Ringworm in dogs is a fungal skin infection, not a worm, and it can pass between dogs, other pets and people. It often shows up as patches of hair loss and crusty skin, and the headline message is to speak to your vet rather than guess, because lots of other skin problems look similar.
At a glance
- What it is: a fungal infection of the skin and coat, also called dermatophytosis
- Who it affects: dogs, cats, people and other animals. The PDSA says puppies, older dogs and dogs that are otherwise unwell are most at risk
- Urgency: contact your vet if you think your dog has ringworm (PDSA), as it is very contagious
- Vet needed? Yes, for diagnosis and treatment
Signs to look for
The PDSA lists raised, red, crusty skin, often in circular patches, plus hair loss, dandruff and mild itchiness. It also points out that ringworm is “not actually a worm and it isn’t always ring shaped”. Blue Cross says the usual picture is areas of hair loss with a crusty covering, most often on the paws, legs, head and ears but possibly anywhere, and that some dogs show no signs at all.
Many other skin conditions look similar, so please do not self-diagnose. Our sick dog symptoms guide helps you judge what to do next.
Causes and risk factors
Ringworm is caused by a fungus and spreads by direct contact. The fungus makes hardy spores (tiny seed-like particles). The PDSA says they can last on bedding, towels and grooming equipment for up to two years.
Blue Cross notes that only broken skin can be infected, so a dog with healthy skin will not pick it up. It says young, elderly and long-haired dogs are more commonly affected. The PDSA also says some dogs get it when run down by another illness.
When to call your vet
Speak to your vet if your dog has patches of hair loss, crusty or scaly skin, or a rash you cannot explain. The PDSA says to contact your vet if you think your dog has ringworm, and calls it very contagious. If anyone at home has a skin rash, see the human section below. If you need a practice, our vets near me guide can help.
- 1. Notice
Patches of hair loss and crusty skin - 2. Speak to your vet
Contact your vet if you think your dog has ringworm - 3. Vet examines
A special lamp, plus hair or skin samples - 4. Options
Treatment options your vet may discuss: coat clipping, medicated baths, tablets - 5. Ongoing care
Wear gloves, wash bedding and follow your vet’s instructions
How vets diagnose it
The PDSA says a vet may use a special lamp to look for ringworm and may send hair or skin samples away for testing. Blue Cross adds that a fur sample can be checked under a microscope, and that growing a sample in a lab is the most reliable test, taking about 10 days.
What vets generally do about it
The PDSA says mild infections occasionally clear without treatment, but your vet decides the plan. Treatment can include clipping the coat around patches, medicated antifungal baths once or twice a week for several weeks, and sometimes a daily antifungal medicine by mouth, often for a month or more. Blue Cross says some dogs have tablets, some lotions or shampoos, and some both, and that failing to follow instructions risks the infection coming back.
Living with it and prevention
Once your vet has advised, the PDSA and Blue Cross suggest:
- Wearing disposable gloves when you handle or treat your dog (Blue Cross adds an apron)
- Washing bedding and soft furnishings, and vacuuming and cleaning regularly
- Keeping your dog to one room during treatment, and away from other pets where possible
- Asking your vet which disinfectants work
- Having other pets checked by a vet
Blue Cross says some tablets should not be handled during pregnancy and that children should not touch an affected dog, so speak to your vet about your household. The PDSA says ringworm can be persistent and that slow recovery may prompt the vet to look for an underlying problem.
If someone in the house gets a rash
The NHS says ringworm spreads through close contact with an infected animal or person, or via items like towels, combs and bedding, and usually shows as a scaly, itchy, ring-shaped rash. It advises speaking to a pharmacist first, and seeing a GP if the rash has not improved after pharmacy treatment, it is on the scalp, or your immune system is weakened. Blue Cross says you cannot catch ringworm if your skin is unbroken, and that children, older people and anyone with a weakened immune system are more at risk.
Related conditions
- Skin infections in dogs
- Mange in dogs
- Hot spots in dogs
- Dog allergies
- Fleas on dogs
- Back to the dog illnesses A-Z
Sources
Frequently Asked Questions
What does ringworm look like on a dog?
Often raised, red, crusty or scaly patches with hair loss, though they are not always ring shaped. Many other skin problems look similar, so speak to your vet rather than guessing.
Can I catch ringworm from my dog?
Yes, it can spread from dogs to people through contact. Blue Cross says you cannot catch it if your skin is unbroken, and that children and people with weakened immune systems are more at risk. Speak to your vet and a pharmacist or GP.
How do vets test for ringworm in dogs?
A vet may use a special lamp, check a fur sample under a microscope, or send hair or skin samples for lab testing. Blue Cross says lab culture is the most reliable test but takes about 10 days.
How long does ringworm last in dogs?
The PDSA says treatment usually takes a few weeks to work, and medicated baths or tablets can continue for a month or more. Ringworm can be persistent, so speak to your vet if it is slow to clear.
This page is general information, not veterinary advice. If you are worried about your dog, speak to your vet. Written by Georgiana & Figo, who are dog owners, not vets. Have a look around Calmshops for everyday dog essentials.
