Veterinary Pathology最新文献

Mycobacterium genavense is a common cause of mycobacteriosis in passerine birds. In a research colony of zebra finches (Taeniopygia guttata), 8 birds were diagnosed with mycobacteriosis. The finches had granulomatous inflammation of the heart and heart-base, most with medial expansion of the great vessels containing foamy macrophages and acid-fast bacilli. Non-cardiac inflammatory lesions associated with acid-fast bacteria were found in 2 birds, and extracardiac bacteria were often in lower quantities. Pan-mycobacterial in situ hybridization detected periaortic bacteria in one bird with similar cardiac lesions that was negative for bacteria via acid-fast staining. Mycobacterium genus PCR and sequencing of pooled fecal samples confirmed the presence of M. genavense within the colony. Heart and great vessel lesions have not been previously recognized as a site of localized infection in passerines. To facilitate diagnosis of mycobacteriosis in zebra finches, routine necropsies should include microscopic examination of the heart base great vessels.

Porcine circovirus 3 (PCV-3) is associated with various pathological conditions, including systemic disease and reproductive disorders; however, its role in skeletal abnormalities has never been elucidated. This study included 36 cases displaying spinal malformations, rib swelling, head edema, gait abnormalities, and/or increased late-term abortions. Investigated animals consisted of 9 aborted fetuses, 9 piglets, 12 weaners, and 6 finishers. Histologically, PCV-3 associated lesions were identified in 23/36 cases (64%), including (peri-)arteritis and rib fractures with prominent callus formation. Central nervous system (CNS) lesions, in addition to vascular changes, comprised meningoencephalitis and gliosis. Thirteen animals (36%) did not display histological lesions. PCV-3 DNA was detected by real-time PCR (qPCR) in 25/36 animals (69%), with high viral loads in the bone and CNS. Three aborted fetuses tested positive for PCV-3 despite lacking macroscopic and histologic lesions. In situ hybridization (ISH) revealed the presence of PCV-3 RNA in multiple organs, including arteries, the heart, CNS, and bone. Signals were detected in periosteal arteries and osteoblasts, within calluses, and in arteries within the surrounding skeletal muscles. This study strengthens the association between PCV-3 and multisystemic inflammatory diseases, expanding its known pathogenicity to include skeletal lesions and spinal deformities. It is the first documentation of PCV-3 genome in histologically altered bone. This finding could suggest a possible etiological role in musculoskeletal abnormalities. In addition, this study is the first to report PCV-3-associated lesions in slaughter-ready finisher pigs. The integration of histological investigations, PCR, and ISH techniques is essential for the diagnosis of PCV-3-associated diseases and related lesions.

Neoplasia is rarely reported in European hedgehogs (Erinaceus europaeus). A retrospective search was conducted by contacting multiple veterinary diagnostic laboratories for cases of lymphoma in European hedgehogs. This resulted in 5 cases, from which clinical, gross, histologic, and immunophenotyping findings were recorded. Most animals (3/5) had skin masses involving the cervical region, 1 hedgehog had dyspnea and lethargy associated with hydrothorax, whereas another exhibited icterus and lethargy. The primary site of the lymphoma was the skin, particularly the neck or head (3/5), the thymus (1/5), and multicentric (1/5). Immunophenotyping confirmed B-cell lymphoma in 2 skin cases, a T-cell lineage for the thymic and multicentric cases, and undetermined for the remaining skin lymphoma. CD3, PAX5, and CD79a were reliable immunohistochemistry markers in formalin-fixed tissues in European hedgehogs. Although uncommon, lymphoma should be considered in the differential diagnosis for adult European hedgehogs with skin nodules, especially those seeming to originate from the neck.

Atypical porcine pestivirus (APPV) is responsible for congenital tremor (CT) type A-II in pigs, a globally distributed neurological disease, with many unresolved questions regarding its pathogenesis and pathology. This descriptive case-control study assessed the viral load of APPV and its association with lesions in the central nervous system (CNS), as piglets born with severe clinical signs of CT recovered from clinical disease. The virus was found in all pigs with CT across 3 age groups (newborn, 3-week-old, 4- to 5-month-old CT pigs) using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The highest viral load was observed in the spinal cord of newborns and in the cerebellum of older groups. No APPV was detected in control pigs. Histologic evaluation revealed variable vacuolization in the CNS white matter of CT-affected pigs, which was most prominent in the spinal cord, cerebellum, and cerebrum of newborns, and in the cerebellum and cerebrum of 3-week-old pigs. Transmission electron microscopy demonstrated hypomyelination in newborn and 3-week-old CT pigs, but myelin levels comparable to those of control pigs in 4- to 5-month-old CT pigs. This research demonstrates the prolonged presence of APPV in the CNS of pigs born with severe signs of CT. Variable white matter vacuolization and hypomyelination can be found up to 3 weeks of age, but myelin levels normalize in older pigs, suggesting a delayed myelination process. Further research is needed to confirm the primary cellular target for APPV in the CNS and to understand how the virus affects the myelination process.

