Journal of Equine Science最新文献

Pre-exercise cooling may prevent exertional heat illness in horses. We hypothesized that pre-exercise cooling before warm-up in a hot environment would not affect performance but would mitigate reductions in body weight and increases in body temperature following exercise. Six trained Thoroughbred horses were studied using a randomized, crossover design with three pre-treatments: 30-min walk on a treadmill at 1.7 m/sec (WALK), 30 min of standing (REST), and a 10-min pre-cooling shower at 26.2 ± 0.8°C (SHOWER). All horses underwent each pre-treatment, followed by a warm-up and main exercise in a hot environment (wet-bulb globe temperature: 32-33°C). After warming up by cantering at 10.0 m/sec for 30 sec, horses exercised on a treadmill with a 6% incline and a speed eliciting exhaustion within 2 min, which was approximately 115% V̇O₂max (relative intensity; 13.5-14.3 m/sec). Run time to exhaustion was recorded, with body weight measured before pre-treatment and after main exercise to calculate weight loss. Heart rate was measured from before pre-treatment to after the main exercise. Plasma lactate concentration (Lac) and pulmonary arterial temperature (a measure of body temperature) were assessed before and after pre-treatment and after the warm-up and main exercise. Weight loss in SHOWER was significantly reduced compared with the other treatments. Pulmonary artery temperatures in WALK after pre-treatment were significantly higher than in the other treatments. No significant differences were observed in heart rate, Lac, or run time. These results suggest that pre-cooling mitigates reductions in body weight and increases in body temperature without affecting performance.

Dareshuri horses are the predominant breed in Fars Province, Iran. Although disorders affecting their maxillary cheek teeth and maxillary sinuses are relatively common, limited fundamental data are available on the dimensions and relationships of these structures at different ages. Given the significant anatomical changes in the heads of young horses as they mature, this study aimed to evaluate age-related changes in the position and anatomical relationships of individual maxillary cheek teeth within the rostral and caudal maxillary sinuses (RMS and CMS, respectively), as well as changes in the lengths and heights of individual sinus compartments during their growth. Radiographs were performed on 29 heads of live, healthy horses aged between 4 months and 5 years and were analyzed using the EConsole1 Radiography Viewer software (V.3, 2017, DRTECH Europe GmbH, Schwalbach am Taunus, Germany). Statistical analyses revealed that the only significant change throughout the study was an increase in the length of the CMS (4.075 ± 0.99 cm; SE), which was more significant in horses up to three years old. At less than 1 year old, the only tooth present in the maxillary sinus was M1. At 1-2 years old, M2 was observed entering the maxillary compartments; PM4 entered the RMS at 2-3 years old, and M3 entered the CMS at 3-4 years old. Eventually at 4-5 years old, PM3, M1, and M2 were present in the RMS, and M2 and M3 were present in the CMS. This information should be of value in the diagnosis and treatment of Dareshuri maxillofacial disorders and used as a reference for further anatomical investigations.

Previous studies have examined the relationship between hair characteristics and temperament traits in various animals. A partial genetic association has been suggested in humans because whorl formation and neurological development occur simultaneously during the fetal period. In the horse industry, anecdotal evidence suggests a link between the forehead whorl position and temperament. In our previous study, the heritability of forehead whorl positioning was h²=0.653, indicating significant genetic contributions in thoroughbreds. Therefore, in this study, we designed a genome-wide association study using 192 Thoroughbred horses to detect candidate genes associated with forehead whorl positioning. The results revealed 11 suggestive markers on chromosomes 2, 14, 15, 19, and 26, although no significant markers were found. Five genes, namely PTTG1, CCNH, RASA1, COX7C, and CLDN1, located near these markers had functions related to skin cell or hair follicle development and temperament. Therefore, these genes may be involved in the positioning of the forehead whorl in Thoroughbreds. The candidate genes identified in this study are expected to contribute to elucidating the genetic factors behind forehead whorl in horses and to help interpret the common process of whorl and temperament development.

