Veterinary Sciences最新文献

Myxomatous mitral valve disease (MMVD) is the most prevalent cardiac disease in dogs. This study aimed to compare the arrhythmogenic profile and heart rate variability (HRV) of dogs with MMVD in stages B1 and B2. Electrocardiographic exams and the medical records of 60 dogs were analyzed, and HRV, P wave dispersion, QT interval dispersion, and QT interval instability parameters were determined. The results showed significantly increased values in stage B2 compared with stage B1 (p < 0.05) regarding P wave maximum and minimum duration (Pmax and Pmin) and short-term instability (STI). In contrast, no statistically significant differences were observed regarding HRV parameters, P wave dispersion, or QT interval dispersion. Our findings showed that cardiac remodeling in stage B2 could not significantly alter the sympathovagal balance and showed little interference with the predisposition of arrhythmias in dogs with MMVD.

This study investigates the impact of the solid-state fermentation products of Lactobacillus plantarum, Candida utilis, and Bacillus coagulans (LCBs) on the growth characteristics, immune function, intestinal morphology, cecum microbial community, and prevention of avian colibacillosis in broilers. One hundred and twenty Hyland Brown broilers (aged one day) were divided randomly into three groups (four replicates of ten broilers per group). (1) The CON group was fed a basal diet. (2) The MOD group was fed a basal diet. On day 40, APEC strain SX02 (1.1 × 10⁵ CFU/g) was administered to the breasts of chickens in this group. (3) The LCBs group was fed a basal diet supplemented with fermentation products (98.5% basal diet + 0.5% Lactobacillus plantarum and Candida utilis solid-state fermentation products + 1.0% Bacillus coagulans solid-state fermentation products). On day 40, the LCBs group received the same treatment as the MOD group. The experiment lasted 43 days. This study found that the average daily gain (ADG) of the LCBs group was significantly higher than that of the MOD group (p < 0.05), indicating that LCBs can significantly increase the ADG of broilers and improve the feed conversion ratio. Furthermore, compared to the MOD group, the heart bacterial load was significantly reduced in the LCBs group (p < 0.05), and the lesions less severe in the heart, liver, and jejunum were observed (p < 0.05). Additionally, the detection of intestinal flora showed a significant increase in the abundance of beneficial bacteria in the cecum of the LCBs group, while the number of Escherichia coli and Shigella decreased significantly. In conclusion, the solid fermentation of Lactobacillus plantarum, Candida utilis, and Bacillus coagulans can improve the growth performance of broilers while also protecting against avian pathogenic Escherichia coli infection. This demonstrates the potential usefulness of these LCBs in feed production.

In humans, tenascin-C (TN-C) expression has been detected in more aggressive neoplasms of the central nervous system, such as gliomas and meningiomas. No study has analyzed the immune expression of TN-C in canine meningioma. The current study aimed to investigate the immunohistochemical distribution of TN-C in different grades of canine meningiomas. Twenty-one cases of canine meningioma (12 grade I, 6 grade II, and 3 grade III) were analyzed. All samples were examined by immunohistochemistry with the following antibodies: TN-C, epithelial membrane antigen (EMA), Ki-67, pan-cytokeratin (Pan CK), and vimentin. The histopathological diagnosis of meningioma was reinforced with the positive labeling of vimentin (moderate to strong) and EMA (mild to moderate) in neoplastic cells in most cases, independently of its grade or subtype. The immunoreactivity of TN-C was irregular: mild in grade I, moderate in grade II, and moderate to severe in grade III neoplasms. Usually, immune positivity was observed in the stroma and perivascular space in all subtypes. In addition, the concentric whorls of neoplastic cells were labeled positive in some psammomatous and transitional meningiomas. The reaction to TN-C was more significant in grade II and III tumors. The immunohistochemical findings of the current study suggest that TN-C can act as a stromal marker, mainly in grade II or III meningiomas.

Heat stress has been one of the key research areas for researchers due to the wide-ranging effects and complex mechanisms of action of its stress product reactive oxygen species (ROS). The aim of this paper is to comprehensively review and summarize the effects of heat stress on ovarian granulosa cells and their mechanism of action. We systematically reviewed the effects of heat stress on ovarian granulosa cells, including intracellular steroid hormone changes, oxidative stress, apoptosis, and mitochondrial function. Meanwhile, this paper discusses in detail several major mechanisms by which heat stress induces apoptosis in ovarian granulosa cells, such as through the activation of apoptosis-related genes, induction of endoplasmic reticulum stress, and the mitochondrial pathway. In addition, we analyzed the mechanism of ferroptosis in ovarian granulosa cells under heat stress conditions, summarized the potential association between heat stress and ferroptosis in light of the existing literature, and explored the key factors in the mechanism of action of heat stress, such as the signaling pathways of Nrf2/Keap1, HSPs, and JNK, and analyzed their possible roles in the process of ferroptosis. Finally, this paper provides an outlook on the future research direction, describing the possible interaction between heat stress and ferroptosis, with a view to providing a theoretical basis for further understanding and revealing the complex mechanism of ferroptosis occurrence in ovarian granulosa cells under heat stress.

We developed and evaluated a semi-nested PCR assay for the detection of Babesia aktasi infection in goats based on the sequence of the B. aktasi 18S ribosomal RNA gene. Following in silico screening, the specificity of the primers was assessed using reference DNA samples, including B. ovis, B. motasi, B. crassa, B. venatorum, B. divergens, B. capreoli, Theileria ovis, and T. annulata. To determine the sensitivity of the method, blood infected with 2% parasitemia of B. aktasi was diluted to 10-fold serial dilutions. The method specifically amplified a 438 bp fragment of B. aktasi DNA, but did not demonstrate cross-amplification with the other hemoparasites tested. The sensitivity assay indicated that this PCR method was able to detect infection at a dilution of 10^-8 of 2% parasitemia (0.074 parasites/200 µL). Ninety-seven blood samples collected from goats were used to analyze for B. aktasi, and the infection was detected in 18.5% of the goats. Additionally, the method was also applied to 44 field DNA samples that were detected to be positive for B. aktasi by reverse line blotting (RLB), and showed 84.1% agreement. The findings revealed that newly developed semi-nested PCR can detect B. aktasi infections in goats with high sensitivity and specificity.

