Veterinary Pathology最新文献

Although rare, tick-borne encephalitis (TBE) is one of the most important and commonly fatal viral diseases affecting the central nervous system (CNS). This arboviral disease is transmitted by ticks and prevalent in widespread parts of Eurasia. Besides humans, several domestic animals such as dogs, horses, and ruminants can also be infected. To our knowledge, there have been no reports of TBE in South American camelids, so far. Here, we present 2 cases of Huacaya alpacas with progressive, therapy-resistant neurologic signs, which were euthanized and submitted for necropsy. Histologic examination of the CNS revealed a moderate lymphohistiocytic meningoencephalomyelitis characterized by perivascular cuffing, glial cell proliferation, neuronal degeneration, and neuronophagia. Tick-borne encephalitis virus (TBEV) infection was confirmed by polymerase chain reaction (PCR), sequencing, immunohistochemistry, and RNAscope in situ hybridization. TBEV should be included as a differential diagnosis in alpacas from endemic regions presenting with neurologic signs.

Silica is a well-known stimulus of granulomatous inflammation in the lungs of humans and other animals. However, it has been poorly studied as a cause of cutaneous inflammation in domestic animals, despite the predominance of silica in traditional (clay-based) cat litter substrates. Here we characterize the clinical and pathologic findings of 13 surgical biopsies from the paws or paw pads of domestic cats submitted to 2 veterinary institutions between 2005 and 2023. Gross lesions often included chronic or intermittent paw pad swelling, ulceration and bleeding, or draining tracts, particularly in the front paws. All biopsies consisted of granulomatous to pyogranulomatous inflammation with birefringent, amorphous to granular, blue-gray, intrahistiocytic material consistent with silica. Raman spectra were collected from 3 biopsy samples at 45 different locations. Using multivariate analysis, the foreign material in the biopsies had similar Raman spectra to multiple brands of silica-based cat litter. Ten of 13 biopsies also contained evidence of plasma cell pododermatitis, suggesting that underlying paw pad disease may predispose some cats to cutaneous cat litter implantation. In these cats, subsequent granulomatous inflammation may obscure the underlying condition and exacerbate clinical disease. Routine polarization of feline paw or paw pad biopsies is recommended to aid in recognition of cat litter granulomas. Careful examination for a predisposing condition is also warranted when cat litter granulomas are identified. Recurrence is common following surgery; affected cats, and predisposed cats with paw pad disease, may benefit from the use of alternate litter substrates to prevent this lesion or its recurrence.

Cutaneous lesions due to papillomavirus (PV) infection are well described in cats. However, there are few reports of similar lesions in the oral cavity. In this case series, 7 cats with in situ carcinomas of the oral mucosa are reported. Lesions appeared histologically like cutaneous Bowenoid in situ carcinomas, and PV-induced cell changes were visible within lesions from 6 cats. A PV etiology was further supported by intense p16^CDKN2A protein immunolabeling within all lesions. Five lesions contained Felis catus papillomavirus (FcaPV) type 3 DNA, while 2 contained FcaPV1 DNA. Cats had clinical signs of drooling and oral pain for over 6 months prior to diagnosis, and the dorsal surface of the tongue was most often affected. Four cats had multiple oral lesions, and 2 cats had oral and skin lesions. Of the 6 cats for which clinical outcome was known, 3 are still alive at least 6 months after diagnosis, 2 died of unrelated causes 7 and 14 months after diagnosis, and 1 cat was euthanatized due to oral pain 18 months after diagnosis. Results suggest PV-associated oral in situ carcinoma is a specific disease entity of cats. Lesions are slowly progressive with pain management allowing long survival times. No cases were known to progress to invasive squamous cell carcinoma, and feline oral squamous cell carcinomas appear to infrequently develop as a progression from these lesions. Due to the marked difference in biological behavior, diagnosticians should differentiate PV-associated oral in situ carcinomas and oral squamous cell carcinomas in cats.

This report describes a series of ethmoid tumors in 6, free-ranging white-tailed deer (Odocoileus virginianus; WTD) in southwest to central Texas, which included 4 plasma cell tumors, 1 adenosquamous carcinoma, and 1 adenocarcinoma. The plasma cell tumors had a distinctive presentation with unilateral to bilateral facial masses located rostromedial to the eyes that were smooth and fluctuant. Upon dissection, these preorbital facial masses consisted of multiloculated, mucus-filled, cystic pockets with 2 having partial extension of the ethmoid tumors into the external facial masses. The 2 carcinomas were larger, unilateral, solid facial masses. All tumors caused extensive destruction of the ethmoid region with the carcinomas being paler, firmer, and more invasive into surrounding areas compared with the plasma cell tumors. Ancillary testing did not reveal an underlying infectious cause, although these reports of multiple WTD across a localized region suggest a possible infectious, environmental, or other shared stimulus.

