Clinical Signs

Early lesions consist of blackheads and black debris on the chin. Sometimes mild scabbing, red bumps, and pimples occur. Lesions may also involve the skin of the upper and lower lips. After time, the pimples can get larger and cause the hair follicles to rupture (furunculosis), which leads to discomfort and bloody drainage.

Diagnostic Tests

Diagnosis is based on the presence of compatible clinical signs and elimination of other possible skin conditions of the chin.

Treatment Options

Secondary bacterial infections are treated with systemic antibiotics for 2-4 weeks. The hair may be clipped and the skin gently washed with a shampoo that contains benzoyl peroxide or ethyl lactate until the lesions have dried out and healed. Gentle washes can then be continued as needed. Topical antibacterial ointments or creams, such as 2% mupirocin, 0.75% metronidazole gel, or products containing clindamycin or tetracycline may also be helpful.

Follow-up Care

If lesions recur and are painful, or if bleeding pimples come back, a recheck visit should be scheduled with your veterinarian. Notify your veterinarian if any other clinical signs arise.

Clinical Signs

Acute moist dermatitis is an intensely itchy to sometimes painful irritation of the skin surface. It develops rapidly and has the following features:

Diagnostic Tests

Diagnosis is based on the typical appearance of the lesion, a history of a very rapid onset, and extreme itchiness. It is usually a single lesion. The location of the lesion may help narrow down the suspected cause.

Treatment Options

It is important to identify and treat the underlying cause. Hair is clipped from the affected area to allow removal of all surface debris by gentle cleansing with a dilute antimicrobial solution (such as chlorhexidine or povidone-iodine). Clipping and cleaning may require sedation, because these lesions can be quite painful.

Topical astringents such as aluminum acetate 2% (Domeboro solution) may be helpful to dry the area. Sometimes systemic steroids are used (see handout on Atopic Dermatitis in Dogs) to break the itch cycle. If there is evidence of a secondary bacterial infection caused by the itching, systemic antibiotics are used. Often, an Elizabethan collar is applied to prevent further trauma and allow the area to heal.

Follow-up Care

Even when the underlying reason for the hot spot is addressed, some dogs repeatedly develop the lesions. Careful attention must be paid to regular grooming, hygiene, flea control, and ear cleaning, especially during hot and humid weather conditions. If systemic antibiotics are instituted, a recheck is often performed to be sure the infection is gone.

Clinical Signs

Symmetrical hair loss occurs on both sides of the trunk, around the neck (especially the collar area), backs of the thighs, and under the tail. The underlying skin frequently turns dark with time. The hair coat has a “puppy coat” appearance.

Diagnostic Tests

Initially, some routine skin and laboratory tests are performed to rule out the more common causes of hair loss. A skin biopsy may be performed to document findings consistent with this disease. Specialized hormone tests may be submitted after other diseases that resemble alopecia X have been eliminated.

Treatment Options

Controversy exists as to whether this disease requires treatment, because it is mainly a cosmetic problem. The best choice of therapy is also debated. Drugs such as melatonin, mitotane, and trilostane have been used for this condition. Melatonin can cause hair regrowth in some animals, but the mechanism of action is unknown. It is considered quite safe but can rarely cause an upset stomach in some dogs. Mitotane (Lysodren) causes hair regrowth in some cases, but this treatment is not always recommended, because the drug has potentially serious side effects. Trilostane has been effective in some cases and often has fewer side effects than mitotane.

The decision whether to treat this condition in your dog requires a thoughtful discussion with your veterinarian, as well as careful weighing of the pros and cons of treatment.

Follow-up Care

If a medication other than melatonin is used, follow-up blood tests are needed to monitor for drug side effects.

Clinical Signs

Mild to severe itchiness of the ears, face, axillae (armpits), feet, and belly occurs. Ear infections are common, as are bacterial and yeast infections caused by the scratching. Signs occur either during a specific pollen season or year round, depending on what the pet is allergic to. Common areas affected in the dog are face, the back of the front legs, and where the front legs and chest meet.

Diagnostic Tests

Diagnosis is often based on a history of itching, scratching, licking, and/or biting the body. Itchiness may occur seasonally or year round, depending on what the animal is allergic to. Your veterinarian also must eliminate other itchy skin diseases, such as parasites. Allergy testing can be supportive of the diagnosis and can be done by intradermal skin testing or blood testing. Both tests can give false-positive and false-negative results, however.

Treatment Options

Treatment is designed to make the pet more comfortable. It is not possible to cure environmental allergy, and dogs do not typically outgrow their allergies as humans do. Components of therapy involve the following:

Follow-up Care

Atopic dermatitis is a lifelong disease and requires long-term management. Recheck examinations are warranted to minimize flare-ups and to monitor response to treatment. As the seasons rotate and time goes on, modifications to therapy are often needed, so good communication between owner and veterinarian is essential. Occasionally, retesting for new allergies may be needed.

