Journal of Veterinary Diagnostic Investigation最新文献

Rotavirus A (RVA; family Sedoreoviridae, taxon species Rotavirus alphagastroenteritidis) is a non-enveloped double-stranded RNA virus that has been reported from both diarrheic and non-diarrheic pigs worldwide. With significant morbidity and mortality rates in neonatal piglets, rotavirus-associated illness adds enormous economic losses to the pig industry. Furthermore, the proximity of humans and pigs facilitates cross-species infection, which results in the formation of novel strains through genetic recombination. We aimed to detect and characterize porcine RVA (PRVA) in Haryana, India, using reverse-transcription PCR targeting the VP6, VP4, and VP7 genes. We detected 46 of 137 (34%) rectal swab samples as positive for PRVA, including 27 of 63 (43%) from diarrheic pigs and 19 of 74 (26%) from non-diarrheic pigs. In addition, phylogenetic analysis revealed the presence of genotypes I1, I5, P[13], P[6], G11, G4, and combinations of G4P[6], G4P[13], and G11P[13] in the pig population of Haryana. G4P[6] was the most common combination found, followed by G11P[13] and G4P[13]. Genotype G11 and the combinations G4P[13] and G11P[13] have not been reported previously in pigs, in India, to our knowledge. Our finding of various genotypes, and their genetic proximity to human RVA, indicates their potential zoonotic importance.

Hair cortisol quantification can be used to understand long-term stress in cats and other animals. The technique is becoming increasingly common; however, there is uncertainty as to the factors that may affect or confound hair cortisol quantification, in particular, hair color. Although some studies show that hair of different colors has different abilities to store cortisol, others do not. We collected hair samples from 27 domestic cats with either black-and-white or ginger-and-white haircoat coloring. From each cat, 2 samples were taken, 1 of white hair and 1 of the other color (black or ginger). Samples underwent cortisol quantification by ELISA, and pairwise analysis was conducted. Hair cortisol was also compared against information provided by the cat owners regarding their cat (e.g., sex, age) and behavioral issues. Black hair contained significantly greater concentrations of cortisol than white hair (p = 0.016). Although ginger hair tended to have higher mean cortisol concentrations than white hair, the difference was not statistically significant (p = 0.613). A significant positive correlation was also found between hair cortisol and behavioral issues reported by owners (p = 0.010). To our knowledge, the impact of the color of the hair on feline hair cortisol concentrations has not been reported previously.

Toxoplasma gondii is an important apicomplexan parasite in veterinary medicine, with swine prevalence varying due to age, geographic distribution, and production program. Samples from a 6-wk-old pig from a small backyard farm with multisystemic disease concerns were submitted to the Iowa State University-Veterinary Diagnostic Laboratory. Gross findings included severe necrotizing enteritis with pseudomembrane formation and edematous, non-collapsing lungs. Histologic findings were severe necrotizing enterocolitis and random multifocal pulmonary and hepatic necrosis with numerous intralesional protozoal cysts consistent with T. gondii. Immunohistochemistry, reverse-transcription real-time PCR (RT-rtPCR), and serologic tests were positive for T. gondii; concurrent influenza A virus, porcine reproductive and respiratory syndrome virus, porcine circovirus 2, African swine fever virus, and classical swine fever virus were ruled out by RT-rtPCR. Given the worldwide distribution and zoonotic potential of T. gondii, the possibility of infection in swine should be considered.

We investigated microRNAs (miRNAs) as potential prognostic biomarkers for equine sarcoid (ES) disease. In a breed-, age-, and sex-matched case-controlled study involving 45 ES-affected and 15 control horses, we assessed the diagnostic, prognostic, and theragnostic value of 3 miRNAs (eca-miR-127, eca-miR-379, eca-miR-432) in horses treated with European mistletoe (Viscum album) extract versus placebo. Whole-blood miRNA concentrations were measured using reverse-transcription quantitative real-time PCR (RT-qPCR) at 3 different times. We found that eca-miR-432 expression was lower in ES-affected (median = -1.93; 95% CI: -2.03 to -.86) compared to control (median = -1.71; 95% CI: -1.92 to -1.6) horses (p = 0.03, r = 0.3; 95% CI: 0.024-0.57) with a median difference of -1.93 versus -1.71, respectively. The ROC curve analysis indicated an area under the curve of 0.71 (95% CI: 0.51-0.84; p = 0.005) with a sensitivity of 74% (95% CI: 61-88%) and a specificity of 73% (95% CI: 39-94%) to diagnose ES. However, none of the miRNAs evaluated had prognostic potential or significant changes in expression following treatment. Additionally, miRNA expression was not influenced by breed, sex, or season. Although whole-blood eca-miR-432 had moderate diagnostic potential for ES, identifying prognostic miRNA biomarkers for ES remains a challenge.

