Areas where the skin is rubbed regularly, such as on the neck along the line of the reins, or behind the thighs where the rug string rubs, are more vulnerable to infection. The skin in these areas is slightly worn away and weakened by the friction. Also areas such as the nose and muzzle are at increased risk, as the horse explores water and feed bowls used by other (possibly infected) horses. Ringworm lives off superficial, dead skin cells and hair, so lesions appear on the skin’s surface. As the infection progresses the damaged hairs are shed, leading to small bald patches. Often there are multiple patches that have the appearance of round, bald, scaly areas. These are often grouped together on the neck, withers, or behind the thighs, although any area can be affected. As the infection becomes mature, the bald areas may coalesce together to form larger bald areas. These patches are often scaly and may have a grey, ‘cigarette ash" tinge to them. Crusts may form over the bald area, but these are not a sign of healing, indeed the crusts can protect the fungi and make it more difficult to treat.
Unfortunately, a common way to catch ringworm is from other infected horses. This can happen simply by rubbing against a fence or stable touched by another infected horse. Indeed, tack such as reins, girths, or saddles, or equipment such as riding boots can become infected and act as a source of transmission from one animal to another. Another problem is that it can take up to three weeks before an infected horse shows signs of the infection. During this time the horse may be in contact with other horses or be transported in a trailer and rub against the walls, which acts as a source of infection for others. However, remember that the fungus that causes ringworm occurs naturally in the environment and in the soil. Contact of the skin with the fungus can lead to colonization of the skin and an infection developing.
It can take around 6 - 15 weeks for self-cure to take place. During this time the horse is a source of infection to other horses. If the lesions are itchy and the horse rubs a lot, the ringworm patches may get infected are require further veterinary attention. Signs of infection include reddening of the area, inflammation, scabs formation, or weeping or discharge from the area.
Imaverol is concentrated and needs dilution prior to use. 1 ml of Imaverol is added to 50ml of water to make a 0. 2% solution. It is best to spray the whole horse for the first treatment, in order to contact any fungus which is present but not yet showing signs of infection. After than it is acceptable to treat the infected areas only with a margin of skin around them to catch any sideways spread. The diluted Imaverol needs to contact the fungus, therefore scabs need to be removed first. This can be done by soaking them in a shampoo Malaseb (containing an antifungal agent, miconazole) and then picking them off or brushing gently with a toothbrush. Take care to wear gloves so that your skin doesn’t become affected. After removing the scabs, thoroughly dry the skin so that water doesn’t further dilute the Imaverol and weaken its action.
The horse receives treatment daily for 7 days. However, this treatment works from the inside out, and takes longer to be effective as the fungus need to contact the chemical in the blood. Also, some of the shed fungus could potentially still be infective.
