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One Horse (one + horse)
Selected AbstractsDiagnosis and surgical treatment of epidural neoplasms in two ataxic horsesEQUINE VETERINARY EDUCATION, Issue 11 2009J. E. Hirsch Summary Two cases of ataxia caused by epidural neoplasia diagnosed with myelography and histopathology are presented in this report. One horse was diagnosed with lymphohistiocytic lymphosarcoma and the other with haemangiosarcoma. In both cases, subtotal dorsal decompression was performed as part of their treatment protocol. One horse was subjected to euthanasia immediately after surgery; however, the other horse recovered well, with no gait abnormalities and a normal myelographic dye column seen at 6 months post surgery. Although both horses were ultimately subjected to euthanasia, subtotal dorsal decompression provides a potential surgical treatment for epidural neoplasia. [source] Arthroscopic reattachment of osteochondritis dissecans lesions using resorbable polydioxanone pinsEQUINE VETERINARY JOURNAL, Issue 5 2004A. J. NIXON Summary Reasons for performing study: Debridement of osteochondritis dissecans (OCD) cartilage lesions results in fibrocartilage and imperfect hyaline repair tissue, and forms a permanent irregularity to the subchondral bone plate. Objective: To evaluate the clinical, radiographic and outcome effects of OCD cartilage flap reattachment for select lesions as an alternative to OCD debridement. Hypothesis: Separated cartilage flaps resulting from OCD lesions may be re-incorporated into the hyaline cartilage surface by reattachment rather than debridement and removal. Methods: Resorbable polydioxanone pins were used to reattach OCD flap lesions in 16 joints of 12 horses. Criteria for attachment, rather than removal, included an unmineralised cartilage flap on preoperative radiographs and a relatively smooth surface with some residual perimeter attachment at surgery. Results: There were 12 subjects, 6 males and 6 females, 7 Thoroughbred or Standardbred weanlings, 3 Warmbloods, 1 Arabian and 1 Quarter Horse, mean age at surgery 6.8 months. All horses had effusion of the affected femoropatellar joint (n = 9), tarsocrural joint (n = 1) or fetlock (n = 2). Radiographic lesions varied in length between 1.8,6.3 cm; reattachment was used in 16 of 18 affected joints and the OCD cartilage was not satisfactory for salvage in 2 stifles. Number of pins required was 2,10. One horse was subjected to euthanasia due to a tendon laceration 8 weeks after surgery; of the remaining 11 horses, mean duration of follow-up was 3.9 years (range 4 months-8 years). Nine of these were sound and had entered work, while 2 were sound but remained unbroken 4 and 6 months post operatively, respectively. Radiographic resolution of the OCD lesion occurred in 14 of 16 pinned joints in the 9 horses with long-term follow-up. The 2 remaining joints had a 3 and a 5 mm mineralised flap in the original defect sites. Conclusions: This study indicated cartilage flap reattachment was an alternative to removal in selected OCD lesions. Potential relevance: Relatively smooth OCD cartilage flaps may be salvaged by reattachment and can result in normal radiographic subchondral contour and a high likelihood of athletic performance. Further case numbers are required to determine which lesions are too irregular or contain too much mineral for effective incorporation after reattachment. [source] Electromyographic and kinematic indicators of fatigue in horses: a pilot studyEQUINE VETERINARY JOURNAL, Issue S33 2001G. R. COLBORNE Summary Muscle fatigue can be quantified using Fourier analysis of the recorded EMG signal. Median frequency is the frequency at which the Fourier profile is bisected, and this measure typically shifts to smaller values during fatigue. This technique was combined with kinematic analysis to describe the time course of fatigue in horses galloping on an inclined treadmill. It was hypothesised that EMG median frequency would decrease in tandem with changes in kinematic variables through the exercise test. Three fit Thoroughbred horses had retroreflective markers placed on their hooves and withers. Surface electrodes were attached to the skin over the forelimb deltoid muscle. After warm-up at walk and trot, each horse galloped at 110% VO2max on a treadmill inclined to 7.5% until fatigue onset. Kinematic data were recorded at 200 Hz for 5 s at 30s intervals, and raw EMG data were recorded at 1024 Hz for 3 s at 15 s intervals. Fatigue onset was the point in time when the horse could not keep up with the treadmill speed with minimal encouragement. One horse performed the entire exercise test on