Iron overload is a leading cause of morbidity and mortality in Egyptian rousette bats (ERBs; Rousettus aegyptiacus) within managed care settings. We compared hepatic iron accumulation and tissue damage in samples collected from managed care bats in a zoo setting, a research colony, and a free-ranging population with the goal of determining if iron overload was a potential cause of morbidity for free-ranging ERBs. Livers from 20 zoo bats, 8 research colony bats, and 69 free-ranging bats were histologically evaluated for fibrosis, necrosis, and iron accumulation in hepatocytes and Kupffer cells. Hemochromatosis was identified only in the zoo population, with hemosiderosis identified in all research colony bats and many free-ranging bats. There were statistically significant associations between age classification, population, and diagnosis and between Marburg virus infection status and histologic liver iron scores. In addition, there were positive associations with statistical significance between age class (juvenile, adult) and histologic iron scores and between population type (zoo bats > research colony bats > free-ranging bats) and histologic iron scores. Excessive hepatic iron storage does not appear to be a source of morbidity within free-ranging ERB populations.

A high mortality event occurred among Malabar groupers (Epinephelus malabaricus) reared for research. The affected fish had scattered reddish patches and ulcers on the skin, accompanied by parasite infestations on the skin surface. Histologic findings included ulcerative dermatitis and keratoconjunctivitis with gram-negative bacilli, and the parasites were often observed on the skin surface. Bacterial examinations and in situ hybridization revealed the presence of Vibrio harveyi in the affected tissues. The parasites were morphologically identified as the subfamily Benedeniinae (Monogenea: Capsalidae), likely Neobenedenia girellae. The monogeneans may have come into contact with the fish at a farm in Okinawa, Japan, and potentially facilitated the opportunistic infection with V. harveyi. This is the first report of vibriosis caused by V. harveyi in Malabar groupers.

Injections have been linked to feline sarcomas (feline injection-site sarcoma; FISS) and cutaneous lymphomas (cutaneous lymphoma at injection site; CLIS). Both tumors often exhibit lymphoplasmacytic inflammation ascribed to injected immunogenic material. CLIS is hypothesized to emerge from transformation and clonal expansion of lymphoid cells following persistent immune stimulation with feline leukemia virus (FeLV) reactivation and transformation. To further study whether the lymphocytic infiltrates associated with FISS can represent a suitable niche for the development of CLIS, 34 cases of FISS were examined. Lymphoid cell phenotypes were assessed using CD3 and CD79 immunohistochemistry. For cases with prominent inflammation, FeLV p27 and gp70 immunohistochemistry and PCR for antigen receptor rearrangements were performed. Male domestic shorthair cats predominated. The mean age was 12.2 years (range: 5-17 years). FISS developed in thoracic (8/34, 24%), flank (7/34, 21%), and interscapular (5/34, 15%) regions. Similar proportions of B and T lymphocytes were found in 11/34 (32%) cases; T-cells predominated in 12/34 (35%) cases, and B-cells predominated in 11/34 (32%). At least one FeLV antigen was expressed in lymphoid infiltrates in 10/18 cases (55%), and in neoplastic fibroblasts in 8/18 cases (44%), while both FeLV proteins were expressed in neoplastic cells in 3/18 cases (17%). One cat had clonal T-cell receptor-gamma and was diagnosed with concurrent FISS and CLIS. This case lacked FeLV expression. FeLV amplification from formalin-fixed paraffin-embedded material was unsuccessful. The expression of FeLV p27 and/or gp70 in neoplastic spindle cells and lymphoid infiltrates raises the possibility of FeLV involvement in the tumorigenesis of FISS and CLISs.

Avian reovirus (ARV), the etiologic agent of poultry viral arthritis/tenosynovitis, frequently presents diagnostic challenges due to its non-specific lesions, ubiquitous nature, and the lack of standardized diagnostic guidelines. We describe cases of poultry arthritis/tenosynovitis, where ARV was the suspected etiology, and investigate the relationship between lesion severity and viral RNA levels using quantitative real-time reverse-transcriptase polymerase chain reaction (qRT-PCR) with RNAScope in situ hybridization (ISH) to support ARV detection and analysis. A total of 51 cases (qRT-PCR positive [n = 38; Ct range = 20.9-35.9] and qRT-PCR negative [n = 13; Ct > 37]) were analyzed, with case selection criteria including clinical lameness, complete histologic examination of the gastrocnemius/digital flexor tendons, and qRT-PCR testing for ARV. A subset of qRT-PCR positive cases (n = 33) and negative cases (n = 8) with the sections showing the most severe histologic lesions were selected for ISH. Histologic scoring of tenosynovitis included inflammation severity; synovial proliferation; and the presence of lymphoid nodules, neovascularization, and fibrosis. The qRT-PCR positive cases had significantly higher histologic scores than negative cases. The ISH detected viral transcripts within synoviocytes and subintimal fibroblasts only in qRT-PCR positive cases (11/33, 33.3%; Ct range = 20.9-32.3). Positive ISH results were also statistically associated with lower Ct values and higher lesion scores. In conclusion, this study aids in ARV diagnostic challenges by linking lesion severity with viral transcription, identifying fibroblasts as ARV-infected cells, and demonstrating ISH as both a valuable diagnostic tool and a means to studying ARV pathogenesis in poultry.

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.