Introduction: The aim of the study was to analyse selected densitometric and geometric parameters in the third metacarpal bone along the long axis in horses. The densitometric parameters included the cortical and trabecular bone mineral density, while the geometric parameters included the cortical, trabecular, and total areas, strength strain index X, strength strain index Y, and the polar strength strain index. Material and Methods: The parameters were analysed using eight sections from 10% to 80% of the length of the bone. Peripheral quantitative computed tomography was used in the study. Statistical analysis was carried out using the Friedman analysis of variance and post-hoc tests. Results: The proximal metaphyseal region showed the highest predicted resistance to bone fractures in the transverse (back-front) plane, the distal metaphyseal region had the highest predicted resistance to transverse and torsional fractures in the transverse (side-side) plane. The cross-sectional area and the shape of the cross-section of the cortical bone of the MCIII had the highest coefficient of variation. The density of the cortical bone was least variable. Conclusions: The cortical area and cortical bone mineral density assumed the highest values in the diaphyseal region, while the highest total area, trabecular area and trabecular bone mineral density values were obtained in the metaphyseal proximal and distal region.

Horses (Equus caballus) are susceptible to tick-borne diseases. Two of them, Lyme borreliosis due to Borrelia burgdorferi and granulocytic anaplasmosis due to Anaplasma phagocytophilum were investigated in Algerian horses. The diseases have been less extensively studied in horses and results pertinent to Algeria have not been published. Blood samples were obtained from 128 horses. IgG antibodies directed against Anaplasma phagocytophilum and Borrelia burgdorferi were detected by an indirect immunofluorescence antibody test (IFAT) and ELISA. The potential effects of age, gender, breed, and health status on seropositivity were also evaluated. Using IFAT, 28 (21.8%) and 25 (19.5%) animals were positive for B. burgdorferi and A. phagocytophilum, respectively. Using ELISA, 19 (14.8%) and 33 (25.9%) animals were positive for these bacteria. The study shows that horses in Algeria are exposed or co-exposed to tick-transmitted zoonotic bacterial species.

In recent years, exercise on a water treadmill has come to have great relevance in rehabilitation and training centres for sport horses. Its use exploits certain physical properties of water, related to the fundamental principles of hydrodynamics, such as buoyancy, viscosity, hydrostatic pressure, and water temperature. These properties together with deliberate specification of the depth of the water and the velocity of the treadmill provide a combination of parameters that can be varied according to the purpose of the rehabilitation or training programme, the disease to rehabilitate, or the healing phase. In the current article, kinematic adaptations to exercise on a water treadmill and the direct application of such exercise to the rehabilitation of superficial and deep digital flexor tendon and accessory ligament injuries and back and joint diseases are described.

Introduction: The objective of the study was immunophenotypic and cytogenetic analysis of mesenchymal stem cells from equine bone marrow and foal umbilical cords during in vitro culture.Material and Methods: The mesenchymal stem cells were obtained from equine bone marrow of three horses and from foal umbilical cords of six foals. The cells were cultured in CO₂ incubators by standard procedure. Quantitative abnormalities of chromosomes, i.e. aneuploidy and polyploidy, and structural aberrations, i.e. breaks in chromosomes and chromatid, were taken into account during the study.Results: The results of cytogenetic analysis of equine bone marrow mesenchymal stem cells at the third and fourth passages indicated that the level of karyotype variability of these cells corresponded to the spontaneous level of karyotype variability typical of the peripheral blood lymphocytes of this species. Equine bone marrow contained several clones of stem cells that differed in the expression of specific nuclear markers characteristic of proliferating cells.Conclusion: Mesenchymal stem cells from foal umbilical cords during in vitro cultivation are characterised by quantitative abnormalities of the chromosomal apparatus.

