Musculoskeletal problems associated with lameness and poor performance in cutting horses: 200 cases (2007-2015).

OBJECTIVE To describe the chief complaints by owners and the types and prevalences of musculoskeletal problems associated with lameness or poor performance in cutting horses. DESIGN Retrospective case series. ANIMALS 200 client-owned cutting horses examined at the Texas A&M University Veterinary Medical Teaching Hospital between January 1, 2007, and December 31, 2015, because of lameness or poor performance. PROCEDURES Medical records were reviewed, and data were collected regarding signalment, history, findings on physical and lameness examinations, results of diagnostic procedures performed, diagnosis, and treatment. Distribution of observed proportions of forelimb and hind limb involvement was compared with a hypothetical distribution of 50% by means of a χ2 test. RESULTS More horses were examined because of a recent decrease in performance (116/200 [58%]) than for lameness (84 [42%]). All horses had at least 1 lame limb, with lameness affecting a total of 281 limbs. Of the 281 lame limbs, 189 (67%) were hind limbs and 92 (33%) were forelimbs. These proportions were substantially different from a hypothetical distribution of 50% hind limbs and 50% forelimbs. The most common performance change was that horses would not reverse direction to follow prespecified individual cattle, and the most common cause of lameness was pain localized to the stifle joint region (69 [35%]). CONCLUSIONS AND CLINICAL RELEVANCE Cutting horses sustained more hind limb than forelimb musculoskeletal problems, and although these horses were more likely to be examined for decreased performance than lameness, veterinarians should be vigilant for problems affecting the stifle joint region.

Evaluation of conjugated linoleic acid supplementation on markers of joint inflammation and cartilage metabolism in young horses challenged with lipopolysaccharide.

Seventeen yearling Quarter Horses were used in a randomized complete block design for a 56-d trial to determine ability of dietary CLA to mitigate joint inflammation and alter cartilage turnover following an inflammatory insult. Horses were blocked by age, sex, and BW, and randomly assigned to dietary treatments consisting of commercial concentrate offered at 1% BW (as-fed) supplemented with either 1% soybean oil (CON; n = 6), 0.5% soybean oil and 0.5% CLA (LOW; n = 5; 55% purity; Lutalin, BASF Corp., Florham Park, NJ), or 1% CLA (HIGH; n = 6) top-dressed daily. Horses were fed individually every 12 h and offered 1% BW (as-fed) coastal bermudagrass (Cynodon dactylon) hay daily. This study was performed in 2 phases: phase I (d 0 to d 41) determined incorporation of CLA into plasma and synovial fluid; phase II (d 42 to d 56) evaluated potential of CLA to mitigate intra-articular inflammation and alter cartilage metabolism. Blood and synovial fluid were collected at 7- and 14-d intervals, respectively, to determine fatty acid concentrations. On d 42, carpal joints within each horse were randomly assigned to receive intra-articular injections of 0.5 ng lipopolysaccharide (LPS) derived from Escherichia coli 055:B5 or sterile lactated Ringer's solution. Synovial fluid samples were obtained at preinjection h 0 and 6, 12, 24, 168, and 336 h postinjection, and analyzed for prostaglandin E2 (PGE2), carboxypeptide of type II collagen (CPII), and collagenase cleavage neopeptide (C2C). Data were analyzed using PROC MIXED procedure of SAS. Horses receiving the CON diet had undetectable levels of CLA for the duration of the study. A quadratic dose response was observed in concentrations of CLA in plasma and synovial fluid (P < 0.01). A negative quadratic dose response was observed for plasma arachidonic acid (20:4) with a reduction in concentration to d 14 in HIGH horses (P = 0.04). Synovial fluid 20:4 tended to decrease in horses receiving the HIGH diet (P = 0.06). Post LPS injection, synovial PGE2 was not affected by dietary treatment (P = 0.15). Synovial C2C was lower in HIGH horses (P = 0.05), and synovial CPII tended to be greater in LOW horses than HIGH and CON horses (P = 0.10). In conclusion, dietary CLA incorporated into plasma and synovial fluid prior to LPS challenge. Dietary CLA did not influence inflammation; however, there was a reduction in cartilage degradation and an increase in cartilage regeneration.