The equine large intestine harbors a diverse array of symbiotic microorganisms. Disruptions in the gut microbiota can lead to various diseases in horses. Probiotics offer promising avenues for enhancing equine health and performance. However, commercial formulations lack robust scientific validation. This study aimed to isolate and identify Lactobacillaceae and Bifidobacterium spp. from horse feces to explore their potential as probiotics. Fecal samples from Thoroughbred horses were subjected to isolation procedures. Lactic acid-producing bacteria were isolated using specific media and identified. The results revealed the isolation of Lactobacillaceae strains, including Limosilactobacillus equigenerosi, Ligilactobacillus equi, Ligilactobacillus agilis, and a Bifidobacterium sp., Bifidobacterium pseudolongum. These findings contribute to the understanding of equine gut microbiota and offer insights into potential probiotic candidates.

We examined the differences in serum iron (Fe) concentrations and related variables between summer and winter in Noma horses. Blood samples were collected from 37 clinically normal horses seven consecutive times: September 2018, February 2019, October 2019, February 2020, September 2020, February 2021, and February 2022. Serum Fe concentrations ranged from 74 μg/dl to 316 μg/dl with a median of 176 μg/dl. The concentrations were lower in stallions compared with mares and geldings, tended to be low at 10-14 years of age, and then increased with age. Serum Fe concentrations were repeatedly low in summer and high in winter. Total iron-binding capacity (TIBC), Fe-saturation rate, hemoglobin (Hb), hematocrit (Ht), MCV, MCH, albumin, cholesterol, sodium (Na), potassium (K), chloride (Cl), and calcium (Ca) were lower in summer than in winter. However, creatinine, total protein, inorganic phosphorus, and Mg were higher in summer. The unsaturated iron-binding capacity, RBC count, blood urea nitrogen (BUN), glucose, and AST levels were not significantly different. Serum Fe concentrations were positively correlated with Hb, TIBC, Fe saturation rate, Ht, MCV, MCH, creatinine, albumin, glucose, cholesterol, AST, Na, Cl, and Ca, but negatively correlated with BUN and K. In Noma horses, serum Fe concentrations might be higher than the reference values for horses and consistently decrease in summer in parallel with Hb and MCV. The lowering of the serum Fe concentrations in summer may be due to a combination of the effects of Fe loss from sweating, dermatitis, insect bites, dietary composition, and/or unknown factors.

Dexamethasone is a common drug used in equine medicine, but when administered inappropriately, it can lead to serious health complications. There is a dearth of data on horse caregivers' knowledge, attitudes, and practices regarding dexamethasone use in Nigeria. Understanding current dexamethasone usage patterns is necessary for developing educational interventions which will then improve equine welfare. This study aimed to assess the knowledge, attitudes, and practices (KAP) of horse caregivers regarding dexamethasone use in Ibadan, Nigeria. A cross-sectional study was conducted amongst a total of 100 horse caregivers in Ibadan using a structured questionnaire. Face-to-face interviews were conducted so as to assess KAP regarding dexamethasone use. Descriptive statistics and chi-square tests were conducted with P≤0.05 considered significant. All respondents were male, and 66% of them were aged 20-39 years. Only 46% of them demonstrated satisfactory knowledge, with 76% of them wrongly identifying dexamethasone as a painkiller rather than a steroid (6%). Attitudes (caregivers' perceptions and willingness to follow veterinary guidance) and practices were satisfactory in 54% of respondents. Facility type significantly influenced attitudes (P=0.036), with commercial stable workers showing poorer attitudes (80% unsatisfactory). Age significantly affected practices (P=0.014), with teenagers demonstrating the worst practices (100% unsatisfactory). Frequency of veterinary consultation significantly affected both attitudes (P=0.025) and practices (P=0.007), with daily interaction showing the best outcomes. Knowledge gaps as well as inappropriate practices regarding dexamethasone use exist among horse caregivers in Ibadan, particularly concerning its classification, mechanism of action, and side effects. We recommend the implementation of educational programmes and encouragement of regular veterinary consultation amongst caregivers.

