Veterinary Research Communications最新文献

The South American coati (Nasua nasua) is increasingly affected by anthropogenic pressures, making safe handling and physiological monitoring essential for conservation programs. This study aimed to characterize electrocardiographic (ECG) parameters in anesthetized free-ranging coatis and establish preliminary reference values. Ten female coatis (3 kits, 4 juveniles, 3 adults) were captured in Iguaçu National Park, Brazil, and chemically immobilized with intramuscular tiletamine-zolazepam (7 mg/kg). ECG recordings were obtained 30 min post-administration using standard bipolar and unipolar limb leads. Parameters measured included P and T wave amplitudes and durations, QRS complex, PR interval (PRi), QT interval (QTi), RR interval (RRi), ST segment, and mean electrical axes. Heart rate variability (HRV) was assessed using time-domain and nonlinear methods. All coatis exhibited normal sinus rhythm with well-defined ECG waveforms. PRi values (0.062 ± 0.005 s) were concordant with predicted allometric values (p = 0.083), indicating appropriate atrioventricular conduction. QRS morphology and mean electrical axis (71°-156°). No significant differences in ECG or HRV parameters were observed across age groups, indicating stable cardiac electrical activity and autonomic regulation. This study provides the first detailed ECG description for anesthetized coatis, expanding knowledge of their cardiac physiology. The reference values can inform clinical monitoring, field procedures, and conservation interventions.

Nontuberculous mycobacteria (NTM) refers to all mycobacteria except Mycobacterium tuberculosis (Mtb) and Mycobacterium leprae (M. leprae). In recent years, its incidence and prevalence have been increasing worldwide, which has attracted the attention of medical and scientific research circles. We determined the immune mechanism of Mycobacterium neoaurum (M. neoaurum) and Bacillus Calmette-Guérin (BCG) by studying the association between M. neoaurum and BCG infection and the release of IL-1β and IL-18, the assembly of inflammatory body, and pyroptosis. Macrophages were infected with M. neoaurum and BCG. The secretion of IL-1β and IL-18 was detected by ELISA, and the gene expression and protein expression of IL-1β, IL-18, NLRP3, AIM2, ASC, caspase-1 and GSDMD were detected by RT-PCR and Western Blot. NLRP3 and AIM2 inflammasome assembly was induced by M. neoaurum and BCG infection in mouse macrophages, which activated caspase-1 and induced the maturation and secretion of IL-1β and IL-18. The secretion of IL-1β and IL-18 were regulated by ATP-dependent K⁺ channel. At the same time, M. neoaurum and BCG infection can also induce pyroptosis. This study was limited by the lack of in vivo mouse experiments. The research findings suggest that the activation of NLRP3 and AIM2 inflammasomes may be involved in the host defense against M. neoaurum and BCG, and the process of pyroptosis may also be related to this.

Severe fever with thrombocytopenia syndrome virus (SFTSV, Bandavirus dabieense) is an emerging tick-borne zoonotic virus causing severe febrile illness with high fatality rates in humans. While ixodid ticks are the primary vectors, secondary transmission through close contact with infected companion animals has also been reported. We describe the clinical characteristics of SFTSV infection in two companion canines from Seoul, Republic of Korea (ROK). Hematological analysis revealed elevated C-reactive protein (CRP) level, increased immature platelet fraction (IPF), leukopenia, and thrombocytopenia. Radiography and abdominal ultrasonography demonstrated splenomegaly, enlarged sublumbar lymph nodes, partial loss of wall layering, and colonic wall thickening; notably, one canine also developed hemorrhagic diarrhea. SFTSV RNA was detected in whole blood by nested PCR, and genotypes were identified as Sub-genotype B-1 and Genotype F. These observations indicate that canine SFTSV infection can manifest with more diverse and severe clinical features than previously recognized. Splenomegaly and colonic abnormalities may serve as useful diagnostic indicators in canine cases. This report emphasizes the importance of considering SFTSV in canines presenting with systemic inflammatory and gastrointestinal signs, and highlights the need for companion animal-based surveillance within a One Health framework. Further studies are warranted to define the full clinical spectrum and to clarify the epidemiological role of canines in SFTS transmission.

