Effect of deracoxib,a new COX-2 inhibitor,on the prevention of lameness induced by chemical synovitis in dogs

Twenty-four healthy, mixed-breed hound-type dogs were evenly and randomly assigned to a placebo control group, one of four dosages of deracoxib (0.3, 1, 3, or 10 mg/kg), or carprofen (2.2 mg/kg). Oral dosing of placebo, carprofen, or deracoxib was done 30 minutes before intraarticular injection of urate crystal suspension for induction of synovitis. Ground reaction forces, subjective clinical lameness scores, pain, joint effusion, and quantitative pain threshold responses were measured in a blinded fashion before induction of synovitis and 2, 4, 6, 8, 12, and 24 hours after injection. The medium and high dosages of deracoxib were effective in preventing lameness and pain associated with synovitis. Carprofen was also somewhat effective in attenuating the severity of urate-induced synovitis but to a lesser degree than the medium dose of deracoxib. Preemptive deracoxib treatment at dosages as low as 1 mg/kg reduced lameness and pain of synovitis associated with intraarticular administration of urate crystals.     

Effect of velocity on ground reaction forces in dogs with lameness attributable to tearing of the cranial cruciate ligament

OBJECTIVE: To ascertain the effectiveness of evaluating ground reaction forces (GRFs) at velocities during walking and trotting in dogs with naturally occurring lameness and determine whether walking would provide sufficient motion to adequately characterize GRFs with respect to trotting. ANIMALS: 29 dogs with a naturally occurring tear of the cranial cruciate ligament. PROCEDURE: Dogs were walked and trotted over a force platform, and GRFs were recorded during the stance phase. Correlation was used to assess the agreement between walking and trotting for GRF The coefficient of variation was calculated to assess the relative variation of outcome variables among the gaits. Group means for walking GRF were compared between dogs that trotted and that failed to trot. RESULTS: GRFs during walking and trotting were highly correlated. The coefficient of variation was smaller for GRFs during walking than during trotting. Dogs that failed to trot had significantly smaller mean values of peak vertical force and vertical impulse during walking, compared with values for dogs that were able to trot. CONCLUSIONS AND CLINICAL RELEVANCE: Either velocity is acceptable for GRF evaluation in dogs. Mean GRF during walking was significantly different between dogs that could and could not trot, principally because dogs with the most severe lameness failed to trot. These dogs would be eliminated from a clinical study, and thus, that study would become biased toward dogs that were less lame. In that situation, differences between interventions may be less pronounced, because they would be evaluated on dogs with less lameness.     

Effect of carprofen, etodolac, meloxicam, or butorphanol in dogs with induced acute synovitis

OBJECTIVE: To compare the analgesic and anti-inflammatory effect of single doses of carprofen, etodolac, meloxicam, and butorphanol in dogs with induced acute synovitis (acute pain model) via kinetic gait analysis and orthopedic evaluation and examine measurement of serum C-reactive protein (CRP) concentration as an indicator of treatment efficacy. ANIMALS: 12 Beagles and 6 additional Beagles that were used only in serum CRP analyses. PROCEDURE: Acute synovitis was induced in right stifle joints of dogs via intra-articular injection of monosodium urate solution. Treatments included butorphanol (0.2 mg/kg, i.v.), carprofen (4 mg/kg, PO), etodolac (17 mg/kg, PO), or meloxicam (0.2 mg/kg, PO); control dogs received no treatment. The procedure was repeated (3-week intervals) until all dogs received all treatments including control treatment. Lameness was assessed on a biomechanical force platform and via orthopedic evaluations of the stifle joints; blood was collected to monitor serum CRP concentration. RESULTS: Compared with control dogs, treated dogs had significantly different vertical ground reaction forces and weight-bearing scores. Greatest improvement in lameness was observed in carprofen-treated dogs. Etodolac had the fastest onset of action. Compared with butorphanol treatment, only carprofen and etodolac were associated with significantly lower pain scores. An increase in serum CRP concentration was detected after intra-articular injection in all dogs; this change was similar among groups. CONCLUSIONS AND CLINICAL RELEVANCE: Carprofen, etodolac, and meloxicam had greater efficacy than butorphanol in relief of acute pain. Carprofen was most effective overall. In this acute pain model, serum CRP analysis was not useful to assess drug efficacy.     

