Dermatophytosis in Animals (Ringworm)

Dermatophytosis in Animals (Ringworm)
By DVM. Supawan Srivises (Dr. Bud)

1. Introduction (บทนำ) Dermatophytosis is a fungal infection of the keratinized tissues, including the skin, hair, and claws. It is one of the most common skin diseases in pets such as dogs, cats, and small mammals (like rabbits and guinea pigs). Crucially, it is a zoonotic disease, meaning it can be transmitted from animals to humans.

2. Causes (สาเหตุ) The infection is caused by fungi known as "Dermatophytes." The most common species found in pets include:

Microsporum canis (most common in cats and dogs)
Microsporum gypseum (found in soil)
Trichophyton mentagrophytes (often carried by rodents)
3. Transmission (การติดต่อ)

Direct Contact: Touching an infected animal.
Indirect Contact: Contact with contaminated environments, bedding, grooming tools, or furniture. Fungal spores (arthrospores) can survive in the environment for many months.
4. Clinical Signs (อาการทางคลินิก) Symptoms can vary but typically include:

Circular patches of hair loss (alopecia).
Redness of the skin (erythema).
Crusting and scaling.
Itching (pruritus), which can range from mild to severe.
Brittle or broken hair shafts.
5. Diagnosis (การวินิจฉัย) Veterinarians use several methods to confirm the infection:

Wood’s Lamp Examination: Using UV light to see if the fungus fluoresces (glows apple-green).
Trichogram: Microscopic examination of the hair.
Fungal Culture (DTM): Placing samples on a special medium to observe fungal growth and color change.
Biopsy/PCR: In complex cases.
6. Treatment (การรักษา) Treatment usually requires a combination of:

Topical Therapy: Antifungal shampoos, creams, or lime sulfur dips to kill spores on the coat.
Systemic Therapy: Oral antifungal medications (prescribed by a vet) for a period of several weeks.
Environmental Cleaning: Disinfecting the house to prevent re-infection.
7. Prevention and Control (การป้องกัน)

Keep your pet's living area clean and dry.
Regularly wash bedding and grooming tools.
If a pet is infected, isolate them from other animals and children.
Wash your hands thoroughly after handling pets.

โรคเชื้อราผิวหนัง
(Dermatophytosis in animals)

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