Pemphigus is the general designation for a group of autoimmune skin diseases involving ulceration and crusting of the skin, as well as the.Various types of autoimmune disorders can affect the skin, such as psoriasis or scleroderma. Learn about common symptoms of these conditions and others. Autoimmune Diseases Immune system failures are a serious threat to your dog's health.
Dog Owner's Guide: Autoimmune diseases. Immune system failures are a serious threat to your dog's health. What is the immune system? The term . Diseases caused by a defective immune system are of particular concern among many purebred fanciers. Due to possible confusion with AIDS, (acquired immune deficiency syndrome), a completely different disease, I have not used this acronym.)The immune system is a marvelous defense network of white blood cells, antibodies, and other substances used to fight off infections and reject foreign proteins. It is a police force patrolling the body, designed to recognize . It is this ability that causes the body to reject skin grafts, blood transfusions, and organ transplants. Like anything else, the immune system can fail, either by not doing its job or by doing it too well. Remember the . In addition, viruses such as FIV of cats, SIV of monkeys, and HIV of people all cause an acquired immunodeficiency syndrome (AIDS) specific to that species. In all these diseases, the defective immune system fails to protect the body, leaving it vulnerable and open to attack by an opportunistic infection. Autoimmune disease, on the other hand, is a different kind of immune system failure. In this situation, the ability of the immune system to recognize the . One specific tissue type such as red blood cells may be affected, or a generalized illness such as systemic lupus may result. What causes the immune system to short circuit and start rejecting normal body tissue? Many theories exist, but the ultimate answer is . Others blame environmental pollutants or food preservatives such as ethoxyquin, an antioxidant found in most dog foods. There is strong evidence for a genetic factor in the development of autoimmune disease in many species. And some cases occur spontaneously, causing damage to kidneys, lungs, or thyroid gland. What implications do autoimmune diseases have for the breeder? If she should become pregnant, the daily medications she takes will cause birth defects in the puppies, including cleft palates and malformed limbs, and produce premature labor or spontaneous abortions. Because of the strong suspicions for genetic transmission of these diseases and potential risks to the bitch and the litter, affected dogs should not be bred. Should a breeding that has produced one or more affected dogs be repeated? To my knowledge, no official guidelines have been developed on which to base that decision, so what follows is my personal opinion. Secondly, if two or more puppies from one litter were diagnosed with any immune disease, I would not recommend repeating that particular breeding or linebreeding related dogs. I would also avoid breeding two dogs if . Until more concrete evidence has been established, veterinarians will rely on conscientious breeders to use their best judgement in researching pedigrees and breeding the best Akitas possible. Levamisole, certain antibiotics, Dilantin (phenytoin), lead, and zinc have all been implicated as potential causes of hemolytic anemia. When the spleen and the rest of the immune system is working to rid the body of old, diseased, or damaged RBCs, it is doing its job appropriately. When a large percentage of cells are affected, and they are removed faster then they can be replaced, AIHA results and the animal shows external signs of the disease. The clinical signs of AIHA are usually gradual and progressive, but occasionally an apparently healthy pet suddenly collapses in an acute hemolytic crisis. The signs are usually related to lack of oxygen: weakness, lethargy, anorexia, and an increase in the heart rate and respirations. Heart murmurs and pale mucous membranes (gums, eyelids, etc.) may also be present. More severe cases also have a fever and . This is due to a buildup of bilirubin, one of the breakdown products of hemoglobin. The diagnosis is usually made on these clinical signs as well as a CBC documenting anemia, often with misshapen or abnormally- clumped RBCs. A Coomb's test may be done to confirm the diagnosis. Corticosteroids are the primary drugs used to treat any autoimmune disease. Very high immunosuppressive doses are used initially to induce a remission, and then the dose is very slowly tapered over many weeks or months to a low maintenance dose. Most affected dogs must be kept on steroids the rest of their lives and are susceptible to relapses. If steroids alone are insufficient, more potent immunosuppressive drugs such as Cytoxan (cyclophosphamide) or Imuran (azathioprine) may be added. These chemotherapeutics are very effective, but the dog must be monitored closely for side effects, including a decreased white blood count. Splenectomy, the surgical removal of the spleen, has also been recommended for nonresponsive cases. This benefits the dog in two ways: less antibodies are made against the RBCs, and the primary organ responsible for their