This study examined the effects of extruded linseed and algae Padina pavonica extract on the reproductive performance, milk production, and gastrointestinal health of female rabbits. Thirty-six nulliparous New Zealand White female rabbits were randomly assigned to three groups (n = 12) with different diets. The control group (CNT) received a standard diet, while the other two groups received modified isoenergetic diets in which part of the CNT diet ingredients were replaced with 5% extruded linseed (L5%) and 5% extruded linseed plus 0.2% Padina pavonica algae extract (L5%PP). The rabbits were monitored from artificial insemination until the weaning of the rabbit kits, evaluating different reproductive parameters. Our results indicate that extruded linseed and alga Padina pavonica extract did not affect the feed intake or body weight of female rabbits. Additionally, no clinically significant histological changes were observed at the gastrointestinal level. The reproductive parameters, including litter size, litter weight, and milk yield, showed no significant differences among groups. Notably, perinatal and pre-weaning mortalities were reduced in litters born to females receiving omega-3 integrated diets (p < 0.05). While these findings are promising, further studies are needed to confirm these results and explore the specific mechanisms by which omega-3 affects reproductive function and litter health.

Providing optimal clinical and behavioral care is a key component of promoting animal welfare for macaques and other nonhuman primates (NHPs) in research. This overlap between critical areas of management is particularly important for NHPs on infectious disease protocols, which often have unique challenges. For example, traditionally these NHPs were often housed alone, which can have behavioral and clinical consequences. However, in the past decade or so, considerable effort has been directed at modifying procedures in an effort to improve animal welfare for this group of NHPs. In this review, we examine some refinements that can positively impact the clinical and behavioral management of macaques on infectious disease studies, including increased social housing and the use of positive reinforcement techniques to train animals to cooperate with procedures such as daily injections or awake blood draws. We also discuss ways to facilitate the implementation of these refinements, as well as to identify logistical considerations for their implementation. Finally, we look to the future and consider what more we can do to improve the welfare of these animals.

Antimicrobial resistance (AMR) surveillance in fecal Escherichia coli isolates from wildlife is crucial for monitoring the spread of this microorganism in the environment and for developing effective AMR control strategies. Wildlife can act as carriers of AMR bacteria and spread them to other wildlife, domestic animals, and humans; thus, they have public health implications. A total of 128 Escherichia coli isolates were obtained from 66 of 217 fecal samples obtained from different wild animals using media without antibiotic supplementation. Antibiograms were performed for 17 antibiotics to determine the phenotypic resistance profile in these isolates. Extended-spectrum β-lactamase (ESBL) production was tested using the double-disc synergy test, and 29 E. coli strains were selected for whole genome sequencing. In total, 22.1% of the wild animals tested carried multidrug-resistant E. coli isolates, and 0.93% (2/217) of these wild animals carried E. coli isolates with ESBL-encoding genes (bla_CTX-M-65, bla_CTX-M-55, and bla_EC-1982). The E. coli isolates showed the highest resistance rates to ampicillin and were fully susceptible to amikacin, meropenem, ertapenem, and imipenem. Multiple resistance and virulence genes were detected, as well as different plasmids. The relatively high frequency of multidrug-resistant E. coli isolates in wildlife, with some of them being ESBL producers, raises some concern regarding the potential transmission of antibiotic-resistant bacteria among these animals. Gaining insights into antibiotic resistance patterns in wildlife can be vital in shaping conservation initiatives and developing effective strategies for responsible antibiotic use.

The Washington National Primate Research Center (WaNPRC) maintains the largest domestic breeding colony of pigtail macaques (Macaca nemestrina) in the United States, with animals housed in small to medium-sized social groups. As part of the animal care plan, a programmatic framework is utilized, which integrates clinical care with socialization considerations for nonhuman primates (NHPs). This framework encompasses the following areas: (1) socialization in the clinical setting; (2) positive reinforcement training (PRT); (3) measures to ensure proper identification and medication distribution; and (4) in-group treatments. The success of this framework is demonstrated by the high socialization rate for hospitalized animals (99.5% social pairing success), with the majority of clinical cases (95%) being treated in social groups. Ultimately, this framework seeks to buffer stressors when animals require clinical care or husbandry manipulations. Taken together, the above components foster an environment that provides a comprehensive approach to NHP medical and behavioral management.

Neonatal and pediatric mortality in kittens could be associated with bacterial infections, complications from inadequate management, congenital malformations, neonatal isoerythrolysis, parasitic diseases, and viral diseases. The complexity of causes, coupled with kittens' physiological and immunological immaturity, complicates the diagnosis and treatment of disease, highlighting the necessity for preventive measures. This study aimed to identify the leading causes of death and the occurrence of congenital malformations in stray kittens. Necropsies were performed on 68 kittens, all aged under two months. Results indicated that respiratory lesions were the leading cause of death in the youngest group, while gastrointestinal problems were more prevalent in older groups. Infectious causes were predominant across all age groups. Congenital malformations were observed in 40% of the animals, with megaesophagus, cardiovascular anomalies, bone defects, and kidney defects being the most prevalent. The findings underscore the critical importance of hygiene in preventing infections and related complications. Promoting sterilization and sanitary control in stray cats is essential to reduce overpopulation and improve living conditions.