Dermatophytosis (Ringworms) in Dogs

Dermatophytosis, also known as Ringworms or Tinea, is a highly contagious fungal skin infection caused by Microsporum Canis, Microsporum Gypseum and Trichophyton Mentagrophytes fungus.

This contagious keratophilic fungi has a global distribution. These fungus are highly adaptable and can survive for up-to 2 years. They are known to affect a variety of animals, wild animals, farm animals, domestic animals including cats and dogs.

Transmission can happen from direct contact with infected animals, from broken hair with infected spores, from infected humans, from contaminated materials and objects like bedding, toys, furniture, rugs etc. Once infection occurs, the parasite invades the growing hair causing hair loss. It then damages the peripheral hair resulting in a ring like shape and causing superficial skin infections. Ringworms affect the skin, hair, claws and nails and common sites affected are the face, tip of the ears, tail and legs. Clinical signs can range from itchiness, hair loss, circular lesions, scaly or greasy skin, bald patches.

All dogs are susceptible to this infection. The severity depends on the age of the dog, the extent of the infection, site affected and its immunity response. Young dogs (under two years), immunocompromised dogs (with existing medical condition or weakened immunity), outdoor dogs, dogs living in contaminated and unhygienic areas and senior dogs (over 7 years) are at high risk of getting infected.

Dermatophytosis is a ZOONOTIC disease – which means humans can easily get affected from an infected pet.

Certain breeds are highly susceptible to this condition.


Ringworms are caused by Microsporum Canis, Microsporum Gypseum and Trichophyton Mentagrophytes fungus and the route of transmission is through the skin. There are various factors which makes a dog susceptible to this highly contagious superficial skin infection.

Clinical Signs & Symptoms

The incubation period for Ringworms can range between 2 weeks to 1 month. Clinical signs are skin related and common symptoms are:

› Bald spots
› Scaling (Dandruff)
› Erythema (Reddened skin color)
› Hyper-pigmentation (dark skin color)
› Pruritus (itchiness)
› Alopecia (Hair loss)
› Intense scratching (on face, limbs
› Mild swelling
› Dermatitis (inflammation of skin)
› Dry skin
› Poor coat condition (scaly or greasy skin)
› Small circular lesions (which resemble small boils, granulomatous lesions)
› Lesions on head, ears and tail
› Scratching of ears
› Inflammation of claw folds


Presence of small circular lesions confirms the presence of ringworms. However, Veterinarians will require a complete history of your dog which includes medical history, vaccination records, existing health concerns, current and previous medications, onset of symptoms, diet, grooming patterns and exercise routine and any information which can help in establishing a correct diagnosis. Ringworms cannot be seen through a naked eye and these conditions can be caused by other infections. Diagnosis is done with a combination of tests. These include routine lab examinations and special tests which can detect the presence of the fungus. These are:

› Physical examination
› Wood’s Lamp test (using specialized black light, ringworms glow fluorescent)
› Fungal Culture test (from skin and hair scrapping of the areas infected)
› Skin Biopsy
› Microscopic examination (of hair from the periphery of the lesion)
› Skin biopsy


Treatment consists of:

› Anti-fungal medications (Oral)
› Antibacterial medications
› Drugs to treat secondary illnesses and diseases
› Prescribed Ointments
› Medicated baths (using shampoos, solutions)
Your veterinarian may ask you to put an Elizabethan collar to prevent the dog from licking these medications – they could prove toxic and may cause digestive issues.


Fungal infections cannot be prevented especially if it is contracted by inhalation. Keeping your cat indoors will reduce the risk of exposure to infectious agents. A stronger immunity will not only fight but will also help in a speedy recovery.

Home Care

Home care should aim at improving the condition. Treatments can take a few days to weeks, depending on the severity. If you observe any behavioral changes, or if the condition does not improve, please contact your veterinarian.

› It is mandatory to provide a stress-free environment for your dog. Keep water and food bowls within reach. Avoid physical activity. Keep your dogs away from any noise and commotions.
› You have to administer and monitor all prescribed medicine as directed by your veterinarian.
› Do NOT travel with your dog.
› Do NOT allow your dog to roam freely. This works two ways, firstly if the cat is infected, it greatly reduces the chances of risk of exposure to other pets and humans and secondly in-case of a healthy pet, it reduces the chances of contracting the infection.
› Use of environmental disinfectants is recommended. Prompt disposal of any and all materials after use is suggested.
› Routine and regular checkups to access the progress. Monitor and administer all medications as directed by your veterinarian and complete the dosage.
› Humans, especially children, pregnant women and ones handling infected pets need to exercise caution. Wear gloves when dealing with a pet, cleaning the litter boxes, disposing any and all contaminated materials, garbage disposals etc. A thorough wash of hands is advised. Practice hygiene.

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