Renal oxalosis has been reported in New and Old-World monkeys. Occasional reports describe a low prevalence of subclinical renal oxalosis, but these typically lack supporting evidence of primary oxalosis or toxicity and may be a natural background lesion. In a retrospective cross-sectional postmortem observation study, 12 of 156 (7.7%) African green monkeys (AGMs) (Chlorocebus sabaeus) from the Behavioural Science Foundation (St. Kitts) colony had histological evidence of oxalate-induced nephrosis (renal oxalosis). Histologically, affected tubules from both the cortex and medulla were ectatic; expanded several times normal size; and lined by attenuated, degenerative, regenerative, or necrotic epithelium with intraluminal, pale yellow, translucent, variably shaped, crystals that were birefringent under polarized light (calcium oxalate). The tubules were often surrounded by multinucleated macrophages. To identify independent predictors of renal oxalosis, we fit a multivariable logistic regression model with robust ("sandwich") standard errors, including sex, age, and birth origin, as categorical covariates. Several enrichment food items were found to be oxalate-rich: sweet potato (95.9 mg/100 g), pumpkin (64.6 mg/100 g), and bananas (169 mg/100 g). There was a significant increase in the prevalence of calcium oxalate concretions with age, from 0% in young monkeys to 18.6% in aged individuals, likely due to longer exposure to oxalate-rich produce and a cumulative effect. Due to the large ingestion of oxalate-rich foods, diet is suspected to be a major cause of subclinical oxalosis in the St. Kitts AGM, raising awareness of this potential background finding during their use as laboratory animals in toxicologic and other research studies.

Hepatic hemosiderosis has not been systematically studied in African green monkeys (Chlorocebus sabaeus). We aimed to determine the prevalence of histologic hepatic hemosiderosis in this species, demographic predictors of its presence and severity, and the quantitative relationship between histological grade and hepatic iron concentration. We evaluated liver samples of 155 African green monkeys from a research colony in St. Kitts (24 juveniles, 89 adults, 42 geriatrics) using histology (hematoxylin and eosin, Perls Prussian blue) to semiquantitatively grade (0-4) hemosiderin deposits. Quantitative hepatic iron was measured via coupled plasma mass spectrometry in 146 samples. Overall, 63.9% (99/155; P < .001 vs 50%) exhibited histological hemosiderin deposits. The grade distribution was 52 (33.5%) grade 0, 29 (18.7%) grade 1, 23 (14.8%) grade 2, 25 (16.1%) grade 3, and 26 (16.8%) grade 4. Wild-caught origin was protective (odds ratio (OR) = 0.10, 95% confidence interval (CI) = 0.04-0.29, P < .001), while geriatric age was associated with iron accumulation (OR = 8.92, 95% CI = 2.06-10.61, P = .003). Ordinal regression confirmed lower odds of higher grades in wild-caught (OR = 0.095, 95% CI = 0.047-0.193, P < .001) and higher odds of higher grades in adult monkeys (OR = 4.2, 95% CI = 1.43-12.35, P = .009). Trend tests (z = 9.81, P < .0001) and Spearman's ρ = 0.82 (P < .0001) confirmed a strong association between pathology and iron burden. Recommended iron requirements may be excessive for certain life stages in this species. Colony-born and younger animals are at highest risk, while adult males show protection. Histological grading correlates strongly with quantitative iron measures, validating its use as a semiquantitative surrogate.

Peripheral odontogenic fibromas (POFs) are benign masses of mesenchymal cells with features of periodontal ligament/gingival ligament fibroblasts and are among the most commonly diagnosed oral masses in dogs. Recently, a subset of hypercellular POFs (hPOFs) has garnered attention due to atypical histologic features giving concern for malignant potential. This retrospective study describes 54 hPOFs characterized by increased cellularity, increased pleomorphism, increased mitotic count, and/or bony remodeling in the absence of inflammation. Data collected from records included signalment, degree of excision, and location of the mass. Follow-up questionnaires were distributed to referring veterinarians to assess biologic behavior and patient outcomes. The hPOFs represented 76/6303 (1.2%) of all canine POF diagnoses in a 12.6-year time frame. Of 29 cases where follow-up data were available, 4/29 (14%) experienced local recurrence, similar to published recurrence rates of typical POFs. No evidence of malignant behavior nor metastasis was identified in any case. The median survival time (17 months) was greater than the median follow-up time for living patients (14 months), and the deaths of 14 patients were all attributed to unrelated illnesses. These results suggest that despite concerning histologic features, hPOFs are not associated with a shorter survival time, nor do they carry a greater risk of local recurrence or metastasis relative to histologically typical POFs. Our findings suggest that hPOFs can be clinically managed similar to typical POFs. Pathologists presented with POFs with hypercellularity, increased pleomorphism, increased mitotic count, and bone remodeling should be aware of hPOF as a potential diagnosis.

