Journal of Veterinary Diagnostic Investigation最新文献

Intracranial sarcomas are rarely reported in dogs. A 9-y-old, castrated male mixed-breed dog was evaluated and euthanized because of a 1-wk history of lethargy, dullness, disorientation, right-sided head tilt, and circling to the right. Grossly, a pale-tan, firm, 1.5-cm mass effaced ~60% of the right-ventral aspect of the pons. Histologically, the mass was composed of elongate neoplastic cells with abundant cytoplasm and round-to-oval nuclei arranged in bundles and supported by collagenous stroma. Anisocytosis and anisokaryosis were moderate, with 11 mitoses in 2.37 mm² (10 FN22/40× fields). The neoplasm was well-demarcated with occasional areas of infiltration in the surrounding neuroparenchyma. Neoplastic cells had widespread cytoplasmic immunolabeling for vimentin, patchy cytoplasmic immunolabeling for myoglobin, weak cytoplasmic immunolabeling for desmin, and rare cytoplasmic immunolabeling for myogenin. Transmission electron microscopy (TEM) revealed bundles of oval-to-elongate neoplastic cells with small-to-medium cytoplasmic aggregates of rough endoplasmic reticulum cisterns. The centrally-to-peripherally located nuclei were round and had one or more compact-to-reticulate nucleoli. Collagen bundles were in intimate contact with the plasma membrane of neoplastic cells and formed the abundant extracellular matrix. Histologic, immunohistochemical, and ultrastructural findings were consistent with an encephalic fibrosarcoma. The myogenic differentiation suggested by immunohistochemistry could not be confirmed by TEM.

Here we describe 2 outbreaks of intoxication by Ricinus communis in cattle in Argentina. In outbreak 1, in 2010, 180 heifers were introduced to a paddock heavily invaded by R. communis. Thirty-two animals developed watery diarrhea, and 6 of them were drooling, and had constant chewing motions, blindness, incoordination, depression, and prostration. Four affected animals died 12-14 h after the onset of clinical signs; another died 4 d later. The surviving 27 animals were removed from the paddock and recovered. At autopsy, several organs were congested and hemorrhagic, and abundant pericarps, leaves, and seeds of R. communis were found in the rumen content. The main microscopic lesion was acute, diffuse, superficial necrotizing gastroenteritis, and intestinal congestion and hemorrhage. In outbreak 2, in 2013, severe neurologic signs were observed in 12 of 300 cows after being introduced into a corn paddock without grain production that had been severely invaded by R. communis. Affected animals were excited and had tremors, drooling, incoordination, and prostration. The herd was immediately transferred to another paddock, and all affected cows recovered without treatment. In outbreak 1, the clinical signs and lesions were characteristic of simultaneous poisoning by R. communis fruits, which contain ricin and cause mainly digestive signs and lesions, and by leaves and pericarps, which contain ricinine and cause nervous signs. In outbreak 2, clinical signs and the recovery of the animals suggest that the intoxication was caused by ricinine, which is present in the leaves of R. communis.

An outbreak of botulism occurred in March 2024 among horses at a Quarter Horse stud farm in Central-West Brazil. After ingesting baleage, 22 of 26 (85%) horses housed in stables and fed baleage became ill. The affected horses had dysphagia, muscular weakness, fasciculations, and progressive recumbency; 13 of 22 (59%) died within a few days. The diagnosis of type C botulism was established based on clinical and epidemiologic findings and confirmed by mouse bioassays, which indicated botulinum toxin type C in liver samples and intestinal contents. Furthermore, PCR testing identified toxigenic Clostridium botulinum in the baleage consumed by the horses.

Conidiobolus sp. causes conidiobolomycosis, an emerging invasive fungal disease that affects humans and animals, mainly in tropical regions. In sheep, the disease has a major economic impact. We report an outbreak of conidiobolomycosis on a sheep farm in the Brazilian Amazon, as well as give a brief review of the subject. Veterinary care was requested on a rural property on which 3 of 35 sheep had developed prostration, facial edema, and exophthalmos. Two of the sick animals died, and a third was referred to the Veterinary Hospital of the Federal University of Acre (Rio Branco, Acre, Brazil). After imaging tests, the animal was euthanized given the advanced clinical stage of the disease. The main autopsy findings were rhinosinusitis with caseous necrosis, destruction of the nasal turbinates, and pulmonary granulomas. Based on our histologic, immunologic, microbiologic, and molecular tests, the outbreak was confirmed to be caused by Conidiobolus lamprauges, a saprozoonotic agent that has not been reported previously in northern Brazil, to our knowledge.