A randomized, controlled trial of the effects of resveratrol administration in performance horses with lameness localized to the distal tarsal joints.

OBJECTIVE To determine the effect of resveratrol administration in performance horses with lameness localized to the distal tarsal joints. DESIGN Randomized, blinded, placebo-controlled clinical trial. ANIMALS 45 client-owned horses with lameness localized to the distal tarsal joints. PROCEDURES All horses received injections of triamcinolone acetonide in the centrodistal and tarsometatarsal joints of both hind limbs. A placebo or a supplement containing resveratrol was fed twice daily by owners for 4 months. Primary outcomes were horse performance as determined by rider opinion (better, worse, or the same) and change in lameness severity from the enrollment examination. RESULTS Complete data were obtained for 21 horses that received resveratrol and 20 that received the placebo. Percentage of riders who reported that the horse's performance was better, compared with worse or the same, was significantly higher for the resveratrol group than for the placebo group after 2 (20/21 [95%] vs 14/20 [70%]) and 4 (18/21 [86%] vs 10/20 [50%]) months. The change in A1:A2 ratio between the enrollment and 4-month recheck examinations was significantly better for horses in the resveratrol versus placebo group. However, subjective lameness scores and degree of asymmetry of pelvis movement did not differ between groups. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that in performance horses with lameness localized to the distal tarsal joints, injection of triamcinolone in the centrodistal and tarsometatarsal joints of both hind limbs followed by oral supplementation with resveratrol for 4 months resulted in reduced lameness, compared with triamcinolone injection and supplementation with a placebo.

Enthesopathy and desmitis of the medial collateral ligament of the cubital joint in 4 horses.

CASE DESCRIPTION: 4 horses with enthesopathy and desmitis of the medial collateral ligament of the cubital joint were examined. CLINICAL FINDINGS: All 4 horses had a history of acute, severe, unilateral forelimb lameness and had signs of pain during manipulation of the affected upper forelimb; 2 also had swelling in the axillary region. There was no improvement in lameness after diagnostic local analgesia below the carpal region, and 1 of 4 horses had mild improvement after cubital joint analgesia. Radiography revealed enthesophyte formation on the radial tuberosity and linear mineralization of the medial collateral ligament in 2 horses and periosteal reaction on the humeral condyle in all 4 horses. One horse had mild osteoarthritis of the cubital joint, and 3 had osteophytosis of the cranial aspect of the radius. Although all horses were initially examined because of an acute onset of lameness, all had chronic abnormalities visible on imaging. Ultrasonography revealed an irregular boney contour and enthesopathy at the insertion of the short medial collateral ligament to the radial tuberosity and desmitis of the short medial collateral ligament. Two horses had radiographic evidence of similar but less severe lesions of the contralateral cubital joint. TREATMENT AND OUTCOME: All horses received phenylbutazone and rest. All horses were free of lameness after a median of 3 months (range, 2 to 4 months) and returned to previous use after a median of 6 months (range, 3 to 8 months). CONCLUSIONS AND CLINICAL RELEVANCE: The results of the present report suggested that performance horses with enthesopathy and desmitis of the medial collateral ligament of the cubital joint may have a good prognosis for return to previous use following appropriate treatment.

Tendinitis of the proximal aspect of the superficial digital flexor tendon in horses: 12 cases (2000-2006).

