Derm's dirty Dozen, The top chronic, recurrent cases destined to cause frustration - DVM
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Derm's dirty Dozen, The top chronic, recurrent cases destined to cause frustration


DVM360 MAGAZINE


  • Disease 5:

Facial Pemphigus foliaceus (PF) in the Chow Chow/Akita This form of pemphigus can be very refractory to treat and is likely a different entity to the naturally occurring truncal pemphigus in other breeds. This form of PF is probably a bit deeper in the dermis histologically than the routine cases of PF. The immunologic mechanism involve antibodies produced against the intercellular substance that "holds" the epidermal skin cells together, thus resulting in dissolution of the cell-to-cell cohesion.

As a result, the canine immune system recruits neutrophils to repair and fill the void in the "space" that has been created by the epidermal cell-to-cell dissolution. This quickly results in a very large pustule (neutrophil-laden, by definition) that spans multiple hair follicles and clinically presents in large crusts due to the fragile and transient nature of the pustules. Most of these pustules occur on the face, paw pads, trunk, nipples and limbs.

Cytology and biopsy are techniques to make a definitive diagnosis. I have occasionally based treatment on a diagnosis solely from cytology, but I would advise against this technique in private practice.

Once diagnosis is made, the treatment focuses on immunosuppression and includes oral corticosteroids and other agents. Prednisone at 2-4mg/kg/day accompanied by azathioprine or chlorambucil is highly recommended. It seems that most dogs with PF are affected long-term, so it therefore seems advisable to incorporate alternative therapies to corticosteroids early on in treatment. Other single-agent therapies include oral cyclosporine (5-20 mg/kg/day). Alternatives to these therapies also include oral tetracycline and niacinamide. Dogs greater than 20 kg are administered 500 mg tetracycline and niacinamide every eight hours, and dogs less than 20 kg are given 250 mg of these two drugs every eight hours. These drugs are immunomodulatory and can aid in the treatment of immune-mediated skin diseases. Lastly, injectable gold therapy can also be considered as a single agent.

  • Disease 6:

Feline cutaneous herpes infection Since the discovery of cutaneous feline herpes infection several years ago, it has been clear that this disease can be chronic. Herpes infection in the cat involves mainly the haired skin of the face but can involve the planum nasale, too. Some cases are preceded by several months or years of upper respiratory symptoms, including episodic sneezing and conjunctivitis. Most of the cases of cutaneous feline herpes infection occur during adulthood. In fact, many cases occur in older cats greater than 5 years of age. After this initial upper respiratory disease, the owner notices lesions on the planum or more likely haired skin of the muzzle. These lesions usually are ulcerated and very crusted. Cytology and histology can reveal primarily eosinophils and some neutrophils, and can mimic eosinophilic granuloma clinically and more likely, histologically. Diagnosis is based upon clinical examination and usually results of histopathology. Often epidermal inclusions bodies of the herpes virus are seen, but not always.

Treatment has included oral lysine, oral interferon, topical and oral acyclovir, and more recently, oral Famvir. Famvir is the trade name of an oral anti-herpes medication for humans, and I have found it to be very helpful and safe in cats. The dosage is 125 mg (one-half of a 250 mg tablet) every eight hours. It costs about $175-200 for a three-week supply. I have not found the other therapies to be of benefit. Famvir is usually administered for at least three to four weeks. The disease is often chronic, and relapses are very common.

Editor’s Note: Next month Dr. Vitale will round out the other six worst cases in Derm’s dirty dozen.


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Source: DVM360 MAGAZINE,
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