Formaldehyde-based fixation is the most used chemical system for histopathological examination worldwide. However, its toxicity is well known, and preservation of gross features, proteins, and nucleic acids is not optimal. Alternative fixatives resulting in similar morphological tissue quality and costs, but with reduced toxicity and with better preservation of gross features, proteins, and nucleic acids would increase operator safety and application possibilities in pathology. This multi-institutional study aimed to compare the morphological, histochemical, immunohistochemical (IHC), and molecular outcomes of fixation with a newly patented, non-toxic, acid-free glyoxal (GAF) fixative with neutral-buffered formalin (NBF). Fifty-nine tissue biopsies and 21 necropsies of different animal species were analyzed. Gross features were preserved after GAF fixation, with no tissue hardening or discoloration. Cellular ultrastructure was better preserved with GAF. Histology, histochemistry, and in situ hybridization results from GAF-fixed samples were mainly equal when compared to NBF-fixed samples, except for the loss of mast cell granules in GAF-fixed samples compared to NBF. IHC analyses showed comparable results with slight and rare protocol adjustment. DNA yields were higher and amplification of selected genes (ie, TP53 and COX1) was more efficient in GAF-fixed biopsies (P < .05). DNA and RNA yields were higher also in necropsy GAF-fixed tissues, but no difference was detected for selected gene amplification (ie, COX1, GAPDH, β-actin). Based on these data, despite not yet being economically competitive, GAF could represent a valuable alternative to NBF for standard laboratory applications, while also improving on-field sampling and teaching applications.

Aliarcobacter butzleri is a Campylobacter-like bacteria associated with watery diarrhea in humans and is infrequently reported in nonhuman primate (NHP) populations. While clinical and microscopic features in humans are indistinguishable from Campylobacter spp. infection, descriptions of A. butzleri-associated colitis in NHP are lacking. Here, we describe the clinical and pathological features of diarrhea and colitis associated with A. butzleri in rhesus macaques using a retrospective approach. Over a 3-year period, A. butzleri was isolated from 10 macaques with diarrhea. Five of the 10 were submitted for necropsy and had features of chronic enterocolitis, consistent with existing literature. However, 40% (2/5) of the cases were characterized by ulcerative colitis, which has not previously been described as a feature of A. butzleri colitis. A. butzleri should be considered a differential diagnosis in cases of diarrhea and enterocolitis in captive rhesus macaques.

Alimentary mycosis is seldom reported in sloths. Through a multi-institutional retrospective study, we described the histological features of fungal infections within the digestive tract of sloths of the Bradypus and Choloepus genera. In addition, panfungal polymerase chain reaction (PCR) targeting the ITS-2 gene was performed in all cases to determine a specific etiology. We retrieved 11 cases of alimentary mycosis in 3 sloth species: Bradypus variegatus (n = 1), Choloepus hoffmanni (n = 7), and Choloepus didactylus (n = 3). Eight were free-ranging, whereas 3 were held in captivity. Nine were females and 8 were juveniles (ranging from 2 weeks to 2 years old). In 64% of the cases, the lesions were gastric in the muscular portion of the prepyloric stomach. In the other animals, the lesions were located in the tongue and/or esophagus. Pustules, erosions, ulcers, and hyperkeratosis within the keratinoid layer with intralesional yeast, pseudohyphae, and hyphae characterized alimentary mycotic infections. Panfungal PCR identified Trichosporon asahii infection in 45% (5/11) of the cases, from gastric, esophageal, and lingual lesions, and Penicillium sp. and Wallemia mellicola in a gastric lesion in 1 case each. Candida sp. infection was not confirmed in any of the cases. Trichosporon asahii has overlapping histological features with Candida and poses a diagnostic challenge when conventional culture or molecular methods are unavailable. Trichosporonosis is a differential diagnosis in cases of fungal alimentary lesions in sloths. Predisposing factors for alimentary mycosis in sloths include age (younger animals), canine distemper virus co-infection, late pregnancy, and chronic antibiotic use.