By Michelle Knowles
Dermatophytosis, or Ringworm as this condition is referred to, is caused by forty or so different keratin–loving fungi dermatophytes with Trichophyton and Microsporum being the most commonly diagnosed.
This condition is zoonotic, passable between animals and humans, and can spread like wildfire if not eradicated from the afflicted pet, all other pets and the entire living quarters where the affected pets live. This can also mean checking and possibly treating human family members as well.
Being a type of fungus, or plant, there is no actual worm. Fungi love warm, dark and wet places. Tightly matted coats or coats that are thick with uncarded undercoat are prime breeding ground for this issue to appear. Although, any coat type, including human, can become infected by contact with an infected individual or an article of clothing or shared object that has been handled by an infected individual.
The symptoms are raised, red, circular lesions where the hair is damaged or lost in the middle. The skin inside the lesion may be flaky and/or moist. Intense scratching and secondary infections may appear as the skin becomes compromised further. It has been further documented that other pets in the household can be carriers of the infection but show no symptoms, so it is always important to treat every pet in the household even when it is found on only one.
A veterinarian visit is necessary in order to get a proper diagnosis. There are internal medications that may need to be prescribed as well as topical treatments that can be performed by a thorough pet aesthetician, groomer or a trained bathing technician. Not every pet will need to have internal medication as well as topical treatments, except for cats.
Topical treatments should be performed one to two times weekly, depending on the vet instructions and the severity of the infection. Each treatment session should include some type of clay mask, such as white or rose kaolin, to bring the skin to a neutral state. This should be followed either by the prescribed anti–fungal shampoo or a medicated shampoo that includes ketoconazole or any of the “zole” family. When accompanied by chlorhexidine, this will also help balance the bacteria that may be overgrown on the skin. Five to ten minutes of soaking in this solution will give the best result.
After rinsing well, a light conditioner should be applied with minerals and collagen added for cell support. In cats, this internal and topical treatment duration may be prolonged in order to keep the infection under control.
When ringworm is found in the salon environment, it is time for a deep cleaning and sanitizing of equipment, tables, hand tools, tubs, and any other area that is contacted by pets and people. It is important to be aware of what ringworm looks like so that you can recognize the symptoms and immediately advise the owner to seek veterinary treatment for the infected pet.
Having a foundational knowledge of Dermatophytosis will help you maintain a safe and hygienic salon environment. 
References:
Simpanya, F.M., 2000. Dermatophytes: their taxonomy, ecology and pathogenicity. In: Kushwaha, R.K.S., Guarro, J. (Eds.), Biology of Dermatophytes and other Keratinophylic Fungi. Revista Iberoamericana de Micología, Bilbao, Spain, pp. 1–12.
Zdovc, I., Miˇcunovi, J., Pirˇs, T., Ocepek, M., 2004. Occurrence of dermatophytes in dogs and cats and their susceptibility to antifungal drugs. Vet. Dermatol. 15 (Suppl. 1), 44.
Pier, A.C., Smith, J.M.B., Alexiou, H., Ellis, D.H., Lund, A., Pritchard, R.C., 1994. Animal ringworm – its aetiology, public health significance and control. J. Med. Vet. Mycol. 32 (Suppl. 1), 133–150.