Ringworm is a skin infection caused by a fungus. It is contagious between dogs, cats, people, and many other animals. It is usually mild but can be serious in very young or weak animals.
Dogs catch ringworm, also known as dermatophytosis, when damaged skin comes into contact with spores shed by an animal with the disease. Direct contact with animals that have it is most common, but hairs and objects can also carry the infection. Healthy animals can clear the disease after a few months, but they can spread it in the meantime. This disease is very contagious but not life-threatening.
What is ringworm?
A contagious skin disease that does not affect other organs.
Caught usually from close contact with affected animals.
Several species of fungus can cause disease.
Healthy skin is very resistant to infection. Minor skin damage or problems with the immune system will allow infection to set in.
Can look like many other skin conditions.
Can also affect claws.
Serious disease is rare, but treatment is advised to reduce spread.
Symptoms of ringworm in dogs
Typically small patches of hair loss with dry, scaly skin.
May be itchy, but often isn’t.
Can cause many different skin changes and may look like many other skin diseases.
It can be just one spot, many spots, or large areas.
Skin may be dry, red, dark, or swollen.
Sometimes there are crusts or scabs.
Infected claws can shed or become deformed.
Some animals will have other conditions, and this can cause other symptoms.
Are some dogs more at risk of getting ringworm than others?
Young puppies and animals with problems affecting their immune system are most at risk of getting ringworm.
Hunting dogs are also at higher risk due to contact with wildlife.
Yorkshire Terriers are at risk of developing severe disease.
Can humans get ringworm from dogs?
Ringworm is a zoonosis, this means that humans can get it from dogs and other animals.
Children and people with a weakened immune system are at higher risk.
Contact your GP if any family members develop skin problems, especially round red spots on their skin.
How is ringworm diagnosed in dogs?
Diagnosis is not always straightforward, as ringworm can look the same as other skin diseases, and some animals can have the fungus on them without having disease.
Some types of ringworm will look fluorescent green under some types of UV light, and this can be checked with a special lamp called a Wood’s Lamp.
Looking at damaged or shed hairs under the microscope may sometimes detect the fungus.
One of the best tests available is incubating skin, hair, or claw samples in the lab to see if the fungus grows. This may take up to two weeks.
Tests looking for the DNA of the fungus, called PCR tests, can also be used but have limitations.
What is the treatment for ringworm in dogs?
Since this is a contagious disease, treatment usually tries to eliminate the fungus and not just the symptoms. As such, tests are needed after the skin gets better to check if the fungus is still around. The approach to treatment will depend on how widespread and how severe the disease is.
Small areas can sometimes be treated with a prescription ointment.
Spread out or large areas usually need a combination of oral medication and medicated washes or shampoos.
Severe disease often requires long periods of treatment (several months).
If there are other diseases present, these usually need to get better before the ringworm does.
You may want to test all other pets and treat them if necessary, otherwise the infection may go back and forth.
Effective treatment requires prescription medications, and using the wrong treatment can make things worse. Always discuss testing and treatment options with your vet.
Tips on how to prevent ringworm from spreading
In dogs, ringworm spreads through spores. These fungal spores are often attached to shed skin scales and hairs.
Confine an affected pet to an area where it has no direct contact with other pets. This area needs to be easy to clean, and this must be done frequently.
Healthy skin can repel infection, but minor abrasions can allow it to break in. Use of gloves and separate clothing are advised when handling an affected pet.
Immunocompromised people and young children should avoid handling affected pets. Frequent and thorough hand washing is very important.
Bowls, trays, toys, bedding, and clothing must be washed frequently. Two consecutive washes with the longest program in the washing machine have been shown to eliminate the spores. Use normal detergent.
Household cleaning products are also effective, as long as all the hair and dust are removed first.
Joii can help with further advice on the best way to keep your house clean and safe.
If any family members develop skin problems, especially round red spots on their skin, contact your GP for a consultation.
When to worry
When you should be worried about ringworm
Call a vet to discuss suspected ringworm to make sure your pet gets safe and effective treatment.
In young puppies, elderly dogs, or those with ongoing health conditions, it may be best to discuss any skin issues with a vet straight away.
This is more urgent if there is swelling, discharge, or they are damaging the skin while scratching.