Spontaneous idiopathic arteritis of the testicular artery in raccoons (Procyon lotor).

The testes and the spermatic cord of raccoons (Procyon lotor, kits to adult breeders; n = 48) were examined. Segmental arteritis confined to the extratesticular portions of the testicular artery was present in raccoons of all ages. The arterial changes were seen in laboratory-confined experimental and control animals as well as in wild-caught raccoons. The lesions consisted of proliferative endarteritis with presence of inflammatory cells within the intima, media, and the adventitial regions of most affected vessels. Some aspects of the proliferative arterial lesions were reminiscent of systemic necrotizing vasculitis (polyarteritis nodosa), an immunologically mediated condition of animals and humans. Etiologic agents were not identified at the affected sites. Arteritis was not attributed to the administration of infectious agents because it was present in raccoons of all age and origin. To our knowledge multifocal arteritis confined to the testicular artery has not previously been documented in raccoons.