Search Results (13)

This experiment evaluated the effects of a nose flap (NF) device and bovine-appeasing substance (BAS) administration on the growth, temperament, immune response, and pasture behavior of calves during weaning. A total of 24 Nellore calves were used in a 2 × 2 factorial arrangement. The factors were the use of an NF or not (NoNF) for 14 d before weaning and the administration of BASs or not (NoBAS) at weaning (d 0). NF vs. NoNF reduced (p ≤ 0.01) the average daily gain (ADG; d −7 to 84; −0.289 vs. 0.378 ± 0.13 kg/d) and the time ruminating but increased (p ≤ 0.05) the exit score from the chute (d 14 and 28) and the time grazing. BAS vs. NoBAS administration increased (p ≤ 0.02) the ADG (d 14 to 84; 0.487 vs. −0.08 ± 0.10 kg/d) and the time grazing, reduced (p < 0.01) the time ruminating, and tended to decrease (p ≤ 0.10) the exit score (d 7, 14 and 28) and the time vocalizing. Treatments did not affect (p ≥ 0.35) serum rabies titer concentration. Thus, the use of NFs reduced growth and increased stress after weaning, while BAS administration increased growth and decreased stress after weaning, altering behavior but not the immune system. According to the results of this experiment, the use of BASs but not NFs is recommended to alleviate weaning stress in beef calves. Full article

Background: The neuropeptide oxytocin has been identified as a potential therapeutic molecule. However, the therapeutic potential of this molecule is limited due to the challenges faced in oxytocin delivery to the brain. Scientific innovation has led to the breakthrough discovery of many modalities to encapsulate molecules for targeted drug delivery, which can enhance oxytocin delivery to the brain. This research aimed to explore a microfluidics-based system that optimizes the formulation of cross-linked bovine serum albumin (BSA) nanoparticles encapsulating oxytocin. Methods: First, the formulation parameters were optimized using a design of experiments (DOE) by evaluating the effect of flow rate, polymer concentration, and the binary solvent mixture polarity on the nanoparticle size. Drug encapsulation efficiency, release, and kinetics profile were characterized. These oxytocin nanoparticles were conjugated to rabies virus glycoprotein (RVG), a brain-targeting ligand, and the conjugation efficiency was determined. Results: The sizes of the nanoparticles were between 50 nm and 75 nm with a <0.4 polydispersity index. The encapsulation efficiency was >80%. Approximately 58% of oxytocin was released from the nanoparticles within the first six hours, showing an initial burst that is ideal for seizure control and thereafter exhibiting the Korsmeyer–Peppas release kinetics. Conclusions: For the first time, we demonstrated the microfluidics method of formulating nanoparticles with particle size of less than 100 nm, with improved encapsulation efficiency and optimal release profile for oxytocin brain delivery. Full article

Toxoplasma gondii is an intracellular protozoan parasite that infects a wide range of vertebrates, including humans. Although cats are the only definitive host, any warm-blooded animal can act as a paratenic host. Throughout the years, this apicomplexan parasite has been studied due to its wide prevalence, zoonotic potential, and host behavioral alterations. Known for its neurological alterations, the rabies virus is one of the most recognized types of zoonosis that, although preventable, still causes deaths in humans and animals worldwide. Due to the overlapping clinical signs of these two pathogens, the objective of this study was to evaluate the prevalence of T. gondii DNA in cerebellum tissue collected for rabies testing; cerebellum tissue from diverse animals is often submitted for this purpose. Between May 2022 and April 2024, we tested 903 cerebellum tissue samples from 22 animal species submitted for rabies testing to the Oklahoma Animal Diagnostic Disease Laboratory. Overall, T. gondii prevalence was 3.96%, with 1.8% found in cats (Felis catus), 1.7% in dogs (Canis familiaris), 0.3% in skunks (Mephitis mephitis), and 0.2% in infected cattle (Bos taurus). Analysis among T. gondii-positive hosts revealed a statistically significant difference in dogs when comparing neutered vs. intact males, with 7.94% (5/63) T. gondii-positive neutered males and 1.61% (3/186) T. gondii-positive intact males (p = 0.02). All the T. gondii-positive samples were negative for rabies. Anamnesis in some of the T. gondii-positive samples included ataxia, aggression, muscle rigidity, lethargy, and seizures, with the latter also described in dogs and aggression in the positive bovine sample. The clinical signs described in the T. gondii-infected hosts can be mistaken for rabies infection; therefore, it is important to consider T. gondii as a differential diagnosis in suspected rabies cases and test for this parasite when negative rabies results are obtained. Full article

