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- Author or Editor: David L. Wilson x
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Abstract
Objective—To evaluate the efficacy and safety of intra-articular administration of ethyl alcohol for arthrodesis of tarsometatarsal joints in horses.
Animals—8 healthy female horses without lameness or radiographic evidence of tarsal joint osteoarthritis.
Procedure—In each horse, 1 tarsometatarsal joint was treated with 4 mL of 70% ethyl alcohol and the opposite joint was treated with 4 mL of 95% ethyl alcohol. Lameness examinations were performed daily for 2 weeks, followed by monthly evaluations for the duration of the 12-month study. Radiographic evaluations of both tarsi were performed 1 month after injection and every 3 months thereafter. Gross and histologic examinations of the tarsi were undertaken at completion of the study.
Results—Horses had minimal to no lameness associated with the treatments. Radiography revealed that 8 of 16 joints were fused by 4 months after treatment, with significantly more joints fused in the 70% ethyl alcohol group. Fifteen of 16 joints were considered fused at postmortem examination at 12 months. Gross and histologic examinations revealed foci of dense mature osteonal bone spanning the joint spaces. Bony fusion appeared to be concentrated on the dorsolateral, centrolateral, and plantarolateral aspects of the joints. Significant differences were not detected between treatment groups for lameness or pathologic findings.
Conclusions and Clinical Relevance—Administration of ethyl alcohol into the tarsometatarsal joint of healthy horses appeared to facilitate arthrodesis of the joint in a pain-free manner. Results warrant further investigation into the potential use of ethyl alcohol in horses clinically affected with osteoarthritis of the tarsometatarsal and distal intertarsal joints.
Abstract
OBJECTIVES
Evaluation of the strength of the novel suture technique by comparison with a 2-interrupted suture technique.
SAMPLE
40 equine larynges.
PROCEDURES
40 larynges were used; 16 laryngoplasties were performed using the currently accepted 2-suture technique and 16 using the novel suture technique. These specimens were subjected to a single cycle to failure. Eight specimens were used to compare the rima glottidis area achieved with 2 different techniques.
RESULTS
The mean force to failure, as well as the rima glottidis area of both constructs, were not significantly different. The cricoid width did not have a significant effect on the force to failure.
CLINICAL RELEVANCE
Our results suggest that both constructs are equally strong and can achieve a similar cross-sectional area of the rima glottidis. Laryngoplasty (“tie-back”) is currently the treatment of choice for horses with exercise intolerance due to recurrent laryngeal neuropathy. Failure to maintain the expected degree of arytenoid abduction post-surgery occurs in some horses. We believe this novel 2-loop pulley load-sharing suture technique can help achieve and, more importantly, maintain the desired degree of abduction during surgery.
Abstract
OBJECTIVE
To compare laryngeal impedance, in terms of air flow and pressure, following arytenoid corniculectomy (COR) versus 3 other airway interventions (left-sided laryngoplasty with ipsilateral ventriculocordectomy [LLP], LLP combined with COR [LLPCOR], and partial arytenoidectomy [PA]) performed on cadaveric equine larynges with simulated left recurrent laryngeal neuropathy (RLN) and to determine whether relative laryngeal collapse correlated with the interventions performed.
SAMPLE
28 cadaveric equine larynges.
PROCEDURES
Each larynx in states of simulated left RLN alone and with airway interventions in the order LLP, LLPCOR, COR, and PA was evaluated in a box model construct that replicated upper airway flow mechanics consistent with peak exercise in horses. Results for impedance, calculated from airflow and pressure changes, were compared between states for each larynx. Multivariable mixed-effects analysis controlling for repeated measures within larynx was performed to calculate the predicted mean impedance for each state.
RESULTS
Results indicated that tracheal adapter diameter, individual larynx properties, airway intervention, and relative laryngeal collapse affected laryngeal impedance. The LLP and LLPCOR interventions had the lowest impedance, whereas the COR and PA interventions did not differ substantially from the simulated left RLN state. Residual intraclass correlation of the model was 27.6 %.
CONCLUSIONS AND CLINICAL RELEVANCE
Although impedance was higher for the simulated left RLN with the COR intervention state than with the LLP intervention state, given the clinical success of PA for treating RLN in horses and the similar results for the COR and PA intervention states in the present study, the use of COR warrants further investigation. The residual interclass correlation suggested that individual laryngeal variation affected impedance and may have a clinical effect.
Abstract
OBJECTIVE
To determine the holding capacity of a 5.5-mm-diameter cortical bone screw when placed in the third phalanx (P3) of horses and assess whether screw placement through the dorsal hoof wall into P3 would be tolerated by clinically normal horses and would alleviate signs of pain and prevent P3 rotation in horses with oligofructose-induced laminitis.
ANIMALS
40 limbs from 10 equine cadavers and 19 clinically normal adult horses.
