Journal of Veterinary Diagnostic Investigation最新文献

A 5-wk-old, 10.6-kg, intact female Leonberger dog was presented for evaluation of a mass on the left ventrolateral thorax that had been present since birth. A biopsy of the mass revealed an invasive, unencapsulated spindle-cell population arranged in bundles and concentric whorls (pseudo-onion bulb formations) with multifocal melanocytic differentiation. Neoplastic cells in pseudo-onion bulbs immunolabeled strongly for glial acidic fibrillary protein and PGP9.5 and moderately for S100 and Sox10. The supporting matrix had strong immunolabeling for laminin. Cells had multifocal immunolabeling for NeuN, melan A, and PNL2. Collectively, these histopathologic characteristics support a diagnosis of congenital nerve sheath tumor, which is rarely described in dogs.

An 11-mo-old, intact male captive kinkajou (Potos flavus) was submitted for postmortem investigation because of emaciation and hindlimb overgrooming. Histologically, alveolar airspaces were filled with fungal structures that were morphologically and histochemically consistent with Pneumocystis spp. PCR of pulmonary tissue was negative for canine distemper virus and positive for Pneumocystis spp. Molecular testing yielded amplification of the Pneumocystis spp. mitochondrial large-subunit rRNA (mtLSU rRNA, 510 bp) and the small-subunit rRNA (mtSSU rRNA, 565 bp). Phylogenetic analysis suggested a potentially novel Pneumocystis lineage associated with P. flavus. Additional nuclear loci are required to confirm its taxonomic status. Gastric and colonic histologic findings included concurrent candidiasis and colonic nematodosis. An underlying immunosuppressive disease was suspected. Further investigation is required to clarify the role of kinkajous in the ecology of fungal pathogens and the causes of immunosuppression in this species, particularly in the context of human-wildlife interactions. Enhanced surveillance and interdisciplinary collaboration are essential to evaluate potential zoonotic risks and inform conservation and public health strategies.

Marker-assisted selection has increasingly relied on single-nucleotide polymorphisms (SNPs) as robust genetic markers, particularly in livestock breeding programs. In pig farming, embryonic mortality significantly affects litter size, and SNPs in reference genes have been implicated as potential causal factors. We developed and optimized a tetra-primer amplification refractory mutation system (T-ARMS) PCR assay for rapid, cost-effective detection of SNPs in 3 candidate genes-TADA2A, PORL1B, URB1-that are associated with embryonic lethality and reproductive performance. Primer sets were designed based on known mutation sites and validated using synthetic gene constructs and porcine genomic DNA from pigs of Duroc and Landrace breeds. Optimization of annealing temperatures and primer concentration ratios yielded distinct and reproducible allele-specific amplicon patterns that were corroborated by PCR-RFLP and Sanger sequencing. Our T-ARMS PCR protocol, which requires minimal equipment and reduces processing time to <3 h, had high specificity and efficiency in differentiating wild-type, heterozygous, and homozygous mutant genotypes in 20 Duroc and 20 Landrace pigs. Our Tetra-ARMS PCR assay is a robust and economically viable tool for SNP genotyping in pig breeding programs, potentially contributing to the reduction of embryonic lethality and the improvement of overall reproductive outcomes.

Neonatal interstitial lung disease occurs within the first 3 wk of life and includes any disease process that affects alveolar septa and, in some species, interlobular septa. Postmortem diagnosis of neonatal interstitial lung disease is challenging because of our incomplete understanding of normal postnatal lung development, especially in altricial species such as dogs and cats, which are born with morphologically and physiologically immature lungs. Most altricial species are born with lungs in the saccular stage of development and continue development to the alveolar stage in the postnatal period. I address normal postnatal lung development in dogs and cats, structural immaturity of the lung, neonatal respiratory distress syndrome, and sepsis. Histologically, neonatal lungs are easily mistaken for infectious pneumonia or structural immaturity based on their thick alveolar septa and hypercellularity. However, by determining the stage of lung development and considering factors such as gestational age, birth weight, and age at death, the degree of lung development may be entirely appropriate for that animal. Neonatal respiratory distress syndrome is a clinical term for inadequate gas exchange. The underlying cause is surfactant dysfunction, which can be primary or secondary. Mature surfactant is essential for neonatal survival but is extremely difficult to assess in a postmortem lung. Sepsis is the leading cause of death in canine and feline neonates; histologic lesions are often subtle given the acute nature of the disease.

