Methods for determining and treating the type of pemphigus in dogs. Pemphigus vulgaris in dogs and cats

Diseases of the pemphigus complex or pemphigus arise as a result of the formation of autoantibodies directed against the epidermal intercellular contents, which leads to separation of cells with the formation of intraepidermal vesicles. The deposition of antibodies promotes physical separation of cells; In addition, it is believed that there is a release of cellular proteases that digest the intercellular substance, further aggravating the pathological condition. Among the forms of pemphigus seen in dogs and cats are - pemphigus erythematosus, pemphigus vulgaris, pemphigus vegetans and pemphigus foliaceus, the latter being the most common autoimmune skin disease in these species, which will be discussed in this article.

Pemphigus Complex Diagnosis in Dogs and Cats

Pemphigus type Pemphigus foliaceus it is more common in middle-aged animals, especially in domestic shorthair cats and in some predisposed breeds of dogs such as the Bearded Collie, Japanese Akitu, Chow Chow, Doberman Pinscher and Newfoundland. It is a vesico-bubbly, erosive dermatitis that causes marked hyperkeratosis in the extremities. Often the muzzle, trunk and abdomen are affected. Pustules, crusting lesions, erythema, alopecia, and secondary pyoderma may also be present. In severe cases pemphigus of dogs and cats cachexia and sepsis may occur secondary to infection.

When present, pustular lesions in canine and feline pemphigus can be evaluated cytologically and non-degenerated granulocytes and acanthocytes can be identified. In pemigus of dogs and cats, intraepidermal and intrafollicular pustules are observed histologically with the presence of superficial perivascular dermatitis and the presence of acanthocytes. The histological presence of acantholysis in dogs and cats with symptoms of pemphigus is a hallmark of the pemphigus complex.

Therapy for dogs and cats with pemphigus

Therapy requires the use of immunosuppressants or immunomodulators. Prednisolone, prednisolone, and methylprednisolone are widely used to treat pemphigus. An initial dose of 2.2 to 4.4 mg/kg every 24 hours is recommended for all three drugs. If the therapeutic response is clearly visible after 14 days, the dosage should be gradually reduced over 30-40 days. Thereafter, a dose of glucocorticoid should be applied every other day, reaching a final protocol of 1 mg/kg every 48 hours, or try to prescribe a lower dose of the hormone. In case of resistant cases of pemphigus in dogs, the use of prednisolone can be combined with azathioprine (2.2 mg/kg every 12 or 24 hours) or cyclophosphamide (50 mg/m2 every 48 hours). Feline pemphigus usually responds well to prednisolone, although a combination of prednisolone and chlorambucil (0.1-0.2 mg/kg every 24 hours or every other day) may be used in resistant cases. Topical glucocorticoids can be used as a single therapy, in localized forms of pemphigus, or used for permanent lesions, as adjunct therapy to systemic treatment. Deaths in cases of pemphigus foliaceus are mainly due to side effects of drugs, secondary infections, or in many cases, the pet owner requires euthanasia.

Pemphigus foliaceus is an autoimmune skin disease characterized by the production of autoantibodies to antigens of skin components and acantholysis. The disease is also idiopathic, but it is likely to develop against the background of induction with various drugs or against the background of chronic inflammatory dermatoses.

Pemphigus foliaceus is the most common form of pemphigus complex disease and the most common autoimmune disease in dogs and cats in general. In dogs, the disease is more common in the elderly and middle age, but it is likely to occur at any age from 3 months. A predisposition has been revealed in such breeds of dogs as Chow Chow and Akita. In cats, the median age of onset is 5 years, but as in dogs, clinical signs are likely to appear at any age.

Clinical signs

In dogs, papules and pustules initially appear, which are difficult to detect intact due to the rich coat and fragility of the primary lesions. Secondary lesions are characterized by the formation of erosions, yellow crusts, epidermal collars and areas of hair loss (alopecia). The development of symptoms can be rapid (1-2 weeks) or gradual (from a month onwards), with the rapid development of the disease, manifestations of systemic signs (eg depression, fever, anorexia, lymphadenopathy) are likely.