OBJECTIVE: To determine clinical signs, ultrasonographic findings, and outcome of horses with tendinitis of the proximal portion of the superficial digital flexor tendon (SDFT; group A horses) and to compare signalment, horse use, and outcome in these horses with that of horses with tendinitis of the midmetacarpal region of the SDFT (group B horses). DESIGN: Retrospective case series. ANIMALS: 12 group A horses and 22 group B horses. PROCEDURES: Medical records were reviewed for signalment, horse use, and outcome information; data for group A horses also included severity of lameness, diagnostic results, and treatment. RESULTS: Most group A horses were aged (mean, 18 years; median, 17 years; range, 11 to 23 years) Quarter Horses (9/12 horses) and had a grade 3 or 4 (on a scale from 1 to 5) forelimb lameness. Most group A horses (8/12 horses) had positive reactions to carpal flexion and were (9/12 horses) sound following ulnar nerve blocks. Ultrasonographic evaluation revealed hypoechoic SDFT lesions (median echogenicity score, 3/4; median fiber alignment score, 3/3; and mean length, 9.75 cm). Group A horses were significantly older and had a poorer outcome for return to previous use (2/12 horses), compared with group B horses (median age, 5 years; 10/22 horses returned to previous use). Thirteen of 22 group B horses were Thoroughbreds. CONCLUSIONS AND CLINICAL RELEVANCE: Tendinitis of the proximal portion of the SDFT was a cause of lameness in aged performance horses; prognosis for return to previous use was poor.

Fractures of the tuber coxa of the ilium in horses: 29 cases (1996-2007).

OBJECTIVE: To determine history; clinical, radiographic, ultrasonographic, and scintigraphic abnormalities; treatment; and outcome in horses with tuber coxae fractures and to describe a useful technique for obtaining a dorsomedial-ventrolateral 50 degrees oblique radiographic view of the tuber coxa of the ilium in standing horses. DESIGN: Retrospective case series. ANIMALS: 29 horses with fractures of tuber coxa. PROCEDURES: Data collected from medical records included signalment; history; horse use; severity and duration of lameness; radiographic, ultrasonographic, and scintigraphic findings; treatment; and outcome. RESULTS: All horses had a traumatic event leading to acute, unilateral hind limb lameness. Eighteen horses had a more severe lameness at the walk than at the trot; 22 of 29 horses had an abnormal gait with the hind limbs tracking to 1 side of the forelimbs. Twenty-four of 29 horses had palpable and visual asymmetry between the affected and unaffected tuber coxae. Twenty horses had radiography performed while sedated but standing, and fractures were reliably identified on the dorsomedial-ventrolateral 50 degrees oblique radiographic views. Twenty-seven (27/29 [93%]) horses returned to athletic use. Horses sustaining partial fractures of the caudal aspect of tuber coxae returned to previous use significantly earlier (mean, 3 months), compared with horses with complete tuber coxae fractures (6.5 months). CONCLUSIONS AND CLINICAL RELEVANCE: Horses with tuber coxae fractures returned to athletic soundness following extended periods of rest. Findings emphasized the need for obtaining a dorsomedial-ventrolateral 50 degrees oblique radiographic view of the tuber coxa of the ilium in horses suspected of sustaining injury to this region.

Fractures of the greater tubercle of the humerus in horses: 15 cases (1986-2004).

OBJECTIVE: To determine clinical and radiographic abnormalities in and outcome of horses with fractures of the greater tubercle of the humerus and to develop a radiographic technique for obtaining a cranioproximal-craniodistal oblique projection of the proximal portion of the humerus in standing horses. DESIGN: Retrospective case series. ANIMALS: 15 horses. PROCEDURES: Data collected from medical records included signalment, history, horse use, severity and duration of lameness, radiographic and ultrasonographic findings, treatment, and outcome. RESULTS: All horses had a history of acute, unilateral lameness. Twelve of 15 had visual or palpable abnormalities in the shoulder region. In 6 of 8 horses, the fracture could be seen on a cranioproximal-craniodistal projection of the proximal portion of the humerus. In 2 horses, this was the only projection on which the fracture could be seen, and in an additional 2, this was the projection on which the fracture could be seen most reliably. Ten horses underwent surgery (fragment removal, 7; open reduction and internal fixation, 2; and exploration without fragment removal, 1), and 5 were treated with variable periods of stall rest and turnout. Eleven horses returned to athletic use, including 9 of the 10 treated surgically and 2 of the 5 treated without surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that horses with fractures of the greater tubercle of the humerus can return to athletic soundness following treatment and emphasized the need for obtaining a cranioproximal-craniodistal radiographic projection of the proximal portion of the humerus in horses suspected to have an injury in this region.