Comparison of opioid and alpha-2 adrenergic receptor location and density in the horse and dog using radioligand binding

Ketamine, a noncompetitive NMDA receptor antagonist, has been shown to provide analgesia in some species. To target the NMDA receptor specifically and to potentially minimize some untoward side-effects, ketamine had been used epidurally. The objective of this study was to determine the analgesic effect of epidurally administered ketamine in dogs with chemically induced synovitis.
Sixteen healthy dogs were used. Dogs were anesthetized with propofol (4 mg kg⁻¹ IV). Synovitis was induced by injecting 1 mL of sodium urate crystal solution (10 mg mL⁻¹) into the right stifle. Dogs were allowed to recover and the synovitis was allowed to develop for 12 hours. The dogs were then anesthetized again using propofol (4 mg kg⁻¹ IV). Lumbosacral epidural injections were performed with each dog receiving either 2 mg kg⁻¹ of ketamine (20 mg mL⁻¹) or an equal volume of placebo (sterile water containing not more than 0.1 mg mL⁻¹ benzethonium chloride). Analgesia was assessed at baseline and then at 12, 14, 16, 18, 20, and 24 hours after induction of synovitis. Ground reaction forces (peak vertical force and impulse area) and overall pain were measured using a force platform and a pain scoring system (numerical rating scale).
Analysis of the data by Repeated Measures anova showed that the dogs developed a significant lameness between the baseline and 12 hours. However, no significant difference in ground reaction forces or total pain score was demonstrated between the treatment and control groups at any other time.
In conclusion, ketamine administered epidurally at a dose of 2 mg kg⁻¹ did not provide significant analgesia in dogs with chemically induced synovitis.     

The effects of epidural deracoxib on the ground reaction forces in an acute stifle synovitis model

OBJECTIVE: To evaluate the efficacy of epidurally administered deracoxib to mediate the signs of a sodium urate crystal-induced stifle synovitis in dogs, and to compare the efficacy of epidural versus subcutaneously administered deracoxib. STUDY DESIGN: Experimental, randomized, blinded, placebo-controlled modified cross-over design. ANIMALS: Random source, adult, mixed breed dogs (n = 24; 14 males, 10 females). METHODS: Sodium urate crystals were used to create a stifle synovitis model to evaluate the efficacy of deracoxib. Dogs were divided into 4 groups: 3 mg/kg epidural deracoxib, 1.5 mg/kg epidural deracoxib, 3 mg/kg subcutaneous deracoxib, and a placebo (vehicle for deracoxib). Force plate and subjective evaluations were made at time 0, 2, 4, 8, 12, and 24 hours post-treatment. Repeated measures ANOVA with Bonferroni-corrected post hoc comparisons was used to determine significant treatment effects. RESULTS: Peak vertical force (PVF) and vertical impulse (VI) were both significantly higher in deracoxib treated dogs compared with placebo. For 3 mg/kg epidural and subcutaneous deracoxib, PVF and VI were significantly greater than for 1.5 mg/kg epidural deracoxib. Overall pain score for all deracoxib-treated dogs was significantly lower than for placebo dogs. CONCLUSIONS: Epidural administration of deracoxib is effective at providing analgesia in an acute joint pain model; however, it does not appear to be more effective than systemic administration. CLINICAL RELEVANCE: Injectable deracoxib is effective in providing analgesia in acute inflammatory conditions of synovial joints.     

Results of arthroscopic versus open arthrotomy for surgical management of cranial cruciate ligament deficiency in dogs

