High Incidence of Polyarteritis Nodosa in the Brains of Culled Sows

Abstract

ABSTRACT. A total of 307 brains of purebred sows obtained from an abattoir were retrospectively examined. These sows were culled with reasons of reproductive failure, urogenital infections, or locomotor problems. The most common macroscopic lesions were cavitations or lacunae in the basal nuclei (9.1%, 28/307) and coarse and thickened leptomeninges with marked vessels (3.9%, 12/307). The most frequent microscopic lesion was polyarteritis nodosa (21.2%, 65/307), which was found in all 40 brains with the above-mentioned gross lesions and in all 25 brains with microscopic cerebral infarcts or cavitations. The affected arteries of polyarteritis nodosa were distributed primarily in the cerebral leptomeninges, basal nuclei, and internal and external capsules. Histopathologically, a characteristic change of the affected arteries was transmural fibrinoid necrosis with severe infiltration of mixed inflammatory cells; narrowing or occlusion of the lumen. The inflammatory cells were chiefly composed of lymphocytes, macrophages, and plasma cells, with a few eosinophils and occasional multinucleated giant cells. Polyarteritis nodosa was found at a high percentage in the brains from culled sows. It may result in cerebral ischemia, infarcts, and hemorrhage, and possibly play a role in the necessity for culling due to locomotor problems. KEY WORDS: brain, culled sow, polyarteritis nodosa.J. Vet. Med. Sci. 67(1): 125-127, 2005 Assessing the reasons for the culling of sows in swine breeding herds is the first step to understanding and controlling the factors influencing sow losses. Common reasons for culling of sows include reproductive failure, urinary infections, locomotor problems, replacement as well as age [3,13]. Data on the role of brain lesions in the need for culling is limited. The objectives of this restrospective study were to examine brain lesions in culled sows and to investigate their role in the culling of these animals.Brains obtained from 307 culled sows of two purebred breeding herds were included in this retrospective study. The included sows all either weighed more than 150 kg or were more than 1 1/2 years old. The actual age and body weight were not determined individually. The majority of culling sows were reported a previous history of locomotor problems, urogenital infections, or reproductive failure. The clinical history of each individual animal was not provided. All animals had been routinely immunized against classical swine fever (hog cholera), pseudorabies, Japanese B encephalitis, and erysipelas. After electric stunning and bleeding, the brains were immediately removed and fixed in 10% neutral buffered formalin for at least one week.Macroscopic examination was performed on each brain. Tissue sections were collected from various regions for histological examination including the olfactory bulb, cerebrum, basal nuclei, geniculi, corpora quadrigemina, hippocampus, medulla oblongata, choroid plexus, and cerebellum. The brain tissues were embedded in paraffin, cut at 6 µm, and routinely stained with ...

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

“…A prevalence of T lymphocytes and macrophages with a high number of MHC II-labelled cells and scattered IgM-and IgG-labelled plasma cells was detected in our cat as previously described (Porter et al, 2003;Liu et al, 2005;Ferreras et al, 2013). A cellmediated immune mechanism was suspected, similar to that described in man (Cid et al, 1994).…”

“…Although PAN involving the coronary arteries, with subsequent myocardial infarction, has been described in man and dogs (Carpenter et al, 1988;Odhav et al, 1994;Yuce et al, 2011), no clinical signs of acute coronary syndrome were identified, and no haemorrhages or infarcts were detected on post-mortem examination in the present case. Central neurological signs, such as circling and seizures, were likely due to involvement of the meningeal vessels and the presence of cerebral infarction as described in sows and dogs with PAN (Carpenter et al, 1988;Liu et al, 2005). The present cat also showed hindlimb paralysis subsequent to necrotizing vascular neuropathy.…”

“…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).…”

“…In veterinary medicine, PAN has been described in blue foxes associated with encephalitozoonosis (Nordstoga and Westbye, 1976), in lambs with sarcocystosis (Landsverk and Bratberg, 1979) and in sheep infected with ovine herpesvirus 2 (Pesavento et al, 2018). 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).…”

Systemic necrotizing polyarteritis in three weaned lambs from one flock

“…4 However, the authors did not report evidence of arterial rupture and hemorrhage in any of the affected blood vessels and organs. Hemorrhage has been recorded in other species involving the mesenteric arteries in the rat, 9 and the leptomeninges of pigs 11 and dogs, the latter associated with juvenile polyarteritis syndrome leading to progressive neurologic signs. 2 In humans, non-fatal retroperitoneal aneurysm formation and rupture involving the gastroduodenal artery has been reported.…”