Pathologic Features of Naturally Occurring Juvenile Polyarteritis in Beagle Dogs

Abstract

Eighteen young Beagle dogs (eight males and 10 females), ages 6-40 months, with canine juvenile polyarteritis syndrome (CJPS), a naturally occurring vasculitis and perivasculitis of unknown etiology, were necropsied, and their tissues were examined by histopathologic and histochemical methods. The condition is characterized by recurring episodes of an acute onset of fever (> 40 C) and neck pain that persist for 3-7 days. The major histopathologic alterations were a systemic vasculitis and perivasculitis. During the febrile, painful period of CJPS, the vascular lesions ranged from a histiocytic-lymphocytic periarterial infiltration to transmural arterial inflammation with concomitant fibrinoid necrosis and vascular thrombosis. Massive periarterial accumulations of inflammatory cells were common and often extended into adjacent tissues. The small- to medium-sized muscular arteries of the heart, cranial mediastinum, and cervical spinal meninges were consistently involved. Vasculitis occasionally occurred in other organ systems. The vascular lesions in dogs examined during clinically normal periods consisted of intimal and medial fibrosis, ruptured elastic laminae, and mild perivasculitis; these lesions were probably related to previous episodes of vasculitis. Eight dogs that had experienced repeated acute episodes also developed splenic, hepatic, and renal amyloidosis. The clinical signs, laboratory abnormalities, and the vascular lesions suggest that the condition may be immune-system mediated. CJPS may serve as a naturally occurring animal model of human immune-system-mediated vasculitides such as polyarteritis nodosa, infantile polyarteritis, and Kawasaki disease.

Differentiating Spontaneous from Drug-Induced Vascular Injury in the Dog

“…Many investigators throughout the world have described this syndrome as Beagle pain syndrome (19), juvenile polyarteritis syndrome (44), necrotizing vasculitis (7,43,46), polyarteritis (1,16,27), arteritis (18,37), periarteritis (45), panarteritis (28,40), and idiopathic febrile necrotizing arteritis (19). The specific clinical and morphological presentation of this syndrome will vary, depending upon the stage of disease.…”

“…Clinically, the disease is characterized by recurrent episodes of fever, body weight loss, and cervical pain manifested by a stiff gait and neck with hunched body position. In some dogs, these clinical signs are not detected, even though acute, subacute, or chronic microscopic arterial lesions are observed in multiple organs (7,16,19,28,44). In the acute febrile phase, typical changes in clinical pathology data include leukocytosis with neutrophilia, elevated acute phase proteins (α-2-globulin and fibrinogen), hypoalbuminemia, elevated platelet counts, and mild regenerative anemia (43).…”

“…Histologically, idiopathic canine polyarteritis manifests itself as an acute to chronic polysystemic arterial disease that affects small to medium muscular arteries in multiple organs (Table 4). The arteries most consistently affected were found in the heart, the cranial mediastinum, and the cervical spinal meninges (44). In the heart, the extramural branches of the right coronary artery are affected more frequently (29,44).…”

“…The arteries most consistently affected were found in the heart, the cranial mediastinum, and the cervical spinal meninges (44). In the heart, the extramural branches of the right coronary artery are affected more frequently (29,44). Snyder et al (44) described the acute arterial changes as ranging from histiocytic-lymphocytic periarteritial infiltration to transmural neutrophilic inflammation with medial fibrinoid necrosis (Figure 2a).…”

“…In the heart, the extramural branches of the right coronary artery are affected more frequently (29,44). Snyder et al (44) described the acute arterial changes as ranging from histiocytic-lymphocytic periarteritial infiltration to transmural neutrophilic inflammation with medial fibrinoid necrosis (Figure 2a). Thrombosis can sometimes be seen in acute arterial changes.…”