Pathology of grey seals Halichoerus grypus in southwest England including pups in early rehabilitation.

Few investigations have examined the pathology of grey seals Halichoerus grypus in southwest England, where it is the most abundant marine mammal. Here, primary pathological findings are presented from 107 post-mortem examinations of grey seals in southwest England between 2013 and 2020. Over three-quarters were pups in their first year of life; the origins of the carcasses reflected the known breeding season and breeding sites of grey seals in the region. Trauma was the most common primary pathological finding (n = 49), followed by infectious disease (n = 36). Traumatic findings included fisheries-related trauma (n = 15), other acute physical traumas (n = 15) and other chronic traumas (n = 19). Infectious disease findings included respiratory infections (n = 21) and gastrointestinal infections (n = 9). There was no difference in the primary pathological findings for seals found dead or that died or were euthanased on the day they were found compared to those dying in early rehabilitation, suggesting that it is appropriate to include findings from seals in early rehabilitation in studies of wild grey seal pathology. Seals that had not been frozen before post-mortem examination were nearly twice as likely to have a primary pathological finding of infectious disease or trauma than those that had been frozen, highlighting the need, wherever possible, to avoid freezing seals prior to post-mortem examination.

Novel Pulmonary Vasculitis with Splendore-Hoeppli Reaction in Grey Seals (Halichoerus grypus) Associated with Otostrongylus circumlitus Infection.

Lungworm infection in seals is an important cause of morbidity and mortality, inducing bronchopneumonia and affecting population dynamics in some areas of the world. We present a series of cases of lungworm infection in grey seals (Halichoerus grypus) associated with novel, significant and unusual pulmonary vascular changes. Grey seals (n = 180) that were stranded, in rehabilitation or in long-term captivity in the UK were subjected to post-mortem examination between 2012 and 2018. Lung tissue was collected from 47 individuals for histopathological examination. Polymerase chain reaction (PCR) on formalin-fixed and paraffin wax-embedded (FFPE) material was attempted for parasite identification on selected sections using lungworm-specific primers, and nematode morphology within sections was evaluated histologically. Fourteen of 47 (30%) of these grey seals showed evidence of segmental granulomatous and eosinophilic vasculitis with an intramural Splendore-Hoeppli reaction in medium to large pulmonary arteries. Intravascular nematodes suggestive of Otostrongylus circumlitus were seen in two cases. PCR on FFPE material was unable to detect a signal on selected tissue sections. Of the 14 affected seals, nine had concurrent bronchopneumonia and four had intra-alveolar/bronchiolar Parafilaroides spp. Thirteen of 14 animals with vasculitis lesions were weaned pups with only one adult affected. Previous pathological descriptions of lungworm infection in grey seals have dealt mainly with the bronchopneumonia. This case series has identified previously unrecorded vascular changes characterized by an intramural Splendore-Hoeppli reaction. Such change would impact on vascular integrity, increasing the likelihood of vascular rupture with pulmonary haemorrhage and increased risk of intravascular coagulation. A host-parasite relationship with the persistence of antigenic material following close contact with, or migration through, the blood vessel wall is suspected.

GM2 gangliosidosis in British Jacob sheep.

GM2 gangliosidosis (Tay-Sachs disease) was diagnosed in 6- to 8-month-old pedigree Jacob lambs from two unrelated flocks presenting clinically with progressive neurological dysfunction of 10 day's to 8 week's duration. Clinical signs included hindlimb ataxia and weakness, recumbency and proprioceptive defects. Histopathological examination of the nervous system identified extensive neuronal cytoplasmic accumulation of material that stained with periodic acid--Schiff and Luxol fast blue. Electron microscopy identified membranous cytoplasmic bodies within the nervous system. Serum biochemistry detected a marked decrease in hexosaminidase A activity in the one lamb tested, when compared with the concentration in age matched controls and genetic analysis identified a mutation in the sheep hexa allele G444R consistent with Tay-Sachs disease in Jacob sheep in North America. The identification of Tay-Sachs disease in British Jacob sheep supports previous evidence that the mutation in North American Jacob sheep originated from imported UK stock.

Oculoglandular syndrome caused by Yersinia pseudotuberculosis in a dairy goat.

An outbreak of ocular disease in a herd of housed dairy goats was characterized by severe granulomatous conjunctivitis and ipsilateral parotid and submandibular lymphadenopathy. In one case submitted for post-mortem examination, Yersinia pseudotuberculosis was isolated from both the conjunctiva and submandibular lymph node. Histopathological examination identified severe chronic active suppurative and lymphoplasmacytic conjunctivitis and suppurative and necrotizing lymphadenitis associated with bacteria of yersinial morphology. Similar pathological changes occur in Parinaud's oculoglandular syndrome in man due to infection with Y. pseudotuberculosis.

Outbreak of wildebeest-associated malignant catarrhal fever in Ankole cattle.

During an outbreak of malignant catarrhal fever in a herd of Ankole cattle in a zoological collection, two adult cows and one adult bull from a herd of 15 died or were euthanased between July and November 2004. The clinical, gross postmortem and histological findings were typical of the disease in uk native domestic cattle. The diagnosis was confirmed by serology in two animals, and by pcr in all three; the pcr provided evidence of alcelaphine herpesvirus type 1 infection in all three animals and also of ovine herpesvirus type 2 infection in one.