Musculoskeletal problems associated with lameness and poor performance among horses used for barrel racing: 118 cases (2000-2003).

OBJECTIVE: To identify types of musculoskeletal problems associated with lameness or poor performance in horses used for barrel racing. DESIGN: Retrospective case series. ANIMALS: 118 horses. PROCEDURE: Medical records were reviewed for information on signalment, history, physical and lameness examination findings, diagnostic tests performed, diagnosis, and treatment. RESULTS: Most horses were examined because of lameness (n = 72 [61%]) rather than poor performance (46 [39%]), but owner complaint was not significantly associated with age or body weight of the horse. The most common performance change was refusal or failure to turn properly around the first barrel (19/46 [41%]). The right forelimb (n = 57 [48%]) was most commonly affected, followed by the left forelimb (51 [43%]), the left hind limb (31 [26%]), and the right hind limb (25 [21%]). In 31 horses (26%), both forelimbs were affected, and in 6 (5%), both hind limbs were affected. The most common musculoskeletal problems were forelimb foot pain only (n = 39 [33%]), osteoarthritis of the distal tarsal joints (17 [14%]), suspensory ligament desmitis (15 [13%]), forelimb foot pain with distal tarsal joint osteoarthritis (11 [9%]), and bruised feet (10 [8.5%]). In 81 (69%) horses, the affected joint was treated with intra-articular medications. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that in horses used for barrel racing that are examined because of lameness or poor performance, the forelimbs are more likely to be affected than the hind limbs, with forelimb foot pain and osteoarthritis of the distal tarsal joints being the most common underlying abnormalities.

Lameness and poor performance in horses used for team roping: 118 cases (2000-2003).

OBJECTIVE: To determine the types of musculoskeletal problems that result in lameness or poor performance in horses used for team roping and determine whether these problems are different in horses used for heading versus heeling. DESIGN: Retrospective study. ANIMALS: 118 horses. PROCEDURE: Medical records of team roping horses that were evaluated because of lameness or poor performance were reviewed to obtain information regarding signalment, primary use (ie, head horse or heel horse), history, results of physical and lameness examinations, diagnostic tests performed, final diagnosis, and treatment. RESULTS: Among horses evaluated by lameness clinicians, the proportion with lameness or poor performance was significantly greater in horses used for heading (74/118) and lower in horses used for heeling (44/118) than would be expected under the null hypothesis. Most horses examined for poor performance were lame. A significantly greater proportion of horses used for heading had right forelimb lameness (26/74 [35%]), compared with horses used for heeling (7/44 [16%]). Horses used for heading had more bilateral forelimb lameness (18/74 [24%]), compared with horses used for heeling (4/44 [9%]). Horses used for heeling had more bilateral hind limb lameness (3/44 [7%]), compared with horses used for heading (0%). The most common musculoskeletal problems in horses used for heading were signs of pain limited to the distal sesamoid (navicular) area, signs of pain in the navicular area plus osteoarthritis of the distal tarsal joints, and soft tissue injury in the forelimb proximal phalangeal (pastern) region. Heeling horses most commonly had signs of pain in the navicular area, osteoarthritis of the metatarsophalangeal joints, and osteoarthritis of the distal tarsal joints. CONCLUSIONS AND CLINICAL RELEVANCE: Horses used for heading were most commonly affected by lameness in the right forelimb. Horses used for heeling had more bilateral hind limb lameness than horses used for heading.

Effects of Carolina rinse solution, dimethyl sulfoxide, and the 21-aminosteroid, U-74389G, on microvascular permeability and morphology of the equine jejunum after low-flow ischemia and reperfusion.

