeye immediately; however, grazing cattle that are far away from working facilities make it difficult to administer treatment when cases of pinkeye arise.
“Prevention of pinkeye is difficult because it is a complicated, multifaceted disease,” says Michell Arnold, DVM, ruminant Extension veterinarian for the University of Kentucky, in a recent article, published on The Ohio State University’s Beef Cattle Letter. “The best plan is to reduce or remove as many risk factors as possible that can result in damage to the corneal surface. Any damage will allow the bacteria to cling to the corneal surface and grow. Many different combinations of contributing factors such as ultraviolet rays from the sun, face flies, excessive eye irritation, nutritional deficiencies, and stress may work together within a herd at one time. Prevention is based on maximizing herd immune status, controlling face flies, minimizing exposure to the bacteria, and maintaining as irritant-free environment as possible.”
Arnold lists five steps to prevent and treat pinkeye, including:
1. Maximize herd immunity
In addition to following good nutrition and vaccination protocols to maintain optimal herd health, Arnold says, “There is no scientific evidence to support feeding excessive levels of any vitamin or mineral, including Vitamin A, will prevent diseases of the eye. However, if trace mineral levels (especially selenium and copper) are very low in an animal, immune function is severely impaired. In these instances, an injectable mineral may be necessary to bring these minerals back within a normal range so vaccines and antibiotics can work.”
2. Control face flies
There are many methods to control fly populations during the summer months, but preventing face flies may be the best way to reduce the spread of pinkeye.
Arnold writes, “Bacteria in the secretions of infected cattle can survive on or in face flies for 2 to 3 days and infect other animals when the flies feed again. Face flies may move as far as four miles during their life so they can easily transfer pinkeye from herd-to-herd and farm-to-farm. Face fly control is challenging. The flies spend only a few minutes at a time on or around the head, which is a difficult area to protect. Application methods that regularly place insecticide around the face and eyes provide the best means of protecting cattle. Insecticide impregnated ear tags or force used dust bags provide the most consistent reductions in fly numbers.”
3. Maintain an irritant-free environment
In addition to good face fly control, mowing tall grass with seed heads, providing shade and clean, cool water (stagnant pond water or dirty automatic waters can be problematic) and reducing sources of stress, such as overcrowding, are important to stopping the spread of pinkeye, says Arnold.
4. Minimize exposure to the bacteria that causes pinkeye — M. bovis and M. bovoculi
Arnold writes, “Early detection of animals with the first clinical signs (tearing, squinting, and blinking) and then prompt, effective treatment are essential to reducing spread to herd mates and limiting damage to the eye. Long-acting antibiotics such as long-acting tetracycline or the prescription antibiotic tulathromycin are labeled for treatment of pinkeye. A veterinarian may prescribe the antibiotics florfenicol, ceftiofur, or others to be used in an off-label manner for treatment as well. Injectable antibiotics are generally the best option because of their long duration of activity and effectiveness in eliminating bacteria.”
5. Consider vaccinating
“Does vaccination work?” asks Arnold. “Immune responses to pili have been shown to be protective in some studies where animals are vaccinated with pili of a certain type and then challenged with a similar strain. A high degree of diversity among pilin genes is likely responsible for why some herds might see a benefit from vaccination while other herds do not; if the vaccine strain stimulates immunity to a pilus type that is also present in the herd, there should be good protection.”
To read more about how M. bovis and M. bovoculi bacterias spread, as well as learn the results of vaccination trials, and more, read the entire article by clicking here.
The opinions of Amanda Radke are not necessarily those of beefmagazine.com or Farm Progress.