Pemphigus in Dogs: Autoimmune Blistering Skin Disease

By Emiel Maddens  ·  Reviewed in consultation with licensed veterinary professionals  ·  Updated June 2026  ·  10 min read

Photo by Anya Prygunova on Unsplash

Pemphigus is a group of autoimmune skin diseases in which the body's immune system mistakenly produces antibodies against desmoglein and other desmosomal proteins that bind adjacent keratinocytes together in the epidermis. When these intercellular connections are disrupted, the skin cells separate from each other, a process called acantholysis, leading to blister formation, pustules, erosions, and crusting. Pemphigus foliaceus is by far the most common form in dogs, accounting for more than 90 percent of canine pemphigus cases.

The disease can be distressing for both dogs and their owners. The pustules and erosions often appear on the face, ears, and footpads, and the secondary crusting and scaling can be severe. Because the lesions resemble bacterial infection, many dogs are initially treated with antibiotics before the autoimmune nature of the disease is recognized. Correct diagnosis requires a skin biopsy, and effective treatment requires immunosuppressive medications that carry their own risks and side effects.

This guide provides a thorough overview of pemphigus in dogs, from the underlying immunology to practical management strategies that help affected dogs maintain a good quality of life.

Types of Pemphigus in Dogs

Pemphigus Foliaceus

Pemphigus foliaceus (PF) is the most common autoimmune skin disease in dogs and the form that veterinarians encounter most frequently. In PF, autoantibodies target desmoglein-1, a desmosomal glycoprotein in the superficial epidermis. This produces acantholysis in the upper layers of the skin, creating fragile pustules that quickly rupture and form adherent yellowish-brown crusts. Common locations include the dorsal muzzle, periocular skin, ear pinnae, and footpads. As the disease progresses, lesions may become generalized, spreading to the trunk, axillae, and groin. Footpad involvement, presenting as hyperkeratosis, fissuring, and pain, is a particularly characteristic finding in canine PF.

Pemphigus Vulgaris

Pemphigus vulgaris (PV) is much rarer than PF in dogs but is more severe. Autoantibodies in PV target desmoglein-3, which is located in the deeper layers of the epidermis and in mucous membranes. This produces deeper acantholysis, larger blisters, and more extensive erosions. The oral cavity is commonly affected, with painful ulcers on the gums, palate, and tongue that make eating difficult. Cutaneous lesions tend to occur at mucocutaneous junctions and areas of friction. PV carries a more guarded prognosis than PF because of its severity and the aggressive immunosuppression required for control.

Other Variants

Pemphigus erythematosus is considered a mild, localized variant of PF that primarily affects the nose, nasal planum, and periocular skin. It has features overlapping with lupus erythematosus and generally carries a better prognosis than classic PF. Pemphigus vegetans is an extremely rare variant characterized by proliferative, vegetating lesions rather than typical pustules and erosions. Paraneoplastic pemphigus, associated with internal malignancies, is exceedingly rare in dogs but has been reported in association with lymphoma and thymoma.

Clinical Signs and Breed Predispositions

What Pemphigus Looks Like

The primary lesion of pemphigus foliaceus is a superficial pustule, but because these are fragile and rupture quickly, the most commonly observed findings are thick, adherent, yellowish-brown crusts overlying erosions and erythema. Lesions often begin on the face, particularly the dorsal muzzle and bridge of the nose, the periocular skin, and the inner surface of the ear pinnae. Footpad involvement produces thick, fissured, painful hyperkeratotic pads that may cause lameness. As the disease progresses, lesions spread to the trunk, ventral body, and extremities. Pruritus is variable, ranging from minimal to severe, and secondary bacterial infection frequently complicates the clinical picture.

Breed Predispositions

Certain breeds are overrepresented among dogs with pemphigus foliaceus. Akitas, Chow Chows, Labrador Retrievers, Dachshunds, Bearded Collies, Newfoundlands, Schipperkes, and English Springer Spaniels show increased incidence. The breed predisposition suggests a genetic component to disease susceptibility, likely involving major histocompatibility complex genes and other immune regulatory loci. Any breed can develop pemphigus, however, and mixed-breed dogs are not exempt. The typical age of onset is four to nine years, although cases have been reported in dogs as young as one year.

Drug-Triggered Pemphigus

In some cases, pemphigus develops following administration of certain medications. Documented drug triggers include trimethoprim-sulfamethoxazole, cephalosporins, and topical flea preventatives. Drug-triggered pemphigus may resolve after discontinuation of the offending medication, or it may persist and require immunosuppressive treatment. A careful medication history should be obtained for any dog newly diagnosed with pemphigus, as identifying and eliminating a drug trigger can significantly alter the treatment approach and prognosis.

Pemphigus foliaceus produces characteristic crusting and pustular lesions, most commonly on the face and footpads.

Photo by Mikhail Nilov on Pexels

Diagnosis: Why Biopsy Is Essential

The Limitations of Clinical Diagnosis

Pemphigus foliaceus can closely resemble other conditions including bacterial pyoderma, dermatophytosis, demodicosis, and drug eruptions. The pustular, crusting lesions are not specific enough for a definitive diagnosis based on clinical appearance alone. Many dogs are treated empirically for bacterial infection before pemphigus is considered, and some respond partially to antibiotics because of secondary bacterial infection overlying the autoimmune disease. This partial response can delay correct diagnosis by weeks or months.