In dogs, the characteristic localization of the lesions is the dorsum of the nose, nasal mirror, eyelids, ears, pads of the fingers, and the ventral surface of the abdomen. The disease often begins with the back of the nose, around the eyes and on the auricle, and subsequently becomes more generalized. In the later stages, depigmentation of the nose is likely to develop. Lesions of the oral cavity and mucocutaneous junction are not typical for pemphigus foliaceus. A characteristic feature of pemphigus foliaceus, however, as well as other autoimmune skin diseases, is the strict symmetry of the lesions.

In cats, the primary lesions appear as pustules, but the most characteristic initial sign is the formation of yellow crusts around the nose and ears. Approximately 30% of cases develop a lesion around the claw bed with the formation of refractory paronychia. The abdomen and thighs are affected in about 10% of cases, with the development of characteristic lesions around the nipple. As in dogs, the disease is characterized by symmetrical lesions.

Diagnosis

A presumptive diagnosis of a high degree of probability is characteristic clinical manifestations and the consistent exclusion of diseases from the list of differential diagnoses. Detection of acanthocytes during cytological examination of intact pustules is extremely characteristic of pemphigus foliaceus. To make a definitive diagnosis, a pathomorphological study is likely to be performed, which reveals subcorneal pustules with acanthocytes, neutrophils, and varying numbers of eosinophils.

It is possible to carry out such research methods as the identification of antinuclear antibodies, immunofluorescence or immunohistochemistry, but they play only an auxiliary role.

Differential Diagnosis

Demodicosis.
Bacterial pyoderma.
Dermatophytosis.
Erythematous pemphigus.
Systemic and discoid lupus erythematosus.
.

Eosinophilic pustulosis.
Drug rash.
Zinc resistant dermatosis.
.
Superficial necrolytic migratory erythema.
(cats).

Treatment

The basis of therapy is the appointment of immunosuppressive doses of prednisone. The initial dose of prednisolone is 2-6 mg / kg per day for 10-14 days, then the dose is gradually reduced over 30-40 days. The initial dose and the duration of achieving remission can vary significantly depending on the individual characteristics of the animal. Alternative corticosteroids with poor efficacy of prednisolone are triamcinolone and dexamethasone. The final goal of treatment is to switch to the regimen of giving the drug every other day at a dose of 1 mg / kg.

In dogs, in the case of an inadequate response to monotherapy with corticosteroids, azathioprine is added to the treatment regimen. Upon reaching control over clinical manifestations, the dosage of drugs is gradually reduced to the minimum and giving drugs every other day (prednisolone day, azathioprine day). Of the other non-steroidal immunosuppressive drugs, chlorambucil, cyclophosphamide, and cyclosporine are likely to be used in dogs. In cats, the use of the above drugs should be treated with great caution.

In both cats and dogs, treatments such as topical corticosteroid preparations and systemic antibiotics for secondary infections are likely.

In any particular case of pemphigus foliaceus, the physician must follow the principle that the treatment should not be worse than the disease itself. In some cases, instead of a significant increase in the dose of immunosuppressive drugs, preference is given to incomplete control of clinical manifestations.

Forecasts

In dogs, the prognosis is variable, in most cases it is possible to achieve a satisfactory quality of life with lifelong maintenance therapy, sometimes a complete remission is achieved, in some dogs it is not possible to achieve an adequate response to therapy and they are euthanized. In cats, the prognosis is closer to favorable, but lifelong maintenance therapy is required in most cases.

Photo 1. Skin lesions on the head of a one-year-old cat with pemphigus foliaceus.

Photo 2. Same cat, lesion on the skin of the abdomen around the nipple.

Valery Shubin, veterinarian, Balakovo

One of the reasons for the attack of the cells of the body by its own lymphocytes can be the similar structure of the cells of the body itself with the antigens of a bacterium or virus, i.e. the lymphocyte "confuses" its own cells with the antigens of infectious agents.

As a rule, the tendency to autoimmune pathology is genetic. Predisposing factors can be UV radiation, infections, uncontrolled and unreasonable use of immunostimulating agents, exposure to any chemicals.

