Does your dog have hairless lesions on the head, face, ears, tail and paws? If the answer is yes then it is highly probable that your pet has ringworm. This reddened and raised circular form is a common fungal infection in dogs. Contrary to what the name implies ringworm is not caused by worms but by the Dermatophytes fungus. It was once thought that the scaly bald patches on the dog’s skin are caused by worms hence the name ringworm. Ringworm that affects humans and animals can be caused by three different types of fungus. Microsporum, the most common is what causes ringworm in dogs. Dermatophytes live on the skin and feed on dead skin tissues. The characteristic circular lesion on the skin will take on irregular shape when the rings connect as the infection progresses. As the fungi living on the hair follicles feed on the hair, hair shafts will be destroyed causing bald patches. Ringworms would not cause the dog discomfort as although it appears otherwise the raised and reddened lesions are not itchy. However, the bald patches will mar the appearance of the pet. Moreover, the dog can pass this fungal infection to other dogs, to other pets and also to the family members.
The ringworm spores can be spread through direct and indirect contact. An infected pet can directly transmit the fungal infection to the human family as dogs are always cuddled and petted. The fungal spores can exist in the environment for a long time. The dog’s bedding, the carpet and even the grooming tools can spread the infection. A dog that has come in contact with contaminated grooming equipments from canine grooming establishments will carry the fungal spores home. Incubation period is from 10 to 12 days. A dog exposed to the fungus will start to have lesions in about 10 to 12 days. The fungi are dermaphtytes meaning they live on the skin but they can as well live on the soil for months. Dogs can grow lesions after coming in contact with infected soil. Healthy dogs are noticed to have a strong resistance against ringworm. The dog may be carrying the fungal infection without manifesting the symptoms. Puppies are more susceptible because of their undeveloped immune system.
Ringworm is not a life threatening health issue. Dogs may not even need treatment as the fungal infection usually run its course. However, aside from marring the appearance of the infected dog, the infection can be easily transmitted to humans and to other pets. A dog owner would not ignore the pet’s condition. A vet visit will be necessary for proper diagnosis and treatment. The circular lesions are telltale signs but a vet would need to conduct other tests. A lamp known as wood’s lamp will be used. The microsporum will glow under the ultraviolet light. The lesion will be examined under a microscope. The most common form of ringworm diagnosis is to grow a culture. The scaly lesion will be scraped to get a sample.
As mentioned, ringworm usually resolves itself even without treatment. However, as this will usually take two to four month, there is a possibility that other pets and also humans will be infected as well. Treatments are administered to prevent the spread of infection. Antifungal drugs will inhibit fungal reproduction. Antifungal creams, dips and shampoos are recommended as well. To speed up the healing process, the lesions must be kept clean, dry and cool. To prevent re-exposure, the environment must be decontaminated. Use a bleach solution (a pint of chlorine and a gallon of water) to clean the kennel, the bed and the blankets of the dog.