Clinical Signs

In the cat, skin nodules are most commonly found on the belly. Draining tracts and red-purple bumps that ooze material may be seen. The condition often becomes chronic or returns after attempted treatment.

Lesions in dogs usually develop after trauma or dog bite wounds. Recurrent abscesses, draining tracts, and large bumps that may ooze are the most common findings. In the dog, the bacterial infection may spread to other areas of the body, including the lungs.

Diagnostic Tests

A biopsy is usually needed to confirm the diagnosis. Samples of the skin and deeper tissues are submitted for microscopic examination and often for culture. The bacteria can be difficult to find, so multiple biopsies may be needed.

Treatment Options

Antibiotic treatment is started with drugs commonly effective against mycobacteria. The medication may be changed based on culture and susceptibility tests. It takes a very long time for these infections to resolve, so antibiotics are often given for months. Some animals are never cured, and the infection relapses once antibiotics are discontinued.

Surgical removal of the affected area is helpful, although poor healing is common if all affected tissue is not removed. Sometimes more than one surgery is needed.

Follow-up Care

Frequent rechecks are often needed to monitor the response to treatment and to determine how long to continue the antibiotics.

Clinical Signs

Sebaceous growths are common in older dogs, especially in the cocker spaniel, Siberian husky, miniature poodle, black and tan coonhound, beagle, and dachshund. Sebaceous tumors are uncommon in the cat, but Persian cats may develop them more often than others. These tumors can occur alone or in small groups, are often yellow-pink in color, and are shaped like a cauliflower. They often have a wart-like appearance. Adenomas are small to medium in size (usually less than ½Epitheliomas are often larger; they may be fingerlike projections or flatlike adenomas. They vary in size from quite small to inches across.

Nodular hyperplasia bumps can resemble sebaceous adenomas or epitheliomas. They usually have a greasy scab on the surface but rarely bother the pet unless they are located between the toes, under the collar, or in some area where they can become irritated. Sometimes, the waxy substance produced may be irritating if it sits on the surface for a while. Some dogs develop dozens of these bumps over their entire body.

Benign hair follicle tumors can range from less than 1 inch to the size of a golf ball or an orange. They often are partially hairless, and if one looks closely, a central depression can usually be seen on the surface. Some of these lesions rupture, exuding gray-white, thick material that may resemble pus but is really material from the hair follicle. The tumors usually occur in middle- to older-aged pets. Some commonly affected breeds are the German shepherd dog, poodles, Kerry blue terrier, Old English sheepdog, and keeshond.

Diagnostic Tests

Removal and biopsy of the tumor allows the exact type to be identified but may not be recommended if the tumor is causing no signs. An aspirate of the mass may be recommended to rule out other skin tumors of similar appearance.

Treatment Options

There may be no need to remove many of these tumors unless they bother the pet or the owner, especially since they usually only cause cosmetic problems. If the tumor bothers the pet, becomes irritated and inflamed, ruptures, or bleeds often, removal may be recommended. Removal may also be recommended for certain sebaceous epitheliomas.

Follow-up Care

Usually, if the tumor is completely removed, no follow-up is required. Most dogs continue to develop more of these tumors throughout their adult lifetime.

Clinical Signs

These mites readily pass among dogs, cats, and humans, so the condition is very contagious. Moderate to marked dandruff and hair loss are the classic signs. Cats may develop red skin and small red bumps with scabs. Other cats may only lick lots of hair off their backs without developing dandruff or bumps.

Diagnostic Tests

Hair and dandruff are collected with the use of acetate tape (such as Scotch tape), a flea comb, or a dull scalpel blade and placed on a glass slide with mineral oil. The mites and/or their eggs can be seen under the microscope. The mites are also sometimes identified in a fecal laboratory test and may be seen without magnification on the skin because they look like “walking dandruff.”

Treatment Options

All dogs and cats in contact with the infected animal are treated. Several topical therapies are available:

Other medications not specifically approved for this condition may be tried, either orally or by injection. The environment must also be treated with an insecticide spray or fogger that is effective against fleas.

Follow-up Care

The pet is checked after 3-4 weeks of therapy to be sure the dandruff and itchiness are improving.

Clinical Signs

Lameness, pain, and licking or biting of the claw occur in varying degrees, depending on the cause. The skin around the claw can be swollen, red, scabbing, and/or oozing. The hair may be lost around the claw. Swollen glands (nearby lymph nodes) are possible, and occasionally fever, depression, and decreased appetite are seen.

