Choose your dog breed


Choose your dog breed:

Ringworm in Dogs

Ringworm or dermatophytosis is one of the contagious skin infections that is pretty common amongst dogs, and in animals in general. It’s caused by a fungus that breaks down keratin contained in hair, skin, and claws. Despite the fact that this is not a deadly disease, it can be uncomfortable for the dog and not very appealing to the eye. Ringworm usually appears as a round, reddish patch without hair on various places from nose and belly to paws. But in some cases, it can cause scales and crusts on the skin. The treatment of ringworm can be long and tedious, but one should stay persistent for successful results. Since this is a disease that can spread to humans and other pets throughout direct contact or contaminated surfaces, it’s important to pay attention to general hygiene and to cleaning places the infected dog resided. In this article we will go into detail about the prevention through good hygiene and how to treat this disease effectively.

What Does Ringworm Look Like on a Dog

Ringworm on a dog's noseRingworm on a dog can appear very similar to other skin diseases dogs can get. There are several ways ringworm can manifest, since ringworms eat the keratin from which the skin, hair and nails are built. But in dogs, it’s mostly the hair follicle that becomes infected.

Some dogs develop dandruff and/or spots of hair loss (round patches) with dry, crusty skin, while in others, reddish lesions can be detected. The affected areas on the body in most cases are not itchy, but there are circumstances where those lesions get inflamed and where scabs can form. In some cases, ringworm can also be asymptomatic. This can be a problem in an environment with more animals present since they can still act as carriers of the disease.

Is Ringworm Contagious?

Ringworm is highly contagious. It can be spread from dogs to owners very easily, as well as to other humans. People can get ringworm from their dogs through direct contact or through contaminated surfaces where dogs leave the fungi spores behind, such as on places they slept, the carpet, couch, clothes, etc. One more reason to be more cautious and to pay more attention to hygiene and to wash hands and clean surfaces is the fact that the fungi spores can survive 12- 20 months in favorable environments. 1Dermatophytosis. The Center of Food Security and Public Health. Retrieved 19 October 2020.

It’s more likely for a human to get infected with ringworm if he has wounds, scratches or other micro lesions on the skin. Or in other cases, if the immune system is weakened. Thus people with chronic diseases, children and older people are more susceptible to catching the fungus.

Unlike in dogs, ringworms in humans can be rather itchy. They appear as a characteristic circular red shape on the skin. The disease goes by several names in human “dermatophytosis” or “tinea.”

Treatment in humans depends on the location the ringworm emerges. If it appears somewhere on the skin, it can be treated with antifungal creams, powders or lotions. But in another case, when the ringworm appears on the scalp, usually it’s necessary to visit a doctor. A more precise treatment must be determined since it’s a more delicate place of infection.

All other domestic animals can get ringworm as well. This should also be kept in mind when the dog is diagnosed with this fungus. To remove all the spores the dog has perhaps left behind, every spot the dog resided should be cleaned and disinfected thoroughly.

Symptoms of Ringworm in Dogs

Dog Ringworm SkinDespite the fact that ringworm is not a life-threatening disease, the easy spreading to humans and other animals should be considered and kept in mind. So what are the things one should look for when suspecting the dog has gotten ringworm? First, the period after infection until the development of first signs can take from 7 to 14 days.

Usually, in the early stages, as the infection starts developing, there are circular areas without hair (alopecia) present. As the process continues, the central area starts to heal, making it look like a patch. In general, the quality of the hair may deteriorate; it becomes brittle and dry. The skin as well can become inflamed and scabby. But in most cases, the lesions are not itchy. Depending on the area the infection took place, claws can also be affected, so they start to become brittle and rough.

It’s not always the case that you notice the characteristic circular patches. In some conditions, there can be seen scales of skin like dandruff, scabs, or even darkened skin (hyperpigmentation). When some of these signs are noticed, a trip to the veterinary clinic for further consulting is recommended.

How Do Dogs Get Ringworm?

For a dog to get ringworm, he must come into direct contact with the fungus, either directly in contact with other dogs or indirectly by coming in contact with the contaminated environment (sleeping in the bed or using the same brush as an infected dog).