Macronyssid and spinturnicid mites are globally distributed ectoparasites of medical and veterinary relevance, with various species known to parasitize bats. Beyond their ecological importance, some macronyssid mites, such as Ornithonyssus bursa, are known to occasionally bite humans and cause dermatitis, highlighting the interface between wildlife, ectoparasites, and human habitats. Understanding the microorganisms harbored by bat-associated mites is therefore important from a One Health perspective, as these arthropods may act as bridge hosts for pathogens among bats, domestic animals, and humans. Although their role in pathogen transmission remains poorly understood, previous studies have reported bacterial agents in these mite groups. This study aimed to investigate the presence of several pathogens in macronyssid and spinturnicid mites collected from bats in Brazil. A total of 393 macronyssid and 210 spinturnicid mites parasitizing bats were analyzed through morphological and molecular approaches. Ehrlichia DNA was the only pathogen detected, found in 3.03% of macronyssid mites and 2.4% of spinturnicid mites from Rio de Janeiro State, previously described on bat-associated chigger mites. These findings underscore the need for further research into the ecological interactions between bats and their ectoparasites and the potential implications of these mites as vectors of zoonotic pathogens.

Equine leishmaniosis, caused by Leishmania infantum and transmitted by infected sand flies, has been increasingly reported in Europe, although clinical and immunological data remain scarce. We describe a 10-year-old mare from southern Spain presenting with periocular nodular lesions. Histopathology and immunohistochemistry confirmed granulomatous dermatitis with intrahistiocytic Leishmania amastigotes. Additionally, Leishmania infantum DNA was detected in paraffin embedded skin biopsy. Following surgical removal of the lesions, sequential serological monitoring using enzyme-linked immunosorbent assay, and immunofluorescent antibody tests were performed over 90 days. Enzyme-linked immunosorbent assay and Western Blot results varied depending on conjugate type (Protein A versus Protein A/G). Western Blot revealed immunoreactivity against multiple Leishmania infantum antigen fractions, including early infection markers 14-16 kDa by conjugated Protein A/G and the absence of band by conjugated Protein A. Immunofluorescent antibody test using an anti-horse IgG fluorescein-labeled conjugate, where titers declined from 1:160 at 45 days to seronegativity by day 90, indicating antibody seroreversion within three months post-surgery. Similar results were detected by enzyme-linked immunosorbent assay with the absence of detection by Protein A but seropositivity was detected by Protein A/G. Finally, no parasitemia was detected by molecular test during the follow-up. This case represents the first documented seroreversion kinetics in equine leishmaniosis and highlights the low and transient humoral response in horses compared to dogs. Our findings underscore the importance of combining histopathology and immunohistochemistry, for the accurate equine leishmaniosis diagnosis, and emphasize the need for further studies to clarify the epidemiological role of horses in Leishmania infantum transmission.

Ophidians host a wide range of pathogens, including many parasite species, some of which may be of public health concern because they can infect other animal species and humans. Herpetariums house snakes in captivity as part of ex-situ conservation initiatives aimed at preserving threatened species. However, stress, immunosuppression, and limited space increase the risk of parasitic infections, including zoonotic diseases. Here, we detect the presence of intestinal parasites in ophidian species housed under conditions of captivity. Twenty specimens representing sixteen species were examined using Teuscher's coproparasitological technique, which combines sedimentation and flotation for enhanced sensitivity. All snakes tested positive for at least one parasite species. Five taxa were identified: Oxyurid nematodes (Oxyurida) (50%), Isospora sp. (45%), Cryptosporidium sp. and Ophidascaris sp. (25% each), and Aspiculuris sp. (15%). Oxyurid sp. and Isospora sp. were the most prevalent parasite species, likely due to their direct life cycles. Although less frequent, Cryptosporidium sp. poses a significant health risk due to its potential morbidity in snakes. The presence of Aspiculuris, a parasite commonly found in rodents, suggests contamination from infected prey. These discoveries highlight the importance of implementing preventive veterinary care, routine parasitological monitoring, and improved biosecurity and feeding practices in captive snake populations. Finally, this study provides valuable data on parasite diversity in Mexican ophidians under human care.