Colic, a major gastrointestinal disease in horses, has a high recurrence rate and can lead to surgery or fatal outcomes, highlighting the need for effective prevention measures. Disruption of the microbiome is a multifaceted problem and can occur from a variety of factors, such as high-concentrate diets, which can then potentially cause colic. However, individual variation in the incidence of colic can occur when under identical management practices. The aim of this study was to characterize the fecal bacterial composition of Japanese draft horses with and without a history of colic in the past two years under identical feeding conditions to determine if specific bacterial taxa are associated with either phenotype. A fecal bacterial community analysis was performed via sequencing of the V3-V4 region of the 16S rRNA gene. The fecal lactate concentration was measured using high-performance liquid chromatography. Our results show a significant decrease in microbial evenness in horses with a history of colic along with an increase in Streptococcus. The fecal lactate concentration was higher in the colic group compared with the non-colic group, which may be attributed to the higher abundance of Streptococcus. Horses without a history of colic were characterized by amplicon sequence variants belonging to bacteria associated with fiber degradation, including Rikenellaceae RC9, Kiritimatiellae, and Clostridium. Overall, our results align with previous studies on equine colic epidemiology and suggest that the bacterial microbiome composition, independent of diet, may be related to the recurrence of colic.

The Tibetan wild ass (Equus kiang) is primarily located on the Tibetan Plateau and in the Ladakh region of India. This species is recognised as the only odd-toed ungulate within the order Perissodactyla, family Equidae, and genus Equus. According to the International Union for Conservation of Nature (IUCN), E. kiang is classified as a species of Least Concern; however, the subspecies Equus k. kiang, which inhabits the Changthang Wildlife Sanctuary in Ladakh, is categorised as Data Deficient by the IUCN. To rigorously assess the validity of the Data Deficient classification of E. k. kiang, a comprehensive literature review was undertaken utilising search terms including "E. kiang", "Asiatic Wild Ass", "Tibetan Wild Ass", and "kiang" on platforms such as PubMed (NCBI) and Google Scholar. The results consistently demonstrated that the majority of the literature concentrates on the ecological and behavioural attributes of the kiang, while there is limited focus on genetic factors. Most genetic studies have prioritised the estimation of genetic diversity and the execution of phylogenetic analyses; however, none have sufficiently investigated the population structure. Notably, there is a significant paucity of research on the whole-genome sequencing of E. kiang, and to date, no nucleotide sequences from India have been submitted to GenBank. Consequently, it can be inferred that while E. kiang is designated as a species of Least Concern, its subspecies, E. k. kiang, remains Data Deficient. It is strongly recommended that future research employ molecular markers such as mitochondrial DNA D-loop markers, microsatellite (MSAT) markers, and single-nucleotide polymorphism (SNP) markers to evaluate the population structure of this resilient equid.

Computed tomography (CT) offers high-resolution, three-dimensional imaging, making it particularly valuable for assessing complex structures, such as the head, especially when conventional radiography and endoscopy are insufficient for a definitive diagnosis. Herein, we present two cases of equine cranial disorders resulting from congenital malformations. In case 1, which had a dentigerous cyst, CT images confirmed the location of the ectopic tooth within the skull and a detailed fistula tube. In case 2, which had temporohyoid osteoarthropathy, CT examination revealed that the stylohyoid bone was malformed, and the inner ear was presumed to be filled with soft tissue with calcification. The information obtained by CT was invaluable, as it allowed for accurate diagnosis and precise surgical planning.

This case report documents the first identified Brucella infection in a 6-year-old male Thoroughbred horse in Libya. The horse exhibited muscle and joint pain, inflammation over the shoulders with a pulpy texture (fistulous withers), stress, fatigue, and potential systemic infection. Its diagnosis was confirmed through serological testing, with agglutination titers of 1/80 for B. melitensis and 1/160 for B. abortus, and a blood culture revealing Gram-negative coccobacilli. After 3 weeks of combination therapy with rifampicin and doxycycline, the inflammation resolved, systemic signs disappeared, the horse's health improved significantly, with restored appetite and reduced levels of stress and fatigue. This novel finding underscores the potential spread of brucellosis across animal species, highlighting brucellosis' spread across animal species and its public health risks. It emphasizes the urgent need for a "One Health" approach, vaccination programs, enhanced diagnostic infrastructure, and international collaboration.