Ringworm in Puppies

Even though dogs of all ages can get the ringworm, puppies, older dogs and dogs with lesions on the skin or with weaker immunity are more susceptible to the infection. Unlike in adult dogs, puppies don’t necessarily develop the usual ring areas of hair loss. There are bald patches with dandruff, crusts, and broken and brittle hair all over the body. While usually in dogs the affected areas are not itchy, puppies can more often develop itchiness. So, unlike in older dogs there are more cases where itchiness is present as well. Diagnosis and treatment of ringworm in puppies is the same as in older dogs.

Diagnosis of Ringworm in Dogs

The first thing the veterinarian will do is perform a physical examination of the dog’s body. If he finds an indication that the dog has ringworm (patches with dry, scaly skin and fur), further diagnostic methods will be conducted.

Usually, the first one to be used is a method that involves the use of a Wood´s lamp, where the fungi fluoresce under the ultraviolet light of the lamp. This method is not fully reliable since a false positive can occur, so it’s mostly used as a screening method.

Microscopic examination is conducted by taking the skin scraping or hair from places where it fluoresces under the Wood’s lamp.

But the most reliable method is growing a fungal culture from samples of skin scrapings or plucked hair. The results can be seen in a couple of days, but in some cases, the final diagnosis results can be prolonged for up to a month.

Since there are various similar skin diseases, the veterinarian could carry out other diagnostic procedures to rule out those potential diseases as well.

Ringworm Treatment for Dogs

After the ringworm has been diagnosed, proper treatment will be determined. The treatment method will depend on the affected area, the severity of the infection, and the symptoms manifested.

There are three different treatment methods: topical, oral therapy and environmental decontamination. Usually, a combination of all of them is needed for successful results in the end.

Topical Therapy for Ringworm in Dogs

Topical treatment is used to prevent the spread of fungus spores into the environment so owners and other animals that come in contact with the dog aren’t affected. Treated with topical therapy, the fungus spores are directly killed, so even if they end up spreading into the environment, they are not infectious.

The most common products used are shampoos, lotions, and ointments that mostly contain either Miconazole or Clotrimazol. Miconazole is usually combined with Chlorhexidine, because in this combination, the results are most efficient.

Oral Therapy for Ringworm in Dogs

With the topical treatment getting rid of the worms already existing on the surface, oral therapy gets to the core of the problem and prevents the fungus from further spread and reproduction. Itraconazole and Terbinafine are options mostly used by veterinarians. The treatment should be continued until the dog tests negative.

Environmental Decontamination

Environmental decontamination is also an important part of ringworm therapy. Improving the conditions where the dog resides can be of great benefit, but there are not many products that are effective. The one that works on 80% ringworm spores is bleach (diluted 1:10). It is effective on any surface that can be bleached. Before bleaching, it’s important to do general cleaning from vacuuming carpets to washing surfaces with soap and detergent, since bleach does not work if there is any dirt present.

Home Remedies for Ringworm in Dogs

There are some home remedies for ringworm in dogs people reach out for instead of conventional therapy. The five most used are apple cider vinegar, oregano oil, lemongrass essential oil, neem oil, and garlic.

These remedies are applied topically to the affected area on the skin. They should be applied several times a day (usually 3-4 times) to have an effect. But, please be informed about the detailed instructions on how to use these remedies, since some of them should be diluted before being used.

Before trying out these unconventional methods, it’s always better for you to consult with your veterinarian.

Untreated Ringworm in Dogs

Treating ringworm can take time, since fungus in general can be very tedious to treat. But one must remain persistent since untreated ringworm can spread to larger areas of the body, provoking even more damage to hair, skin and nails. Also, the possibility of causing infections in humans and other animals becomes even higher.

How to Prevent Ringworm in Dogs?

Given that there is no way to prevent the dog from getting ringworm on the outside, the things that can help to minimize the possibility of getting the infection include cleaning the places where the dog sleeps, cleaning the grooming brush regularly, and vacuuming to remove hair and skin cells.


As with any other fungal infections, ringworm can become tiresome and repetitive since it can take a long time for it to be fully cured. Causing round patches of hair loss, this fungal infection is not life-threatening, but it can be very uncomfortable. The high potential to spread to humans and other pets should be kept in mind. Thus, the treatment must be conducted properly with all caution possible. Combining topical and oral treatment together with environmental decontamination is the key for a successful treatment. Cleaning and keeping good hygiene of your dog and the environment is the best prevention for this disease.

Frequently Asked Questions (FAQs) about Ringworm in Dogs

What Are the First Signs of Heartworm in Dogs?