OBJECTIVE: To evaluate effects of Carolina rinse solution, dimethyl sulfoxide (DMSO), and 21-aminosteroid, U-74389G, on microvascular permeability and morphology of the equine jejunum after low-flow ischemia and reperfusion. ANIMALS: 20 healthy adult horses. PROCEDURE: Under anesthesia, full-thickness biopsy specimens of a distal portion of the jejunum were obtained for baseline measurements. In addition to a control segment, 2 jejunal segments were identified as sham-operated or experimental segments. Experimental segments underwent 60 minutes of low-flow ischemia and 3.5 hours of reperfusion. Treatments were as follows: U-74389G (3 mg/kg, IV; 6 horses), DMSO (20 mg/kg, IV; 6) diluted in 1 L of saline (0.9% NaCl) solution, local perfusion (via jejunal artery) of Carolina rinse solution (0.5 mL/kg; 4), and local perfusion of lactated Ringer's solution (0.5 mL/kg; 4). RESULTS: Jejunal microvascular permeability was significantly lower after treatment with Carolina rinse solution or DMSO, compared with U-74389G or lactated Ringer's solution treatments. After DMSO treatment, serosal- and submucosal-layer edema was significantly increased in experimental segments, compared with control or sham-operated segments; however, edema increases were significantly less than for lactated Ringer's solution or U-74389G treatments. Significant decreases in intestinal wet weight-to-dry weight ratio were found following Carolina rinse solution or DMSO treatments, compared with lactated Ringer's solution or U-74389G treatments. Edema formation and leukocyte infiltration in jejunal segments of horses treated with lactated Ringer's solution or U-74389G were increased, compared with Carolina rinse solution or DMSO treatments. CONCLUSIONS AND CLINICAL RELEVANCE: Carolina rinse solution and DMSO may be protective against ischemia-reperfusion injury in the equine jejunum.

Heel bulb lacerations in horses: 101 cases (1988-1994).

OBJECTIVE: To determine clinical history, structures involved, treatment, and outcome of lacerations of the heel bulb and proximal phalangeal region (pastern) in horses. DESIGN: Retrospective study. ANIMALS: 101 horses. PROCEDURES: Medical records of horses with lacerations of the heel bulb and pastern were reviewed, and follow-up information was obtained. RESULTS: 75 horses were Quarter Horses. Most horses were not treated with antimicrobial drugs prior to referral. Mean +/- SD time from injury to referral was 24 +/- 45 hours (range, 1 to 168 hours). Lacerations were most frequently caused by contact with wire or metal objects. In 17 horses, lacerations involved synovial structures; the distal interphalangeal joint was most commonly affected. One horse was euthanatized after initial examination. Wound treatment consisted of cleansing, lavage, debridement, lavage of affected synovial structures, suturing of fresh wounds, and application of a foot bandage or cast. Fifty-six horses were treated with systemically administered antimicrobial drugs. Follow-up information was collected for 61 horses. Fifty-one horses returned to their intended use and had no further complications; 10 horses had complications associated with the wound, and of those horses, 5 were euthanatized and 1 horse died from an unrelated cause. Horses with lacerations that involved synovial structures had worse outcomes than horses with lacerations that did not involve synovial structures. CONCLUSIONS AND CLINICAL RELEVANCE: Horses that sustain heel bulb lacerations can successfully return to their intended use. Involvement of the distal interphalangeal joint is associated with poor prognosis.

Gracilis muscle injury as a cause of lameness in two horses.

Injury to the gracilis muscle can cause acute, severe lameness in horses. Two female Quarter Horses that were used for barrel racing sustained gracilis muscle tear injuries. The site of injury was localized by direct infiltration of the area with mepivacaine. The extent of muscle tearing and seroma formation was determined via ultrasonographic evaluation. One horse developed fibrotic myopathy approximately 3 months after the original injury and underwent surgery to transect a palpable fibrous band at the previous injury site. Both horses returned to barrel racing 5 to 6 months after the injury These results suggest that horses sustaining a gracilis muscle injury have a good prognosis for returning to athletic use after an adequate period of muscle healing; however, fibrotic myopathy or muscle atrophy could be a complication of the injury resulting in persistent gait deficits.

Injection of corticosteroids, hyaluronate, and amikacin into the navicular bursa in horses with signs of navicular area pain unresponsive to other treatments: 25 cases (1999-2002).