PROCEDURES
In part 1 of a 3-part study, a 5.5-mm-diameter cortical bone screw was inserted by use of a lag-screw technique through the dorsal hoof wall midline into P3 of 40 cadaveric limbs and tested to failure to determine screw pullout force. In part 2, 6 horses had 5.5-mm-diameter cortical bone screws placed in both forefeet as described for part 1. Screws were removed 4 days after placement. Horses were monitored for lameness before and for 2 weeks after screw removal. In part 3, 13 horses were randomly assigned to serve as controls (n = 3) or undergo screw placement without (group 2; 6) or with (group 3; 4) a washer. Following the acquisition of baseline data, horses were sedated and administered oligofructose (10 g/kg) via a stomach tube. Twenty-four hours later, screws were placed as previously described in both forefeet of horses in groups 2 and 3. Horses were assessed every 4 hours, and radiographic images of the feet were obtained at 96 and 120 hours after oligofructose administration. Horses were euthanized, and the feet were harvested for histologic examination.
RESULTS
The mean ± SD screw pullout force was 3,908.7 ± 1,473.4 N, and it was positively affected by the depth of screw insertion into P3. Horses of part 2 tolerated screw placement and removal well and did not become lame. All horses of part 3 developed signs of acute lameness, and the distance between P3 and the dorsal hoof wall increased slightly over time. The change in the ratio of the dorsal hoof wall width at the extensor process of P3 to that at the tip of P3 over time was the only variable significantly associated with treatment.
CONCLUSIONS AND CLINICAL RELEVANCE
Placement of a 5.5-mm-diameter cortical bone screw through the dorsal hoof wall into P3 had sufficient holding power to counteract the pull of the deep digital flexor tendon in approximately 500-kg horses, and placement of such a screw was well tolerated by clinically normal horses but did not alleviate signs of pain in horses with oligofructose-induced laminitis. Further research is necessary before this technique can be recommended for horses with naturally occurring acute laminitis.
Abstract
OBJECTIVES
To characterize the 3-D geometry of the equine larynx replicating laryngeal hemiplegia and 4 surgical interventions by use of CT under steady-state airflow conditions. Secondly, to use fluid mechanic principles of flow through a constriction to establish the relationship between measured airflow geometries with impedance for each surgical procedure.
SAMPLE
10 cadaveric horse larynges.
PROCEDURES
While CT scans were performed, inhalation during exercise conditions was replicated for each of the following 5 conditions: laryngeal hemiplegia, left laryngoplasty with ventriculocordectomy, left laryngoplasty with ipsilateral ventriculocordectomy and arytenoid corniculectomy, corniculectomy, and partial arytenoidectomy for each larynx while CT scans were performed. Laryngeal impedance was calculated, and selected cross-sectional areas were measured along each larynx for each test. Measured areas and constriction characteristics were analyzed with respect to impedance using a multilevel, mixed-effects model.
RESULTS
Incident angle, entrance coefficient, outlet coefficient, friction coefficient, orifice thickness, and surgical procedure were significantly associated with upper airway impedance in the bivariable model. The multivariate model showed a significant influence of incident angle, entrance coefficient, and surgical procedure on impedance; however, the orifice thickness became nonsignificant within the model.
CLINICAL RELEVANCE
Laryngeal impedance was significantly associated with the entrance configuration for each procedure. This suggested that the equine upper airway, despite having a highly complex geometry, adheres to fluid dynamic principles applying to constrictions within pipe flow. These underlying flow characteristics may explain the clinical outcomes observed in some patients, and lead to areas of improvement in the treatment of obstructive upper airway disease in horses.
Abstract
Objective—To assess the safety and efficacy of alcohol-facilitated ankylosis of the distal intertarsal (DIT) and tarsometatarsal (TMT) joints in horses with osteoarthritis (bone spavin).
Design—Prospective clinical trial.
Animals—21 horses with DIT or TMT joint-associated hind limb lameness and 5 nonlame horses.
Procedures—11 horses (group 1) underwent lameness, force-plate, and radiographic examinations; following intra-articular analgesia, lameness and force-plate examinations were repeated. Nonlame horses were used for force-plate data acquisition only. Following localization of lameness to the DIT and TMT joints, contrast arthrographic evaluation was performed; when communication with the tibiotarsal joint was not evident or suspected, 70% ethyl alcohol (3 mL) was injected. Group 1 horses underwent lameness, force-plate, and radiographic examinations every 3 months for 1 year. Ten other horses (group 2) underwent lameness and radiographic examinations followed by joint injection with alcohol; follow-up information was obtained from owners or via clinical examination.
Results—Significant postinjection reduction in lameness (after 3 days to 3 months) was evident for all treated horses. Twelve months after injection, 10 of 11 group 1 horses were not lame; lameness grade was 0.5 in 1 horse. Follow-up information was available for 9 of 10 group 2 horses; 7 were not lame, and 2 remained mildly lame (1 had a concurrent problem in the injected limb, and the other had DIT joint collapse that precluded needle entry).