A 4-y-old male Labrador Retriever was submitted for autopsy following radiographic examination by the owner, a veterinarian, which had revealed 3 embedded projectiles. Autopsy revealed a single entrance wound on the left flank. Using flap-by-flap dissection, the trajectory of the projectile was traced through the skin and lumbar musculature to its location where it had perforated the abdominal aorta, causing fatal acute hemoperitoneum. Remarkably, the copper-coated pellet (Diabolo) was found in the lumen of the right femoral artery, consistent with projectile embolism. No external trauma was present at that site. Embolization can occur when a projectile enters the vasculature and travels to a distal location, typically requiring low residual kinetic energy and a vessel of sufficient caliber. Although well documented in human forensic medicine, projectile embolism is exceedingly rare in veterinary cases. To our knowledge, embolization of a projectile in the femoral artery in a dog has not been reported previously. Our case highlights the importance of comprehensive radiographic imaging before autopsy and illustrates the diagnostic value of correlating radiologic findings with meticulous gross examination in veterinary forensic pathology cases.

The reliability of assumptions made about prevalence for pooling optimization varies greatly among target pathogens and surveillance strategies. When prevalence is unknown and difficult to anticipate, surveillance programs risk generating additional costs if pooling is suboptimal. Different methods of approximating optimal pool size (OPS) vary in precision of optimization, required sampling information, and the logistical demands placed on a laboratory workflow. Hence, it can be unclear how to assess compatibility between pooling optimization methods and the priorities of a surveillance program, sampling practices for the target population, and infection dynamics of the target pathogen. Our aim was to determine the relative performance in maximizing testing economy and cost reduction in different surveillance programs by simulating different pooling optimization methods on data from 280 submissions for bovine viral diarrhea virus (BVDV) surveillance (Nebraska Veterinary Diagnostic Center) and 111 submissions for Theileria orientalis surveillance (Virginia Tech Animal Laboratory Services). True prevalence, OPS, and historical prevalence were determined for each submission, and different optimization methods using fixed pool sizes, historical prevalence, and prevalence estimation testing were trialed on the data through Monte Carlo simulations. Contrasting results were observed between the 2 target pathogens, with historical prevalence being the most reliable optimization method for BVDV and the least reliable method for T. orientalis, which required significantly more tests than truly optimized pooling (p <0.05). Our results demonstrate the need to consider the interplay of infection dynamics, sampling practices, and surveillance priorities when selecting a pooling optimization approach.

White spot syndrome virus (WSSV; family Nimaviridae; taxon species White spot syndrome virus) is a major viral pathogen that poses a significant threat to the global shrimp industry, with early detection being the most effective strategy for disease control. We developed a CRISPR-Cas12a-based dual-target detection assay for WSSV, specifically targeting the VP28 gene (gene product is a major envelope protein) and WSSV366 (a latency-associated gene), optimized using Indian WSSV isolates. Our CRISPR RNAs for both targets had high efficiency, and we evaluated the assay using fluorescence-based and lateral flow strip (LFS) endpoint detection. In fluorescence assays, the Cr-WSSV assay (without recombinase polymerase amplification, RPA) detected WSSV at 3 × 10⁵ copies/μL; RPA integration significantly enhanced sensitivity, allowing detection at as low as 20 and 200 copies for VP28 and WSSV366, respectively, with 100% specificity. We developed a CRISPR-based LFS assay with optimized FAM-biotin reporter concentrations of 100 nM and 250 nM, yielding robust and reproducible results for improved field applicability. Performance evaluation confirmed lack of cross-reactivity to other WOAH-listed shrimp pathogens, while maintaining detection limits of 20 and 200 copies of VP28 and WSSV366. Clinical validation further demonstrated that the RPA-Cr-WSSV-LFS assay successfully detected WSSV366 even in VP28-negative samples, underscoring the importance of detecting WSSV366 in latent infections. Our rapid, cost-effective, and highly sensitive CRISPR-Cas-based assay enhances WSSV surveillance and biosecurity in shrimp aquaculture by incorporating structural and latency-associated gene markers, making it a promising alternative to conventional molecular testing.