The nature of autoimmune diseases in cats is not yet well understood. With pemphigus, disturbances in the functioning of the animal's immune system lead to an attack on its own cells of the epidermis. The destruction of skin cells and the release of their contents is clinically manifested by the formation of blisters.

One of the reasons for the attack of the cells of the body by its own lymphocytes can be the similar structure of the cells of the body itself with the antigens of a bacterium or virus, i.e. the lymphocyte "confuses" its own cells with the antigens of infectious agents.

The second reason may be a violation of screening of autoreactive lymphocytes at the stage of their maturation. If a lymphocyte at the stage of maturation is not able to distinguish host cells from foreign antigens, then such a lymphocyte must be destroyed. Sometimes the destruction mechanisms are violated.

Autoimmune antibodies: the body produces antibodies that attack healthy tissues and cells as if they were pathogenic.

Prolonged exposure to the sun.

Some breeds may have a hereditary predisposition.

Types of pemphigus

Four types of pemphigus are known to affect dogs: pemphigus foliaceus, pemphigus erythematous, pemphigus vulgaris, and pemphigus vegetative.

In pemphigus foliaceus, autoantibodies are located in the outermost layers of the epidermis and blisters begin to form on healthy skin. Erythematous pemphigus proceeds in almost the same way as leaf-shaped, but less painful.

Pemphigus vulgaris is characterized by the formation of deeper ulcers, as antibodies accumulate in the lower layers of the epidermis. As for vegetative pemphigus, it affects only dogs and is considered the rarest variety.

Vegetative pemphigus resembles pemphigus vulgaris, but is much milder with the formation of less painful ulcers.

Clinical signs

Since exfoliative pemphigus is most common in cats, we first look at the symptoms of this type of disease:

• Generalized pustular eruptions (pictured), multiple crusts, small ulcers, redness and itching of the skin, with the head, ears and groin most often affected.

• In other cases, large papules filled with a cloudy liquid are observed.

• Large cysts often form in the thickness of the skin.

• In severe cases, the gums are also involved in the process, resulting in problems with the teeth (up to their loss).

• Similarly, the nail beds are involved in the process, the claws of the animal begin to stagger, sometimes fall out. The process is very painful, gives the animal severe suffering.

• Swollen lymph nodes, when they are probed, the cat clearly shows signs of displeasure. The animal becomes lethargic, fever and lameness increase (if the claws are involved in the process). Note that all these signs are characteristic only for the severe course of the process.

• Secondary bacterial infection is possible due to seeding with pyogenic microflora of opened papules and ulcers.

In dogs of the Akita Inu and Chow Chow breeds, a predisposition to this disease is noted. The causes leading to the development of the disease include idiopathic, as well as those associated with the use of drugs. Lesions spread to the muzzle and ears, fingers, abdomen near the nipples, and a generalization of the process can be observed when the lesions are spread over the entire surface of the body. Lesion progression begins with erythematous maculae, followed by pustules, epidermal collars, erosions, and yellow-brown crusts. Clinically, skin lesions may be accompanied by distal limb edema, fever, drowsiness, and lymphadenopathy. Differential diagnoses include pyoderma, dermatophytosis, demodicosis, zinc-dependent dermatosis, discoid lupus erythematosus, erythema multiforme, leishmaniasis, sebadenitis.

