Atopica Treatment for Dogs With Perianal Fistula
Atopica, the veterinary formula of the immunosuppressant drug cyclosporine, was originally formulated to manage atopic dermatitis, an allergic skin condition caused by a variety of allergens. Atopica has been found to be an effective treatment for other canine diseases such as perianal fistula, a condition that causes painful and often ulcerated lesions around a dog's anus. A high percentage of dogs suffering from perianal fistulas are German shepherds.
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Atopica
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Atopica and cyclosporine come in capsule form. Atopica can only be obtained by prescription from a veterinarian and works by suppressing the dog's immune system. It belongs to a class of drugs known as immunosuppressants that counteract a body's malfunctioning immune responses. The ideal dosage for treating perianal fistulas is unknown, so your veterinarian may have you try different doses to determine what works for your dog.
Dr. Wendy C. Brooks, DVM, and educational director of VeterinaryPartner.com, explains that because Atopica "is a relatively expensive medication, a pharmacological trick is often used get a higher blood level from a lower dose." The antifungal drug ketoconazole, used concurrently with cyclopsporine, interferes with the liver enzymes' removal of ingested cyclosporine. When a low dose of ketoconazole is added, the cost of the cyclosporine "may be cut in half."
Perianal Fistulas
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Perianal fistulas, also called anal furunculosis, occur most commonly in middle-aged dogs, although younger and older dogs can be afflicted. German shepherds are particularly prone, possibly because "they have a larger number of glands in the perianal area than other breeds, or due to the way their tails are set and carried," according to Drs. Foster and Smith of PetEducation.com. German shepherds also seem to experience more "immune-mediated diseases, which may be a component of this condition."
Dr. Carlos Souza, DVM, writing for Acvs.com, cautions that "heredity may play some role in its development; thus, dogs with perianal fistulas should not be bred."
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Treatment of Perianal Fistulas
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High quality diets may decrease the occurrence of inflammatory and allergic intestinal problems associated with perianal fistula. The American College of Veterinary Surgeons explains that medical treatment may include: "a change in diet to a high quality, novel protein diet," antibiotics, oral anti-inflammatory drugs, like prednisone or immunosuppressive drugs such as Atopica, and topical ointments such as Tacrolimus.
Anal sac removal helps some dogs, but any other surgical treatment is a last resort. Surgery, including tail amputation, was once common and some veterinarians still recommend it but, before considering or agreeing to major surgery, seek a second opinion, do research and consult with people whose dogs have perianal fistulas.
Benefits of Atopica
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When Atopica or modified cyclosporine was used in dogs for "the treatment of perianal fistulas, an approximate 80 percent healing rate was found," according to the Veterinary Information Network. Prognosis for initial healing of early lesions is good but, unfortunately, the condition is likely to recur and usually requires lifelong medical management with special diets, home care and immunosuppressant drugs.
Side Effects of Atopica
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Your dog may experience gastrointestinal distress when first taking Atopica. The company that produces Atopica explains on its website, us.Atopica.com, that "as with all drugs, side effects may occur. In a field study, the most common side effects were gastrointestinal," such as nausea, vomiting, diarrhea and loss of appetite, affecting three out of 10 dogs during the first day or two of treatment but usually resolving within a week.
Dogs on Atopica may develop a thicker coat and shed more than usual. Other side effects include: footpad calluses, gum proliferation and red, swollen ear flaps. When cyclosporine was discontinued, these symptoms either resolved or improved.
Warnings
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Avoid giving Atopica and cyclosporine to dogs with liver or kidney disease, stomach ulcers, a history of cancer and certain blood disorders. Do not use with pregnant or lactating dogs, dogs under six months of age or very small dogs.
Because Atopica suppresses the immune system, prolonged use can result in bacterial or fungal infections that allow microorganisms that would normally be fought off to become disease-forming. While on Atopica treatment, dogs should not be vaccinated, as there is a risk that an active infection could be induced.
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References
Resources
- Photo Credit german shepherd image by Vaida from Fotolia.com tablets image by Marek Kosmal from Fotolia.com dogs face image by leafy from Fotolia.com
