Ask the Vet

Dr. Ken McMillan, Contributing Columnist

READER: I have a herd of Brahman-influenced cattle in Georgia. We have never had to deal with ringworm, but this year, I bought 50 black, 600-pound heifers from sale barns. Of that group, about six have signs of ringworm. I've read a good bit on cures, like the idea that warm weather helps. But, what can I do about the areas around their eyes?

DR. McMILLAN: Ringworm, or dermatophytosis, is a common problem with livestock. It can be caused by many fungal species, but the most common is Trichophyton verrucosum.

These fungal organisms reproduce by spores that infect other animals when they rub against each other or contaminated objects in the environment. Spores can survive for years on trees, fencing, barns, feedbunks, hay rings, show equipment and any other object. Ringworm is most common in calves, in winter and in temperate climates. It presents gray-white scaling patches of hair loss. Lesions are often around eyes but may also appear on the face, chest, trunk and legs. Several species of ringworm can be transmitted to humans. With any ringworm outbreak, always look at the overall health of the animals first. Quality nutrition, including minerals, is critical for the immune system to help get rid of infection. Always treat for external parasites including lice, mites and flies, as anything that makes cattle itch can damage skin, opening a door to ringworm. You are correct about warmer weather helping. Many times, ringworm self-cures with warm weather and shorter hair coats. Cattle also tend to congregate less in close quarters during warmer months.

The only practical treatment for ringworm is topical. Betadine, 2% iodine, chlorhexidine, lime sulfur and topical antifungal ointments can be used. For these treatments to be effective, crusts and scales must be removed by brushing, scraping or scrubbing. At least two treatments three to five days apart are recommended. These treatments can be used around the eyes, but they should not get into the eyes. Collect the crusts or scales you remove, and burn or properly dispose of them. Clean all equipment and common areas, including chutes, pens and alleys. Environmental treatment helps reduce future cases. Remember, anyplace cattle may have rubbed can be contaminated.

Many products labeled to treat ringworm in the environment have not been proven effective. Household bleach at a 1:32 concentration (1/2 cup of bleach to 1 gallon of water), Virkon S and accelerated hydrogen peroxide products such as the Rescue line can be effective. Before spraying, remove as much organic material as possible by scrubbing with detergents and/or pressure washing. Steam pressure washing is best.

READER: We found a newborn calf, very weak and trying to nurse, but the first-calf heifer kept kicking at it. The heifer's front two teats were swollen and red, and she was agitated and ran off. We took the calf home and are bottle-raising it. Any tips on what to do?

DR. McMILLAN: There is a good chance the cow has mastitis or inflammation of the udder. Mastitis is most commonly caused by a bacterial infection. This is more difficult to diagnose and treat in beef cows than in dairy cows, but the ideal treatment is the same -- stripping out the udder as often as possible. Mastitis tubes infused directly into the affected quarter(s) are indicated in most cases.

For beef cows, I recommend keeping cow and calf separated for a few hours after infusion so the antibiotic is in contact with the bacteria longer and has a chance to absorb into tissues. In cows that are visibly sick, more intensive treatment may be needed. Injectable antibiotics can be helpful in some cases, however, many do not reach effective levels in the udder. Nonsteroidal, anti-inflammatory drugs can reduce pain and inflammation. Intravenous and/or oral fluids may also be helpful in very sick cows.

Another possibility is that this heifer has "blind quarters." That means there is no open teat canal, so milk is trapped in the quarter. Some heifers may not be good mothers, and the quarters become swollen because the calf is not allowed to nurse. Lastly, some cows develop mastitis before they even calve, and the udder may be scarred and nonfunctional.

If possible, get this cow up and try to figure out what is going on. She likely needs to be culled, but she may also need treatment, especially with active mastitis or blind quarters. And, don't forget the calf. Even if you gave it colostrum when you found it, there is a good chance it may not have absorbed adequate immunoglobulins. Calves need to aggressively nurse or be given at least 2 quarts of high-quality colostrum or colostrum replacer with at least 100 grams of IgG (immunoglobulin G) as soon after birth as possible. At the 24-hour mark, colostrum is no longer absorbed. Your veterinarian can do a quick blood test to see if there was a "failure of passive transfer," meaning calves are more likely to get sick, most commonly from respiratory or gastrointestinal diseases.

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-- Please contact your veterinarian with questions pertaining to the health of your herd. Every operation is unique, and the information in this column does not pertain to all situations. This is not intended as medical advice but is purely for informational purposes.

-- Write Dr. Ken McMillan at Ask The Vet, 2204 Lakeshore Dr., Suite 415, Birmingham, AL 35209, or email vet@progressivefarmer.com

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