OBJECTIVE: To evaluate postoperative morbidity in dogs after experimental cranial cruciate ligament transection and immediate stifle stabilization using an arthroscopically assisted or open arthrotomy technique. STUDY DESIGN: Experimental, prospective study. ANIMALS: Thirteen mature, healthy dogs. METHODS: Dogs were randomly assigned to 1 of 2 groups. Seven underwent open arthrotomy while 6 underwent arthroscopy of 1 stifle joint. Cranial cruciate ligaments were transected and debrided and all stifles were stabilized using 2 lateral extracapsular fabellar-tibial sutures. Minimally invasive suture placement was employed in the arthroscopy group. All animals were evaluated for 9 weeks using kinetic gait assessments, comfortable stifle range of motion measurements, thigh girth measurements, differential cell counts of synovial fluid, and subjective scores of behavior, limb use, and lameness. RESULTS: Significant differences in postoperative morbidity were observed during the 9-week postoperative period. Greater peak vertical force for 8 weeks (P=.015), vertical impulse for 6 weeks (P=.044), comfortable stifle range of motion for 9 weeks (P=.017), comfortable stifle flexion for 4 weeks (P=.005), and operative limb thigh circumference (P=.020) for 9 weeks were observed for the arthroscopy group. A trend towards a lower differential mean synovial polymorphonuclear cell count in the arthroscopy group was seen at 4 and 8 weeks postoperatively. No differences in subjective evaluation scores were noted. CONCLUSIONS: In this study population, significant differences were seen between the arthroscopy and arthrotomy groups for peak vertical force, vertical impulse, comfortable stifle range of motion, comfortable stifle flexion, and thigh circumference data. CLINICAL RELEVANCE: The results of this study suggest that short-term postoperative morbidity may be reduced in dogs receiving arthroscopic joint surgery with a limited approach for stifle stabilization as compared with a traditional open arthrotomy technique.     

A pilot study: sodium urate synovitis as an acute model of inflammatory response using objective and subjective criteria to evaluate arthritic pain in cats

Sodium urate (SU) synovitis was evaluated as a model for feline arthritic pain using a placebo‐ and positive‐controlled (meloxicam) randomized blinded controlled single crossover design. Monosodium urate crystals [20 mg (1 mL) rod‐shaped] were injected into alternate stifles of trained anesthetized cats (n = 3) with a 28 day washout. During the first trial phase, two cats received meloxicam (0.1 mg/kg, PO), a nonsteroidal anti‐inflammatory drug (NSAID), for three days before and on the day of SU injection; the third cat received placebo. Treatments and stifles were switched for the second trial. Total force, contact pressure and area of the fore and hind limbs were measured using a pressure mat one day and 0.5 h before, and 2, 4, 6, 8, 10, 24, and 30 h post‐SU injection. Skin temperature, joint circumference, analgesia, lameness, and visual analogue scale (VAS) pain scores, were measured at the same times. Comparisons were made for each time and for areas under the curve (AUC) using original and change from baseline; P < 0.05 was significant. Significant differences in force mat data and subjective data were found for the hind limb data (total force and total contact pressure at 6, 10, and 30 h; analgesia and VAS for pain at 4 h; lameness at 10, 24, and 30 h) and for AUC₀→_24h and AUC₀→_30h (total force, total contact pressure, and mean lameness score) and for differences from BL AUC₀→_10h (total contact area) and AUC₀→_24h (total contact area and mean lameness score) and AUC₀→_30h (total force, total contact area, and mean lameness). No cats required rescue analgesia. Injection of 1 mL of monosodium urate into the stifle of a cat causes moderate transitory pain and was suitable for assessing analgesic efficacy of an NSAID with a pressure mat and subjective criteria.     

Caudal cruciate ligament damage in dogs with cranial cruciate ligament rupture

Objective: To investigate the incidence of caudal cruciate ligament (CaCL) damage in dogs with cranial cruciate ligament rupture (CCLR). Study Design: Prospective clinical study. Animals: Dogs (n=24) admitted for surgical stabilization of the stifle after CCLR and 8 healthy dogs with intact cranial cruciate ligament (CCL) and CaCL studied as controls. Methods: Preoperative radiographs and stifle joint images (arthrotomy, 6; arthroscopy, 18) were collected from dogs with CCLR. Severity of arthritis, synovitis, CCL damage, and CaCL damage were assessed using numerical rating scales. The CaCL was probed to determine whether minor fraying or a full thickness defect in the ligament was present. Data collected from the study population were compared with the control population of dogs. Results: The CaCL was damaged in 21/24 (88%) of dogs with CCLR; 6/24 (25%) had a full thickness defect in the CaCL. Severity of stifle synovitis and severity of damage to the CaCL were positively correlated (P<.05). Conclusions: The CaCL is damaged in a high percentage of dogs with CCLR. A significant and positive correlation exists between the degree of synovitis present and the extent of CaCL damage. Clinical Relevance: In dogs with CCLR, cruciate ligament pathology typically involves both the CCL and CaCL. As the severity of synovitis and the extent of CaCL damage are related, this observation supports the hypothesis that stifle synovitis may contribute to CCL and CaCL degeneration and subsequent damage.     