The ability to accurately and rapidly identify causative agents of infectious diseases facilitates precise treatment, improves clinical outcomes, and augments epidemiology studies. For many veterinary and zoonotic pathogens, however, simple molecular tests for species identification are not available. Actinobacillus equuli causes severe diseases, such as sleepy foal disease, septicemia, and meningitis in horses and pigs. A. equuli can also cause severe diseases in humans bitten by infected animals. Existing A. equuli identification methods are biochemical tests, 16S rRNA gene amplification followed by DNA sequencing, and MALDI-TOF MS. Nonetheless, differentiating among Actinobacillus spp. by these methods is still challenging. We identified novel DNA markers specific to A. equuli by computational genome analysis. We then designed PCR primers specific to A. equuli based on A. equuli marker sequences. We validated 2 A. equuli-specific PCR assays using genomic DNA from 10 strains of A. equuli, 15 strains of other Actinobacillus species, and 5 other bacterial species. Both assays gave the PCR products of expected sizes for genomic DNA of all 10 strains of A. equuli but not for those of other Actinobacillus and other bacterial species. Our novel PCR assays can accelerate A. equuli identification and disease diagnosis, leading to timely and appropriate antimicrobial treatment, and enable high-resolution epidemiologic studies.

Ectopic splenic tissue (accessory spleen or splenosis) occurs as dark-red-to-brown or purple nodules outside the spleen. Accessory spleens are congenital lesions histologically identical to a normal spleen. Splenosis results from implantation of splenic tissue following splenic rupture and lacks features of normal spleen. However, these distinctions have been largely applied to human cases, and the terms are often used interchangeably in domestic animals. Here we describe ectopic splenic tissue in 46 canine surgical biopsy specimens examined at the Athens Veterinary Diagnostic Laboratory, 2000-2024. The omentum (39 cases) and mesentery (5) were the most commonly affected sites. Original diagnoses were accessory spleen (28 cases), splenosis (14), accessory spleen or splenosis (2), and ectopic splenic tissue and normal splenic tissue (1 each). Updated diagnoses, modified after histologic assessment for a fibrous capsule, smooth muscle trabeculae, and white and red pulp, were accessory spleen (37 cases) and splenosis (9). Concurrent splenic lesions were reported in 12 cases in which accessory spleens were diagnosed and only 2 splenosis cases, confirming that the histologic diagnosis of accessory spleen and splenosis is not always correlated with the clinical history and gross findings (no splenic lesions vs. splenic lesions with rupture). For that reason, ectopic splenic tissue may be a more inclusive and better term for these lesions. Hemangiosarcoma was diagnosed in the spleen in 4 of the 12 cases with splenic masses, which underscores the importance of the differentiation between ectopic splenic tissue and hemangiosarcoma.

Bone marrow (BM) samples in dogs are typically acquired from hematopoietically active trabecular BM at appendicular skeletal sites, such as the proximal humerus and femur, or axial skeletal sites, such as pelvis, sternum, and rib. Suitability for in vivo biopsy varies by site, but equivalency of BM composition at different sites is uncertain. We sought to determine whether the composition of BM is comparable in humerus, ilium, rib, and sternum. Samples from each site were obtained within 24 h after death from 30 dogs with spontaneous disease submitted for postmortem examination. Tissues were fixed in acetic acid-zinc-formalin, demineralized with EDTA, and assessed by 4 independent raters for hematopoietic cellularity, granulocytic:erythrocytic (G:E) cell ratio, megakaryocyte (MKC) number, and presence of hemosiderin. Statistical analysis showed lower cellularity, MKC number, and hemosiderin in ilium than in rib, higher cellularity in rib and sternum than in humerus and ilium, and lower G:E cell ratio in rib than in humerus (p < 0.05). Analysis of covariance indicated that most differences between sites were attributable to individual animal variation rather than site or rater. Differences overall were of small magnitude, and values for each parameter were similar to those reported in healthy younger dogs. We concluded that samples from any of the 4 sites are suitable to approximate composition of BM at the other sites.

With the revision of the World Organisation for Animal Health (WOAH) Terrestrial Manual on equine rhinopneumonitis in 2024, 3 recommended qPCR primer-probe sets were added for the detection of equid alphaherpesvirus 1 (EqAHV1; formerly equine herpesvirus 1 [EHV1]; family Orthoherpesviridae, taxon species Varicellovirus equidalpha1), also known as equine abortion virus. We compared the sensitivity and specificity of the 3 qPCR primer-probe sets to determine the most reliable set. Sets gB1H and gB1P, which target the glycoprotein B (gB) gene of EqAHV1, detected all 10 copies and even lower copy numbers. In contrast, set gC1 (ISO 17025-accredited method used at the WOAH reference laboratory), which targets the glycoprotein C (gC) gene, failed to detect ≤10 copies of EqAHV1. Our results showed the lower sensitivity of gC1, which was not improved by modification of primer and probe concentrations. gB1P detected not only EqAHV1 but also equid alphaherpesvirus 4 (EqAHV4; Orthoherpesviridae, Varicellovirus equidalpha4), likely owing to an erroneous amplification of the homologous EqAHV4 gB gene, indicating that gB1P is not suitable for the detection of EqAHV1 with high specificity. We then compared gB1H with gB1D, a set recommended in the previous version of the Manual, using 120 nasal swabs collected from febrile horses. gB1H had slightly higher sensitivity than gB1D. gB1H proved to be the most reliable primer-probe set for detecting EqAHV1, with high sensitivity and specificity. Nevertheless, individual laboratories are encouraged to validate these methods under their own conditions before implementation.