OBJECTIVE: To determine history, clinical and radiographic abnormalities, and outcome in horses with signs of navicular area pain unresponsive to corrective shoeing and systemic nonsteroidal anti-inflammatory drug administration that were treated with an injection of corticosteroids, sodium hyaluronate, and amikacin into the navicular bursa. DESIGN: Retrospective study. ANIMALS: 25 horses. PROCEDURE: Data collected from the medical records included signalment, history, horse use, severity and duration of lameness, shoeing regimen, results of diagnostic anesthesia, radiographic abnormalities, and outcome. RESULTS: 17 horses had bilateral forelimb lameness, 7 had unilateral forelimb lameness, and 1 had unilateral hind limb lameness. Mean duration of lameness was 9.2 months. All horses had been treated with corrective shoeing and nonsteroidal anti-inflammatory drugs for at least 6 months; 18 had previously been treated by injection of corticosteroids and sodium hyaluronate into the distal interphalangeal joint. Fourteen horses had mismatched front feet, and 21 horses had signs of pain in response to application of pressure over the central aspect of the frog. Palmar digital nerve anesthesia resulted in substantial improvement in or resolution of the lameness in all horses. Twenty horses (80%) were sound and returned to intended activities 2 weeks after navicular bursa treatment; mean duration of soundness was 4.6 months. Two horses that received numerous navicular bursa injections had a rupture of the deep digital flexor tendon at the level of the pastern region. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that navicular bursa treatment may provide temporary improvement in horses with signs of chronic navicular area pain that fail to respond to other treatments.

Diagnosis, treatment, and farriery for horses with chronic heel pain.

In conclusion, horses with heel or navicular area pain vary, and no one treatment option is suitable for all horses. Each horse must be evaluated individually to determine which structure in the palmar aspect of the foot is injured, severity of disease, horse and hoof conformation, and horse use and level of performance expectation before a treatment plan can be developed. Overall, there are many treatment options to help these horses to perform their intended athletic event.

Hoof wall surgery in the horse: approaches to and underlying disorders.

Because of the hoof capsule, surgery of the equine foot is often perceived to be quite difficult. Knowledge of the specific disease entities that require surgical intervention as well as an in-depth understanding of the anatomy of the tissues beneath the hoof capsule is a definite prerequisite to successful surgical treatment. This article details the surgical approaches used to treat septic navicular bursitis, septic pedal osteitis, infection of the collateral cartilages, and keratomas. The principles used to treat these conditions can be applied to a variety of other conditions for which access through the hoof wall is required.

Osteomyelitis secondary to trauma involving the proximal end of the radius in horses: five cases (1987-2001).

OBJECTIVE: To determine clinical, radiographic, and scintigraphic abnormalities in and treatment and outcome of horses with trauma-induced osteomyelitis of the proximal aspect of the radius. DESIGN: Retrospective study. ANIMALS: 5 horses. PROCEDURE: Data collected from the medical records included signalment; history; horse use; degree of lameness; radiographic, ultrasonographic, and scintigraphic findings; treatment; and outcome. RESULTS: Duration of lameness prior to referral ranged from 14 to 60 days. Mean severity of lameness was grade 3 of 5, and all horses had a single limb affected. All horses had signs of pain during elbow joint manipulation and digital palpation over the lateral aspect of the proximal end of the radius. Radiographic lesions consisted of periosteal proliferation, osteolysis, and subchondral bone lysis. Scintigraphy in 3 horses revealed intense pharmaceutical uptake diffusely involving the proximal end of the radius. Two horses had sepsis of the elbow joint. All horses were treated with antimicrobials long-term; 1 horse was also treated by local perfusion of the radial medullary cavity through an indwelling cannulated screw. At follow-up, all horses had returned to their previous function. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that osteomyelitis of the proximal end of the radius can result from a traumatic injury to the antebrachium. Because lesions may be an extension of septic arthritis, a thorough examination of the wound area and elbow joint is recommended. Prolonged systemic antimicrobial treatment can result in a successful outcome.