Diagnostic Tests

A known traumatic event to the claw can suggest the cause. Examination of debris from the fold of skin at the base of the claw under the microscope may be helpful, especially if evidence of bacterial or fungal infection or cancer cells are found. Sometimes bacterial and fungal cultures are submitted. X-rays of the area are sometimes needed. Biopsy of the skin and claw may be done in certain cases.

Treatment Options

A common treatment is removal of any broken, loose, or painful claws. Sometimes the claws are so loose that they can simply be pulled off. More often, the toe is too sore to allow this, so the animal must be sedated and the claw removed. Foot soaks may make the pet more comfortable. If bacterial infection is present, appropriate antibiotics are given for at least 4-8 weeks and 2 weeks beyond clinical cure. If there is a fungal infection, antifungal agents are typically given for up to 3-6 months. Rarely, treatment may require amputation of the end of the toe for tumors or to resolve difficult fungal infections.

Follow-up Care

Recheck visits are needed for those pets with infection, because the infection can be difficult to resolve. Some dogs with certain tumors are monitored for metastasis (spread) by checking lymph nodes and performing chest x-rays periodically (depending on the tumor).

Clinical Signs

Lameness, pain, and licking or biting of the claws may be seen, depending on the cause. The skin around the claws can be swollen, red, scabby, and/or oozing. Hair loss around the claws is common. Glands (lymph nodes) nearest the affected claws may be swollen, and occasionally fever, depression, and decreased appetite are seen. Signs of the underlying disease process are also present.

Diagnostic Tests

Debris from the skin folds around the claws and scrapings of the skin can be examined under the microscope for infection, mites, and cells that are seen with immune diseases. Laboratory tests are usually needed to look for possible underlying diseases and causes. Biopsy of the claw and skin can also be helpful.

Treatment Options

Treatment of secondary bacterial infections is important. Immune-mediated diseases require aggressive therapy to suppress the immune system, which often involves steroids and other medications.

Other therapies may be tried depending on the underlying cause and whether a specific cause can be determined. For example, if a food allergy is suspected, a food elimination trial may be done for at least 8 weeks. Omega-6 and omega-3 fatty acid supplements can be tried for a minimum of 3-4 months. Oral vitamin E can be tried. Oral tetracycline and niacinamide or pentoxifylline may be helpful in some cases. Gelatin (Knox) or biotin may be given to strengthen the claws.

If the disease does not respond to conventional therapy and affects only a few claws, a declaw procedure with removal of the tip of the toe and claw may be considered. If a tumor is suspected or confirmed based on x-rays and a biopsy, then a toe amputation is often performed.

Follow-up Care

Claws grow very slowly, so it is important to monitor them every few months for improvement. Typically, rechecks are performed every 2-3 months until the disease is controlled, which can take a long time. Many cases are not cured, so rechecks may be needed every 6-12 months.

Since all of the medications used to treat the immune-mediated diseases have potential side effects, blood and urine tests are monitored, sometimes every 2 weeks. The dosages of medication are tapered as the pet’s signs improve, and the animal is monitored for worsening of the signs, which may require increasing the medication again. With certain underlying causes or conditions (such as pemphigus, allergy, inherited disorders), therapy is lifelong.

Clinical Signs

Early lesions include redness and loss of pigment of the skin and nose. As lesions worsen, the cobblestone architecture of the tip of the nose is lost. Later, skin may become quite raw, and scabs can be seen.

Diagnostic Tests

The clinical appearance can suggest the diagnosis, but a biopsy is needed to absolutely determine the presence of this condition, since several other diseases create a similar appearance. Specialized examination of the biopsy specimens may be needed to determine the presence of an autoimmune reaction in which the immune system is attacking the skin cells. Other laboratory tests may be recommended prior to starting therapy to determine whether it is safe to start certain medications.

Treatment Options

Avoiding exposure to the sun and using sunscreens are important measures to protect the skin from ultraviolet light. Topical therapy (applied directly to the skin) with steroids or immune-modulating drugs may be successful in mild cases. Systemic therapy with oral vitamin E, steroids, and other immune-suppressive drugs is indicated if topical therapy is ineffective and for severe cases. Numerous drug options are available for this disease, and some of them have potential side effects that require careful monitoring.

Follow-up Care

After treatment has been started, recheck visits are usually scheduled about every 2-4 weeks to evaluate the response to therapy. Once clinical remission has been achieved, the visits are often continued at 1-month intervals as the drug dosages are being tapered, and then every 6 months during maintenance therapy. If systemic therapy is used, laboratory tests are periodically needed to monitor for side effects from the medications and to make sure no secondary infections are starting.

Clinical Signs

In dogs, four different clinical presentations have been described:

Cats often develop well-defined bumps within the skin of the head and neck that are surrounded by hair loss, redness, and dandruff. In both dogs and cats, the glands (lymph nodes) may be enlarged, and the animal may not feel well.

