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You might have heard about ringworm, the easily transmitted infection that turns your lovingly groomed dog into a mangled mess of red lesions and patchy fur. Panicked, you obsessively ran a brush through your dog’s coat and after making doubly sure that there were no worms to be found, you may have started to feel elated. Not so fast! Ringworm is not really a worm, it’s a fungus — and it’s not the kind of fungus that grows up as a horned, obvious mushroom on your dog’s forehead. Confusing right?

If  it’s  not  a worm, then what is it?

Ringworm is a microscopic fungus more similar to yeasts and moulds than to your average Portobello mushroom. These fungi feed on keratin, an essential component of the skin, hair, and nails found in animals, including humans. This disease usually wreaks havoc on puppies or dogs with weakened immune systems, and shows up as round granulomatous lesions or oozing boils. A ringworm infection can also cause an inflammation around your dog’s claws. This disease thrives in poorly managed, damp, overcrowded places, and absolutely revels in cases of malnutrition.

There are three different fungi that are the most common culprits of ringworm in dogs. Each of these species is spread around the globe with varying distributions according to different geographical locations.

Contrary to what the name might imply, the natural host for Microsporum canis is actually the cat. This does not mean that dogs are exempt from its mischief. It easily infects dogs, causing lesions by colonizing their skin and fur. It is also very capable at contaminating the surrounding environment, lying in wait for their next victim over long stretches of time. Microsporum canis is particularly common in Iran, while having lower incidence throughout the rest of the world, and being completely absent from equatorial Africa.

Rodents are the natural reservoir species of Trichophyton mentagrophytes. This fungus is not exclusive to rodents, but also infects a wide range of other animals, including our canine companions.

It is relatively uncommon for Microsporum gypseum to be the perpetrator of a ringworm infection. It usually occurs in dogs, other animals and humans that inhabit more rural areas or those that regularly take part in agricultural activities.

With these species of fungi being of a zoonotic nature (i.e. a disease or condition that spread between animals and humans; as previously explained in our article about vaccinations), these conditions will not stop at only affecting your dog. If a dog with ringworm is not treated and properly managed, it is not uncommon that the disease will find its way to the owner and other pets, making the situation even harder to manage.

Ringworm is not usually a very serious disease in itself, but if not treated, the integrity of the skin may be compromised, and the condition can lead to other, more serious secondary infections. If your dog starts losing hair, and suddenly shows up with a reddened or darkened, crusty, bald spot, you might want to put on a pair of gloves, and rush it to your most trusted veterinarian.

Diagnosis, prevention and treatment

It is only possible to reliably identify the agent causing dermatophytosis by means of fungal culture, microscopic examination or a skin biopsy.

The best thing one can do to prevent the spread of this condition, is to properly quarantine the infected animal. Disinfecting the environment and properly disposing of any material that might be considered contaminated (i.e. bedding and toys), is also suggested in order to manage this condition. If other pets are present in the household, skin and hair samples should be taken from them in order to check whether these are infected as well. It is also useful to make sure that there are no vermin spreading this disease and shedding spores in your pet’s environment. It is also suggested to treat all the pets in the household with preventative treatment to prevent the disease from spreading to your other pets too.

If the infection is superficial, the veterinarian might only prescribe an antifungal cream that can be applied directly onto the lesion. Contrary to many a dog’s fashion sensibilities, such cases might call for the dog to wear an Elizabethan collar which helps to prevent the dog from licking off the topically applied medicine. In cases where the infection is more severe, antifungal drugs designed for systemic application could be prescribed by the veterinarian.

If your pet gets diagnosed with this disease, please do give it your most urgent attention, because if it puts a ring on you or your dog, it isn’t going to look pretty.