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I think my dog has ringworm. What should I do?

Ringworm is a type of fungal infection in the skin. Ringworm infection is caused by microscopic fungi (dermatophytes) feed on the keratin layers of the skin. The name ‘ringworm’ comes from the fact that the ringworm rash is often circular with the edge of the lesion appearing as a red ring. Ringworm can affect dogs, humans and in fact most mammal species, and usually appears as changes to the skin such as flakey dry patches, hair loss and redness. Our vet discusses ringworm in this article.

This article was written by a FirstVet vet


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Symptoms of ringworm in dogs

Ringworm can appear in many different ways. There are often typical lesions for ringworm on the skin, although infections do not always appear in these ways. In addition, typical ringworm lesions may ressemble other skin conditions, such as hot spots in dogs. Ringworm in dogs can look like:

  • Circular moist patches of hair loss with an outer red ring

  • Patches of hair loss with a crusty or scaly appearance

  • Most commonly ringworm appears on the paws, legs, head or ears, but can be anywhere on the body.

  • Shapes of lesions can be multiple or singular

  • Patches of short, broken or poor hair growth

  • Patches of very flakey skin with lots of dandruff

How do dogs get ringworm?

Ringworm is contracted by direct contact with an infected animal, or contact with a contaminated object, which could be any surface including brushes, bedding or carpet. Environmental sources are also important because spores can survive for months on outdoor objects such as fence posts or in soil. Livestock can also be a common source of infection. These are some of the most common ways in which domestic pets and humans contract ringworm.

Ringworm in dogs can spread to the humans they live with, or other pets, such as cats or rabbits.

Not all contact guarantees infection, it is more common in the young, old or immunosuppressed individuals. Contact with broken skin such as a cut or graze significantly increases the risk of an infection.

How do you know if your dog has ringworm? Diagnosis of ringworm in dogs

As there isn’t one single way that signs of ringworm appear, it can be quite difficult to spot. Usually if your pet has skin lesions that are spreading, not improving, or look like ‘typical’ ringworm, then they need to have a sample taken for laboratory tests to look for the fungi.

A diagnosis is usually made by taking samples of skin and hair from the edge of the lesion for a fungal culture or other tests to identify the infectious agent. Your vet may look at the skin lesions using a specific light called a Wood’s lamp, as some species of the fungus will glow under ultraviolet light. However, this test isn’t 100% reliable as not all species of ringworm fluoresce.

Treatment of ringworm in dogs

How is ringworm treated in dogs? Once the fungi have been confirmed in the samples taken from your dog’s skin, treatment is started. This is usually with a combination of ringworm cream, tablets and shampoos/baths. These are anti-fungal drugs, such as itraconazole, often require several weeks to months of treatment to treat the infection. It is imperative that you use gloves when applying topical treatment and wash your hands thoroughly.

Reducing close contact with the infected dog and other members of the household during the infection is recommended, as long as it does not risk the animal’s welfare. Ringworm treatment for dogs is only effective if it contains anti-fungal agents, which are usually prescription-only and available from your vet. Home remedies for ringworm are nearly always ineffective and delay appropriate treatment starting.

Environmental treatment of ringworm

As we know, spores linger many months in the environment so it is important to take steps to decontaminate all affected areas:

  • Try to contain the affected dog in one room of the house. Infected dogs will remain contagious for around 3 weeks after treatment has started. Use rooms with minimal soft furnishings that are easy to clean

  • Throw away any bedding you can. Household items that the pet has come into contact with should be soaked in bleach solution (500 mls chlorine bleach in 4 gallons of water) and then hot washed to removed the spores

  • Vacuum thoroughly to remove skin cells and pet hair to decontaminate the house. Carpets can be steam cleaned. Discard the vacuum cleaner bag. Do not use brooms, which can trap infected material

  • Disinfect all surfaces with an appropriate cleaning product

Untreated ringworm infections in dogs

If your dog has a fully functional immune system it is likely it will overcome the infection. However, allowing the lesions to spread around the body will make it more infectious to humans and other animals. Delayed treatment may also make it necessary to treat with a longer course of medication. The more lesions the pet has the higher the environmental contamination is likely to be. For these reasons it is always recommended to treat your dog’s ringworm promptly.

Will my dog recover from ringworm?

With the correct treatment of ringworm started promptly, and a fully functional immune system, your dog should start to recover within a few weeks. Those dogs with other concurrent health problems, or a severe infection, treatment is often more challenging. However, the overall prognosis is very good.

Please note, if you or any other household members have skin lesions it is imperative you speak to your GP or local pharmacist. Inform them of any skin conditions that your pets have had and if they have tested positive for ringworm.

Still have questions?

If you are concerned about your dog and would like more advice please book an online video appointment to have a chat with one of our FirstVet vets.

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