Diagnostic Tests

Because this disease is so rare, it is not very high on anyone’s list of suspicions. It is common for routine tests to be performed first for the more common skin diseases and for laboratory tests to be submitted looking for the cause. If these do not reveal a cause, skin biopsy is often recommended. Examination of the biopsy reveals the presence of skin lymphoma, although special testing may be required to confirm that it involves T cells. Once the diagnosis is made, further testing may be needed to prove that the cancer involves only the skin.

Treatment Options

Treatment of this disease involves chemotherapy. The most common drug chosen is lomustine (CCNU), but several other drugs (such as prednisone, cyclophosphamide, vincristine, chlorambucil, doxorubicin, and methotrexate) have shown some success. Some of the chemotherapeutic drugs are given orally, whereas others must be given intravenously. Each is given at a different frequency, in a strict protocol that will be outlined by your veterinarian. Throughout chemotherapy, blood tests must be run to monitor for the side effects of these drugs.

Follow-up Care

Recheck visits are needed in some cases to administer the chemotherapy and in all cases to monitor the skin for response to treatment. Blood samples are also drawn at the recheck visits to monitor for side effects from the chemotherapy.

Clinical Signs

Typically, a symmetrical hair loss occurs on both sides of the dog in the “saddle region” of the trunk, with subsequent darkening of the underlying skin. Rarely, it occurs on one side only or along the top of the dog’s back. The hair loss usually has a well demarcated border that may resemble a map. Spontaneous regrowth of hair usually occurs within 3-8 months.

The condition often occurs every year at about the same time (either spring or fall), yet some animals (20%) lose their hair only once. Sometimes the hair loss skips a year. The extent of the hair loss can vary from year to year.

Diagnostic Tests

Diagnosis is based on the following factors: classic clinical signs occurring in a dog of a compatible breed, a seasonal history, elimination of other possible causes of the hair loss, and a biopsy of the skin. Timing of the biopsy can be important, because a biopsy taken late in the seasonal cycle of hair loss can show normal skin since the hair is about to grow in.

Treatment Options

The hair typically regrows on its own at the end of the season. Since this hair loss is only a cosmetic condition, no therapy is usually needed. Melatonin therapy is effective in some dogs if started before hair loss begins; therefore, it must be started before the typical start of the seasonal cycle.

Follow-up Care

No follow-up is necessary for those dogs whose seasonal hair loss is predictable. Dogs that do not regrow hair in 3-8 months should be evaluated for other diseases that mimic this one.

Clinical Signs

The condition may be restricted to only a certain area on the surface of the body, or it may be generalized. Red bumps, pimples, hair loss, lesions resembling blood blisters, and bleeding, scabbing, and tenderness of the skin are often seen. Sometimes the pet is itchy. Lymph nodes (glands) are often enlarged, especially those closest to the infection.

Diagnostic Tests

A presumptive diagnosis can often be made based on typical physical examination findings. More specific tests, such as examining skin material under the microscope on a slide or skin biopsy, are helpful to confirm the diagnosis. Bacterial culture of the skin helps to identify the specific bacteria involved and aids in selection of the proper systemic antibiotic. Other testing may be needed to search for an underlying or contributing cause.

Treatment Options

Any underlying cause must be identified and treated. Antibiotics are given for a minimum of 4 weeks or for 2 weeks or more after complete resolution of all clinical signs. Antibiotics are often given for a total of 6-12 weeks.

Antiseptic shampoos (such as those containing benzoyl peroxide, chlorhexidine, or ethyl lactate) may be used once or twice weekly to aid in removal of scabs and debris as the animal heals.

Follow-up Care

Monitoring of both the infection and any underlying cause is done via recheck visits. If the problem comes back shortly after discontinuation of medication (within 2-4 weeks), notify your veterinarian, because this may indicate that the infection was not cleared, and many months of therapy may be needed.

Clinical Signs

Demodicosis is called localized when hair loss occurs only in isolated, patchy areas. Comedones (blackheads) may also be present. Pimples and small red bumps may occur and indicate a secondary bacterial infection. Localized demodicosis is rarely itchy.

With generalized demodicosis, hair loss and lesions may occur over the body and be extensive. Blackheads, pimples, red bumps, and bleeding areas may be present. Scabs often indicate secondary infection, which can cause itchiness.

Diagnostic Tests

Diagnosis is based on finding Demodex canis mites in samples taken from the skin. Samples are taken by scraping the skin or plucking hairs and are examined under the microscope. Rarely, a skin biopsy is needed to identify the mite. Other laboratory testing may be indicated in dogs with adult-onset demodicosis.

Treatment Options

Localized and demodicosis are treated differently:

Stay updated, free articles. Join our Telegram channel

Join