Cytology as a Screening Tool

Impression cytology from a ruptured pustule or the underside of a lifted crust can provide supportive evidence for pemphigus. The hallmark cytological finding is acantholytic keratinocytes, which are large, round, darkly staining epithelial cells surrounded by clusters of neutrophils (rafts of acantholytic cells). While this finding is suggestive, it is not pathognomonic, as acantholytic cells can occasionally be seen in severe bacterial infections. Cytology is most useful as a rapid screening test that raises suspicion and prompts a biopsy referral.

Histopathology: The Gold Standard

Definitive diagnosis of pemphigus requires skin biopsy with histopathological examination by a veterinary dermatopathologist. Biopsy specimens should be taken from the freshest, most intact lesions available, ideally an intact pustule. The classic histological finding is subcorneal or intragranular acantholysis with neutrophilic infiltration. Acantholytic cells floating within the pustule cavity are characteristic. Direct immunofluorescence testing can detect antibody deposition at the intercellular spaces of the epidermis, providing additional confirmation. Multiple biopsy specimens from different lesion stages improve diagnostic accuracy.

Ruling Out Differential Diagnoses

The biopsy workup should include bacterial and fungal cultures, skin scrapings for mites, and special stains to rule out infectious causes. Dermatophytosis and demodicosis can produce acantholytic changes that mimic pemphigus histologically, so these must be excluded before an autoimmune diagnosis is confirmed. Drug history review is essential to evaluate the possibility of drug-triggered disease. Only after infectious and drug-related causes have been excluded can a definitive diagnosis of autoimmune pemphigus be made.

Treatment: Immunosuppressive Therapy

Glucocorticoids as Induction Therapy

Systemic glucocorticoids, typically prednisone or prednisolone, are the first-line treatment for pemphigus foliaceus. Induction doses of 2 to 4 mg/kg/day (divided twice daily for the first two weeks) are used to bring the disease under control, with response typically seen within one to three weeks. Once lesions are controlled, the dose is gradually tapered over weeks to months to the lowest effective maintenance dose. Many dogs require lifelong low-dose glucocorticoid therapy, and side effects including polyuria, polydipsia, polyphagia, weight gain, panting, and increased infection risk must be monitored and managed.

Steroid-Sparing Immunosuppressants

Because of the significant side effects of chronic glucocorticoid therapy, steroid-sparing agents are commonly added to allow glucocorticoid dose reduction. Azathioprine is the most commonly used adjunctive immunosuppressant in dogs, typically started simultaneously with glucocorticoids. It takes two to four weeks to reach full effect, after which the glucocorticoid dose can be tapered more aggressively. Mycophenolate mofetil is an alternative with a potentially more rapid onset. Cyclosporine has been used in some cases but is generally considered less effective for pemphigus than for atopic dermatitis. Chlorambucil, a low-dose alkylating agent, may be considered for cases refractory to azathioprine.

Monitoring During Immunosuppressive Therapy

Dogs receiving immunosuppressive therapy require regular laboratory monitoring. A complete blood count should be checked every two weeks initially, then monthly, to monitor for azathioprine-induced bone marrow suppression. Liver enzymes should be monitored regularly, as both glucocorticoids and azathioprine can cause hepatotoxicity. Urinalysis monitors for urinary tract infections, which are more common in immunosuppressed patients. Regular skin cytology confirms ongoing disease control and detects secondary infections early.

Managing Secondary Infections

The immunosuppressive therapy required to control pemphigus paradoxically increases the risk of secondary bacterial and fungal skin infections. Dogs on immunosuppressive protocols should receive regular topical antiseptic care with chlorhexidine spray or medicated shampoo to reduce the microbial burden on their compromised skin. Any sudden worsening of skin lesions during treatment should prompt cytology to differentiate a pemphigus flare from secondary infection, as the treatments differ markedly: a flare requires increased immunosuppression, while an infection requires antimicrobial therapy.

Prognosis and Long-Term Outlook

Response Rates and Remission

The majority of dogs with pemphigus foliaceus respond to immunosuppressive therapy, with studies reporting clinical improvement in 70 to 90 percent of cases. Complete remission, defined as resolution of all active lesions, is achieved in approximately 50 to 70 percent of treated dogs. However, most dogs require ongoing maintenance therapy to prevent relapse. A minority of dogs, estimated at 10 to 20 percent, achieve durable remission off all medication, a state called complete drug-free remission. The likelihood of achieving this varies by severity and breed.

Relapse and Disease Flares

Relapses are common in pemphigus and can be triggered by stress, intercurrent illness, drug withdrawal, or vaccination. Rapid taper of immunosuppressive medication is a frequent cause of relapse and should be avoided. When a flare occurs, temporary dose escalation usually regains control, but each flare increases the cumulative drug exposure and associated side effects. Identifying and minimizing triggers, maintaining consistent medication schedules, and monitoring closely during high-risk periods help reduce relapse frequency.

