Lymphocytic Thyroiditis in the Dog

Abstract

Abstract— —A 0.4 per cent incidence of lymphocytic thyroiditis was seen in 4,500 dogs examined. The haematological and biochemical investigations failed to reveal any results of diagnostic significance. The histological features were reminiscent of a human Hashimoto's disease. Whilst the condition was similar to that seen in man, several significant differences were noted. A genetically linked auto‐immune aetiology was considered the most likely. Résumé— —La morbidité de la thyroïdite lymphocytaire constatée au cours de l'examen de 4.500 chiens atteignait 0,4 pour cent. Les examens hématologiques et biochimiques n'ont donné aucun résultat d'intérêt diagnostique. Les caractéristiques histologiques constatées évoquaient la maladie de Hashimoto chez I'homme. L'état des chiens étudiés ressemblait en principe à la maladie rencontrée chez I'homme, mais plusieurs différences ont été nottés. Il y a lieu de croire à une auto‐immunitéà corrélation génétique. Zusammenfassung— —Bei 4500 untersuchten Hunden wurde lymphocytische Thyreoiditis mit einer Häufigkeit von 0,4% beobachtet. Die hämatologischen und biochemischen Untersuchungen lieferten keine Ergebnisse von diagnostischer Bedeutung. Die histologischen Besonderheiten erinner‐ten an die Hashimotosche Krankheit des Menschen. Obwohl der Zustand dem beim Menschen auftretenden glich, wurden doch mehrere Unterschiede bemerkt. Eine genetisch bedingte autoimmune Ätiologie wurde für am wahrscheinlichsten gehalten.

Influence of Lymphocytic Thyroiditis on Iodine Metabolism in the Beagle

“…(Hashimoto's type) has been recognized and studied in dogs only in the past few years (1)(2)(3)(4)(5). Although it has a familial incidence in the dog (3,5) no overt physiologic changes or clinical signs have been useful in its diagnosis ( 1, 2 , 4, 5 ) .…”

“…Severe lymphocytic thyroiditis in the beagle is accompanied by a large reduction to almost complete absence of colloid (1)(2)(3)(4)(5). The mean size and weight of the gland is not significantly altered (S), and the loss of colloid is obviously compensated by increases in the number of epithelial cells and the occurrence of inflammatory cells.…”

“…The mean size and weight of the gland is not significantly altered (S), and the loss of colloid is obviously compensated by increases in the number of epithelial cells and the occurrence of inflammatory cells. Also, in severe thyroiditis the more numerous epithelial cells have the characteristics of parafollicular cells (1)(2)(3)(4)(5) ; residual follicular cells are morphologically distinct and arranged in colloid-containing follicles.…”