Mostly, there are no visible signs of heartworm in dogs, long after the actual infestation. But when they do appear, you will most likely notice a persistent dry cough, loss of appetite, loss of weight and apathy. This means the disease has already progressed, so you should seek the help of a vet immediately. These symptoms can indicate a whole list of other diseases that should be determined, so a proper therapy should be conducted.

How Long Can a Dog Live With Heartworms?

Left untreated, the disease is fatal. The lifespan depends on the size of the dog, its general health condition and the number of worms present. But even when the treatment is carried out, depending on the stage of the infection, the pet can be left with the damage the worm has already made to the heart and lungs, which has to be monitored with treatment.

What do Heartworms Look Like?

Since the heartworm belongs to nematode (roundworms) phylum, they look like 'cooked spaghetti.'

How do You Know if Your Dog Has Heartworms?

Mostly there are no noticeable symptoms, especially in the beginning of the infection. It may take a long time for first symptoms to appear, but if they do, usually the dog has a persistent cough, loss of appetite, and is generally apathetic. These are warning signs, and the dog should be immediately taken to the vet. Regular testing is the best way to prevent this.

How Much is a Heartworm Test in the USA?

If you suspect your dog has heartworms, or if you just want to do an annual check-up, you should expect a price range from $45-$50. Whereas the treatment can be from $400-$1000.

How Common is Heartworm in Dogs?

The incidence of heartworm disease in dogs is increasing, with the coastal regions being more affected, taking into account climate and the vectors. One out of 200 dogs is getting infected with heartworms.

Are Heartworms Contagious in Dogs?

Heartworms are NOT contagious; only mosquitoes can infect the animal throughout the bite. Mosquitoes are the ones responsible for transmitting the parasites from one dog to another.

How to Get Rid of Heartworm in Dogs?

After confirmed diagnosis, the vet will treat your dog with suitable medications according to the state of infection. And in extreme cases, the vet may suggest surgery to physically remove the worms. To learn more about the treatment, please read the 'Treatment of Heartworm in Dogs' section.

What do Heartworms Look Like in Dogs?

Heartworms have an impact on several organs from heart, lungs, and kidneys to the liver, and the clinical signs vary as well. But mostly the disease is reflected on the heart and lungs with their accompanying symptoms.

Can Heartworm in Dogs Be Cured?

Dogs with heartworms can be cured if diagnosed on time and with the appropriate therapy. This is why you should use preventatives and do regular testing.

Can Cats Get Heartworms?

Cats cannot get parasites directly from dogs; the only infection path is through mosquito bites. As in humans, cats are not heartworms’ final destination. This is why the disease manifests itself often very differently. The cat gets infected either with just a few or no adult worms because of their petite body structure. Therefore, the infection can be left unnoticed. But the damage can be done, nevertheless, even by immature worms; cats can develop heartworm associated respiratory disease (HARD). The symptoms can range from very mild to extremely serious and heavy. When developed, the symptoms are usually a cough, a lack of appetite, asthma-like attacks, vomiting and weight loss. They can even get seizures or faint, and like dogs, they get an accumulation of fluid in the abdomen. The problem is that sometimes they do not develop any of the symptoms, but suddenly just collapse or even die. It is important to consider the fact that there is no medication that can be used for the treatment of heartworms in cats because the ones designated for dogs are ineffective. So the only way is to prevent the infection in the first place.

Dr. Iman Krijestorac (DVM)
Dr. Iman Krijestorac (DVM)
Dr. Iman is a young, ambitious veterinarian working in a small animal vet station while volunteering in the local dog shelter. Zoonotic and infectious diseases are one of her major interests, together with dog nutrition and diet for which she attended several seminars and conferences. She has always had a heart for big dogs, she has an old Appenzeller Sennenhund going by the name "Yoda".

Readers' Comments

Related Articles

Most Read Articles

Glucosamine for Dogs

Glucosamine is a popular supplement for dogs, often used for treating joint problems.

Dog Joint Pain

Joint pain can occur in dogs of any age. Learn about the possible causes and treatments.

Dog GPS Collar & Tracker Review

How to find your dog if he gets lost? This widget monitors the dog's location, activity, and health.

Pet Stain Remover

Learn how to remove bad odors and all kinds of dog stains in the most effective way.

Dog Shampoo

How often should you bath your dog? Should you use a human or dog shampoo?