Systemic necrotizing polyarteritis in three weaned lambs from one flock

Abstract

Systemic necrotizing polyarteritis was diagnosed in three 7-11-mo-old lambs from the same flock. Aneurysmal dilation and rupture of the gastroduodenal artery in 1 lamb resulted in fatal hemorrhage. All lambs had severe necrotizing vasculitis involving the small intestine, abomasum, mesentery, kidney, and heart with concurrent lymphocytic enteritis. Immunohistochemistry for T- and B-lymphocytes and macrophages found a T-cell- and macrophage-dominant transmural vascular infiltrate and T-cell-associated enteritis. PCR analysis for pestivirus failed to identify infection in 1 lamb, and more extensive viral microarray techniques applied to the second and third lamb failed to detect viral nucleic acid. The identification of 3 cases within 1 flock raises the possibility of a common etiology; however, no cause was established. A genetic etiology was not considered likely as not all of the lambs were related. The presence of concurrent T-lymphocyte-associated enteritis raises the possibility of an immune-mediated disease process linking the vasculitis and enteric lesions.

Systemic Necrotizing Vasculitis in Sheep Is Associated With Ovine Herpesvirus 2

“…Systemic necrotizing vasculitis is a rare, sporadic disease recognized in individuals or clusters of sheep. 9,11,20,22,26 The histologic lesions have been considered typical of "polyarteritis nodosa" (PAN), which also has been reported in pigs, 15 cats, 5 dogs, 23 rats, 21 and humans. 7,10 Many veterinary reports use a definition of PAN derived from human studies, which is a necrotizing arteritis of medium or small arteries without vasculitis in arterioles, capillaries, or venules.…”

“…S1b) or previously performed (case Nos. 3-8), 8,26 demonstrated that transmural arterial infiltrates were predominantly lymphocytic (Suppl. Fig.…”

Polyarteritis Nodosa in a Cat with Involvement of the Central and Peripheral Nervous Systems

“…In veterinary medicine, PAN is a common disease of laboratory animals, affecting mainly male rats (Lepherd et al, 2013). It has been described in blue foxes (Alopex lagopus) (Nordstoga and Westbye, 1976), cynomolgus macaques (Macaca fascicularis) (Albassam et al, 1993;Porter et al, 2003), sheep (Landsverk and Bratberg, 1979;Ferreras et al, 2013;Wessel et al, 2017;Pesavento et al, 2018), cattle (Filippich and Mudie, 1972), pigs (Hamir, 1980;Liu et al, 2005), dogs (Carpenter et al, 1988;Snyder et al, 1995) and cats (Altera and Bonasch, 1966;Campbell et al, 1972).…”

“…A relationship with streptococcal infection has been suspected in pigs (Liu et al, 2005). However, no infectious agents have been detected in most cases of PAN in animals (Carpenter et al, 1988;Snyder et al, 1995;Porter et al, 2003;Wessel et al, 2017).…”

High copy number of ovine gammaherpesvirus 2 DNA associated with malignant catarrhal fever–like syndrome in a lamb

“…SNP in sheep is an infrequently reported syndrome of unknown etiology, although several viruses, including BDV, BTV, EHDV, and OvHV-2, have been speculated. 13 A 2017 published report on a case of SNP in sheep clearly demonstrates how difficult it is to confirm a diagnosis associated with such lesions, 18 reinforcing the need to rely on other parameters such as agent identification to establish a definitive diagnosis. Confirmation of OvHV-2-induced MCF in species other than sheep can be routinely carried out in veterinary diagnostic laboratories with the detection of OvHV-2 DNA in blood or tissue samples by PCR, in combination with compatible histologic lesions.…”