Establishing diagnosis

Among the possible side effects in dogs, anemia, leukopenia, thrombocytopenia, pancreatitis can form. In this regard, at the initial stage, every 14 days (for 2 months), then every 30 days (for 2 months) and, finally, every 3 months for the entire period of giving azathioprine, clinical and biochemical blood parameters in dogs should be monitored. In general, when it comes to monitoring the general health of patients treated for pemphigus, it should be remembered that every 6 months, all those who are given glucocorticoids require a routine examination. It includes a clinical and biochemical blood test, a clinical urinalysis and a urine culture for bacterial flora.
Features of therapy in cats is that if it is not possible to reduce the dose of prednisolone, then chlorambucil is introduced into the regimen. Dosing regimen, precautions and monitoring for chlorambucil therapy in cats are the same as for azathioprine in dogs. The initial dose of chlorambucil is 0.1-0.2 mg/kg daily.
Dogs not responding to azathioprine may also be treated with chlorambucil. Vitamin E at doses of 400-800 IU 2 times a day and essential fatty acids can be used as adjuvant therapy in dogs, as they have anti-inflammatory and antioxidant properties.
In dogs, a combination of tetracycline and niacinamide may be used because the combination has many anti-inflammatory and immunomodulatory properties. Which, in turn, allows the use of these drugs for the treatment of various immune-mediated skin diseases, such as discoid lupus erythematosus, lupus onychodystrophy, metatarsal fistula of German shepherds, aseptic panniculitis, vasculitis, dermatomyositis and others. Doses for dogs weighing less than 10 kg are 250 mg of each drug every 8 hours. And for dogs weighing more than 10 kg - 500 mg of both drugs every 8 hours. In the presence of a clinical effect, which can occur no earlier than after a few months, the drugs begin to be reduced - first to a double dose, and then to a single daily dose. Side effects are rare and are usually associated with the use of niacinamide. These include vomiting, anorexia, drowsiness, diarrhea, and elevated serum liver enzymes. Tetracycline may lower the seizure threshold in dogs.
In cats, doxycycline at a dose of 5 mg/kg 1-2 times a day can be used as an immunomodulator. After oral administration of doxycycline, cats must then be given at least 5 ml of water, as otherwise there is a high risk of esophageal stricture. In the absence of success from the proposed therapy with prednisolone (high doses are required) or if there is no success from its various combinations with other agents (antioxidants, immunomodulators), it is suggested to try switching to dexamethasone or triamcinolone as recommendations. The initial dose of drugs is 0.05-0.1 mg / kg 2 times a day, and then gradually reduced in the same way as in the case of prednisolone.
High-dose glucocorticoid pulse therapy is suggested as a last choice for intractable cases of exfoliative pemphigus. After such pulse therapy, upon reaching the effect, continue to give prednisolone at the recommended doses with a gradual decrease in the drug, as described above.

There are two protocols for pulse therapy:

Clinical cases of exfoliative pemphigus in our practice

Case 1 On March 7, 2012, 1.5-year-old Labrador Martin was admitted to our clinic. From the anamnesis it followed that this animal is kept at home, in the summer it is in the country, there are no contacts with other animals, the owners did not have any skin problems. Akana food has been used as feeding for the last three weeks, before that, beef, rice, and buckwheat were present in the diet. There were no seasonal manifestations of Martin's skin disease. At the time of admission, the owners noted severe itching, which was localized in the head, limbs, sides, abdomen, and back of the animal. The damage started a few weeks ago. Antibiotics were used as therapy: ceftriaxone - 7 days; ciprofloxacin - 7 days; ceftazidime - 7 days; Convenia was used two days before admission. According to the owners, such a change of antibiotics was carried out by the attending physician due to the absence of any effect from antibiotic therapy.
Examination revealed multiple lesions, including pustules and mostly crusts on the patient's head, back, abdomen, flanks, and extremities (Figures 1-3).

As differential diagnoses, we considered skin infections (demodecosis, dermatophytosis, secondary pyoderma) and pemphigus foliaceus. The scrapings were negative. The cytology of the smear included single bacteria (which did not correspond much to a similar clinical picture in pyoderma), without neutrophilic phagocytosis. The neutrophils we found in this smear were non-degenerative. At the same time, a significant amount of acantholytic keratinocytes was determined.
A biopsy was suggested, sowing on dermatophytes (the owners refused to sow). As a temporary therapy, it was proposed to continue the trial antibiotic therapy, but to arrive at the appointment after the end of the effect of the convenia drug (cefovecin - a cephalosporin of the 3rd generation) to conduct preliminary crops in order to select an antibacterial drug. The owners agreed only to a biopsy, unfortunately, without accepting our other proposals, and returned to their doctor for further treatment. After some time, the owners of the animal asked for the results of histology, confirming one of our differential diagnoses - pemphigus foliaceus (Figure 1). They refused to discuss treatment regimens. We do not know about the further fate of this patient.

