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Immunodeficiency diseases in dogs manifest themselves as an increased susceptibility to infection. This is due to abnormalities in one or more components of the immune system. These can be caused by a primary genetic defect or acquired as a result of another disease process which temporarily or permanently damages the immune system. The congenital immunodeficiencies are usually seen at a young age; the acquired impairment can occur at any age. Recurrent respiratory infections, dermatitis and deep skin infections, chronic diarrhea, stunted growth, adverse reactions to modified live vaccines, and oppomunstic infections (with usually harmless organisms) are commonly associated with ilmnunodeficiencies in dogs. Testing for immunodeficiencies is not simple. Most straight forward is evaluation of the serum concentrations of the common immunoglobulins IgG JgM and IgA.. The published normals are all from adult animals so caution is advised when applying values to puppies. This is a relatively new field in veterinary medicine, we will probably be able to diagnose more cases in the future as index of suspicion and testing capabilities improve. The following is a short list of primary congenital ilmmmodeficiencies known to affect certain breeds of dogs. It is likely that other breeds are also affected but may not have been recognized. Selective IgA deficiency: This is a common entity in humans, predisposing to childhood infections and allergic reactions. Beagles, Shar Peis and German Shepherds have been diagnosed this condition. Most have recurrent upper respiratory infections with Bordetella and more inlIalant allergies than normal dogs. Treatment of the conditions is symptomatic. One 3-year old Shepherd in om clientele with tllls condition has been treated for bronchopneumonia almost quarterly during his first 2 years. Transient Hypogammaglobulinemia ofInfancy: This disorder is self-limiting but the puppy's immune system does not produce sufficient immunoglobulins until 5-7 months of age to protect the dog from respiratory and other bacterial infections. X-linked immunodeficiency. Pups are missing components of the cell mediated and humoal immune systems and rarely survive past infancy. Females are carriers in the x-linked form. Affected males are notably stunted in their growth from 3 weeks on. They usually die between 2 and 4 months of age from systemic bacterial or viral infections. Serum IgA and IgG are low. Bone marrow transplantation has helped humans with tins disease.
Canine Cyclic Neutropenia: This defect was first reported in gray collies but can be caused by a recessive gene in other breeds as well. In the dog, cyclic fluctuation of white blood cells and all cellular blood elements OCCllIevery 8-] 2 days. Severe recurrent bacterial infections involving the respiratory tract or the GI tract are common as are nose-bleeds. Affected individuals usually do not survive beyond 3 years of age. Granulocytopathy Syndrome: Neutrophils are present in unusual numbers in this disorder but appear to function poorly so that affected animals have severe infections of the skin, toes, gums and lymphnodes. The first described in the Irish Setter. Similar neutrophil deficiencies have been reported in groups of related Weimaraners and Dobennans. The genetics are as yet unclear.
SECONDARY ACQUIRED Acquired Immlmodeficiencies are the more common. They may be divided into Immunosuppression as a complication of come other disease or immunosuppression as a complication of chemotherapy or immunosuppressive therapy. Failme to receive colostmm will cause a low 19G level for 2-3 months in a newborn pup making it vulnerable to infections until its own immune system produces enough antibody to protect it. Antibiotic therapy may have to be given for the susceptible period in these animals' lives.
IMMUNOSUPPRESSION DUE TO VIRAL DISEASES: Canine distemper and parvoviruses particularly are know to immunosuppressive. Metabolic disorders: A wasting syndrome had been described in Weimaraners that responded to growth hormone replacement even though the dog had a T-cell immundeficiency. a sinrilar T-cell deficiency has occurred in Bull Terriers but appears to be related to a defect in the absorption and metabolism of zinc. Most dogs died by 7 months of bronchopneumonia. Affected dogs had chronic skin problem especially of the feet and around the eyes. The did not respond to zinc supplementation. Diabetes, hypothyroidism and cushings disease can also lead to .. ImmlillesuppresslOn. To summarize: Immondeficiencies have been reported in dogs though they tend not to be easily recognized. Many breeds have been affected with primary (congenital) immunodeficiencies, usually at a young age. All breeds and ages can exhibit signs of the more common acquired immunodeficiencies. In all cases, recurrent, difficult to treat infectiollS should arouse suspicion that an immunodeficiency exists.
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