Autogenous osteochondral grafting for treatment of stifle osteochondrosis in dogs

Objective— To develop and assess clinical outcomes for osteochondral autografting for treatment of stifle osteochondrosis (OC) in dogs. Study Design— Retrospective case series. Animals— Dogs with stifle OC (n=10). Methods— Osteochondral autografting was developed and optimized in canine cadavers and purpose‐bred research dogs using the Osteochondral Autograft Transfer System (OATS). Dogs with stifle OC (n=10 dogs, 12 stifles) were then treated using the OATS system. Outcomes were assessed by radiography (n=12), magnetic resonance imaging (1), second‐look arthroscopy (9), lameness scoring (12), and telephone survey of owners (10 clients, 12 stifles) 6–15 months after surgery. Results— Complications were documented in 4 of the 12 stifles treated and included peri‐incisional seromas (3) and marked stifle effusion (1). Subjective assessment of follow‐up radiographs revealed evidence of integration of the grafts with maintenance of subchondral bone surface architecture. Subjective assessment of follow‐up MRI in 1 stifle revealed evidence for incorporation of grafts with restoration of articular surface contour. Second‐look arthroscopy 6–30 weeks after surgery revealed maintenance of articular cartilage at the graft site. Dogs were significantly (P<.001) less lame at follow‐up compared with preoperative scores. Based on follow‐up owner surveys, only 2 dogs had no pain or lameness; the other dogs were judged to have mild pain and/or lameness. All owners noticed improvement in the dogs' quality of life after surgery. Conclusion— Osteochondral autografting deserves consideration and further evaluation as a primary treatment option for stifle OC in dogs. Clinical Relevance— Osteochondral autografting for treatment of lateral femoral condylar OC lesions in dogs using OATS instrumentation is safe and results in improved function and quality of life based on owners' perception 6–15 months after treatment.     

Evaluation of analgesia provided by the administration of epidural ketamine in dogs with a chemically induced synovitis

OBJECTIVE: To determine if epidural ketamine provides analgesia in dogs with a chemically induced synovitis. STUDY DESIGN: Prospective randomized experimental trial. ANIMALS: Thirty-two healthy, adult mongrel dogs (13-30 kg). METHODS: (Part I) Synovitis was induced in the right stifle of 16 dogs and allowed to develop for 12 hours. Epidural injection at the lumbosacral space of either ketamine (2 mg kg(-1); n = 8) or placebo (n = 8) was performed. Limb use and pain were measured using a force platform and numerical rating scale (NRS). Assessments were performed before and at 12, 14, 16, 18, 20, and 24 hours after the induction of synovitis. (Part II) Epidural injection of either ketamine (n = 8) or placebo (n = 8) was performed immediately before the induction of synovitis. Analgesia was assessed as in Part I. Assessments occurred before and at 2, 4, 6, 8, and 12 hours after the induction of synovitis. RESULTS: (Part I) Vertical ground reaction forces (VGRF) significantly decreased and NRS scores of total pain significantly increased after the induction of synovitis in all dogs (p < 0.05). No significant differences in VGRF or NRS scores were measured between treatment groups at any assessment period. (Part II) Dogs that received ketamine had significantly lower NRS scores 2 hours after treatment (p < 0.05). NRS scores did not differ between groups at any other evaluation. VGRF did not differ significantly between treatment groups at any assessment period. CONCLUSION: Epidural ketamine at a dose of 2 mg kg(-1) administered after the development of synovitis does not provide significant levels of analgesia. Administration of ketamine before the induction of synovitis significantly decreased the NRS score 2 hours post-induction. CLINICAL RELEVANCE: Administration of epidural ketamine before tissue injury may provide analgesia of short duration in dogs.     

