Tawanhathai Apichaimongkonkun

Trypanosomosis (Surra), caused by the hemoflagellate protozoan Trypanosoma evansi, has a negative impact on animal health and the livestock economy in many countries, including Thailand. Molecular epidemiological data and integrative control approaches for small-scale farms remain limited. This study determined the prevalence of Trypanozoon infection and its associated risk factors in Thai livestock under an integrative control approach. Molecular tools were used to characterize T. evansi typing. A total of 947 blood samples were collected from cattle and buffalo across 123 small-scale farms in 16 provinces covering four regions of Thailand, with diagnostic results and control recommendations communicated to farmers within 14 days. The ITS2-positive samples were then subjected to further molecular characterization, together with two dogs, seven horses, and an in vitro T. evansi isolate, comprising 40 Trypanozoon-positive samples. These were characterized using PCR targeting the TBR primer, maxicircle NADH5, VSG RoTat 1.2, and minicircle B, followed by ITS2-based phylogenetic analysis. Risk factors were assessed using Chi-square and Fisher’s exact tests, logistic regression, a generalized linear mixed model, and Firth’s penalized logistic regression. The overall prevalence of Trypanozoon infection was 3.17% (30/947), detected exclusively in beef cattle in the Northern region (15.30%; 30/196), specifically in Lampang (46.15%, 12/26), Tak (23.08%, 3/13), and Phrae (17.24%, 15/87) Provinces. No infections were reported in the Northeastern, Central, or Southern regions. Male sex, age under one year, and residence in the Northern region were significant individual-level risk factors, while farm-level lacrimation and the presence of Stomoxys were significantly associated with infection. Molecular characterization identified T. evansi type A and type non-A/B, with no type B or maxicircle-positive samples detected. Phylogenetic analysis grouped the Thai isolates with previously reported isolates from Thai deer and cattle, Iranian camels, and Colombian dogs. On follow-up, no Trypanozoon infection was detected in revisited farms. These findings confirmed that T. evansi, comprising types A and non-A/B, continues to circulate in Thai livestock, particularly in beef cattle in Northern Thailand. Data from this study can be used for surveillance and future development of more effective diagnostic systems.

African horse sickness (AHS), a life-threatening disease caused by African horse sickness virus serotype 1 (AHSV-1), emerged in Thailand in February 2020 with 607 cases and a 93% fatality rate. The outbreak was mitigated by vector control and a live attenuated virus (LAV) vaccine. Information regarding viremia and immunity after infection and vaccination during outbreaks are essential for controlling disease transmission. This study evaluated these parameters in 15 infected naïve horses and 11 vaccinated horses during the 2020 outbreak. Whole blood was collected and subjected to RT real-time PCR to detect viremia up to 52 weeks post-infection. ASHV-specific antibodies were accessed by blocking ELISA until 37 weeks post-vaccination. In both groups, viremia appeared in the first week and lasted until week 5 in 25% of the horses. Moreover, seroconversion occurred at week 5 in 73.3% of infected horses and at week 3 in 90% of vaccinated horses. Antibodies persisted in both groups until the end of study, with more uniform levels in vaccinated animals. Chronological relations among clinical signs, viremia, and immunity were analyzed. These findings support the use of insect-proof housing for horses for at least 5 weeks after exposure or vaccination, and provide essential insights into AHSV epidemiology and control.

External hoof characteristics, balance, and conformation have been extensively studied in horses; however, mules remain understudied in these aspects. This study evaluated the size, shape, and symmetry of untrimmed and unshod forelimb hooves, compared the symmetry between forelimb hooves and stratified external forelimb hoof measurements based on the body condition score of mules raised in the foothill plains of northern Thailand. The forelimb hooves of 38 mules were photographed and 33 parameters, including angular and linear measurements, were analyzed. A multivariate analysis was used to explore the influence of sex, age, and body condition scores (BCS) on angular, linear, and area parameters. Additionally, one-way ANOVA followed by Tukey’s test was used to compare these parameters across different BCS groups. Despite the absence of shoeing and trimming, these mules exhibited optimal left–right forelimb hoof symmetry, with no significant (p < 0.05) differences in: outer wall length and inner wall length (OWL–IWL: Left 0.11 ± 0.66 cm; Right −0.12 ± 0.43 cm); sole length and sole width (SL^S–SW: Left 1.65 ± 0.76 cm; Right 1.46 ± 0.89 cm); dorsal hoof wall length and heel length (DHWL–HL: Left 4.00 ± 0.80 cm; Right 3.81 ± 0.72 cm); and frog length and frog width (FL–FW: Left 3.88 ± 1.13 cm; Right 3.82 ± 0.18 cm). However, significant (p < 0.05) differences were observed within each body condition score group for forelimb hoof measurements for DHWL, IWL, heel separation (HS), heel bulb distance (HBD), SW, FW, and FL, while sex and age had no significant differences across the study variables. These findings provide valuable insights into mule welfare and management, contributing to understanding of the interplay between overall health and hoof conformation in the study area.

External hoof characteristics, balance, and conformation have been extensively studied in horses; however, mules remain understudied in these aspects. This study evaluated the size, shape, and symmetry of untrimmed and unshod forelimb hooves, compared the symmetry between forelimb hooves and stratified external forelimb hoof measurements based on the body condition score of mules raised in the foothill plains of northern Thailand. The forelimb hooves of 38 mules were photographed and 33 parameters, including angular and linear measurements, were analyzed. Despite the absence of shoeing and trimming, these mules exhibited optimal left-right forelimb hoof symmetry, with no significant (p < 0.05) differences in: outer wall length and inner wall length (OWL - IWL); sole length and sole width (SLS - SW); dorsal hoof wall length and heel length (DHWL - HL); and frog length and frog width (FL - FW). However, significant (p < 0.05) differences were observed within each body condition score group for forelimb hoof measurements for DHWL, IWL, heel separation (HS), heel bulb distance (HBD), SW, FW, and FL. These findings provide valuable insights into mule welfare and management, contributing to understanding of the interplay between overall health and hoof conformation in the study area.

Background and Aim: The medical treatment of horses with nephrosplenic entrapment (NSE) of the large colon through administrating phenylephrine and rolling during general anesthesia was effective and less expensive than surgical treatment. However, the selection of drugs for non-surgical treatment of NSE is not a usual method for clinical practice. This study aimed to identify the effects of combined drugs on the cardiac and splenic response in horses and provide information on the NSE of the large colon for clinical application. Materials and Methods: Six healthy Thai native crossbred horses were enrolled in this study. Horses received two protocols with a withdrawal period of 14 days: Group 1 received xylazine (0.5 mg/kg IV) and adrenaline (1 mcg/kg IV), and Group 2 received xylazine (0.5 mg/kg IV) and adrenaline (3 mcg/kg IV). Heart rate (HR), HR variability (HRV), heart dimensions, and the splenic response of six horses were measured before the sedation, 30 and 60 min later, and 65, 70, 75, 80, 90, and 100 min after adrenaline administration. Doppler was used to obtain systolic blood pressure. Results: The HRV low-frequency and high-frequency power ratios decreased after using xylazine. Hypertension was observed after adrenaline administration. In this study, there were only minimal differences in the HR and respiratory rate between groups. However, overall cardiac and splenic parameters were statistically higher in Group 2. Conclusion: This study suggested that xylazine and three micrograms of adrenaline preserved the cardiac autonomic activity balance and were safe to use non-surgical applicability in horses.