destruction is removed. An animal can live quite normally without a spleen. Blood transfusions are rarely used. Adding foreign protein can actually intensify the crisis state, increase the amount of bilirubin and other breakdown products the liver must process, and suppress the bone marrow's natural response to anemia. In a life- threatening anemia, cross- matched blood may be transfused along with immunosuppressive therapy. Immune- mediated thrombocytopenia. ITP is the destruction of . Clinical signs of this disease include bruising; excessive bleeding following trauma, at surgery, or during estrus; or blood in the urine or stool. These patients do not usually present in the crisis state that AIHA patients can exhibit, and they relapse less frequently. Before ITP can be diagnosed, many more common diseases must be ruled out. These include, but are not limited to, warfarin poisoning, various clotting disorders (hemophilia, Von Willebrand's disease), bladder or prostate infection or cancer, and intestinal parasites. A CBC, platelet count, and clotting profile are needed. A bone marrow biopsy is helpful as well, and a Coomb's test may be run if other autoimmune diseases are suspected. Treatment is the same as for AIHA - - large doses of corticosteroids and the addition of cyclophosphamide or vincristine if steroids alone fail. Splenectomy can be performed; however, the surgical risk is greater in a patient with ITP due to the poor clotting ability. Transfusion of fresh whole blood or of platelet- rich plasma can be helpful in ITP. Prognosis in AIHA is guarded. Those cases presenting in a fulminating crisis state often die before aggressive therapy can be instituted, while others may not achieve or maintain remission. In ITP, the prognosis is usually favorable, although ovariohysterectomy is recommended once platelet counts are normal. This decreases the risk of uterine hemorrhage should a relapse occur. As discussed last month, affected dogs and bitches should not be used for breeding stock, due to the effects of the steroids and the risk of genetic transmission of the susceptible state. Autoimmune diseases of the skin. As a group, autoimmune diseases of the skin are uncommon to rare in frequency. Diagnosis is often difficult, especially for the general practitioner who may see one or two cases during a career. Skin biopsy and immunofluorescent staining are generally required to diagnose one of these diseases, and the prognosis for recovery may vary. Our old friends the corticosteroids are the primary mode of therapy. Such areas include the eyelids, lips, nostrils, anus, and prepuce or vulva. There may also be skin lesions in the groin or axillae (armpits). The blisters are thin, fragile, and rupture easily. The skin lesions are described as red, weeping, ulcerated placques. In contrast, the lesions of . It is thought to be a more benign form of pemphigus vulgaris. The blisters are only temporary; redness, crusting, scales, and hair loss are more common presenting signs. Pemphigus foliaceous usually begins on the face and ears and often spreads to the feet, footpads, and groin. Secondary skin infections are common, and fever, depression, and anorexia may occur in severe cases. Ultraviolet light aggravates this form of pemphigus and can lead to a misdiagnosis of nasal solar dermatitis (Collie nose). It is considered a benign form of pemphigus foliaceous. The same type of vesicles and ulcers may be found in the mouth, at mucocutaneous junctions, and in the axillae and groin. Differentiation is possible only through biopsy. Evaluation of the vesicles is critical to the diagnosis, and because they rupture so soon after formation, a dog must often be hospitalized and examined every two hours until the biopsies can be taken. It is most common in Collies and Shelties; more than 6. The lesion is often described as a . The black pigments of the nose, lips, eyelids, footpads, and anus fade to pink or white, and there is an acute uveitis (inflammation of the eyes) Early treatment may prevent blindness, but the pigment loss is usually permanent. As you can see by the above descriptions, many autoimmune diseases are similar in appearance. Except for discoid lupus, there is no breed, sex, or age predilection for these problems. As in other autoimmune diseases previously discussed, the primary goal of therapy is to suppress the body's immune response with large doses of systemic glucorticoids. More potent drugs like Cytoxan or Imuran are used if steroids fail. Gold therapy has been advocated for the pemphigus group or pemphigoid. In cases where nasal depigmentation has occurred, tattooing the affected area helps prevent the sunburn and squamous cell carcinoma that may follow. The prognosis for discoid lupus is usually good, but it is variable in the other diseases. Many dogs with VKH are euthanized due to blindness. Breeding affected dogs is not recommended. Currently, little information exists on the heritability of autoimmune skin diseases. Systemic lupus erythematosis. The classic example of a multi- systemic autoimmune disease is systemic lupus erythematosis (SLE), also known as lupus.
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May 2017
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