Dermatophytosis (Ringworm)
Learn what the condition is, how it may be detected early, how it is treated or managed, and which breeds or species are linked to it.
Condition snapshot
A concise guide to the condition’s pattern, detection, management and urgency.
Human-health precautions may applyFollow veterinary and public-health hygiene advice, especially for pregnant or immunocompromised people.
Limit spread while seeking adviceSeparate affected animals when practical and obtain veterinary guidance on contacts, cleaning and return to normal mixing.
This snapshot is a general guide, not a diagnosis or treatment plan. New, severe or worsening signs require veterinary assessment.
About the condition
Dermatophytosis, commonly called ringworm, is a fungal infection of keratinised tissues including hair, the superficial skin layer and claws. Despite the name, no worm is involved. In cats, Microsporum canis is a particularly important cause. Kittens, long-haired cats, stressed animals and cats living in crowded environments are at increased risk.
Lesions vary widely. Some cats develop circular areas of hair loss, scale, broken hairs or crusting, while others have only subtle coat changes. The face, ears and forelimbs are common sites. Long-haired cats can carry infection with minimal visible lesions and spread fungal spores into the environment.
Ringworm is contagious to other cats, dogs and people. Transmission occurs through direct contact and contaminated hairs or environmental material. Spores can persist for months, which is why household cleaning matters as much as treating the visible lesions.
The infection is often self-limiting in healthy cats, but waiting for spontaneous resolution allows ongoing environmental contamination and human exposure. Successful control combines systemic antifungal therapy, topical treatment and environmental decontamination rather than relying on one element alone.
Because infected hairs act like tiny carriers of spores, apparent cure of the skin lesion is only part of control. A cat can look much better while contaminated hair remains in bedding, carpet or grooming equipment. Environmental reduction of spore load is therefore a practical part of treatment, not simply extra housekeeping.
Unexplained patchy hair loss, scale, crusting and broken hairs are common feline ringworm presentations, particularly after shelter or multi-cat exposure. Because some infected cats show minimal lesions, contact history is important. Long-haired cats can be particularly difficult to assess visually. Its zoonotic importance means infection can affect human household members as well as animal contacts.
Screening & Early Detection
A Wood’s lamp can be a useful rapid screening tool for certain strains of Microsporum canis when used correctly. Fluorescing hairs should be examined or sampled rather than assuming that any skin fluorescence confirms ringworm. Fungal culture, PCR and microscopic examination provide stronger diagnostic evidence.
In group housing, screening may include examination of all cats and targeted culture or PCR because asymptomatic carriers can maintain an outbreak. Environmental sampling may be used during outbreak control to judge contamination rather than to diagnose an individual cat in isolation.
Early feline diagnosis limits exposure and prevents months of repeated reinfection. A cat should not be declared clear solely because the coat looks normal; the veterinarian may recommend follow-up testing depending on the diagnostic method and household risk.
Diagnosis cannot be made reliably from appearance alone because mites, bacterial infection, allergy and other skin diseases can look similar. Wood’s lamp examination can identify fluorescence in some M. canis infections, but not all. Microscopic hair examination, fungal culture and PCR are used to confirm infection and monitor selected cases.
Treatment & Management
Treatment generally combines systemic and topical antifungal therapy. Oral drugs such as itraconazole are commonly used because infection involves hair follicles that topical products alone may not reach reliably. Lime sulfur rinses or other veterinarian-recommended topical treatments help reduce spores on the coat and environmental shedding.
Clipping may be considered in selected long-haired cats with extensive disease, but close shaving can cause skin trauma and spread contaminated hairs if performed poorly. Treatment duration is guided by clinical response and, in many cases, repeat fungal testing rather than a fixed number of days.
Environmental control is essential. Loose hair should be removed by frequent vacuuming, washable bedding cleaned appropriately and hard surfaces disinfected with a product effective against dermatophyte spores. Overcrowding should be reduced and infected cats separated where practical, while still providing adequate social and environmental welfare.
Most healthy cats recover well, but treatment can take several weeks. Failure often reflects inadequate environmental cleaning, poor medication adherence, reinfection or an unrecognised carrier. Because ringworm is zoonotic, gloves and hand hygiene are sensible during treatment, especially for children or immunocompromised household members.
Treatment is therefore usually recommended, especially in multi-pet households.
Breeds or species affected
Abyssinian
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American Bobtail
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American Curl
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American Shorthair
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American Wirehair
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Arabian Mau
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Aegean
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Australian Mist
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Balinese
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Bengal
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Birman
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Bombay
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British Longhair
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British Shorthair
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Burmese
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Burmilla
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Chartreux
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Chausie
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Colorpoint Shorthair
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Cornish Rex
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Cymric
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Devon Rex
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Domestic Longhair
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Domestic Medium Hair
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Domestic Shorthair
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Donskoy
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Egyptian Mau
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European Shorthair
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Exotic Shorthair
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Havana Brown
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Highlander
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Himalayan
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Japanese Bobtail
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Khao Manee
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Korat
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Kurilian Bobtail
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LaPerm
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Lykoi
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Maine Coon
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Manx
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Minuet
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Minskin
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Munchkin
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Nebelung
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Norwegian Forest Cat
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Ocicat
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Oriental Longhair
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Oriental Shorthair
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Persian
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Peterbald
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Pixiebob
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RagaMuffin
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Ragdoll
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Russian Blue
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Savannah
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Scottish Fold
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Scottish Straight
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Selkirk Rex
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Siamese
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Siberian
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Singapura
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Snowshoe
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Somali
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Sphynx
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Thai
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Tonkinese
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Toybob
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Toyger
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Turkish Angora
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Turkish Van
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Bambino
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Cheetoh
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Dwelf
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Elf Cat
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Genetta
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Kinkalow
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Lambkin
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Serengeti
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Skookum
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Ukrainian Levkoy
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