Scintigraphic evaluation of dogs with acute synovitis after treatment with glucosamine hydrochloride and chondroitin sulfate

OBJECTIVE: To evaluate the effects of orally administered glucosamine hydrochloride (GlAm)-chondroitin sulfate (CS) and GlAm-CS-S-adenosyl-L-methionine (SAMe) on chemically induced synovitis in the radiocarpal joint of dogs. ANIMALS: 32 adult mixed-breed dogs. PROCEDURE: For 21 days, all dogs received a sham capsule (3 groups) or GlAm-CS (prior treatment group) in a double-blinded study. Unilateral carpal synovitis was induced by injecting the right radiocarpal joint with chymopapain and the left radiocarpal joint (control joint) with saline (0.9% NaCl) solution. Joints were injected on alternate days for 3 injections. After induction of synovitis, 2 groups receiving sham treatment were given GlAm-CS or GlAm-CS-SAMe. Another group continued to receive sham capsules (control group). Joint inflammation was quantified, using nuclear scintigraphy, before injection of joints and days 13, 20, 27, 34, 41, and 48 after injection. Lameness evaluations were performed daily. RESULTS: Dogs given GlAm-CS before induction of synovitis had significantly less scintigraphic activity in the soft-tissue phase 48 days after joint injection, significantly less uptake in the bone phase 41 and 48 days after joint injection, and significantly lower lameness scores on days 12 to 19, 23, and 24 after injection, compared with other groups. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of results of this study suggest that prior treatment with GlAm-CS for 21 days had a protective effect against chemically induced synovitis and associated bone remodeling. Prior treatment with GlAm-CS also reduced lameness in dogs with induced synovitis.     

Kinematic analysis of the hind limb during swimming and walking in healthy dogs and dogs with surgically corrected cranial cruciate ligament rupture

OBJECTIVE: To determine hip, stifle, and tarsal joint ranges of motion (ROM) and angular velocities during swimming and walking in healthy dogs and dogs with surgically corrected cranial cruciate ligament (CCL) rupture. DESIGN: Prospective clinical study. ANIMALS: 13 healthy dogs and 7 dogs with CCL rupture. PROCEDURE: Dogs with CCL rupture were enrolled in a postoperative aquatic rehabilitation program and evaluated 21 to 35 days after surgery. Dogs were filmed while swimming in a pool and while walking at a fast (1.3 m/s) or slow (0.9 m/s) pace on a treadmill. Maximal angles of extension and flexion, ROM, and angular velocities were calculated. RESULTS: In healthy dogs, swimming resulted in a significantly greater ROM in the hip joint than did walking, but in dogs with CCL rupture, ROM of the hip joint did not vary with swimming versus walking. For dogs in both groups, swimming resulted in significantly greater ROM of the stifle and tarsal joints than did walking, primarily because of greater joint flexion. Stifle joint ROM was significantly lower in dogs with CCL rupture than in healthy dogs, regardless of whether dogs were swimming or walking. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that following surgical management of a ruptured CCL in dogs, swimming resulted in greater ROM of the stifle and tarsal joints than did walking. This suggests that if ROM is a factor in the rate or extent of return to function in these dogs, then aquatic rehabilitation would likely result in a better overall outcome than walking alone.     

In vitro effects and in vivo efficacy of a novel cyclooxygenase-2 inhibitor in dogs with experimentally induced synovitis

OBJECTIVE: To determine cyclooxygenase-2 (COX-2) selectivity, pharmacokinetic properties, and in vivo efficacy of ML-1,785,713 in dogs. ANIMALS: 21 healthy male and female mixed-breed dogs and 24 healthy male Beagles. PROCEDURE: Selectivity of ML-1,785,713 for inhibiting COX-2 was determined by comparing the potency for inhibiting cyclooxygenase-1 (COX-1) with that of COX-2 in canine blood. Pharmacokinetic properties were determined after i.v. (2 mg/kg) and oral (8 mg/kg) administration in female mixed-breed dogs. In vivo efficacy was evaluated in male mixed-breed dogs with urate crystal-induced synovitis. Prophylactic efficacy was evaluated by administering ML-1,785,713 two hours before induction of synovitis whereas therapeutic efficacy was determined by administering ML-1,785,713 one hour after induction of synovitis. RESULTS: Blood concentrations that resulted in 50% inhibition of COX-1 and COX-2 activity in vitro were 119.1 microM and 0.31 microM, respectively, and selectivity ratio for inhibiting COX-2 relative to COX-1 was 384. ML-1,785,713 had high oral bioavailability (101%), low systemic clearance (77 mL/min/kg), and an elimination half-life of 5.9 hours. ML-1,785,713 was efficacious when administered prophylactically and therapeutically to dogs with urate crystal-induced synovitis. CONCLUSIONS AND CLINICAL RELEVANCE: ML-1,785,713 is a novel, potent COX-2 inhibitor that is the most selective COX-2 inhibitor described for use in dogs to date. ML-1,785,713 has oral bioavailability and low systemic clearance that is comparable to other non-steroidal anti-inflammatory drugs. It is effective after prophylactic and therapeutic administration in attenuating lameness in dogs with urate crystal-induced synovitis. Drugs that specifically inhibit COX-2 and not COX-1 at therapeutic doses may have an improved tolerability profile, compared with nonselective non-steroidal anti-inflammatory drugs.     

