Journal of Equine Veterinary Science最新文献

Mastication is the initial phase of digestion and is crucial to equine health due to its role in saliva production and food particle reduction. Hay nets have been promoted to slow the rate of hay consumption, with many styles of slow feeders available. Limited research has shown that nets may slow consumption, but no research has examined their effect on the horse's chewing frequency and patterns. The objective of this study was to compare chew frequency (CF, total number of chews/kg consumed) and chew duration (CD, total minutes chewed/kg consumed), as well as distribution of chews over a feeding period, of horses eating bermudagrass hay in three styles of hay nets [large mesh (LM), small mesh (SM), bottom hole (BH)] as compared to a control of loose hay (CTL). Treatments were assigned in a replicated Latin square 4 × 4 using eight horses. Horses were given a 24-hr acclimation period prior to recording their chewing patterns over a 24-hr period using an automated halter fit with a pressure-sensor noseband. Results indicate that CF was not influenced by treatment. However, SM resulted in longer CD as compared to CTL (P = 0.007). Additionally, BH resulted in a higher percentage of chews completed in the first 240 min compared to SM (P = 0.039), indicating more rapid consumption. Results of this study indicate hay nets may not influence the number of chews a horse performs while masticating hay, but small mesh feeders may increase the CD and reduce early consumption rate.

Twin pregnancy in mares is one of the leading causes of abortions. Abortion invariably impacts both fetuses. This report describes an unusual case of a twin surviving to term following the abortion of its co-twin at 9 months in a 7-year-old Egyptian Arabian mare. At the time of abortion at 9 months of gestation, the size of the aborted fetus was equivalent to one of approximately 5 months of age while the age of the live co-twin was 9 months. Both fetuses were males. A skin sample was collected from the aborted fetus and hair samples were collected from the dam, sire and live foal for parentage analysis. The parentage analysis confirmed that both fetuses were by the same dam and sire stallion. The authors suggest several scenarios to explain this condition. This report describes a unique case of a twin surviving to term following the abortion of its co-twin at 9 months in a mare.

Horses are the most challenging of the common companion animals to anesthetize. Induction of anesthesia in the horse is complicated by the fact that it is accompanied by a transition from a conscious standing position to uncconconscious recumbency. The purpose of this article is to review the literature on induction of anesthesia with a focus on the behavioral and physiologic/pharmacodynamic responses and the actions and interactions of the drugs administered to induce anesthesia in the healthy adult horse with the goal of increasing consistency and predictability.

The neonatal Fc receptor (FcRn) is the receptor responsible for bidirectional transport of immunoglobulin G (IgG) across cells, maintenance of IgG levels in serum, and assisting with antigen presentation. Unfortunately, little is known about FcRn in horses. Therefore, the objective of this study was to provide fundamental information regarding the location of FcRn in equine tissues. Tissues were collected from six horses of mixed breed, age, and sex immediately following euthanasia. Sampling locations included the respiratory tract, gastrointestinal tract (GIT), other visceral organs, cornea, and synovial membrane of the stifle and carpal joints. Tissues for histological analysis were fixed, cross sectioned, and stained for FcRn. Areas of interest were captured and analyzed with data represented as relative fluorescence (RF) to indicate FcRn abundance. Tissues for qPCR analysis were placed in RNAlater and relative quantification (RQ) of FcRn transcripts (FCGRT) was calculated using the 2^−ΔΔCT method, normalized to the geometric mean of three reference genes (ACTB, GADPH, HPRT1). Data were analyzed using the general linear model procedure of SAS. Abundance of FcRn differed between tissue types by immunofluorescence and qPCR analysis (P < 0.01). Joint synovium and respiratory tract tissues had the highest RF, GIT tissues expressed moderate RF, and other visceral organs had the lowest RF. Conversely, liver and kidney tissues had the highest RQ while the stomach and cornea had the lowest RQ. These data lay the foundation for future studies regarding FcRn and IgG in horses and their roles in disease prevention and treatment.

Equine bladder neoplasms are rare. This report aimed to describe the clinical signs and treatment of urothelial carcinoma (UC) in a mule. Cystoscopy of a 20-year-old female mule with a one-week history of hematuria and anemia revealed vascular congestion in the mucosa and an intraluminal, pedunculated mass in the dorsal bladder region. Histopathological examination revealed UC. Initial therapy consisted of four weekly cystoscopic guided injections of fluorouracil. At the fourth chemotherapy session, a paler and more friable tumor mass was observed. Consequently, we opted to surgically remove it during cystoscopy. Following mass excision, patient comfort, gross appearance of urine, and the hematocrit returned to normal. Repeat cystoscopy examinations revealed no gross appearance of tumor recurrence 18 months after treatment. Bladder neoplasms clinically resemble urolithiasis and cystitis and should be considered a differential diagnosis in cases of anemia and hematuria.

