Veterinary Pathology最新文献

Herpesviruses are among the most significant viral pathogens that affect captive and free-ranging testudines. Moreover, herpesviruses are known to establish latent infections. In this report, we describe 2 cases of Trachemys herpesvirus infection in captive adult black-bellied sliders (Trachemys dorbigni) submitted for necropsy after a 2-week history of respiratory signs and oral lesions. Gross examination revealed severe diphtheric stomatitis, rhinitis, tracheitis, esophagitis, gastritis, and reddened lungs. Histologically, there were multifocal areas of necrosis with syncytial cells and fibrin deposition. Intranuclear amphophilic to eosinophilic inclusions were frequent in epithelial and syncytial cells, especially in the respiratory tract. Oral cavity and esophageal swabs were collected during necropsy and subjected to a multiplex nested PCR assay targeting herpesvirus DNA. The amplified DNA was sequenced and analyzed phylogenetically, confirming the virus as Trachemys herpesvirus. This is the first detailed description of clinical disease and associated lesions caused by Trachemys herpesvirus infection.

Lymphocryptoviruses (LCVs), members of the Gammaherpesvirinae subfamily, are associated with chronic fibrotic diseases in humans and animals. This study investigated LCV infection in 7 orangutans (Pongo pygmaeus), including 2 recent cases with severe respiratory disease and 5 archival cases analyzed retrospectively. Comprehensive necropsies were conducted on the recent cases, and all 7 underwent histopathological evaluation, quantitative polymerase chain reaction (qPCR), and in situ hybridization (ISH). LCV was detected in 3 cases (43%) by qPCR, including the 2 recent cases and 1 archival case. The highest viral loads, as determined by the qPCR, were observed in the lungs of positive cases. Histological examination revealed significant pulmonary interstitial fibrosis and vascular remodeling in all LCV-positive cases, and type II pneumocyte hypertrophy was most prominent in an acute case. Masson's trichrome staining confirmed varying degrees of fibrosis in the pulmonary interstitium and perivascular stroma. LCV DNA, identified through ISH, was observed in alveolar macrophages, endothelial cells of pulmonary capillaries, and spindle cells within fibrotic regions of the lung and heart. Viral isolation from lung tissue in 1 recent case was successful, demonstrating cytopathic effects in Vero cells. Genetic sequencing revealed a novel LCV strain closely related to Pongo pygmaeus lymphocryptovirus-1 and Macacine lymphocryptoviruses. These findings link LCV infection to fibrotic pulmonary lesions in orangutans. Further studies are essential to elucidate the mechanisms of LCV-related disease and its implications for wildlife conservation.

Canine appendicular osteosarcoma (OSA) is a highly metastatic tumor in dogs. Mortality due to metastatic disease is common and frequently occurs within 1 year of diagnosis despite standard-of-care treatment. Treatment includes amputation for palliation and chemotherapy for metastatic disease. Current histologic grading schemes and biomarkers are poor at predicting clinical outcome. Novel prognostic and therapeutic markers are required to improve patient care. MicroRNAs (miRNAs) are small molecules expressed by all cells and released into bodily fluids. Studies in human and canine OSA cell lines, tissues from the primary site, and blood have demonstrated the role of miRNAs in metastatic progression of OSA and its prognostication. We sought to investigate the miRNA profile of primary OSA tissue and compare it to pulmonary metastases and normal lung tissue by real-time quantitative polymerase chain reaction (PCR). Multiple miRNA and multiple variable models were investigated in primary OSA tissue to predict clinical outcome. Thirteen miRNAs had similar expression between primary and metastatic OSA but were different from normal lung tissue. MiR-9-5p, miR-196a-5p, and miR-196b were expressed in metastatic OSA but lacked expression in almost all normal lung samples. In multiple variable models for overall survival and disease-free interval, only miRNAs were selected as significant variables. This study found miRNAs that are nearly exclusively expressed in metastatic pulmonary OSA and could serve as novel therapeutic targets. MiRNAs were also found to be important prognostic biomarkers in tissue and improved prognostic ability as miRNA signatures.

Lesions associated with perianesthetic death (PAD) postmortem submissions are infrequently reported in the literature, with no studies comparing findings between general and referral practices (RPs). This study compared PAD postmortem submissions in cats from a referral teaching hospital (referral practice, RP) and general practices (GP) in Saskatchewan. In the RP, death was most commonly due to euthanasia (15/23, 65%), with most cases having severe underlying disease. In GP, most deaths were unassisted (37/45, 82%), and most animals (33/37, 89%) had an undiagnosed condition or an unknown cause of death. The American Society of Anesthesiologists (ASA) physical status classification was high (ASA III-V) in 16/23 (70%) of RP cases and low (ASA I-II) in 38/45 (85%) of GP cases. Cats with limited medical history accounted for 5/23 (22%) of the RP submissions and 17/45 (38%) of the GP submissions. Reporting of gross examination findings and tissues collected for histologic examination were inconsistent. For example, although the presence of negative pressure within the thoracic cavity is evaluated routinely during a complete postmortem examination, its presence (or absence) was only reported in 4/45 (9%) of cases where the animal died unassisted. No significant difference was found in determining the cause of death between RP and GP when euthanized cases were excluded (P = .445). A standardized perianesthetic postmortem checklist is proposed to enhance reporting and improve diagnostic consistency.