Evaluation of the dose–response relationship of oral robenacoxib in urate crystal‐induced acute stifle synovitis in dogs

The objective of the study was to establish the dose–response relationship for robenacoxib, a selective cyclooxygenase (COX)‐2 inhibitor, in a urate crystal model of acute synovitis. In a randomized partial Latin square design trial, 12 beagle dogs were administered orally single doses of robenacoxib (0.5, 1, 2, 4 and 8 mg/kg), placebo and the positive control meloxicam (0.1 mg/kg), 3 h after injection of sodium urate crystals into a stifle joint. Dogs were assessed for weight bearing on a force plate and by subjective clinical orthopaedic observations. Robenacoxib produced dose‐dependent improvement in weight bearing, and decreased pain on palpation and joint swelling, over the dose range 0.5–2 mg/kg with no further increase in effect over the range 2–8 mg/kg. For weight bearing on the force plate, the ED₅₀ of robenacoxib was 0.6–0.8 mg/kg. The onset of action and time to peak effect of robenacoxib were faster (respectively, 2–2.5 h and 3–5 h) than for meloxicam (respectively, 3 h and 6 h). Robenacoxib significantly inhibited COX‐2 at all doses, with dose‐related activity. Robenacoxib did not inhibit COX‐1 over the dose range 0.5–4 mg/kg, but produced transient inhibition at 8 mg/kg. In conclusion, oral administration of robenacoxib over the dose range 0.5–8 mg/kg demonstrated significant analgesic and anti‐inflammatory efficacy in dogs.     

Prevalence of cranial cruciate ligament rupture in a population of dogs with lameness previously attributed to hip dysplasia: 369 cases (1994-2003)

OBJECTIVE: To determine the prevalence of cranial cruciate ligament rupture (CCLR) in dogs with lameness previously attributed to canine hip dysplasia (CHD). DESIGN: Retrospective study. ANIMALS: 369 client-owned dogs. PROCEDURES: Hospital medical records from 1994 to 2003 were reviewed for dogs in which the referring veterinarian had diagnosed hip dysplasia or hip pain. Dogs were designated as having hind limb lameness because of partial or complete CCLR or CHD. RESULTS: 8% of dogs were sexually intact females, 43% were spayed females, 14% were sexually intact males, and 35% were castrated males. Mean age was 3.8 years (range, 3 months to 15 years). The most common breeds were the Labrador Retriever (21%), German Shepherd Dog (13%), and Golden Retriever (11%). The prevalence of CCLR as the cause of hind limb lameness was 32% (95% confidence interval, 27.2% to 36.8%). The distribution of CCLR among hind limbs was left (29%), right (28%), and bilateral (43%). Of 119 dogs with CCLR, 94% had concurrent radiographic signs of CHD, 92% had stifle joint effusion, and 81% had a cranial drawer sign. CONCLUSIONS AND CLINICAL RELEVANCE: On the basis of the high prevalence of CCLR in dogs referred for lameness because of CHD, it is important to exclude other sources of stifle joint disease before making recommendations for treatment of CHD.     

Force plate gait analysis at the walk and trot in dogs with low-grade hindlimb lameness.

