Evaluation of a broad range real-time polymerase chain reaction (RT-PCR) assay for the diagnosis of septic synovitis in horses.

Septic synovitis is a potentially debilitating and life-threatening disorder in horses. We hypothesized that a universal bacterial real-time PCR (RT-PCR) assay would have improved sensitivity and decreased turn-around time for detection of bacteria in synovial fluid (SF) samples. Forty-eight SF samples were collected from 36 horses that presented to two referral institutions with suspected septic synovitis. Universal RT-PCR, bacterial culture and SF analysis were performed on all samples, and an interpretation on the sample being septic or not was derived by three board certified specialists from the history, clinical assessment and SF characteristics. RT-PCR results were compared to a composite standard comprised of positive culture and interpretation by all three specialists of samples as "septic". For 41 of 48 samples (85%), culture and RT-PCR results were concordant. Compared to the composite standard, 83% of samples were correctly classified by RT-PCR (turn-around time of approximately 4 hours). Relative sensitivity and specificity of RT-PCR were 87% and 72% respectively, and 56% and 86% for culture. Hence, universal RT-PCR was a rapid and highly sensitive test, which may accelerate diagnosis and improve outcome for horses with septic synovitis.

La synovite septique est une condition potentiellement débilitante et mortelle chez les chevaux. Nous avons émis l'hypothèse qu'une épreuve universelle d'amplification en chaîne par la polymérase en temps réel (RT-PCR) pourrait avoir une sensibilité augmentée et une diminution du délai d'obtention des résultats pour la détection de bactérie dans des échantillons de liquide synovial (SF). Quarante-huit échantillons de SF ont été prélevés à partir de 36 chevaux présentés à deux centres de référence avec une synovite septique suspectée. L'épreuve RT-PCR universelle, la culture bactérienne et l'analyse du SF ont été effectuées sur tous les échantillons et une interprétation à savoir si l'échantillon était septique ou non était obtenue de trois spécialistes certifiés à partir de l'histoire du cas, de l'évaluation clinique et des caractéristiques du SF. Les résultats du RT-PCR ont été comparés à un composite standard consistant en une culture et une interprétation positives par les trois spécialistes d'échantillons comme étant «septique¼. Pour 41 des 48 échantillons (85 %), les résultats de la culture et du RT-PCR concordaient. Comparativement au composite standard, 83 % des échantillons ont été classés correctement par le RT-PCR (délai d'obtention des résultats approximatif de 4 heures). La sensibilité et la spécificité relatives du RT-PCR étaient de 87 % et 72 %, respectivement, 56 % et 86 % pour la culture. Ainsi, l'épreuve RT-PCR universelle était un test rapide et hautement sensible, ce qui pourrait accélérer le diagnostic et améliorer le sort des chevaux avec une synovite septique.(Traduit par Docteur Serge Messier).

Clinical use of antimicrobial regional limb perfusion in horses: 174 cases (1999-2009).

OBJECTIVE: To describe the clinical use of regional limb perfusion with antimicrobials (A-RLP), complications, and outcome in a large series of patients. DESIGN: Retrospective case series. ANIMALS: 174 horses. PROCEDURES: Medical records of horses treated with A-RLP between 1999 and 2009 were reviewed. Signalment, primary complaint, horse use, etiology, duration of clinical signs, previous treatment, structures involved, concurrent conditions, A-RLP characteristics, additional treatments, complications, and outcome were recorded. At long-term follow-up, 2 outcomes were investigated: survival rate and return to previous use at the same or higher level. Univariate and multivariate logistic regression analyses were conducted. RESULTS: Group 1 (96 horses) included septic synovitis. Group 2 (50 horses) included extrasynovial lacerations (23 horses) and fresh, minimally contaminated intrasynovial lacerations without evidence of established synovial infection (27 horses). Group 3 (28 horses) included miscellaneous other conditions. Only minor complications were reported in 12.26% of horses that received IV (n = 155) and 33% of horses that received intraosseous (27) A-RLP. Horses with septic synovitis had a lower survival rate (53.43%) than did horses with lacerations (91.89%). Within group 2, no significant differences in short- or long-term outcomes were found between horses with extrasynovial and fresh, minimally contaminated intrasynovial lacerations. For the horses returning to previous use, 80% of horses with septic synovitis and 72.72% of horses with lacerations were performing at the same or higher level at the time of follow-up. CONCLUSIONS AND CLINICAL RELEVANCE: The results of the present study indicated that A-RLP is a safe technique with minimal adverse effects. The IV route presented fewer complications than intraosseous injection. Horses with infection of synovial structures had a lower survival rate than did those with acute, minimally contaminated intrasynovial lacerations. The latter had a similar prognosis for horses with extrasynovial lacerations treated with A-RLP.

Tilt table recovery of horses after orthopedic surgery: fifty-four cases (1994-2005).

OBJECTIVE: To describe an assisted anesthetic recovery technique using a tilt table for horses after high-risk orthopedic-related procedures and to evaluate outcome. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Anesthetic recoveries (n=54) for 36 horses. METHODS: Medical records (April 1994-October 2005) for horses that had high-risk orthopedic surgery and recovery from general anesthesia on a tilt table were reviewed. Information about the surgical procedure, anesthetic and recovery period was analyzed. RESULTS: Of 54 anesthetic recoveries, 1 horse (1.9%) had complete failure of internal fixation during recovery and was euthanatized. Six (11% recoveries) horses failed to adapt to the tilt table system, which necessitated transfer to a conventional recovery room. Complications without important consequences for clinical outcome (skin abrasions, myositis, cast breakage, partial implant failure) occurred during 8 (15%) recoveries. CONCLUSIONS: A tilt table recovery system was associated with minimal incidence of serious complications. Potential disadvantages of the system are the number of personnel required, longer recovery time, and the need for a specialized table. CLINICAL RELEVANCE: A tilt table is a useful system for recovering horses believed to be at increased risk of injury during anesthetic recovery after high-risk orthopedic-related procedures.