Quality of Life Considerations

Most dogs with well-managed pemphigus foliaceus enjoy a good quality of life. The side effects of medications, particularly glucocorticoids, are often the primary concern for long-term quality. Weight management, controlled exercise, and dietary optimization help mitigate some glucocorticoid side effects. Footpad involvement may require ongoing management with moisturizing balms and padded surfaces. Regular veterinary rechecks ensure that the treatment regimen is optimized for both disease control and minimal side effects.

Living with a Dog with Pemphigus

Daily Care Routines

Dogs with pemphigus benefit from gentle daily skin care. Crusts can be softened with warm water compresses and gently removed, as accumulated crust traps bacteria and promotes secondary infection. Topical chlorhexidine applied to affected areas after crust removal helps control surface bacteria. Avoid harsh grooming or bathing that could traumatize fragile skin. Protect footpads with dog boots during walks on rough or hot surfaces if pad involvement is present.

Vaccination Considerations

Vaccination has been reported as a trigger for pemphigus flares in some dogs. Decisions about vaccination should be made in consultation with both the primary care veterinarian and the dermatologist. Titer testing to assess existing immunity may allow deferral of non-essential boosters. Core vaccinations for rabies are legally required in most jurisdictions, and accommodations such as pre-treatment with increased immunosuppressive doses around vaccination time may be considered for dogs with vaccine-triggered flares.

Emotional Support for Owners

Managing a chronic autoimmune disease is emotionally challenging for pet owners. The unpredictability of flares, the complexity of medication schedules, the side effects of treatment, and the financial burden of ongoing veterinary care all contribute to caregiver stress. Support groups, both online and through veterinary school dermatology services, can provide valuable peer support and practical advice. Open communication with your veterinary team about concerns, expectations, and financial constraints helps build a sustainable long-term management plan.

Pemphigus in Dogs FAQ

Q: What is pemphigus foliaceus in dogs?

Pemphigus foliaceus is the most common autoimmune skin disease in dogs. The immune system produces antibodies against desmoglein-1, a protein that holds skin cells together in the upper epidermis. This causes the cells to separate (acantholysis), leading to pustule formation, erosions, and thick adherent crusts, most commonly on the face, ears, and footpads.

Q: How is pemphigus diagnosed?

Definitive diagnosis requires skin biopsy with histopathological examination by a veterinary dermatopathologist. The characteristic finding is subcorneal acantholysis with neutrophilic pustule formation. Cytology showing acantholytic keratinocytes surrounded by neutrophils supports the diagnosis but is not sufficient alone. Bacterial and fungal cultures help rule out infectious causes.

Q: Can pemphigus be cured?

Pemphigus cannot be cured in most dogs, but it can usually be well-controlled with immunosuppressive therapy. Approximately 50 to 70 percent of dogs achieve clinical remission on medication, and 10 to 20 percent may eventually achieve drug-free remission. Most dogs require lifelong low-dose immunosuppressive therapy to prevent relapse.

Q: What are the side effects of pemphigus treatment?

The primary medications, glucocorticoids and azathioprine, carry significant side effects. Glucocorticoids cause increased thirst, urination, appetite, weight gain, panting, and increased infection risk. Azathioprine can cause bone marrow suppression and liver toxicity. Regular blood work monitoring is essential to detect and manage these side effects early.

Q: Is pemphigus contagious?

No. Pemphigus is an autoimmune disease, not an infectious disease. It cannot be transmitted between dogs or from dogs to humans. The immune system mistakenly attacks the body's own skin proteins. While the secondary bacterial infections that can accompany pemphigus involve transmissible bacteria, the underlying disease itself is not contagious.

Sources

Olivry, T. (2006). A review of autoimmune skin diseases in domestic animals: I. Superficial pemphigus. Veterinary Dermatology, 17(5), 291-305.

Bizikova, P., et al. (2015). Review: clinical and histological manifestations of canine pemphigus foliaceus. Veterinary Dermatology, 26(2), 67-e19.

Mueller, R.S., et al. (2006). Treatment of pemphigus foliaceus and pemphigus erythematosus in dogs with azathioprine and glucocorticoids. Veterinary Record, 159(17), 533-536.

Rosenkrantz, W. (2004). Pemphigus: current therapy. Veterinary Dermatology, 15(2), 90-98.

Gomez, S.M., et al. (2004). An unusual presentation of canine pemphigus foliaceus. Veterinary Dermatology, 15(1), 44-49.

Related Reading

• Discoid Lupus in Dogs, Another autoimmune skin disease that affects the nose and face
• Pyoderma in Dogs, Understanding the secondary infections that complicate autoimmune skin disease
• When to See a Veterinary Dermatologist, Complex skin diseases that benefit from specialist care
• Managing Multiple Skin Conditions, Balancing autoimmune disease treatment with infection control

Emiel Maddens

Founder of Vetified. Develops topical antifungal and antimicrobial formulations for companion animals. Vetified products are listed on DailyMed and manufactured through FDA-registered facilities in the United States.