OBJECTIVE: To evaluate the accuracy of force plate gait analysis at the walk and trot in dogs with low-grade hindlimb lameness. MATERIAL AND METHODS: Nineteen healthy dogs and 41 dogs with low-grade unilateral hindlimb lameness due to stifle or hip joint problems were walked and trotted over a force plate. Peak vertical forces (PVF) were recorded, and a symmetry index (SI) was calculated from the PVF of the hindlimbs. 'Cut-off' values were determined from the SI of the normal dogs. These cut-off values were used to discriminate lame dogs from normal ones. Sensitivity and specificity were evaluated for measurements at walk and trot, and the Cohen's Kappa coefficient (k) was used to determine the agreement between clinical lameness and force plate measurements, and between force plate results at walk and trot. Receiver Operating Characteristics (ROC) curve were plotted for both gaits to evaluate accuracy. RESULTS: The sensitivity of the measurements at walk was 0.63, and specifity was 0.95. The sensitivity of the measurements at trot was 0.90, and specificity was 1.0. Moderate agreement was found between force plate measurements at walk and trot, and between clinical gait assessment and force plate measurements at walk. Good agreement was found between clinical gait assessment and measurements at trot. ROC analyses revealed the trot (94.7% [91.7%; 97.7%]) to be the more accurate test than the walk (85.0% [80.1%; 89.9%]). CONCLUSION: The trotting gait was more sensitive and accurate than the walking gait for the differentiation of dogs with a low-grade hindlimb lameness from normal ones using force plate gait analysis.     

Association between subjective lameness grade and kinetic gait parameters in horses with experimentally induced forelimb lameness

OBJECTIVE: To evaluate the association between subjective lameness grades and kinetic gait parameters and assess the variability in kinetic parameters in horses with experimentally induced forelimb lameness. ANIMALS: 32 horses. PROCEDURES: Forelimb lameness was induced in each horse via injection of lipopolysaccharide into 1 metacarpophalangeal joint (40 experimental trials). Subjective lameness grading and 13 kinetic gait parameters (force plate analysis) were assessed before (baseline) and at 12, 18, and 24 hours after lipopolysaccharide injection. While horses were trotting, kinetic gait analysis was performed for 8 valid repetitions at each time point. Repeated-measures analyses were performed with 8 repetitions for each kinetic parameter as the outcome, and lameness grades, time points after lipopolysaccharide injection, and repetition order as explanatory variables. Sensitivity and specificity of kinetic parameters for classification of horses as sound or lame (in relation to subjective lameness scores) were calculated. Between- and within-horse variabilities of the 13 kinetic parameters were assessed by calculation of coefficients of variation. RESULTS: Subjective lameness grades were significantly associated with most of the kinetic parameters. Vertical force peak and impulse had the lowest between- and within-horse coefficients of variation and the highest correlations with subjective lameness grade. Vertical force peak had the highest sensitivity and specificity for lameness classification. Vertical force peak and impulse were significantly decreased even in horses with mild or unobservable lameness. CONCLUSIONS AND CLINICAL RELEVANCE: Among the kinetic gait parameters, vertical force peak and impulse had the best potential to reflect lameness severity and identify subclinical forelimb gait abnormalities.     

Synovitis in dogs with stable stifle joints and incipient cranial cruciate ligament rupture: a cross-sectional study

Objective: To evaluate stifle joints of dogs for synovitis, before development of joint instability and cranial cruciate ligament rupture (CrCLR). Study Design: Cross‐sectional study. Animals: Dogs (n=16) with CrCLR and stable contralateral stifles; 10 control dogs with intact CrCL. Methods: Arthritis and tibial translation were graded radiographically. Synovitis severity and cruciate pathology were assessed arthroscopically. Presence of inflammatory cells in synovial membrane biopsies was scored histologically. CrCLR stifle pairs and control stifles were compared. Results: Radiographic evidence of arthritis, cranial tibial translation, and arthroscopic synovitis were increased in unstable stifles, when compared with stable contralateral stifles in CrCLR dogs (P<.05). Arthroscopic synovitis in both joints of CrCLR dogs was increased compared with controls, was correlated with radiographic arthritis (S_R=0.71, P<.05), and was present in all stable contralateral stifles. Arthroscopically, 75% of stable stifle joints had CrCL fiber disruption, which correlated with severity of synovitis (S_R=0.56, P<.05). Histologic evidence of synovitis was identified in all CrCLR dogs, but was only significantly correlated with arthroscopic observations in stable stifles (r²=0.57, P<.005). Conclusion: Synovitis is an early feature of the CrCLR arthropathy in dogs before development of joint instability clinically. Severity of synovitis is correlated with radiographic arthritis in joints with minimal to no clinically detectable CrCL damage.     

