Journal of Veterinary Diagnostic Investigation最新文献

The lung is composed of conducting airways, a gas-exchange region, and a dual circulatory system. Any of these components may be altered in respiratory disease, and complicated cases can be a diagnostic challenge. For veterinary pathologists, a solid foundation in normal anatomy is essential for recognition of patterns of disease. Additionally, the structure of the lungs informs the function; therefore, knowledge of how normal structures are disrupted provides insight into the pathogenesis of lung diseases. We detail the organizational structure, microanatomy, and cell types of the lungs of several species of veterinary importance: cattle, horses, pigs, sheep, goats, dogs, cats, mice, and rats. Animals with a thick pleura and interlobular septa have associated separation of secondary lobules, whereas those with a thin pleura lack interlobular septa and have indiscernible secondary lobules. The transition between terminal bronchioles and gas-exchange regions, presence of respiratory bronchioles, and cellular composition of the bronchioles are highly variable among species. Other species variations include bronchial structure and glands, collateral ventilation, and patterns of blood supply to the conducting airways, gas-exchange regions, and pleura. Examples of histopathologic correlates offer relevance of pulmonary microanatomy to the veterinary pathologist.

Canine extramedullary plasmacytomas are typically benign tumors of the skin, oral cavity, and alimentary tract that are cured by surgical excision. This tumor is rarely metastatic and aggressive. We report an unusual plasmacytoma in a dog that had been presented because of dyspnea. Aside from evidence of pleural effusion, no cutaneous lesions or other abnormalities were detected on physical examination. Nearly 2 L of pleural fluid were removed by thoracocentesis, and a sample was submitted for cytologic examination. The pleural fluid had increased protein and cell concentrations, with a predominance of individualized, large, round, atypical cells. Those cells frequently had Russell body-like intracytoplasmic structures, as seen on microscopic examination of modified Wright-stained concentrated slide preparations. Together, these findings were strongly supportive of a neoplastic plasma cell exudate. Immunohistochemical (CD3, CD20, MUM1, IgG, λ light chain) staining and B-cell PCR for antigen receptor rearrangement analysis performed on formalin-fixed, paraffin-embedded pleural cell-pellet sections confirmed a novel, clonal, IgG lambda extramedullary plasmacytoma with Mott cell differentiation that was most likely metastatic from a non-cutaneous primary site. Metastatic plasma cell neoplasia with voluminous serous cavity effusion carries a grave prognosis in humans, but has not been reported previously in dogs, to our knowledge.

Chronic wasting disease (CWD) continues to be detected across the United States and globally; enhanced detection is critical for disease management. Silica nanoparticles (SiNPs) have shown promise in reducing time-to-detection for the real-time quaking-induced conversion (rtQuIC) assay in white-tailed deer (WTD) retropharyngeal lymph nodes (RPLNs). We aimed to document such decreased time-to-detection in 3 Wyoming, USA, cervid species. Additionally, we investigated maximum slope (max slope) as a metric of differentiating CWD status by rtQuIC testing, and how the receiver operating characteristic (ROC) may be useful for setting thresholds for QuIC outcomes. We performed rtQuIC testing, with and without SiNPs, on postmortem RPLNs from 39 WTD (Odocoileus virginianus), 40 mule deer (O. hemionus), and 40 Rocky Mountain elk (Cervus canadensis nelsoni). To measure effects of using SiNPs in the rtQuIC assay (nano-rtQuIC), median time-to-thresholds (tTh) for each sample replicate from QuIC and nano-rtQuIC was obtained using ROC thresholds. We found that nano-rtQuIC decreased the median tTh by 4.9, 5.3, and 3.6 h in WTD, mule deer, and elk, respectively. When using nano-rtQuIC, test sensitivity decreased by 5% in elk and by 4.8% in mule deer RPLN samples, whereas test sensitivity increased in WTD from 83.3% to 95.2%, indicating inhibition under the 50°C rtQuIC condition for WTD. Mechanisms of inhibition of rtQuIC by WTD RPLNs, comparatively by species, are unknown, but SiNPs and max slope analysis helped optimize rtQuIC test results. Interlaboratory validation and testing in a broader range of biological cervid samples would be useful for confirming these initial findings.

The number of pet minipigs, also called micro- or mini-pigs, has increased. Although cardiovascular diseases, particularly congenital malformations, are well documented in industrial and laboratory minipigs, they have not been reported in pet minipigs, to our knowledge. Detailed cardiac examination in awake pigs is challenging and typically requires sedation or anesthesia, making awareness of potential cardiac conditions essential. We present clinical and pathology findings from 3 pet minipig autopsies: aortic dissection, myxomatous valve degeneration, and ventricular septal defect. These cases highlight the need for increased awareness and investigation of cardiovascular diseases in pet minipigs.

Streptococcus lutetiensis is a gram-positive organism in the non-enterococcal Lancefield group D Streptococcus bovis/S. equinus complex. S. lutetiensis has been reported as a cause of septicemia, endocarditis, and meningitis in humans, mastitis in dairy cows, and systemic streptococcosis in sea otters. A 3-mo-old reticulated giraffe (Giraffa reticulata) with a history of suspected failure of passive transfer (FPT) was submitted for postmortem examination, revealing bacterial septicemia, fibrinosuppurative polyarthritis, and embolic glomerulonephritis, with intravascular gram-positive cocci and microthrombosis in multiple organs. Bacterial culture and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry detected S. lutetiensis. S. lutetiensis septicemia was likely the result of FPT in this giraffe calf.

