The short version
Immune-deficiency diseases have serious consequences and often lower the body’s defenses against infection. Some are inherited, and others are caused by viral infections or cancer.
Deficiencies in Phagocytosis
Phagocytosis is an essential mechanism of the immune system. Phagocytes are cells that engulf (phagocytize), digest, and kill foreign invaders. Phagocytes rapidly respond to infections as part of the nonspecific (innate) immune response. They can also serve as part of the adaptive immune system by presenting antigens to other cells in the adaptive system, thereby alerting them to the presence of the foreign invaders. Phagocytes are produced in the bone marrow, spread throughout the body via the bloodstream, and then gather in either tissue or the blood. Within tissues, they are found in the skin and mucous membranes, spleen, lymph nodes, the coverings of the brain and spinal cord, bone marrow, and near blood vessels throughout the body.
Phagocytosis
A deficiency in phagocytosis can be caused by a low number of phagocytes in the blood or by a defect in their ability to act normally. They can be congenital (a birth defect) or acquired (caused by diseases or drugs). The deficiency causes an increased susceptibility to bacterial infection of the skin, respiratory system, and gastrointestinal tract. These infections respond poorly to antibiotics.
Leukocyte Adhesion Deficiency
Leukocyte adhesion deficiency results from the absence of an essential receptor on white blood cells. This prevents white blood cells from exiting the bloodstream to defend the body against infections. Affected dogs repeatedly suffer from severe bacterial infections and delayed wound healing. The condition has been diagnosed in Irish Setters and also occurs in people.
Complement Deficiency
Complement is a set of small immune system proteins that helps other parts of the immune system fight off infections. A congenital lack of the complement protein C3 has been described in Brittany Spaniels. These dogs developed recurrent bacterial infections, especially skin diseases and pneumonia. Although complement is necessary for activating some types of white blood cells, bacterial infections do not always develop in individuals with complement deficiencies, because there are other ways to activate the system even if one pathway is blocked. Diagnosis is based on a blood test showing reduced levels of the protein.
A congenital deficiency in the inhibitor of the complement protein C1 has been recognized in people and occurs rarely in dogs. This can lead to uncontrolled complement activation and inflammation. Affected dogs have repeated bouts of facial swelling.
There is no specific treatment for complement deficiencies. Vaccination and antibiotics are used to prevent and treat infections. As with all inherited diseases, animals used in breeding programs must be carefully chosen to prevent passing the disease to future generations.
Immunoglobulin (Antibody) Deficiency
Immunoglobulin (antibody) deficiency is due to a failure of the body to produce antibodies (immunoglobulins). This deficiency can be acquired (caused by other diseases) or congenital (present at birth). Congenital deficiencies of one type of immunoglobulin (immunoglobulin A, or IgA) have occurred in Beagles, German Shepherds, and Chinese Shar-Peis, leading to respiratory infections, digestive system disorders, skin disease, or allergies.
Acquired deficiencies occur in puppies that do not receive adequate antibodies from their mothers. For older animals, the cause is often a decrease in antibody production.
Immunoglobulin deficiency can occur as part of any disease that disrupts the production of antibodies in the body. For example, certain tumors (such as lymphosarcoma and plasma cell myeloma) cause the production of abnormal antibodies, which decreases production of normal antibodies. Some viral infections, including canine distemper and parvovirus, can damage the tissues that produce antibody-forming cells. Some puppies also have a transient antibody deficiency that can put them at increased risk for respiratory infections from 1-6 months of age, but these dogs improve by the time they are 8 months old.
Frequently asked questions
Immunodeficiency disease in dogs?
The Merck Veterinary Manual covers this in the article linked on this page. Immune-deficiency diseases have serious consequences and often lower the body’s defenses against infection. Some are inherited, and others are caused… If your dog is unwell, contact your veterinarian — this page is educational, not a diagnosis.
Immune system diseases in dogs?
The Merck Veterinary Manual covers this in the article linked on this page. Immune-deficiency diseases have serious consequences and often lower the body’s defenses against infection. Some are inherited, and others are caused… If your dog is unwell, contact your veterinarian — this page is educational, not a diagnosis.
Immune deficiency illnesses?
The Merck Veterinary Manual covers this in the article linked on this page. Immune-deficiency diseases have serious consequences and often lower the body’s defenses against infection. Some are inherited, and others are caused… If your dog is unwell, contact your veterinarian — this page is educational, not a diagnosis.