Introduction: The study aimed to clarify the changes in the concentration of inflammatory mediators, proteases, and cartilage degradation biomarkers in the synovial fluid of joints in an equine osteoarthritis model. Material and Methods: Osteoarthritis was induced in eight Mongolian horses by a sterile intra-articular injection of amphotericin B, which was injected into the left carpal joint in a dose of 2 mL (25 mg/mL). The control group comprised five horses which were injected with an equal dose of sterile physiological saline into the left carpal joint. Synovial fluid was obtained at baseline and every week after injection. Test methods were based on ELISA. Results: In the course of the osteoarthritis, the concentration of biomarkers in joint synovial fluid showed an increasing trend. IL-1, IL-6, MMP-9, MMP-13, ADAMTS-5, CS846, GAG, HA, CTX-II, and COMP concentrations sharply increased before the onset of significant symptoms of lameness, whereas TNF-α, MMP-2, and MMP-3 concentrations rose sharply after the occurrence of such symptoms. Conclusion: The results obtained confirm that the concentrations of IL-1, IL-6, MMP-9, MMP-13, ADAMTS-5, CS846, GAG, HA, CTX-II and COMP increase substantially in equine osteoarthritis, which provides a theoretical basis for the rapid diagnosis of the disease.

Introduction: Foot quality is essential to the horse’s movement. The barefoot approach favours the animal’s welfare. Environment and selection determine hoof characteristics. Material and Methods: Hoof characteristics of eight Anglo-Arabian (AA) and nine Haflinger (HA) horses were studied. After a preliminary visual analysis of feet, nail samples were collected after trimming for physico-chemical analysis. The parameters were submitted to analysis of variance. A principal component analysis and a Pearson correlation were used to compare mineral contents. Results: The hooves of both breeds were healthy and solid. The hooves of HA horses were longer than those of AA horses (14.90 ±0.30 cm vs 13.10 ±0.60 cm), while the AA hoof was harder than the HA hoof both in the wall (74.55 ±2.95 H vs 60.18 ±2.67 H) and sole (67.00 ±5.87 H vs 43.0 ±4.76 H). In comparison with the sole, the AA hoof wall also had a lower moisture percentage (12.56 ±0.67% vs 20.64 ±0.76%), while crude protein and ash contents were similar in both regions. The AA hoof showed a higher Se content, while the HA hoof had a higher level of macroelements. The negative correlations of K with Cu, Fe, Ni, Pb, and Zn in the AA hoof may indicate osmoregulation activity. Conclusion: The hoof morphology of AA and HA horses met the literature parameters for mesomorphic horses. Both breeds had healthy and well-conformed hooves, useful for sport and recreation activities.

Introduction: Leptospirosis affects a wide range of mammals, humans, and even a few poikilothermic animal species. In Pakistan, serological studies of equine leptospirosis have reported a prevalence of over 40%, but no study has ever been conducted towards molecular detection of Leptospira in horses. Material and Methods: Blood samples from 128 horses were screened using ELISA and 41 positive samples were examined for the presence of leptospiral DNA using specific primers for 16S rRNA gene. Results: Out of 41 tested samples, 20 samples were found to be PCR-positive, revealing a fragment of 306 bp after gel electrophoresis. Sequencing and phylogenetic analysis of positive samples revealed circulation of pathogenic Leptospira spp. in Pakistani horses. No evidence of circulation of intermediate species was found in this study. Conclusion: This study reports the first molecular evidence of equine leptospirosis in Pakistan and lays ground for further research in this area. It also confirms the efficiency of 16S rRNA for the diagnosis of equine leptospirosis.

OBJECTIVE To determine the median time to maximum concentration (tmax) of amikacin in the synovial fluid of the tarsocrural joint following IV regional limb perfusion (IVRLP) of the drug in a saphenous vein of horses. ANIMALS 7 healthy adult horses. PROCEDURES With each horse sedated and restrained in a standing position, a 10-cm-wide Esmarch tourniquet was applied to a randomly selected hind limb 10 cm proximal to the point of the tarsus. Amikacin sulfate (2 g diluted with saline [0.9% NaCl] solution to a volume of 60 mL) was instilled in the saphenous vein over 3 minutes with a peristaltic pump. Tarsocrural synovial fluid samples were collected at 5, 10, 15, 20, 25, and 30 minutes after completion of IVRLP. The tourniquet was removed after collection of the last sample. Amikacin concentration was quantified by a fluorescence polarization immunoassay. Median maximum amikacin concentration and tmax were determined. RESULTS 1 horse was excluded from analysis because an insufficient volume of synovial fluid for evaluation was obtained at multiple times. The median maximum synovial fluid amikacin concentration was 450.5 μg/mL (range, 304.7 to 930.7 μg/mL), and median tmax was 25 minutes (range, 20 to 30 minutes). All horses had synovial fluid amikacin concentrations ≥ 160 μg/mL (therapeutic concentration for common equine pathogens) at 20 minutes after IVRLP. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that, in healthy horses, maintaining the tourniquet for 20 minutes after IVRLP of amikacin in a saphenous vein was sufficient to achieve therapeutic concentrations of amikacin in the tarsocrural joint.

