Yes,thyroid disease in Boxers occurs primarily as hypothyroidism, or impaired thyroid gland function with low thyroid hormone levels. It often develops slowly over several months or years. The animal's body, for as yet unknown reasons, forms antibodies against its own thyroid gland resulting in partial or complete destruction of the gland and the subsequent inability to produce adequate thyroid hormone. Many breeds, including the boxer, seem to be genetically predisposed to hypothyroidism. Affected animals may be listless, develop coarse haircoats, have significant hair loss, gain weight, experience infertility and/or fetal resorption or show neurologic problems. In some cases, abnormal test results may preceed the clinically apparent stage of the disease._ A_simple thyroid test (T4) obtained from your veterinarian is often inaccurate and can give falsely low readings in normal dogs with concurrent non-thyroid illness and normal values when thyroid disease is in the early stages. More definitive testing may be obtained by performing a panel of tests which include Total T4, TGAA (thyroglobulin autoantibodies), cTSH (canine thyroid stimulating hormone), so-called "free T4 by equilibrium dialysis," and sometimes T3 and free T3. This panel is currently not available from all diagnostic laboratories and must be sent to one of several reference laboratories by your veterinarian._ Repeat testing may be recommended at regular intervals, because the disease can be slow to develop and current test results may not predict future abnormalities. Your veterinarian may not feel the need for these additional tests if the dog has no clinical signs of hypothyroidism, but owners who suspect their animals of being hypothyroid despite normal values on simple T4 tests and/or those who suspect_an hereditary condition due to knowledge of affected relatives may wish to pursue more definitive testing as a screening mechanism in consultation with their veterinarian. Further information is available on the OFA web site: http://www.offa.org