🧬 Vet Guide 2025: Pemphigus Foliaceus in Dogs and Cats – Autoimmune Skin Disease Explained 🐶🐱

By Dr Duncan Houston, BVSc

Pemphigus foliaceus (PF) is an autoimmune skin disease that affects dogs and cats. While rare, it's one of the most commonly diagnosed autoimmune skin conditions in veterinary dermatology. It causes painful sores, scabs, and pustules—especially on the face, ears, and paws. In this 2025 guide, we’ll explore what PF is, how it’s diagnosed, and how it’s treated long term. 🐾

🔬 What Is Pemphigus Foliaceus?

PF is an autoimmune disorder—meaning the immune system mistakenly attacks the body’s own tissues. In this case, it targets the skin, particularly the structures holding skin cells together. The result is the formation of pustules (pimples) and crusts, which can rupture and leave open sores. 😣

• 🧠 PF is not contagious
• 🧬 Affects the skin and sometimes nails (especially in cats)
• 📈 Often appears suddenly and worsens without treatment

🐕🐈 Who Gets Pemphigus Foliaceus?

PF can occur in any breed of dog or cat, though it is more frequently diagnosed in:

• 📅 Middle-aged to older pets
• 🐶 Dogs with facial pustules or limb lesions
• 🐱 Cats with nail bed crusting or pus around claws

It also occurs in other species like horses, goats, and humans, but this guide focuses on dogs and cats. 🐾

📍 What Does PF Look Like?

Common Signs Include:

• 🩹 Pustules (pimples filled with pus)
• 🌕 Yellow scabs and crusts
• 🔴 Sores and hair loss
• 🐾 Limping or paw pain if the paws are affected
• 🤒 Fever or lethargy

In dogs and cats, lesions most often affect the:

• 👃 Nose and muzzle
• 👂 Ears and ear flaps
• 🐾 Paws
• 🦴 Back and legs

In cats, nail beds may ooze pus or crust over. PF is often itchy, though not always. 🎯

🔎 Diagnosing Pemphigus Foliaceus

Because PF looks like other skin diseases—like bacterial infections, ringworm, or mange—your vet will need to perform tests to confirm it. 🧪

Common Diagnostic Tools:

• 🔬 Skin Cytology: Checks for bacteria, yeast, or Demodex mites
• 🧫 Skin Biopsy: Confirms autoimmune activity by examining deeper skin layers

Only a biopsy can confirm PF. Your vet may also do bloodwork and skin cultures to rule out infection. 📋

💊 Treating Pemphigus Foliaceus

PF requires immunosuppressive treatment to stop the immune system from attacking the skin. Treatment is lifelong for most pets, though some may eventually taper off meds. 💉

Common Medications:

• 💊 Corticosteroids: Prednisone or dexamethasone are first-line treatments to stop inflammation fast
• 💊 Immunosuppressants: Azathioprine, cyclosporine, mycophenolate mofetil (used in difficult cases)
• 🧼 Antibiotics or antifungals: Used if secondary infections are present

⚠️ Close monitoring and dose adjustments are essential to reduce side effects. Frequent rechecks are a must. 🔁

📅 How Long Will Treatment Last?

Most pets will need to stay on medication long term. Some may reach remission and taper down, while others need consistent therapy to stay comfortable. 💡

Expect:

• 📅 Regular veterinary visits every 2–4 weeks early on
• 🩸 Occasional bloodwork to monitor for medication side effects
• 🛡️ Lifelong skin protection and parasite prevention

📲 Ask A Vet for Skin Support

If your dog or cat has crusty skin, sores, or an undiagnosed skin issue, AskAVet.com can help. 🩺

With the Ask A Vet App, you can:

• 📸 Send images of your pet’s skin
• 💬 Ask about biopsy or treatment plans
• 📅 Get medication reminders and follow-up tips

📝 Final Thoughts

Pemphigus foliaceus is a serious but manageable condition with proper veterinary care. Early diagnosis and a strong treatment plan are essential to reduce pain and improve quality of life. If you suspect PF, consult your vet or connect with Ask A Vet to get answers quickly and compassionately. 🐶🐱