Intra‐articular opioid analgesia is effective in reducing pain and inflammation in an equine LPS induced synovitis model

Reasons for performing study: Intra‐articular administration of morphine as a local analgesic and anti‐inflammatory drug is widely used in human medicine. In equids, little is known about its clinical analgesic and anti‐inflammatory efficacy. Objectives: To use an inflammatory orthopaedic pain model to investigate the analgesic and anti‐inflammatory effects of intra‐articularly administered morphine as a new treatment modality in horses with acute arthritis. Methods: In a crossover study design, synovitis was induced in the left or right talocrural joint by means of intra‐articular injection of 0.5 ng lipopolyssacharide (LPS). The effect of 120 mg morphine, intra‐articularly administered at 1 h after induction of synovitis, was evaluated using both physiological and behavioural pain variables. Synovial fluid was sampled at 0, 4, 8, 28 and 52 h after induction of synovitis and analysed for total protein concentration, leucocyte count and for prostaglandin E₂, bradykinin and substance P concentrations by ELISA. Ranges of motion of metatarsophalangeal and talocrural joints were measured as kinematic variables with the horses walking and trotting on a treadmill under sound and lame conditions. Clinical lameness scores and several behavioural variables related to the perception of pain were obtained. Results: LPS injection caused marked transient synovitis, resulting in increased concentrations of inflammatory synovial fluid markers, clinical lameness, joint effusion and several behavioural changes, such as increased time spent recumbent, decreased limb loading at rest and decreased time spent eating silage. Intra‐articular morphine resulted in a significant decrease in synovial white blood cell count, prostaglandin E₂ and bradykinin levels and improvement in clinical lameness, kinematic and behavioural parameters, compared to placebo treatment. Conclusions: Intra‐articular morphine offers potent analgesic and anti‐inflammatory effects in horses suffering from acute synovitis. Potential relevance: Local administration of opioids may be useful for horses with acute inflammatory joint pain and offers possibilities for multimodal analgesic therapies without opioid‐related systemic side effects.     

Proximal tibial intraarticular ostectomy for treatment of canine cranial cruciate ligament injury

OBJECTIVE: To report a technique for surgical alteration of the slope of the tibial plateau by a proximal tibial intraarticular ostectomy (PTIO) after injury to the canine cranial cruciate ligament (CCL) and to determine the outcome. STUDY DESIGN: Prospective clinical study. ANIMALS: Dogs (n=52) with CCL injury in 60 stifle joints. METHODS: CCL injury was treated by lateral stifle arthrotomy, removal of CCL remnants, and appropriate meniscal surgery. PTIO was performed to remove a wedge of bone from the proximal aspect of the tibia. The ostectomy site was reduced and stabilized using a bone plate and screws applied to the medial surface of the tibia as well as a craniocaudal positional screw. Dogs were evaluated at 6 weeks, 6, and 12 months by complication assessment, lameness scores, stifle range of motion (ROM), thigh circumference, radiographic assessment, degenerative joint disease (DJD) scores, and surgeon and owner evaluation of function. RESULTS: Lameness scores improved by 6 and 12 months in all but 1 dog. Thigh circumference and DJD were increased at 6 and 12 months. Complications occurred in 20% of dogs with all but 1 occurring perioperatively or within 6 weeks; most common were injury to the long digital extensor tendon (4 dogs) and plate failure (3); 2 other dogs required surgery to treat complications. Most owners (98%) reported that lameness had improved by 12 months; 90% were extremely or very satisfied with the procedure and 90% would have the same procedure performed on another dog. CONCLUSION: PTIO to level the tibial plateau provided a satisfactory clinical outcome in dogs >20 kg with CCL injury and the complication rate was similar to tibial plateau levelling osteotomy (TPLO). Stifle osteoarthritis continued to progress radiographically. CLINICAL RELEVANCE: PTIO represents an alternative to TPLO that does not require specialized surgical equipment.