Case 2 On November 28, 2012, a 2-year-old Scottish Longhair cat named Tori was admitted to our clinic. From the anamnesis it followed that the animal lives in an apartment, the owners of the cat from an early age, the animal had no skin problems at the time of purchase. There was contact with a domestic cat 2 months prior to the onset of problems, and there were no skin problems in the pet that was in contact and there were no further problems. The owners have no skin problems. Hills dry cat food was used as food.
As complaints, the owners noted that a few months ago their animal had crusts on the ears, on the muzzle, on the stomach around the nipples. Of the general symptoms, some apathy and slight itching were noted at the sites of lesions on the skin. Antibiotics and corticosteroid hormones (prednisolone) were used as therapy. Against the background of the use of prednisolone, the picture improved somewhat. Twice there was some spontaneous improvement, which lasted for some time, and then the picture resumed.
When examining Tori, it was noted that as lesions at the time of admission, there were crusts on the ears, head, and nipples (photo 4-5). No pustules were found.
The following differential diagnoses were considered as bacterial inflammation of the skin, dermatophytosis, pemphigus (which, from our point of view, was the most likely differential diagnosis).

Research at the time of initial treatment:

• LUM - negative;
• Trichogram - no hair destroyed by dermatophytes;
• Scrapings - negative;
• Smears from under the crust: the result is the presence of acanthocytes (photo 6), neutrophils in large numbers; bacterial flora is absent.

Text of the article and photo 1-44 from the book SMALL ANIMAL DERMATOLOGY A COLOR ATLAS AND THERAPEUTIC GUIDE

KEITH A. HNILICA, DVM, MS, DACVD, MBA Copyright © 2011

Translation from English: veterinarian Vasiliev AB

Peculiarities

Pemphigus foliaceus in dogs and cats is an autoimmune skin disease characterized by the production of autoantibodies against a component of adhesion molecules on keratinocytes. The deposition of antibodies in intercellular spaces causes cells to detach from each other within the upper layers of the epidermis (acantholysis). Pemphigus foliaceus is probably the most common autoimmune skin disease in dogs and cats. Animals of any age, sex, or breed may be affected, but Akita and Chow Chow dogs may be predisposed among dogs. Pemphigus foliaceus in cats and dogs is usually an idiopathic disease, but in some cases it can be caused by drugs or may occur as a consequence of a chronic skin disease.

Primary lesions are superficial. However, intact pustules are often difficult to find because they are covered with hair, have a fragile wall and are easily torn. Secondary lesions include superficial erosions, crusts, scales, epidermal collars, and alopecia. Lesions of the nasal planum, auricles, and pads of the fingers are unique and characteristic of an autoimmune skin disease. The disease often begins on the bridge of the nose, around the eyes, and on the pinna before it becomes generalized. Nasal depigmentation is often associated with facial skin lesions. Skin lesions have variable itching and their severity may weaken or intensify. Finger pad hyperkeratosis is common and may be the only symptom in some dogs and cats. Oral lesions are rare. Mucosal junctions in dogs are minimally involved in the process. In cats, lesions around the nail bed and nipples are a unique and common feature of pemphigus. With generalized skin lesions, lymphadenomegaly, swelling of the extremities, fever, anorexia and depression can occur simultaneously.

Differential diagnosis of pemphigus foliaceus in dogs and cats

Includes demodicosis, superficial pyoderma, dermatophytosis, other autoimmune skin diseases, subcorneal pustular dermatosis, eosinophilic pustulosis, drug dermatosis, dermatomyositis, cutaneous epitheliotropic lymphoma, and

Diagnosis

1 Rule out other differential diagnoses

2 Cytology (pustules): neutrophils and acantholytic cells are visible. Eosinophils may also be present.

3 Antinuclear antibodies (ANA): negative, but false positives are common

4 Dermatohistopathology: subcorneal pustules containing neutrophils and acantholytic cells, with varying numbers of eosinophils.

5 Immunofluorescence or immunohistochemistry (skin biopsy specimens): Detection of intracellular antibody deposition is characteristic, but false positive and false negative results are common. Positive results must be confirmed histologically.