An 11-y-old spayed female American rabbit (Oryctolagus cuniculus) was presented for autopsy with a left maxillary mass. Grossly, the mass was firm, pale-tan, and firmly adhered to the left maxillary bone. Similar masses were observed in the lungs, liver, and kidneys. Histologically, the mass was poorly demarcated, unencapsulated, highly infiltrative, and densely cellular, consisting of neoplastic cuboidal-to-polygonal cells arranged in acini and occasional tubules anchored in a delicate fibrous stroma. Neoplastic cells were positive for anti-keratin/cytokeratin AE1/AE3 antibody. Similar neoplastic cells were present in the lungs, liver, and kidneys. Histopathologic and immunohistochemical findings were consistent with an adenocarcinoma. Based on the anatomy and histology of the rabbit lacrimal gland and adjacent lacrimal gland structures, we concluded that this was an adenocarcinoma arising from the accessory lacrimal gland. To our knowledge, adenocarcinoma originating from the accessory lacrimal gland has not been documented previously in a rabbit.

Mycobacterium celatum is a slow-growing, non-tuberculous mycobacterium with occasional branching morphology that has been reported mainly in immunocompromised human patients and rarely in other animal species. A 5-y-old female ferret was presented to a veterinary clinic with a history of anorexia and lethargy; peripheral lymphadenopathy, splenomegaly, and pneumonia were detected. Despite treatment, progressive deterioration of the ferret's health led to euthanasia of the animal. Autopsy revealed numerous small 1-4-mm white nodules in the lung, spleen, and kidneys. Histologically, the kidney and lung nodules were pyogranulomas containing slender, elongate acid-fast bacilli with occasional branching. Bacterial culture was negative after 5 d of aerobic incubation. A PCR assay of kidney tissue was positive for Mycobacterium spp., with 100% DNA sequence similarity to M. celatum. M. celatum can cause systemic infection in humans and animals resembling tuberculoid mycobacterial infection. The diagnosis can be challenging due to cross-reactivity with tuberculosis-specific molecular assays and slow growth on bacterial culture. Although M. celatum has been reported elsewhere in ferrets more commonly than in other animals, M. celatum has not been reported previously in any animal species in North America, to our knowledge. M. celatum should be included as a potential pathogen in systemic mycobacterial infections, especially in ferrets.

Diagnosis of lymphoid hyperplasia and neoplasia due to lymphoproliferative disease virus (LPDV; Retroviridae, Alpharetrovirus) infection in turkeys is challenging due to histopathologic similarities with nonspecific inflammation and cellular responses to other retroviral infections. Localization of LPDV RNA or protein antigens within affected tissues, which has previously not been shown, would allow for more definitive diagnoses. We evaluated formalin-fixed paraffin-embedded tissues from 32 turkeys, including 15 naturally infected wild turkeys, 11 experimentally infected domestic turkeys, and 6 uninfected wild and domestic turkeys, using RNAscope in situ hybridization (ISH) and immunohistochemistry (IHC). ISH probes targeted a segment of the gag gene, and IHC antibodies were designed to recognize the capsid protein. Tissues from 4 infected turkeys were subjected to concurrent ISH and IHC labeling. All infected turkeys had ISH and IHC cytoplasmic and/or nuclear labeling of lymphocytes in at least one tissue, including within lymphoid tumors. ISH labeling was widely scattered in lymphocytes, whereas IHC labeling distribution was more limited. Spleen consistently exhibited the strongest and most widespread ISH and IHC labeling in both wild and domestic turkeys. Labeled lymphocytes typically were localized to splenic germinal centers and around periarteriolar lymphoid sheaths in the thymic cortex. Lymphocytes occasionally had simultaneous ISH and IHC labeling in selected cases. No uninfected turkeys had ISH or IHC labeling. Our 2 methods of LPDV detection in formalin-fixed paraffin-embedded tissues can aid in distinguishing lymphoid proliferation due to LPDV from other etiologies and further characterize pathogenesis.