Feline diffuse iris melanoma (FDIM) is a common ocular neoplasm, typically affecting older cats, characterized by progressive hyperpigmentation and potential malignancy. This study evaluated the diagnostic value of iris biopsies in distinguishing FDIM from benign iris melanosis. Seventeen cases with suspected FDIM were analyzed through ex vivo iris biopsies and corresponding enucleated globes. Histological evaluation by 8 pathologists revealed an average concordance of 81.6% between biopsy and globe diagnoses. The reliability of biopsy samples was influenced by tissue quality, with 12/136 slides deemed non-diagnostic due to artifacts or insufficient tissue. While biopsy retrieval offers a less invasive alternative to enucleation, its effectiveness is limited by technical factors, including tissue handling and sampling techniques. The results suggest that iris biopsies can be valuable for diagnosing advanced FDIM but require skilled execution. Further studies should explore early-stage FDIM and melanosis to better assess the diagnostic potential of biopsies across various disease stages.

Lymphoma is a common neoplasm in cats, in which alimentary lymphoma is a common subtype, and it is usually diagnosed in elderly, feline leukemia virus (FeLV)-negative cats. This study aimed to describe the pathological features of lymphoma with involvement of the alimentary tract in FeLV-antigen-positive cats. In a 12-year retrospective study, 32 necropsied and FeLV-infected cats with lymphoma affecting the alimentary tract were identified. Twenty-one cases were multicentric lymphomas with secondary involvement of the alimentary tract, and the remaining 11 cats were considered to have primary alimentary lymphoma. The small intestine was the most common anatomic location (23/32; 72%), followed by the large intestine (19/32; 59%) and stomach (18/32; 56%). In 22/32 cases (69%), multiple organs within the alimentary tract were concomitantly affected. Thickening of the intestinal and gastric walls was the most common gross lesion (23/32; 72%), while mural nodules were observed in 16/32 cats (50%). The mesenteric lymph nodes were frequently affected (22/32; 69%). Most lymphomas were composed of large (17/32; 53%) and intermediate cells (14/32; 44%). B-cell lymphomas were more frequent (24/32; 75%), and diffuse large B-cell lymphoma was the most common diagnosis (15/32; 47%). In 31/32 (97%) cases, FeLV gp70 antigen was detected in neoplastic lymphocytes by immunohistochemistry. Lymphomas affecting the alimentary tract may be observed in FeLV-infected, young adult cats, in which large to intermediate cell and B-cell lymphomas are more frequently observed, and small cell T-cell intestinal lymphoma is unlikely to be diagnosed.

Eight rodents were submitted for necropsy after being found in soft drink beverages. To determine whether the postmortem changes in these mice were consistent with contamination at the time of bottling/canning or after the beverage was opened by the consumer, we conducted a study of the effects of prolonged rodent submersion in soft drinks. Thirty unmanipulated laboratory mice, euthanized for other reasons, were placed in bottled beverages (diet and regular cola, sweet and unsweetened tea, seltzer water, and water) for time intervals ranging from 3 days to 2 months. Starting at the 1-week time point, all rodents submerged in sealed carbonated beverages at room temperature showed severe, full-body gas distention. This change was not seen if the bottle was uncapped or if the beverage was refrigerated. Other significant changes included staining of the incisors starting at 1 week in the colored beverages (colas, teas), and erosion of the occlusal surface of the incisors starting at 2 weeks in the acidic beverages (colas, teas, seltzer). Visceral decomposition increased with time in all the beverages, but was most rapid in the regular cola. The mice submitted for necropsy showed no gas distention, no incisor erosion, and visceral decomposition similar to the experimental mice at the 1-week time point. As the interval between production and opening ranged from 3 weeks to 3 months, these results suggest that the rodents entered the beverage containers after they were opened by the consumer.

The lymphatic system plays an essential role in the drainage of fluids, proteins, and cells from tissues. However, it facilitates the dissemination of cancer cells, favoring progression and the development of metastases. The present study aimed to characterize the intratumoral and peritumoral lymphatic vessel density and to evaluate their prognostic value in canine cutaneous mast cell tumors (MCTs). The lymphatic vessels from intratumoral and peritumoral areas were identified and quantified in 57 tumor samples from 51 dogs (28 low-grade and 29 high-grade MCTs), using immunohistochemistry with an anti-LYVE1 antibody. The results were compared with histological grades, mortality due to the disease, and post-surgical survival of the patients. The number of peritumoral lymphatic vessels was higher in high-grade MCTs (P = .0370) and in dogs that died due to the disease (P = .0215), while no statistically significant differences were found for intratumoral lymphatic vessel counts. Dogs that had MCTs with peritumoral lymphatic vessel counts higher than 113 had shorter post-surgical survival times, with a median survival of 122 days (P = .0080; hazard ratio = 4.886). No association was detected between lymphatic vessel counts and the presence of lymph node metastases. Our results suggest that peritumoral lymphatic vasculature is a prognostic indicator for post-surgical survival in cases of canine cutaneous MCTs.