Rabies, a zoonotic viral disease, poses a significant threat due to its adaptability to diverse environments. Herbivore rabies, predominantly affecting cattle, horses, and goats in Brazil, remains a concern, results in substantial losses in the livestock industry, and poses risks to public health. Rabies virus transmission, primarily through hematophagous bats in Latin America, underscores the need for effective strategies, and vaccination plays a crucial role in controlling herbivorous rabies, with systematic vaccination beingly the primary method. Efforts to control rabies in herbivores include vaccination campaigns, public awareness programs, and the enhancement of surveillance systems. Despite these initiatives, rabies persists and imposes an economic burden and a significant health risk. Economic impacts include losses in the livestock industry, trade restrictions on livestock products, and financial burdens on governments and farmers owing to control measures. Despite the considerable costs of campaigns, surveillance, and control, investing in rabies vaccination and control not only safeguards livestock, but also preserves public health, reduces human cases, and strengthens the sustainability of the livestock industry. Mitigating the impact of herbivorous rabies in Brazil requires integrated approaches and continuous investments in vaccination, surveillance, and control measures to protect public health and ensure the sustainability of the livestock industry, thus contributing to food and economic security. Full article

The water buffalo (Bubalus bubalis) has great adaptability to rustic environments and more variable conditions than cattle, who generally share the habitat. Diseases carried by buffaloes are relatively unknown and ignored and could be transmissible; an imbalance occurs between pathogens, environment, and susceptible hosts, generating a severe animal health problem. Also relevant is the effect of climate change on the populations of vectors that transmit viral diseases. The discovery of new virus variants that can pass from bovine (Bos) to buffalo or vice versa or to humans has highlighted the relevance of viruses crossing the host barrier. This review discusses the clinical viral diseases most reported in the water buffalo, characteristics, epidemiology, and recent findings about disease behavior, interaction with other species, the host, vectors, and pathogens. Diseases reviewed include Foot and Mouth Disease, Rinderpest, Malignant Catarrhal Fever, Infectious Bovine Rhinotracheitis, Bovine Viral Diarrhea, and Rabies. Also, vector-borne diseases include Lumpy Skin Disease, Ephemeral Fever, and Blue Tongue. The review also considers emerging viruses such as Buffalo Pox and Schmallenberg and, finally, other viruses such as papillomatosis. The knowledge and epidemiology of buffalo viral diseases must be constantly reconsidered and updated for adequate prevention and control programs. Full article

Rabies is a fatal neglected tropical zoonosis, and its significance for domestic herbivores in the rural cycle is probably associated with rainforest deforestation, livestock, and agricultural expansion. This epidemiological survey aimed to study the occurrence of rabies in bovines and equines in the state of Rondônia, located in the Brazilian’s Legal Amazon, between the years 2002 and 2021, correlating these findings with the prophylactic strategies adopted by the local sanitary agency for rabies control. During this period, 201 cases were observed in bovines and 23 in equines. A downward trend in rabies incidence was observed for both domestic herbivores. Rabies did not show a higher occurrence in any specific time of the year, and epidemic periods varied during some years for bovines and equines. Using the Generalized estimating equations (GEE) method, a multiple model approach was obtained with the explanatory variables significantly associated with the decrease in rabies incidence in cattle and horses during the study period: the ratio of treated bats and ratio of vaccine doses sold. Furthermore, the ratio of printed educative material was positively associated with rabies incidence. Despite a decreasing trend in rabies occurrences in this Amazon rainforest area, likely due to the actions taken by the animal sanitary agency, rabies remains endemic and requires monitoring, as well as prophylactic strategies to control this disease. Full article

