Investigation of the Frequency of Detection of Common Respiratory Pathogens in Nasal Secretions and Environment of Healthy Sport Horses Attending a Multi-Week Show Event during the Summer Months.

Little information is presently available regarding the frequency of the silent shedders of respiratory viruses in healthy sport horses and their impact on environmental contamination. Therefore, the aim of this study was to investigate the detection frequency of selected respiratory pathogens in nasal secretions and environmental stall samples of sport horses attending a multi-week equestrian event during the summer months. Six out of fifteen tents were randomly selected for the study with approximately 20 horse/stall pairs being sampled on a weekly basis. Following weekly collection for a total of 11 weeks, all samples were tested for the presence of common respiratory pathogens (EIV, EHV-1, EHV-4, ERAV, ERBV, and Streptococcus equi ss equi (S. equi)) using qPCR. A total of 19/682 nasal swabs (2.8%) and 28/1288 environmental stall sponges (2.2%) tested qPCR-positive for common respiratory pathogens. ERBV was the most common respiratory virus (17 nasal swabs, 28 stall sponges) detected, followed by EHV-4 (1 nasal swab) and S. equi (1 nasal swab). EIV, EHV-1, EHV-4 and ERAV were not detected in any of the study horses or stalls. Only one horse and one stall tested qPCR-positive for ERBV on two consecutive weeks. All the other qPCR-positive sample results were related to individual time points. Furthermore, only one horse/stall pair tested qPCR-positive for ERBV at a single time point. The study results showed that in a selected population of sport horses attending a multi-week equestrian event in the summer, the frequency of the shedding of respiratory viruses was low and primarily restricted to ERBV with little evidence of active transmission and environmental contamination.

Radiological prevalence of osteoarthritis of the cervical region in 104 performing Warmblood jumpers.

BACKGROUND: Cervical osteoarthritis (OA) has been documented as a potential source of pain and poor performance in sport horses. OBJECTIVES: To assess the prevalence of cervical OA in a population of Warmblood jumpers and its correlation with age, level of performance, neck pain and mobility. STUDY DESIGN: Descriptive observational study. METHODS: Warmblood jumpers free of lameness or neurological disorders were selected. Cervical pain and range of motion of the neck were subjectively assessed. Left to right lateral views were taken at C3-C4, C4-C5, C5-C6 and C6-C7. The presence of OA at the cervical articular process joints (APJs) was evaluated and graded as absent, mild or moderate to severe by three board-certified radiologists. The agreement between radiologists and the potential associations between OA grades with age and other variables were statistically assessed (P < .05). RESULTS: One hundred and four horses were included [median age = 10 years (range 6-18 years)]. Agreement between radiologists varied from fair to substantial (Kappa-weighted 0.37-0.61). The C6-C7 APJ was most commonly affected by OA with only 32.7% of APJ considered free of radiographic abnormalities at this location versus 60.5% at C5-C6, 81.7% at C4-C5 and 84.6% at C3-C4. Horses competing in higher level classes (peak of performance) had significantly higher OA grades at C6-C7 (P = .013). There was no association between age, age when started jumping, neck pain and neck range of motion with the presence of OA on radiographs. MAIN LIMITATIONS: Open enrolment and lack of orthogonal views. CONCLUSIONS: This study showed that, although there is a range of interpretation of radiographic findings of the APJ, OA of the caudal cervical region is not rare in performing sound Warmblood jumpers. This suggests that OA in the caudal cervical region may be of low clinical significance.

Correlation of dickkopf-1 concentrations in plasma and synovial fluid to the severity of radiographic signs of equine osteoarthritis.

OBJECTIVE: The purpose of this study was to determine whether there was a correlation between circulating and intra-synovial Dkk-1 and radiographic signs of equine osteoarthritis. METHODS: Circulating and intra-synovial Dkk-1 levels were measured in clinical cases using a commercially available human Dkk-1 ELISA. Radiographs were performed of the joints from which fluid was collected and these were assessed and scored by a boarded radiologist for joint narrowing, subchondral bone sclerosis, subchondral bone lysis, and periarticular modelling. Comparisons were made between radiographic scores and the concentrations of Dkk-1 using a Kruskal-Wallis one-way ANOVA. Correlations were calculated using Kendall's statistic. RESULTS: A total of 42 synovial fluid samples from 21 horses were collected and used in the analysis. No significant correlation was identified between Dkk-1 concentrations and radiographic signs of osteoarthritis. Intra-synovial Dkk-1 concentrations were significantly greater (p <0.001) in low motion joints (mean concentration, 232.68 pg/mL; range, 109.07-317.17) when compared to high-motion joints (28.78 pg/mL; 0.05-186.44 pg/mL) (p <0.001). CLINICAL SIGNIFICANCE: Low motion joints have significantly higher concentrations of Dkk-1 compared to high motion joints. Further research is needed to establish the importance of this finding and whether potential diagnostic or therapeutic applications of Dkk-1 exist in the horse.

Besnoitiosis in a miniature donkey.

A 1-year-old male miniature donkey (Equus asinus) from a herd of eight was presented with a 9-month history of pruritic dermatitis, lethargy and anorexia. Physical examination revealed diffuse lichenification and scales involving the skin of the face, head and dorsum from the neck to the pelvis. The main histological alteration within the superficial and deep dermis was the presence of multiple large, spherical, thick walled, protozoal Besnoitia cysts. In addition, the inflammatory response consisted of a moderate, superficial and deep perivascular, mixed mononuclear cell infiltrate, with epidermal hyperplasia and compact orthokeratosis. Based upon the large size of the protozoal cysts and the ultrastructural features of the bradyzoites contained therein (conoid, polar ring, rhoptries, micronemes and microtubules), a diagnosis of cutaneous besnoitiosis was established. Treatment with trimethoprim-sulphamethoxazole resulted in significant clinical improvement. To our knowledge, this is the first reported case of besnoitiosis in a miniature donkey in North America.