Surgical site infection (SSI) is a common complication after celiotomy in horses, leading to increased morbidity and costs. Increased concern about antibiotic resistance justifies evaluation of alternative preventive approaches, such a Manuka honey which has displayed antimicrobial properties. Pectin-Honey Hydrogels (PHH), composed by Manuka honey and pectin provide a moist wound environment and microbial growth inhibition. The aim of the study was to evaluate the effectiveness of PHHs in preventing SSI in horses subjected to emergency laparotomy. Horses undergoing laparotomy were evaluated. Horses were randomly divided into two groups: Group 1 received PHH application onto the sutured linea alba before skin closure, while Group 2 received no treatment. Horses with postoperative antimicrobial administration or survival of less than 5 days were excluded. The incidence of SSIs was reported as percentages and compared between groups. Out of 44 horses enrolled in the study, only thirty-six were ultimately included. Exclusions occurred either due to death before 5 days postoperatively (2 horses) or the administration of postoperative antimicrobials (6 horses). The median length of hospitalization was 9 days (range 8–14 days). The overall occurrence of SSI was 19.4 %. One out of eighteen horses (5.5 %) in Group 1 and 6 out of 18 (33.3 %) horses in Group 2 developed SSI. Group 2 had an 8.5-fold increased risk of SSI (p = 0.035, OR = 8.5, 95 % CI. 0.9–80.07). No macroscopically visible adverse reactions were associated with PHH. PHH placed at the abdominal incision during surgery was safe and reduced the prevalence of SSI in horses.

Persistent stallion-like behavior is a common sign of cryptorchidism in supposed geldings. The presence of testicular tissue can be evaluated by analyzing hormones such as testosterone and anti-Müllerian hormone (AMH). Here, we used hormonal analysis to investigate relationships between the likely presence of testicular tissue and stallion-like behavior in samples submitted from presumptive geldings (n = 1,202), retrospectively. Most geldings with stallion-like behaviors had serum concentrations of testosterone (851/1,056; 80.6 %) and AMH (682/877; 77.8 %) below the laboratory reference range for cryptorchids (< 60 pg/mL and ≤ 0.15 ng/mL for testosterone and AMH, respectively). A total of 13 samples (13/716; 1.8 %) showed AMH concentrations typical for geldings but testosterone above the cryptorchid range. Conversely, 31 samples (31/716; 4.3 %) had high AMH, suggesting cryptorchidism, but testosterone concentrations implied no testicular tissue. Among the cryptorchid stallions, the AMH and testosterone concentrations did not vary based on the season. However, age categories affected the concentration of both hormones among the presumptive true cryptorchid stallions. The results of this study demonstrate that undesirable behavior in geldings is rarely associated with the presence of testicular tissue, as assessed by these two hormonal biomarkers. This information highlights the complexity of behavior and demonstrates that persistent stallion-like behavior in geldings could be related to factors other than the presence of testicular tissue.

A study comprising 74 colic and 74 control horses admitted to an animal hospital was performed. Faecal samples were collected and analysed for dry matter concentration, particle size distribution using wet-sieving, and sand presence through a sand sedimentation test. Data on horse breed, age, gender and basic feeding variables was collected and analysed using χ²-tests. Faecal dry matter concentration, particle size distribution and sand score was compared between colic and non-colic horses, and between horses with different colic types, using one-way ANOVA. Results showed that colic and non-colic horse groups were similar in breed, age, gender and basic feeding variables. Faecal dry matter concentration, particle size distribution and sand score were similar among colic and non-colic horses. Horses diagnosed with “unknown colic cause” had higher proportion of particles >0.5 <1.0 mm size compared to horses with colic due to impactions in caecum or colon, torsion or gas accumulation (P<0.05), but this difference was very small and most likely not of biological importance. Faecal dry matter concentration and sand score were similar among horses with different types of colic. Increased knowledge of the composition of particles of different size in equine faeces may enhance our understanding of digesta passage rate in colic and non-colic horses, which is needed to develop preventative measures of certain types of colic.

This study aimed to compare the digestibility of tropical grasses by horses by the in vivo method using mobile nylon bags with the in vitro digestibility method using horse feces as a source of inoculum. Five horses were used in a 2 × 5 factorial design with randomized blocks featuring two methods (in vivo and in vitro) and five grasses: Tifton 85 hay (Cynodon spp.), sixweeks threeawn grass (Aristida adsencionis, Linn), Alexandergrass (Brachiaria plantaginea (Link) Hitchc.), capim-de-raiz (Chloris orthonoton, Doell), and Sabi grass (Urochloa mosambicensis). No difference (P>0.05) was found between the in vivo and in vitro methods regarding nutrient digestibility of Sabi grass and sixweeks threeawn. Tifton 85 was the only grass that showed differences (P<0.05) between the two methods concerning the apparent digestibility of all nutrients. Alexandergrass, Tifton 85, and capim-de-raiz exhibited the best digestibility of dry matter, neutral detergent fiber, acid detergent fiber, and organic matter by the mobile bag method compared to the in vitro method. Tifton 85 and capim-de-raiz had higher crude protein digestibility by the mobile bag method than by the in vitro method. The mean retention time of the mobile bags in the digestive tract of the horses was 43.69 h. The bags with samples of sixweeks threeawn and Sabi grass had shorter retention times than capim-de-raiz and Alexandergrass (P<0.0001). It is concluded that, for sixweeks threeawn and Sabi grass, digestibility in horses can be assessed using the in vitro method in place of the mobile nylon bag method.