Introduction: Rabies is caused by a virus belonging to the genus Lyssavirus and family Rhabdoviridae, which can infect any mammal including humans. Hematophagous, fructivorous, and insectivorous bats have become the main reservoir of sylvatic rabies in Latin America. In the sylvatic cycle, hematophagous bats are usually the main reservoir. In contrast, dogs and cats fulfil this critical role in the urban cycle. However, in rural areas, the most affected animals are bovines. They show clinical signs such as behavioural changes, hypersalivation, muscle tremors, spasms caused by extensive damage to the central nervous system, and death from respiratory paralysis. Objective: To describe the spatiotemporal distribution of bovine rabies in Colombia from 2005 to 2019. Methods: Retrospective cross-sectional descriptive observational study, based on the monthly reports of the Colombian Agricultural Institute (ICA) on the surveillance of bovine rabies in Colombia from 2005 to 2019, retrieved from its official website. The data were converted to databases in Microsoft Access 365^®. Multiple epidemiological maps were developed with the GIS software Kosmo RC1^® 3.0 coupled to the shape files (.shp) of all the country’s municipalities. Results: During the study period, 4888 cases of rabies were confirmed in cattle, ranging from a peak of 542 cases (11.1%) in 2014 to 43 in 2019 (0.88%). From 2014 to 2019, there has been a significant reduction in the annual national number of cases (r² = 0.9509, p < 0.05). In 2019, 32.6% of the cases occurred in January, and 48.8% occurred in the department of Sucre. In 2009, the maximum number of spatial clusters (13) occurred in the Orinoquia region, where other clusters were also identified in 2005, 2006 and 2008. In 2018, 98 outbreaks were identified that led to the death of cattle and other animals, 28.6% of them in the department of Sucre. In the first half of 2019, of 38 outbreaks, 55.2% were identified in Sucre. Conclusions: It is necessary to review the current national program for the prevention and control of rabies in cattle, incorporating concepts from the ecology of bats, as well as the prediction of contagion waves of geographical and temporal spread in the context of the OneHealth Approach. Sylvatic rabies remains a threat in Colombia that requires further study. Full article

Desmodus rotundus bats show a complex social structure and developed adaptive characteristics, considered key features of a pathogen disseminator, such as the rabies virus, among bats and other mammals, including cattle and humans. Our aim was to understand the correlation between the environment and the ecological features of these bats in bovine rabies outbreaks. Geostatistical analyses were performed, covering 104 cattle positives for rabies, between 2016 and 2018, in 25 municipalities, in addition to the characteristics of D. rotundus colonies mapped during this period in the state of São Paulo, Brazil. Data from the shelters showed that 86.15% were artificial, mainly abandoned houses (36.10%) and manholes (23.87%), in addition to demonstrating a correlation between these shelters and a higher concentration of bovine rabies cases. Due to their adaptive capacity, these bats choose shelters close to the food source, such as livestock. In Brazil, D. rotundus is the main transmitter of rabies and the cause of outbreaks in cattle and deaths in humans, considering the advance of humans in previously preserved ecosystems. There seems to be a correlation between the impact of anthropic changes on the environment, mainly for the expansion of pasture for cattle and the outbreaks of bovine rabies in this area. Full article

Rabies is a fatal viral infection that causes enc ephalitis in warm-blooded animals, including humans. Dog-transmitted rabies is considered eradicated in Mexico; however, rabies is not being tested in livestock with neurological symptoms (one of the main manifestations of rabies disease). In this case report, we describe a rabies case in a white-tailed deer in the Santo Domingo ranch, in Catazajá, Chiapas, Mexico, where white-tailed deer are kept under captivity, and are meant for human consumption. This is the first report of a rabies case in white-tailed deer in Mexico. We also describe the challenges to obtain a rabies diagnosis and the lack of public health policies to ensure containment of the disease, as well as the lack of awareness among farmers in the area. One single confirmed case of rabies indicates that more animals are affected by the disease. The risk for human health and economical losses will remain unknown until rabies tests are routinely performed in animals that present neurological symptoms. Full article

Tissues from two cows with neurological signs that were admitted to the Vetsuisse Faculty under suspicion of rabies and bovine spongiform encephalopathy (BSE), respectively, were further analyzed for this case report. After histopathological examination and exclusion of BSE and rabies, the animals were diagnosed with etiologically unresolved disseminated non-suppurative encephalitis. Using next-generation sequencing, we detected the full genome of bovine polyomavirus 2 (BoPyV2) in brain samples from both animals. This virus has been identified in beef samples in three independent studies conducted in the United States and Germany, but has not been linked to any disease. Analysis of the two new BoPyV2 genome sequences revealed close phylogenetic relationships to one another and to BoPyV2 isolates detected in beef samples. In situ hybridization demonstrated the presence of viral nucleic acid in all investigated brain areas and in areas with signs of inflammation in both animals. Thus, we provide the first evidence that BoPyV2 is a probable cause of non-suppurative encephalitis in cattle, and encourage further molecular and serological testing to elucidate the disease’s epidemiology, as well as experimental transmission studies to prove causality between the infection and disease. Full article

