A case of nerve sheath tumor followed by multicentric high-grade T-cell lymphoma in an African pygmy hedgehog (Atelerix albiventris).

A 3-year-old intact male African pygmy hedgehog was presented at the Teaching Hospital of the Faculty of Veterinary Medicine, University of Belgrade, with a growth on the left side of its abdomen. After clinical examination, the mass was surgically removed, and histopathological findings indicated a nerve sheath tumor. The hedgehog fully recovered after surgery and was euthanized eight months later due to the appearance of multicentric changes in the internal organs. Further necropsy and macroscopic, cytologic, histopathologic, and immunohistochemical findings revealed that the tumor was a multicentric high-grade T-cell lymphoma. This is an unusual case of an African pygmy hedgehog with two different neoplasms-a nerve sheath tumor followed by lymphoma.

Highly Pathogenic Avian Influenza H5N8 Outbreak in Backyard Chickens in Serbia.

In winter 2016/2017, the highly pathogenic avian influenza virus H5N8 was detected in backyard poultry in Serbia for the first time. The second HPAI outbreak case in backyard poultry was reported in 2022, caused by subtype H5N1. This is the first study that documents the laboratory identification and pathology associated with highly pathogenic avian influenza in poultry in Serbia during the first and second introduction waves. In both cases, the diagnosis was based on real-time reverse transcriptase PCR. The most common observed lesions included subepicardial hemorrhages, congestion and hemorrhages in the lungs, and petechial hemorrhages in coelomic and epicardial adipose tissue. Histologically, the observed lesions were mostly nonpurulent encephalitis accompanied by encephalomalacia, multifocal necrosis in the spleen, pancreas, and kidneys, pulmonary congestion, and myocardial and pulmonary hemorrhages. In H5N8-infected chickens, immunohistochemical examination revealed strong positive IHC staining in the brain and lungs. Following these outbreaks, strict control measures were implemented on farms and backyard holdings to prevent the occurrence and spread of the disease. Extensive surveillance of birds for avian influenza virus did not detect any additional cases in poultry. These outbreaks highlight the importance of a rapid detection and response system in order to quickly suppress outbreaks.

First Report of Sarconema eurycerca Heart Infection in Mute Swans in Serbia.

BACKGROUND: The Sarconema eurycerca heart infection may be one of the main causes of death in swans and geese due to severe heart lesions. To date, there have been no reports of Sarconema eurycerca in mute swans (Cygnus olor) in Serbia and this parasite has never been morphologically characterized in wild birds from this region. METHODS: In spring 2021, eight dead mute swans (Cygnus olor) were collected during avian influenza surveillance on the territory of the Province of Vojvodina and submitted to Scientific Veterinary Institute "Novi Sad" to determine the cause of death. The presence of highly pathogenic avian influenza subtype H5N1 was determined in all swans using molecular methods. RESULTS: Necropsy of the swans revealed changes characteristic for highly pathogenic avian influenza infection, such as severe haemorrhages and necrosis in different organs. Three of the eight swans showed massive subepicardial haemorrhages and myocarditis with intralesional 2-4 cm long whitish roundworms. Histopathologically, haemorrhages and many adult heart worms were observed in the myocardium. Based on morphological features of parasites, infection by Sarconema eurycerca was concluded. CONCLUSION: According to the available scientific literature, the presence of heart roundworms in swans has not yet been confirmed in our country. This report is the first published case of cardiac filariasis associated with S. eurycerca infection in mute swans in the Republic of Serbia.

Comparative pathological findings in mute swans (Cygnus olor) naturally infected with highly pathogenic Avian influenza viruses H5N1 and H5N8 in Serbia.

The aim of this study was to compare pathological lesions and viral antigen expression in the organs of mute swans (Cygnus olor) naturally infected with highly pathogenic avian influenza virus subtypes H5N1 and H5N8. The examination was conducted on the carcasses of 22 mute swans which died during the avian influenza outbreaks in Serbia in 2006 and 2016-2017. Avian influenza virus subtype H5N8 isolated from mute swans in 2016-2017 was clustered within the 2.3.4.4 clade group B. After necropsy, lung, liver, spleen, pancreas, kidney and brain tissues were sampled for histopathology and immunohistochemical examination. Avian influenza virus nucleoprotein polyclonal antibodies were used for detecting the viral antigen in the examined tissues. The most significant gross lesions were necrosis and haemorrhages in the pancreas. Major histological lesions were multifocal necroses in the pancreas, spleen and liver, non-purulent encephalitis, lung congestion and oedema. Immunohistochemical demonstration of HPAIV nucleoprotein in pancreas and brain was strongly consistent with histological lesions in both infected groups. Our findings showed that pancreas was the most affected organ in all examined mute swans. In addition to increased mortality rate, similar pathological findings were detected in mute swans naturally infected with highly pathogenic avian influenza viruses H5N1 and H5N8.

Association of the severity of lung lesions with carcass and meat quality in slaughter pigs.

The aim of this study was to determine the association of lung lesions with carcass and meat quality traits in slaughter pigs and to describe the main morphological features associated with lung lesions. Macroscopic lesions on the lungs were detected in 67.09% of a total of 79 pigs examined. Histopathological examination revealed that acute and chronic interstitial pneumonia represented the commonest changes, detected in 26.67% and 33.33% of the cases, respectively. Bronchopneumonia was found in 33.33% of the cases. By immunohistochemical examination, 26.67% of the lungs showed the presence of severe peribronchiolar and perialveolar infiltration composed predominantly of CD3+ T lymphocytes, which finding may be indicative of viral pneumonia. Regarding the production traits, it was confirmed that pigs with severe lung lesions had the lowest liveweight, hot carcass weight and meatiness, the highest pH value 45 min after slaughtering (pH45) and the highest incidence of dark, firm, dry (DFD) and pale, soft, exudative (PSE) meat. The presence of lung lesions significantly downgraded carcass value and caused a significant deterioration in pork quality.

Histological and immunohistochemical characteristics of cerebral amyloid angiopathy in elderly dogs.

BACKGROUND: Cerebral amyloid angiopathy (CAA) is a disorder characterized by amyloid deposition in the wall of cerebral blood vessels. The deposits of amyloid occur frequently in the blood vessels of the frontal, parietal and occipital cortex. OBJECTIVE: To examine the characteristics of CAA classified according to the Vonsattel scale in elderly dogs histologically and immunohistochemically as well as the semi-quantitative evaluation of the amyloid deposits in the different segments of the brain. ANIMALS AND METHODS: The brains of 36 dogs of different breeds and sexes, which had been routinely necropsied, were used and divided into two groups: dogs from 1 to 5 and 10 to 18 years old. The tissue sections were stained by hematoxylin-eosin, Congo red and immunohistochemically. RESULTS: Amyloid was accumulated in the wall of cerebral blood vessels in 70% of dogs over the age of 10 years predominantly in the frontal cortex. CAA was demonstrated in elderly dogs as follows: in the frontal cortex (n = 19 or 63%), the parietal cortex (n = 12 or 40%), the hippocampus (40%) and the cerebellum (n = 5 or 17%). The deposits of amyloid in the wall of blood vessels detected by Congo red staining were also Aß1-14 and Aß1-42 immunohistochemically positive. Most commonly, the amyloid deposits affected a moderate number of blood vessels. The accumulation of amyloid was immunohistochemically revealed in the blood vessel walls as well as in the senile plaques and neurons. CONCLUSION: The amount of amyloid in the arterial walls increased with age in dogs, whereas the amyloid accumulated in plaques was Congo red negative.