A 3-mo-old domestic shorthair cat was presented with multiple fractures. Bone morphology was normal radiographically, with no long bone deformity or increased bone translucency. A bone biopsy from the ilium was examined histologically, revealing that bone matrix in the trabeculae extended from the growth plate, but cartilage remained in the distal trabeculae. Osteoblasts were observed at the bone surface via immunohistochemical detection with an anti-RUNX2 antibody. Whole-genome sequencing identified a homozygous missense mutation (valine to methionine) in the zinc-dependent metalloprotease domain of BMP1, a gene associated with human osteogenesis imperfecta type 13. In silico analysis predicted that this mutation would disrupt BMP1 protein function, which could affect type I collagen processing. Our findings suggest that a missense mutation in BMP1 may cause feline osteogenesis imperfecta.

Feline coronavirus (FCoV) infects both domestic and wild felids and has the potential to cause feline infectious peritonitis (FIP), a progressive and often fatal systemic disease. Although rapid diagnosis and treatment are crucial in cases of FIP, conventional reverse-transcription quantitative real-time PCR (RT-qPCR) requires RNA extraction and specialized equipment, limiting its use for timely testing in general veterinary practice. We evaluated the performance of a direct RT-qPCR method using the PicoGene PCR1100 system (GoFoton, Ibaraki, Japan), which omits the RNA extraction step and delivers results within ~40 min. Compared with FCoV culture supernatants and extracted RNA, we estimated the limit of detection of this direct RT-qPCR method to be 150 copies/reaction-a detection sensitivity equivalent to that of conventional RT-qPCR targeting the FCoV 3'-UTR. We observed no cross-reactivity with other feline viruses or SARS-CoV-2. We subsequently analyzed 28 pleural and abdominal effusions collected from cats suspected of having FIP to compare the direct RT-qPCR method with the conventional approach. The sensitivity of the direct RT-qPCR method was 95.5% (95% CI: [78.2, 99.2]) and the specificity was 100% (95% CI: [61.0, 100.0]), which supports the use of the PCR1100 system as a rapid and user-friendly point-of-care tool for the detection of FCoV RNA in effusion samples.

The genus Salmonella, particularly Salmonella enterica subsp. enterica serovars Choleraesuis and Typhimurium, poses significant challenges to swine production and leads to economic losses from conditions such as septicemia and enterocolitis. We evaluated the effects of experimental infection with Salmonella Typhimurium on clinical signs and anatomopathologic outcomes in pigs. Twenty 90-d-old pigs were divided into 2 groups: G1 received an oral inoculum of 10⁸ cfu of Salmonella Typhimurium; G2 served as a control. Pigs were monitored clinically for 30 d; postmortem examinations and microbiologic analyses were conducted. No significant differences were found in rectal temperature or weight between groups; however, diarrhea episodes were noted in the challenged group starting on day 5 post-inoculation. Isolates of Salmonella Typhimurium were detected intermittently in the challenged group; all positive samples came from pigs without diarrhea. Macroscopic lesions in G1 pigs included button-shaped ulcers in the ileocecal region, enlarged or hemorrhagic mesenteric lymph nodes, and hyperplasia of lymphoid tissue in the colon.

A 9-mo-old, castrated male Saint Bernard dog was presented for evaluation of periorbital swelling, severe uveitis, and secondary glaucoma. Concurrently, chest radiographs had evidence of pneumonia. Enucleation was performed after failure of aggressive medical management. Histopathology of the globe confirmed severe necrosuppurative panophthalmitis and periocular cellulitis with myriad intra- and extracellular bacteria forming long filamentous chains. The bacteria were gram-positive and GMS-positive but acid-fast-negative. Next-generation sequencing (NGS) was performed on formalin-fixed, paraffin-embedded (FFPE) tissue from the eye. We identified a bacterium in the Actinomycetaceae family with a 100% BLAST match, suggestive of the previously described Actinomyces catuli strain (CCUG 41709). Clinical improvement followed enucleation and continued medical management, leading to reduction of the periocular swelling and resolution of the lung disease. Uveitis is common in dogs and is the most common cause of glaucoma. In many cases of bacterial uveitis, the exact bacterial organisms remain unknown if culture is not performed before fixation. Actinomyces sp. should be considered in patients with severe endophthalmitis or panophthalmitis, especially with evidence of systemic disease. NGS on FFPE samples may be a useful tool for identifying infectious organisms, especially in cases in which culture is not an option.

Avian influenza, caused by the avian influenza A virus (IAV), threatens poultry and public health. H6 subtype avian IAV is a low-pathogenic virus with hosts ranging from poultry and wild birds to mammals. H6 persists latently in poultry, which enables silent transmission and cross-species risk. The few fluorescence quantification assays that exist for H6 are mostly multiplexed. We developed a rapid, sensitive, efficient, monoplex fluorescence reverse-transcription qPCR (RT-qPCR) assay for H6 IAV. Specific primers and a TaqMan-MGB probe were designed based on the conserved hemagglutinin (HA) gene region of H6 IAVs from the GISAID database. The reaction components and conditions were optimized, and the assay was evaluated for specificity, sensitivity, and reproducibility. The optimized assay had excellent specificity, with no cross-reactivity with other avian viruses, including IAV subtypes H1-5, H7, H9, and H10, Newcastle disease virus, infectious bronchitis virus, fowl adenovirus, infectious laryngotracheitis virus, chicken anemia virus, Mycoplasmopsis (Mycoplasma) gallisepticum, and M. synoviae. Our method had a detection limit of 8.2 × 10⁰ copies/μL, which is 1,000 times more sensitive than conventional RT-PCR. The intra- and inter-assay CVs for all tested concentrations were both <1.5%, indicating good reproducibility. When applied to clinical swab samples, the sensitivity of our fluorescence RT-qPCR assay was 98.8% and specificity was 96.2% compared with traditional virus isolation. Our method could provide strong technical support for the early detection, monitoring, and prevention of H6 subtype IAV infection.