6 Bacterial culture (pustule): usually sterile, but sometimes bacteria are detected if secondary infection is present.

Treatment and prognosis

1. Symptomatic treatment with crust removal shampoos may be helpful.

2. To treat or prevent secondary pyoderma in dogs, appropriate long-term systemic antibiotic therapy (minimum 4 weeks) should be given. Dogs treated with antibiotics during the run-in phase of immunosuppressive therapy had a significantly longer survival time than dogs treated with immunosuppressive drugs alone. Antibiotic therapy should be continued until immunosuppressive therapy has brought pemphigus under control.

3. The goal of treatment is to control the disease and its symptoms with the least dangerous drugs used in the lowest possible doses. Typically, a combination therapy (see ) should be used that will minimize the side effects of any monotherapy. Depending on the severity of the disease, more or less aggressive drugs are selected for treatment. To obtain remission, higher doses are initially used, which are then reduced over 2-3 months to the lowest effective dose.

• Topical treatment applied twice a day, in the form of steroid-containing drugs or tacrolimus, will help to reduce focal inflammation and will reduce the doses of systemic drugs required to control symptoms. Once remission is achieved, the frequency of drug use should be minimized to reduce local side effects.
• . Conservative systemic treatment (see Table) includes drugs that help reduce inflammation with few or no side effects. These drugs help reduce the need for more aggressive therapies such as steroids or chemotherapy drugs.
• Steroid therapy is one of the most reliable and predictable treatments for autoimmune skin diseases; however, side effects associated with the high doses required to control symptoms can be severe. Although glucocorticoid therapy alone may be effective in maintaining remission, the required doses may lead to undesirable side effects, especially in dogs. For this reason, the use of non-steroidal immunosuppressive drugs, alone or in combination with glucocorticosteroids, is usually recommended for long-term maintenance treatment.

Immunosuppressive doses of oral prednisolone or methylprednisolone should be given daily (see Table). After the lesions resolve (after approximately 2-8 weeks), the dose should be tapered gradually over several (8-10) weeks to the lowest possible dose given every other day that supports remission. If there is no significant improvement within 2-4 weeks of starting treatment, a concurrent skin infection should be ruled out and then alternative or additional immunosuppressive drugs should be considered. Alternative steroids in cases refractory to prednisolone and methylprednisolone include triamcinolone and dexamethasone (see Table)

In cats, treatment with immunosuppressive doses of triamcinolone or dexamethasone is often more effective than therapy with prednisolone or methylprednisolone. Oral triamcinolone or dexamethasone should be given daily until remission (approximately 2-8 weeks), then the dose should be reduced to the least possible and least frequent that maintains remission (see Table). If unacceptable side effects develop or if significant improvement is not achieved within 2-4 weeks of starting treatment, consider using alternative glucocorticosteroids or non-steroidal immunosuppressive drugs (see Table).

• . Non-steroidal immunosuppressive drugs that may be effective include cyclosporine (Atopica), azathioprine (dogs only), chlorambucil, cyclophosphamide, mycophenolate mofetil, and lefunomide (see Table). A positive effect is observed within 8-12 weeks after the start of treatment. Once remission is achieved, gradually try to reduce the dose and frequency of non-steroidal immunosuppressive drugs for long-term maintenance treatment.

4 Prognosis is cautious to good. Although some animals remain in remission after immunosuppressive therapy is tapered off and withdrawn, most animals require lifelong treatment to maintain remission. Regular monitoring of clinical symptoms, blood tests with treatment adjustment as necessary is necessary. Potential complications of immunosuppressive therapy include unacceptable drug side effects and immunosuppression-induced bacterial infections, dermatophytosis, or demodicosis.

Photo 1 Pemphigus foliaceus in dogs. Adult Doberman with pemphigus foliaceus. Note the diffuse nature of the lesions.

Photo 2. Pemphigus foliaceus in dogs. Same dog in photo 1. Alopecia, crusting and papular lesions on the muzzle are evident. Note the similarity of lesions to folliculitis: however, the pattern of distribution of lesions is unique.

Photo 3. Pemphigus foliaceus in dogs. Alopecia, crusting, papular dermatitis on the face. Lesions of the nasal planum and auricles are characteristic of an autoimmune skin disease.

