Magnetic resonance imaging was useful for providing a diagnosis when other imaging techniques did not definitively identify the cause of lameness. Subchondral bone damage was clearly identified by MR imaging and should be considered as a cause of lameness in horses in which radiographic findings are unremarkable.

We describe the clinical, imaging, and necropsy findings of two horses with severe injury of the collateral ligaments of the distal interphalangeal (DIP) joint diagnosed using magnetic resonance (MR) imaging. In MR images it was possible to examine the collateral ligaments of the DIP joint from the origin at the middle phalanx to the insertion on the distal phalanx. Both horses in this report had abnormal high signal intensity within the collateral ligaments of the DIP joint, and one horse had abnormal high signal intensity within the bone of the distal phalanx on short tau inversion recovery (STIR) and T2-weighted imaging sequences. High signal intensity on STIR and T2-weighted images represents abnormal fluid accumulation indicative of inflammation, within ligament, tendon, or bone on these imaging sequences. Abnormalities were confirmed on necropsy in both horses. Injury of the collateral ligaments of the DIP joint should be considered as a source of pain in horses with lameness localized to the foot.

Preparation of the distal interphalangeal joint arthrocentesis site with each of these techniques significantly reduces the bacterial flora to a similar level for arthrocentesis in horses with and without evidence of skin contamination. Clinical Relevance- Aseptic preparation of the skin over the distal interphalangeal joint may be accomplished with any of these techniques.

Thoracic rib resection can provide access to diaphragmatic hernias in adult horses. Thoracoscopy or a flank incision, or both, may aid in determining which rib is best resected.

Objective-To compare the analgesic efficacy of administration of butorphanol tartrate, phenylbutazone, or both drugs in combination in colts undergoing routine castration. Design-Randomized controlled clinical trial. Animals-36 client-owned colts. Procedures-Horses received treatment with butorphanol alone (0.05 mg/kg [0.023 mg/ lb], IM, prior to surgery and then q 4 h for 24 hours), phenylbutazone alone (4.4 mg/kg [2.0 mg/lb], IV, prior to surgery and then 2.2 mg/kg [1.0 mg/lb], PO, q 12 h for 3 days), or butorphanol and phenylbutazone at the aforementioned dosages (12 horses/group). For single-drug-treated horses, appropriate placebos were administered to balance treatment protocols among groups. All horses were anesthetized, and lidocaine hydrochloride was injected into each testis. Physical and physiological variables, plasma cortisol concentration, body weight, and water consumption were assessed before and at intervals after surgery, and induction of and recovery from anesthesia were subjectively characterized. Observers assessed signs of pain by use of a visual analogue scale and a numerical rating scale. Results-Significant changes in gastrointestinal sounds, fecal output, and plasma cortisol concentrations were evident in each treatment group over time, compared with preoperative values. At any time point, assessed variables and signs of pain did not differ significantly among groups, although the duration of recumbency after surgery was longest for the butorphanol-phenylbutazone-treated horses. Conclusions and Clinical Relevance-With intratesticular injections of lidocaine, administration of butorphanol to anesthetized young horses undergoing routine castration had the same apparent analgesic effect as phenylbutazone treatment. Combined butorphanolphenylbutazone treatment was not apparently superior to either drug used alone. (J Am Vet

Results of the present study indicated that use of a mechanical morcellator with a 2-portal technique for bilateral laparoscopic ovariectomy in clinically normal equids eliminated the need for a larger laparotomy incision as well as a third portal. Few complications occurred, and clients were satisfied with the procedure. The morcellator technique may offer advantages over other techniques but should only be used by experienced laparoscopic surgeons following adequate training.

Background: Despite frequent clinical use, information about the pharmacokinetics (PK), clinical effects, and safety of butorphanol in foals is not available.Objectives: The purpose of this study was to determine the PK of butorphanol in neonatal foals after IV and IM administration; to determine whether administration of butorphanol results in physiologic or behavioral changes in neonatal foals; and to describe adverse effects associated with its use in neonatal foals.Animals: Six healthy mixed breed pony foals between 3 and 12 days of age were used. Methods: In a 3-way crossover design, foals received butorphanol (IV and IM, at 0.05 mg/kg) and IV saline (control group). Butorphanol concentrations were determined by high-performance liquid chromatography and analyzed using a noncompartmental PK model. Physiologic data were obtained at specified intervals after drug administration. Pedometers were used to evaluate locomotor activity. Behavioral data were obtained using a 2-hour real-time video recording.Results: The terminal half-life of butorphanol was 2.1 hours and C 0 was 33.2 AE 12.1 ng/mL after IV injection. For IM injection, C max and T max were 20.1 AE 3.5 ng/mL and 5.9 AE 2.1 minutes, respectively. Bioavailability was 66.1 AE 11.9%. There were minimal effects on vital signs. Foals that received butorphanol spent significantly more time nursing than control foals and appeared sedated.Conclusions and Clinical Importance: The disposition of butorphanol in neonatal foals differs from that in adult horses. The main behavioral effects after butorphanol administration to neonatal foals were sedation and increased feeding behavior.

Temporary intra-articular administration of antibiotic-impregnated PMMA may be an effective way to treat septic joints that require constant high concentrations of antibiotics.