OBJECTIVE To investigate the effects of orally administered trazodone on intraocular pressure (IOP), pupil diameter measured in the vertical plane (ie, vertical pupil diameter [VPD]), selected physical examination variables, and sedation level in healthy equids. ANIMALS 7 horses and 1 pony. PROCEDURES Food was withheld for 12 hours prior to drug administration. After baseline (time 0) sedation scoring, physical examination, and measurement of IOP and VPD, equids received 1 dose (approx 6 mg/kg) of trazodone orally. Examination and measurement procedures were repeated 0.5, 1, 2, 4, 8, 12, and 24 hours after drug administration. Blood samples were collected at each time point for analysis of plasma trazodone concentrations. Repeated-measures analysis was used to compare examination results between downstream time points and baseline. RESULTS 7 of 8 equids had mild sedation from 0.5 to 8 hours after treatment; compared with baseline values, mean IOP was significantly lower from 0.5 hours to 8 hours, mean VPD was significantly smaller at 0.5 hours, and mean rectal temperature was significantly lower from 1 to 8 hours after drug administration. Adverse effects (signs of excitement in 1 equid and sweating in 4) were self-limiting and considered minor. Mean maximum plasma concentration of trazodone was 1,493 ng/mL 0.75 hours after administration, and terminal half-life of the drug was 9.96 hours. CONCLUSIONS AND CLINICAL RELEVANCE The described oral dose of trazadone elicited sedation with a few self-limiting adverse effects in the study sample. Drug effects on IOP and VPD may alter ocular examination findings. Further investigation is warranted prior to use of trazodone for sedation in equids, particularly those with ophthalmic conditions.

OBJECTIVE To investigate the effects of triamcinolone acetonide (TA) and methylprednisolone acetate (MPA) on the viability of resident cells within the fibrocartilage on the dorsal surface of the deep digital flexor tendon (FC-DDFT) and fibrocartilage on the flexor surface of the navicular bone (FC-NB) of horses. SAMPLE 12 to 14 explants of FC-DDFT and of FC-NB from grossly normal forelimbs of 5 cadavers of horses aged 9 to 15 years without evidence of musculoskeletal disease. PROCEDURES Explants were incubated with culture medium (control) or TA-supplemented (0.6 or 6 mg/mL) or MPA-supplemented (0.5 or 5 mg/mL) medium for 6 or 24 hours. Explant metabolic activity and percentage of dead cells were assessed with a resazurin-based assay and live-dead cell staining, respectively, at each time point. Drug effects were assessed relative to findings for the respective control group. RESULTS Application of TA (at both concentrations) did not significantly change the cell viability of FC-DDFT explants. For FC-NB explants, TA at 6 mg/mL significantly reduced the metabolic activity and increased the percentage of dead cells at both time points. With either MPA concentration, FC-DDFT and FC-NB explants had reduced metabolic activity and an increased percentage of dead cells at 24 hours, whereas only MPA at 5 mg/mL was cytotoxic at the 6-hour time point. CONCLUSIONS AND CLINICAL RELEVANCE In ex vivo explants, TA was less cytotoxic to equine FC-DDFT and FC-NB cells, compared with MPA. Further work is warranted to characterize the drugs' transcriptional and translational effects as well as investigate their cytotoxicity at lower concentrations.