BCOA Bulletin January-February-March 2008 - the Basenji Club of ...

FROM THE OFA HEALTH FILEBreedTHYROIDISM IN BASENJIS – BASED ON STATISTICS FROM MICHIGAN STATE UNIVERSITYBreed Rank Number of Evaluations Percent Autoimmune Thyroiditis Percent EquivocalBASENJI 35 741 10.8 5.5RankTHYROIDISM IN BASENJIS – BASED ON STATISTICS FROM OFANumber ofEvaluationsPercentNormalPercent AutoimmuneThyroiditisPercent IdiopathicHypothyroidismPercent EquivocalBASENJI 13 93 77.4 9.7 0.0 12.9General Thyroid InformationAutoimmune thyroiditis is the most common cause of primaryhypothyroidism in dogs. The disease has variable onset, but tendsto clinically manifest itself at 2 to 5 years of age. Dogs may beclinically normal for years, only to become hypothyroid at alater date. The marker for autoimmune thyroiditis, thyroglobulinautoantibody formation, usually occurs prior to the occurrence ofclinical signs. Therefore, periodic retesting is recommended.The majority of dogs that develop autoantibodies have them by 3to 4 years of age. Development of autoantibodies to any time in thedog’s life is an indication that the dog, most likely, has the geneticform of the disease. Using today's technology only a small fractionof false positive tests occur.As a result of the variable onset of the presence of autoantibodies,periodic testing will be necessary. Dogs that are negative at 1year of age may become positive at 6 years of age. Dogs shouldbe tested every year or two in order to be certain they have notdeveloped the condition. Since the majority of affected dogs willhave autoantibodies by 4 years of age, annual testing for the first 4years is recommended. After that, testing every other year shouldsuffice. Unfortunately, a negative at any one time will not guaranteethat the dog will not develop thyroiditis.The registry data can be used by breeders in determining whichdogs are best for their breeding program. Knowing the status ofthe dog and the status of the dogs lineage, breeders and geneticcounselors can decide which matings are most appropriate forreducing the incidence of autoimmune thyroiditis in the offspring.Dogs should not receive any type of thyroid supplementation for 3months prior to thyroid testing.OFA Thyroid ProceduresPurposeTo identify those dogs that are phenotypically normal forbreeding programs and to gather data on the genetic diseaseautoimmune thyroiditisExamination and ClassificationEach dog is to be examined by an attending veterinarian andhave a serum sample sent to an OFA approved laboratory for testingaccording to the enclosed application and general informationinstructions. The laboratory fee will be determined by the approvedlaboratory. All OFA forms and the OFA fee are submitted with thesample to the approved lab. Check with the referral laboratory forspecial sample handling and tests for registry purposes.CertificationA breed database number of will be issued to all dogs foundto be normal at 12 months of age. Ages will be used in thecertification process since the classification can change as the dogages and the autoimmune disease progresses. It is recommendedthat reexamination occur at ages 2,3,4,6, and 8 years.Preliminary EvaluationEvaluation of dogs under 12 months of age can be performedfor private use of the owner since the few dogs are already positiveat that age. However, certification will not be possible at that age.Dogs with Autoimmune ThyroiditisAll data, whether normal or abnormal is to be submitted forpurposes of completeness. There is no OFA fee for entering anabnormal evaluation of the thyroid into the data bank. Informationon results determined to be positive or equivocal will not be madepublic without explicit written permission of the owner.Thyroid AbnormalitiesThyroid abnormalities fall into several categories—two typeswill be defined by the registry.Autoimmune ThyroiditisIdiopathically Reduced Thyroid FunctionAutoimme thyroiditis is known to be heritableEquivocal ResultsThose dogs with laboratory results that are questionable,therefore not definitive, will be considered as equivocal. It isrecommended that the test the repeated in three to six months.The laboratory certification process will include qualitycontrol, quality assurance and reagent certification. Laboratoriesmay apply and, if successful, will be approved to perform analysisfor OFA thyroid certification. A site visit by a qualified veterinaryendocrinologist chosen by the OFA will be required and continuedquality assurance and quality control will be necessary to maintaincertification. Fully certified status can be obtained by passing thesite visit and passing the results of the first OFA quality assuranceassay result test. The approved laboratory must be contacted forthe appropriate submission forms, sample handling procedures,and laboratory service fee before collecting the sample.SEE THE FOLLOWING PAGE FOR LABORATORIESThe Basenji Club of America, Inc. BULLETIN - 33