Ringworm In Dogs & Cats: Signs, Symptoms & Treatment

Ringworm is one of the most common skin infections diagnosed in both dogs and cats. Despite its name, ringworm isn’t caused by worms it’s a fungal infection that affects the skin, hair and nails of pets and can easily spread to people.

Understanding what ringworm looks like, how it spreads and how to treat it can help protect your entire household.

To support your learning, this article includes clear images to help you recognise ringworm early.

Understanding Ringworm in Pets

What Ringworm Actually Is

Ringworm is a contagious fungal infection caused by dermatophytes fungi that live on the skin surface. The most common species are:

• Microsporum canis
• Microsporum gypseum
• Trichophyton mentagrophytes

These fungi thrive in warm, humid environments and can survive for months on surfaces, bedding and grooming tools.

How Ringworm Spreads

Ringworm spreads through:

• Direct contact with an infected pet
• Contaminated environments (furniture, bedding, carpets, brushes)
• Shared spaces like shelters or grooming rooms

Because the fungus sheds through hair and skin flakes, even mild infections can contaminate large areas.

Risk Factors

Your pet is more likely to get ringworm if they are:

• Young (puppies & kittens)
• Elderly
• Long-haired
• Living in multi-pet homes
• Under stress
• Immunocompromised

Identifying Ringworm: Signs & Symptoms

For visual clarity, here are real-world examples of what ringworm looks like in pets:

Early Symptoms in Dogs

Dogs may show:

• Circular patches of hair loss
• Red, scaly skin
• Brittle or broken hair
• Itching (but not always)
• Darkened or crusty patches

Early Symptoms in Cats

Cats often show:

• Small circular bald spots
• Grey, scaly dry skin
• Broken whiskers
• Patchy coat
• Mild itchiness
• Sometimes NO visible symptoms (common in kittens)

Advanced Symptoms

If untreated, signs may progress to:

• Widespread hair loss
• Severe crusting
• Oozing lesions
• Thickened skin
• Secondary bacterial infections

Cats especially long-haired breeds may hide symptoms until the infection is widespread.

Causes of Ringworm in Dogs & Cats

Fungal Species

Different fungi cause ringworm, and cats are most often infected by Microsporum canis which spreads easily across pets and humans alike.

Environmental Causes

The fungus can survive 12-18 months in:

• Bedding
• Carpet
• Furniture
• Grooming tools

Zoonotic Risk

Ringworm is zoonotic, meaning:

• Pets → humans
• Humans → pets
• Pets → pets

Children, elderly individuals, and immunocompromised adults are higher-risk.

Diagnosing Ringworm

Vets use multiple tools to diagnose ringworm accurately.

Wood’s Lamp Examination

A special UV lamp that may show a yellow-green fluorescence on infected hairs though not all fungi glow.

Fungal Culture

The gold standard. Hairs are placed in a culture medium to confirm fungal growth.

PCR Testing

Quick, highly accurate test detecting fungal DNA.

Treatment Options for Dogs & Cats

Topical Treatments

Vets may prescribe:

• Antifungal shampoos
• Lime sulfur dips
• Medicated creams or ointments

These reduce surface fungi and limit spread.

Oral Medications

For more severe cases:

• Itraconazole
• Terbinafine
• Griseofulvin

These target fungal infection from within.

Environmental Cleaning

A MUST to prevent reinfection:

• Wash bedding in hot water
• Vacuum carpets & upholstery daily
• Disinfect surfaces with veterinary-recommended products
• Dispose of shed hair promptly

How Long Treatment Takes

Treatment typically takes:

• 4-8 weeks for mild cases
• 12+ weeks for severe infections

Patience and consistency are key.

Preventing Ringworm Spread in Multi-Pet Homes

Isolation Steps

Keep infected pets in a separate room if possible.

Cleaning & Disinfection

Clean high-touch surfaces:

• Floors
• Couches
• Pet bedding
• Litter boxes
• Grooming combs

Monitoring Other Pets

Check for:

• New bald spots
• Scaling
• Itching

Early detection prevents outbreaks.

When to See a Vet

Seek veterinary care if:

• Your pet has spreading bald patches
• The infection worsens despite treatment
• You have multiple pets
• A person in your home develops a rash

Children are especially vulnerable, so early treatment protects the whole family.

FAQs

1. Is ringworm painful?

Usually no but it may become itchy or inflamed.

2. Can ringworm go away on its own?

Rarely. Most pets need vet-directed treatment.

3. Can humans catch ringworm from pets?

Yes it is zoonotic.

4. How long until my pet is no longer contagious?

Usually after 1-2 weeks of consistent treatment, but depends on severity.

5. Should I shave my pet?

Only under veterinary direction shaving can worsen inflammation.

Conclusion

Ringworm in dogs & cats is highly contagious but very treatable with proper care. Early detection, good hygiene, and vet-approved medications are essential for clearing the infection and protecting your household.

If you suspect ringworm, contact your veterinarian promptly to prevent spread and speed recovery.