Introduction: To achieve the global goal of canine-mediated human rabies elimination by 2030 there is an urgent need to scale-up mass dog vaccination activities in regions with large dog populations that are difficult to access; a common situation in much of India. Oral rabies vaccination may enable the vaccination of free-roaming dogs that are inaccessible to parenteral vaccination, and is considered a promising complementary measure to parenteral mass dog vaccination campaigns. WHO and OIE have published detailed minimum requirements for rabies vaccines and baits to be used for this purpose, requiring that baits must not only be well-accepted by the target population but must also efficiently release the vaccine in the oral cavity. For oral rabies vaccination approaches to be successful, it is necessary to develop baits which have a high uptake by the target population, are culturally accepted and amenable to mass production. The aim of this study was to compare the interest and uptake rates of meat-based and an egg-based prototype bait constructs by free roaming dogs in Goa, India. Methods: Three teams randomly distributed two prototype baits; an egg-flavoured bait and a commercial meat dog food (gravy) flavoured bait. The outcomes of consumption were recorded and compared between baits and dog variables. Results: A total of 209 egg-bait and 195 gravy-bait distributions were recorded and analysed. No difference (p = 0.99) was found in the percentage of dogs interested in the baits when offered. However, significantly more dogs consumed the egg-bait than the gravy-bait; 77.5% versus 68.7% (p = 0.04). The release of the blue-dyed water inside the sachet in the oral cavity of the animals was significant higher in the dogs consuming an egg-bait compared to the gravy-bait (73.4% versus 56.7%, p = 0.001). Conclusions: The egg-based bait had a high uptake amongst free roaming dogs and also enabled efficient release of the vaccine in the oral cavity, whilst also avoiding culturally relevant materials of bovine or porcine meat products. Full article

Rabies is a fatal zoonotic disease transmitted by the bite of a rabid animal. More than 95% of the human rabies cases in India are attributed to exposure to rabid dogs. This study evaluated the utility of a lateral flow immunochromatographic assay (LFA) (Anigen Rapid Rabies Ag Test Kit, Bionote, Hwaseong-si, Korea) for rapid post mortem diagnosis of rabies in dogs. Brain tissue was collected from 202 animals that were screened through the Government of Goa rabies surveillance system. The brain tissue samples were obtained from 188 dogs, nine cats, three bovines, one jackal and one monkey. In addition, 10 dogs that died due to trauma from road accidents were included as negative controls for the study. The diagnostic performance of LFA was evaluated using results from direct fluorescence antibody test (dFT); the current gold standard post mortem test for rabies infection. Three samples were removed from the analysis as they were autolysed and not fit for testing by dFT. Of the 209 samples tested, 117 tested positive by LFA and 92 tested negative, while 121 tested positive by dFT and 88 tested negative. Estimates of LFA sensitivity and specificity were 0.96 (95% CI 0.91–0.99) and 0.99 (95% CI 0.94–1.00), respectively. The LFA is a simple and low-cost assay that aids in the rapid diagnosis of rabies in the field without the need for expensive laboratory equipment or technical expertise. This study found that Bionote LFA has potential as a screening tool in rabies endemic countries. Full article

Mass parenteral vaccination remains the cornerstone of dog rabies control. Oral rabies vaccination (ORV) could increase vaccination coverage where free-roaming dogs represent a sizeable segment of the population at risk. ORV’s success is dependent on the acceptance of baits that release an efficacious vaccine into the oral cavity. A new egg-flavored bait was tested alongside boiled bovine intestine and a commercially available fishmeal bait using a hand-out model on the Navajo Nation, United States, during June 2016. A PVC capsule and biodegradable sachet were tested, and had no effect on bait acceptance. The intestine baits had the highest acceptance (91.9%; 95% confidence interval (CI), 83.9%–96.7%), but the fishmeal (81.1%; 95% CI, 71.5%–88.6%) and the egg-flavored baits (77.4%; 95% CI, 72.4%–81.8%) were also well accepted, suggesting that local bait preference studies may be warranted to enhance ORV’s success in other areas where canine rabies is being managed. Based on a dyed water marker, the delivery of a placebo vaccine was best in the intestine baits (75.4%; 95% CI, 63.5%–84.9%), followed by the egg-flavored (68.0%; 95% CI, 62.4%–73.2%) and fishmeal (54.3%; 95% CI, 42.9%–65.4%) baits. Acceptance was not influenced by the supervision or ownership, or sex, age, and body condition of the dogs. This study illustrates that a portion of a dog population may be orally vaccinated as a complement to parenteral vaccination to achieve the immune thresholds required to eliminate dog rabies. Full article