Photo 4. Pemphigus foliaceus in dogs. The same dog from photo 3. Alopecia, crusting, papular dermatitis on the face and nasal planum are characteristic of an autoimmune skin disease. Note the similarity of the lesions to folliculitis; however, follicles are absent from the nasal planum, making these lesions a unique feature.

Photo 5. Pemphigus foliaceus in dogs. Crusted erosive dermatitis on the nasal planum with depigmentation and loss of the normal "paving" texture is a unique feature of autoimmune skin disease.

Photo 6. Pemphigus foliaceus in dogs. Same dog in photo 5. Nasal planum lesions are a characteristic feature of an autoimmune skin disease.

Photo 7. Pemphigus foliaceus in dogs.. Crusted papular dermatitis on the auricles of a dog with pemphigus foliaceus. Lesions of the nasal planum, auricles, and pads of the fingers are characteristic features of autoimmune skin disease.

Photo 8. Pemphigus foliaceus in dogs. Alopecia, crusting dermatitis on the margin of the auricle in a Doberman with pemphigus foliaceus. Note the similarity of the lesions to scabies; however, this dog did not have intense itching.

Photo 9 Pemphigus foliaceus in dogs.. Alopecia and crusting papular dermatitis in a Dalmatian. Note the similarity of the lesions to folliculitis.

Photo 10 Pemphigus foliaceus in dogs. Alopecia with crusty papular eruption on the trunk.

Photo 11 Pemphigus foliaceus in dogs. Hyperkeratosis and crusting on the pads of the fingers are characteristic of an autoimmune skin disease. Note that the lesions are on the pad itself more than on the interdigital spaces of the skin. The latter is typical of allergic dermatitis or bacterial or fungal pododermatitis.

Photo 12 Pemphigus foliaceus in dogs. Hyperkeratosis and scabs on the pads of the fingers.

Photo 13 Pemphigus foliaceus in dogs. Hyperkeratosis and crusting on the scrotum of a dog with pemphigus foliaceus.

Photo 14 Pemphigus foliaceus in dogs. Depigmentation of the nasal planum with loss of the normal "cobblestone" texture is an early change associated with autoimmune skin disease.

Photo 15 Pemphigus foliaceus in dogs. Severe moist dermatitis is a rare presentation in pemphigus foliaceus.

Photo 16. Pemphigus foliaceus of cats. Dermatitis of the facial part of the muzzle (alopecia, crusts, papular rash) in a cat. Pay attention to the similarity with dermatitis of the muzzle of Persian cats.

Photo 17. Feline pemphigus foliaceus. Close-up view of the cat in photo 16. Cortical papular dermatitis with alopecia on the muzzle and auricles is a characteristic feature of an autoimmune skin disease.

Photo 18. Feline pemphigus foliaceus. Same cat in photo 16. Crusted, papular rash on the ears is a unique feature of autoimmune skin disease.

Photo 19. Feline pemphigus foliaceus. Same cat in photo 16. Crusted, erosive dermatitis with alopecia around the nipples is a common and unique feature of pemphigus foliaceus in cats.

Photo 21. Hyperkeratosis and scabs on the pads of the fingers are a common feature of autoimmune skin disease.

Photo 22. Feline pemphigus foliaceus. Crusted nail bed dermatitis (paronychia) is a common and unique feature of pemphigus foliaceus in cats.

Photo 23. Feline pemphigus foliaceus. Paronychia and hyperkeratosis of the paw pads in a cat with pemphigus foliaceus.

Photo 24 Pemphigus foliaceus in dogs and cats. Microscopic image of acantholytic cells and numerous neutrophils. Lens magnification 10

Photo 25 Pemphigus foliaceus in dogs and cats. Microscopic image of acantholytic cells. Lens magnification 100

Photo 26. Pemphigus foliaceus in dogs. Pronounced scabs on the pads of the fingers of the affected dog.

Photo 27 Pemphigus foliaceus in dogs. Severe cortical footpad lesions developed within a few weeks in a middle-aged dog.

Photo 28.Severe cortical lesion of the muzzle with alopecia in a cat. The nasal planum is affected, but not to the extent usually seen in dogs.