Conclusions and Clinical Relevance—Intra-articular alcohol injection in horses with bone spavin resulted in a rapid (usually within 3 months) reduction in lameness and joint space collapse.
Abstract
Case Description—9 first-lactation dairy cows in a closed dairy herd had swelling in the forelimbs and forelimb lameness. Mycoplasmal arthritis and mastitis were diagnosed.
Clinical Findings—Swelling of the carpal joint, diffuse subcutaneous edema from the carpal to metacarpophalangeal joints, and forelimb lameness were evident in 9 first-lactation cows 7 to 21 days after parturition. Diagnostic testing revealed that 3 of 3 bulk-tank milk samples, 3 milk samples from cows with clinical mastitis, 2 fluid samples obtained from arthritic joints, and samples from the lungs and spleen of a cow that had died yielded positive results for Mycoplasma spp. Nucleic acid sequence analysis performed by use of a PCR assay on the joint fluid and lung tissues confirmed infection with Mycoplasma bovis.
Treatment and Outcome—Affected cows were treated by IM administration of flunixin meglumine and dexamethasone for 3 days. All cows were nonresponsive to treatment (3 cows died, and the other 6 were culled). Follow-up culture for Mycoplasma spp of milk samples from the bulk tank and from all lactating cows was recommended to screen for chronic subclinical carriers.
Clinical Relevance—Mycoplasmal infections may cause unusual initial clinical signs or an atypical history. When dairy cattle, including those residing in closed herds, have lameness, swelling of the carpal or metacarpophalangeal joints, edema of the distal portions of the forelimbs, or polyarthritis, infection with Mycoplasma spp should be investigated. Delay in diagnosis of mycoplasmal infections in dairy herds can result in substantial financial loss and the establishment of chronic subclinical carriers.
Abstract
Objective—To describe clinical manifestations of cutaneous and ocular habronemiasis in horses and evaluate outcome of treatment.
Design—Retrospective study.
Animals—63 horses.
Procedure—The diagnosis was made on the basis of history, clinical signs, and identification of calcified concretions (sulfur granules) in lesions. Histologic examination of biopsy specimens was used to confirm the diagnosis. Case horses were compared with a control population of 12,720 horses examined during the same period.
Results—Arabians, gray horses, and horses with diluted coat colors were overrepresented; Thoroughbreds were underrepresented. Lesions were identified most often during the summer and early fall. The medial canthus of the eye, male genitalia, third eyelid, and distal portions of the extremities were the most commonly affected locations. Twenty-five lesions were biopsied, and results of histologic examination were consistent with a diagnosis of habronemiasis. However, nematode larvae were seen in only 11 (44%) biopsy specimens. Treatment consisted of surgical removal (7 horses) or medical treatment (56) consisting of debulking granulation tissue and topical, intralesional, or systemic treatment with corticosteroids. All horses were treated with ivermectin.
Conclusions and Clinical Relevance—Results suggest that cutaneous and ocular habronemiasis should be considered when examining a horse during the summer months with a proliferative, moist, granulomatous lesion. Treatment should be aimed at decreasing the size of the lesion, reducing inflammation, and preventing recurrence. In general, the prognosis was good, and healing occurred within a few weeks. Fly control and regular deworming with ivermectin are recommended to reduce the incidence of habronemiasis. (J Am Vet Med Assoc 2003;222: 978–982)
Abstract
Objective—To evaluate clinical findings, complications, and outcome of horses and foals with third metacarpal, third metatarsal, or phalangeal fractures that were treated with transfixation casting.
Design—Retrospective case series.
Animals—29 adult horses and 8 foals with fractures of the third metacarpal or metatarsal bone or the proximal or middle phalanx.
Procedures—Medical records were reviewed, and follow-up information was obtained. Data were analyzed by use of logistic regression models for survival, fracture healing, return to intended use, pin loosening, pin hole lysis, and complications associated with pins.
Results—In 27 of 35 (77%) horses, the fracture healed and the horse survived, including 10 of 15 third metacarpal or metatarsal bone fractures, 11 of 12 proximal phalanx fractures, and 6 of 8 middle phalanx fractures. Four adult horses sustained a fracture through a pin hole. One horse sustained a pathologic unicortical fracture secondary to a pin hole infec-tion. Increasing body weight, fracture involving 2 joints, nondiaphyseal fracture location, and increasing duration until radiographic union were associated with horses not returning to their intended use. After adjusting for body weight, pin loosening was associated with di-aphyseal pin location, pin hole lysis was associated with number of days with a transfixation cast, and pin complications were associated with hand insertion of pins.
Conclusions and Clinical Relevance—Results indicated that transfixation casting can be successful in managing fractures distal to the carpus or tarsus in horses. This technique is most suitable for comminuted fractures of the proximal phalanx but can be used for third metacarpal, third metatarsal, or middle phalanx fractures, with or without internal fixation.