Four beef cows grazing in a mountainous grassland area had acute onset of drooling, frothy oral discharge, hyperemic mucous membranes, diarrhea, anorexia, dyspnea, and recumbency. Two cows died within 7-8 h of the onset of signs; the remaining 2 cows succumbed 24 h later. Scattered, 3-6-mm, gray-white solids were found on the grassland, suggesting potential contamination. Postmortem examination found abdominal distension, nasal hemorrhage, and distended rumens containing undigested forage. Hemorrhagic lesions were observed in the reticulum, omasum, abomasum, jejunum, and ileum. Yellow, 2-3-mm granular solids were identified in the rumen contents. Toxicologic analysis using scanning electron microscope-energy dispersive X-ray spectroscopy and high-performance liquid chromatography-inductively coupled plasma-mass spectrometry detected high concentrations of trivalent arsenic [As(III), up to 1,070 mg/kg] and pentavalent arsenic [As(V), up to 1,180 mg/kg] in the rumen contents and grassland solids. Elemental analysis revealed magnesium, aluminum, calcium, arsenic (As), silicon, carbon, and oxygen in the residues, suggesting industrial byproducts from As removal processes.

Between 2008 and 2024, fowl adenovirus (FAdV) genotypes were determined by hexon gene sequencing for 1,362 samples: 1,234 from 9 Canadian provinces and 128 samples from the United States. Most genotyped samples were from Ontario (681), followed by Alberta (243), Nova Scotia (116), British Columbia (77), Quebec (58), Saskatchewan (21), Manitoba (20), Newfoundland (16), and Prince Edward Island (2). Most samples (1,285) were related to inclusion body hepatitis (IBH); 77 samples were submitted for other reasons. Four FAdV genotypes (FAdV2, FAdV8a, FAdV8b, FAdV11) were associated with IBH-related submissions. Between 2008 and 2014, the most common strains associated with IBH outbreaks were FAdV11 and FAdV8a. However, since 2015, the identity of FAdVs involved in IBH outbreaks has shifted, with FAdV8b becoming the most frequent IBH-associated strain, largely displacing FAdV8a and FAdV11. In a much smaller group of 77 samples from non-IBH submissions, 10 FAdV genotypes were detected: FAdV1, FAdV2, FAdV3, FAdV4, FAdV6, FAdV7, FAdV8a, FAdV8b, FAdV9, and FAdV11. Although FAdV4 is a recognized causative agent of hepatitis-hydropericardium syndrome worldwide, no association with clinical disease was reported in the birds included in our study. Our comprehensive 17-y analysis of FAdV circulation patterns will support the development of control measures and vaccination programs to reduce the impact of FAdV-related outbreaks.

Two Actinobacillus pleuropneumoniae (APP) isolates from clinical cases of porcine pleuropneumonia in Japan, positive for ApxIA, ApxIIA, and ApxIVA, were nontypeable using the agar gel diffusion (AGD) test but positive in the capsular serovar 1-specific PCR assay. Nucleotide sequence analysis revealed that gene clusters involved in the biosynthesis of the capsular polysaccharide (CPS) and lipopolysaccharide O-polysaccharide of the isolates were identical to those of serovar 1 reference strain 4047. The main difference found in the CPS loci was a loss of 7 nucleotides at the 3'-end of the cps1D gene in the atypical isolates, which is responsible for the defect in CPS production. Consistent with the serologic and molecular findings, transmission electron microscopic analysis confirmed the absence of detectable capsular material in the 2 atypical isolates. Collectively, our results suggest that this type of APP, defective in CPS production, may severely hamper serologic typing of the pathogen.

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.