the same lead, while the other 2 horses changed leads periodically, interrupting the changes in both the EMG and kinematic measurements. Overall, through the course of the trials, mean stride length increased by 0.34 m and stride duration increased by 0.03 s. Vertical excursion of the trunk marker increased by 0.03 m. For the horse that did not change lead, median frequency of the EMG signal decreased by 36%. In the other 2 horses, lead changes were interspersed between smaller decreases in median frequency, whereupon median frequency recovered to starting levels immediately following a lead change. The median frequency decreased by 12-20% between lead changes. Kinematic changes are more global indictors of fatigue, while the EMG indicators are dependent upon lead changes. [source] Considerations for pacing of the cricoarytenoid dorsalis muscle by neuroprosthesis in horsesEQUINE VETERINARY JOURNAL, Issue 6 2010N. G. DUCHARME Summary Reasons for performing study: The success rate of prosthetic laryngoplasty is limited and may be associated with significant sequelae. Nerve muscle pedicle transplantation has been attempted but requires a year before function is restored. Objective: To determine the optimal parameters for functional electrical stimulation of the recurrent laryngeal nerve in horses. Methods: An experimental in vivo study was performed on 7 mature horses (2,21 years). A nerve cuff was placed on the distal end of the common trunk of the recurrent laryngeal nerve (RLN). In 6 horses the ipsilateral adductor branch of RLN was also transected. The electrodes were connected to programmable internal stimulator. Stimulation was performed using cathodic phase and then biphasic pulses at 24 Hz with a 0.427 ms pulse duration. Stimulation-response experiments were performed at monthly intervals, from one week following implantation. The study continued until unit failure or the end of project (12 months). Two of the horses were stimulated continuously for 60 min to assess onset of fatigue. Results: Excellent arytenoid cartilage abduction (mean arytenoid angle of 52.7°, range 48.5,56.2°) was obtained in 6 horses (laryngeal grades I or II (n = 3) and III (n = 2). Poor abduction was obtained in grade IV horses (n = 2). Arytenoid abduction was maintained for up to a year in one horse. Technical implant failure resulted in loss of abduction in 6 horses at one week to 11 months post operatively. Mean tissue impedance was 1.06 kOhm (range 0.64,1.67 kOhm) at one week, twice this value at 2 months (mean 2.32, range 1.11,3.75 kOhm) and was stable thereafter. Maximal abduction was achieved at a stimulation range of 0.65,7.2 mA. No electrical leakage was observed. Constant stimulation of the recurrent laryngeal nerve for 60 min led to full abduction without evidence of muscle fatigue. Conclusions: Functional electrical stimulation of the recurrent laryngeal nerve leading to full arytenoid abduction can be achieved. The minimal stimulation amplitude for maximal abduction angle is slightly higher than those for man and dogs. Clinical relevance: This treatment modality could eventually be applicable to horses with recurrent laryngeal neuropathy. [source] Endurance exercise is associated with increased plasma cardiac troponin I in horsesEQUINE VETERINARY JOURNAL, Issue S36 2006T. C. HOLBROOK Summary Reason for performing study: Information is lacking regarding the influence of long distance exercise on the systemic concentration of cardiac troponin I (cTnl) in horses. Objectives: To determine if the concentration of cTnl in horses competing in 80 and 160 km endurance races increases with exercise duration and if cTnl concentrations can be correlated with performance data. Methods: Blood samples for the measurement of cTnl and 3 min electrocardiogram recordings were obtained from horses prior to, during and after completion of 80 and 160 km endurance races at 3 ride sites during the 2004 and 2005 American Endurance Ride Conference competition seasons. Results: Full data sets were obtained from 100 of the 118 horses. Endurance exercise was associated with a significant increase in cTnl over baseline in both distance groups. Failure to finish competition (poor performance) was also associated with an increased cTnl concentration over baseline at the time of elimination when data from both distances were combined. Other than one horse that developed paroxysmal atrial fibrillation, no arrhythmias were noted on the 3 minute ECG recordings that were obtained after endurance exercise in either distance group. Conclusions: Systemic concentrations of cTnl increase in endurance horses competing in both 80 and 160 km distances. