Brown dog itchy

Ringworm can look like other skin conditions.

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Ringworm in dogs: causes and treatment

By Dr. Stephanie Holmes BVetMed BSAVA PGCertSAECC MRCVS Veterinarian

Updated on the

Not only is ringworm contagious to dogs, but to other animals and humans too. So if you think your pet has it, here's how to deal with it as soon as possible.

Ringworm is an infection in dogs that can also be contagious to other animals and humans (i.e. it's zoonotic). It is not actually caused by a worm but by fungal infections. It generally causes a skin lesion that heals in the centre and spreads outwards thus forming a ring that is often scabby and inflamed. It is not often itchy. You will see patchy hair loss.

How can you tell if your dog has ringworm?

Ringworm is not common and can look like other skin conditions. If your dog has a crusty skin lesion with patchy hair loss with a ring like appearance with central healing, this raises the index of suspicion. To diagnose, a vet will examine your dog, take a full history and run some tests that will confirm whether your dog has ringworm, and guide the appropriate therapy. These tests may include using an ultraviolet light, as some ringworm will shine an apple green colour, and look into culture taken from the brushing of your dog’s coat and skin.

How did my dog get ringworm?

Most commonly dogs catch ringworm from direct contact with another animal or human who is suffering from the condition. This would need to be in contact with broken skin, so any wounds, skin conditions or a flea infestation would make a dog more likely to catch ringworm.

Animals with lowered immune systems, such as geriatric dogs, puppies and dogs on immunosuppressant drugs, are more at risk of catching ringworm.

Ringworm fungal spores can live in the environment, so dogs may also catch ringworm from bedding, clippers or grooming equipment that have previously been in contact with animals who have ringworm.

How do you get rid of ringworm on a dog?

Getting rid of ringworm in dogs may take some time, and it is important to treat the environment too, as the fungal spores can potentially live up to 18 months off an animal. Isolating the dog into one room or an easy clean area of the house is useful. Clipping the hair, if it is a long-haired dog, and the fur around the lesion is a good idea as this will aid treatment. This hair must be carefully collected and disposed of (burning is usually recommended). The tools used for grooming will need thorough disinfection and you must wear gloves when handling your ringworm dog.

The rest of the environment your dog has been in should be vacuumed, steam cleaned and disinfected, where appropriate. Bedding and toys are probably best disposed of. Your dog will need treatment prescribed by a vet until a negative culture test proves that your dog is clear of ringworm.

How do you treat ringworm on dogs?

There are a variety of anti-fungal treatments that will need to be prescribed by a vet. It is usually recommended that long-haired animals are clipped carefully and the fur disposed of to reduce the spores and allow good access for any topical treatments, e.g. shampoos, creams or ointments.

Based on the vet's findings they will prescribe creams, ointments, shampoos or tablets to be given orally. They may also give a combination of those treatments. It is important to wear gloves when administering the treatment, and an apron when shampooing.

How can I treat ringworm on my dog at home?

A vet will prescribe the appropriate medications and show you how and when to administer them. Your pet may be prescribed washes, ointment, tablets or a combination of treatments. It is really important that you follow the instructions carefully and only stop treatment when advised by the vet. Wear gloves when handling or giving any medications.

How long does ringworm last in a dog?

Usually simple cases of ringworm can last up to six weeks. Occasionally, in more severe cases, dogs might need treatment for months – the treatment is continued until a negative culture is obtained.

Can ringworm go away on its own?

In a healthy dog ringworm might go away on its own, but this would take at least six weeks. It is always recommended to treat any animal with ringworm, due to its contagious nature to other pets and the zoonotic potential – that is the risk to people, especially children, the elderly and those who are immunocompromised.

If not treated appropriately and with a stringent hygiene measure for the environment followed, your dog may end up becoming reinfected.

What cures ringworm fast?

The fastest cure for ringworm will be the correct treatment regime as prescribed by a vet aimed at the specific ringworm detected on diagnostic tests (e.g. culture). 

Isolating your dog to one room of the house to minimise spread, vacuuming, steam cleaning, disinfection with a product that kills ringworm spores, and disposing of your dog's bedding and toys will also aid in treatment to reduce the chances of reinfection.

How contagious is ringworm from dog to human?

Ringworm is contagious to people, but it is only caught through broken skin, for example if you have a scratch or eczema. People with lowered immune systems are more at risk of catching ringworm e.g. children, elderly people, people with weakened immune systems (immunocompromised – such as people on chemotherapy, AIDS sufferers, people undergoing transfusions or transplants). It is recommended not to allow children to touch your pet when the pet has ringworm. And when you are treating your dog wear gloves and an apron.

Can I touch my dog if he has ringworm?

You can still stroke your dog if they have ringworm, although it is recommended to not allow children, the elderly or people with lowered immune systems to do so. If you have any broken skin, it is advisable to wear gloves when petting your dog and avoid stroking on or near the ringworm lesions (the scabby areas).

Can you use athlete's foot cream for ringworm on a dog?

Athlete's foot creams contain certain anti-fungal agents that may be effective against ringworm in dogs. But always use them under the guidance of a vet. Multiple treatments including tablets and washes may be required, and treatment needs to be continued until the ringworm has gone, which will only be known by the vet by doing culture tests from your dog’s coat and skin.

Can I use Lotrimin for ringworm on my dog?

Lotrimin is another human over-the-counter medication usually used for oral thrush, nappy rash, vagina, yeast infections and some types of ringworm, including athlete's foot in people. The active ingredient may be useful for some types of ringworm in dogs, but must be used under the guidance of a vet, and usually following culture results to guide therapy.

What can I put on my dog's ringworm?

Only put medications on the ringworm as directed by a vet and always make sure that you wear gloves – due to how contagious ringworm is.

When should I see a vet?

It is recommended to seek veterinary advice if you notice any skin problems in your dog. It is especially important if these are areas of the skin that are balding and crusty, and if you suspect your dog might have ringworm. It may also be advisable to seek veterinary advice if you, or a member of your household, are diagnosed with ringworm, as pets can occasionally be asymptomatic carriers – which means they can have ringworm but show no signs of illness themselves.

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