The objective of this study was to evaluate the impact of grazing pastures with low (Low group) and high (High group) percentages of Epichloë coenophiala-infected tall fescue on ovarian blood flow and activity in beef cows subjected to a Fixed-Time Artificial Insemination (FTAI) protocol. Cows in the Low group (n = 18) grazed for 79 days on a pasture where fescue accounted for 13% of the available forage, with an endophyte infection rate of 96%. Meanwhile, cows in the High group (n = 18) grazed for the same period on a pasture where fescue represented 73% of the available forage, with an endophyte infection rate of 94%. Consumption of pasture with a high percentage of endophyte-infected (E+) fescue was associated with an increase in the rectal temperature, a decrease in the size and the blood flow of the dominant follicle, lower plasma progesterone (P4) concentration, and an increased number of cysts. In addition, the plasma concentration of metabolic hormones, namely triiodothyronine and cortisol, was similar between groups. In conclusion, consuming pastures with a high percentage of endophyte-infected fescue affected the ovarian blood flow and activity without affecting the metabolic hormones in beef cows.

The red fox (Vulpes vulpes) is known to be a reservoir host of various vector-borne protozoan parasites. However, the impact of infections caused by Babesia canis on the health status of the red fox remains unknown, and research on this topic conducted on fox populations in Poland and worldwide has been fragmentary. It is known that these animals can become infected with Babesia canis, but it is unclear whether a clinical form of the disease can develop in them. This study aimed to present for the first time the cases of clinical babesiosis in foxes in Poland. The observations covered four foxes aged 3-6 years with apathy, anemia, brown color of urine and thrombocytopenia. The PCR and sequencing results confirmed that all the animals had been infected with Babesia canis protozoa. The diagnosis of clinical cases of babesiosis due to B. canis in foxes from this region of Europe suggests a contribution of red foxes to the establishment of this animal species as a new reservoir of B. canis. These animals may play a role as a host for B. canis, and previously unexposed red fox populations may be more prone to infection in areas colonized by D. reticulatus.

The intensive mariculture of S. aurata can promote aquaculture development, although it can also pose challenges because of predatory behavior and environmental stressors caused by intensification. The objective of this study is to alleviate stress and prevent cannibalism, thereby improving the fish's performance and welfare. A 90-day growth experiment investigated the dietary inclusion of melatonin (ML) on Sparus aurata performance, physiology, immunity, histopathology, and welfare when grown in saline groundwater (36 ppt) at stocking densities (SD) of 50 fish/500 L‒tank (SD₅₀) and 100 fish/500 L‒tank (SD₁₀₀). Six fish groups in triplicate were fed three increasing levels of ML (0, 25, and 50 mg/kg^- 1 diet) expressed as T1, T2 and T3 under SD₅₀, and T4, T5, and T6 under SD₁₀₀. Fish (n = 1350) weighing 16.46 ± 0.18 g/fish were grown using a flow-through system and a daily feeding rate of 4%. The results revealed significant declines in nitrogen by-product (NH₃ and NO₂) levels of fish fed ML in a dose density-dependent manner. Fish fed ML under both densities showed significantly improved growth indices, FCR, growth hormone, and crude protein content compared with those fed the control diet, with T2 and T6 groups achieving the highest values. ML augmentation enhanced serum lipase, protease, immunoglobulin, albumin, globulin, antioxidants, and proinflammatory cytokine interleukin-1β and lowered serum cortisol, glucose, ALT, AST, and ALP. Under both densities, the ML-fish presented healthier livers and intestines than those fed the control diet, which showed marked liver vacuoles and steatotic changes. The ML-SD interaction showed superior fish performance, particularly in groups T2 and T6; thus, it is recommended to administer dietary melatonin at 25 mg/kg for seabream reared at 50 fish per 500-liter tank and 50 mg/kg for those cultivated at 100 fish per 500-liter tank using groundwater.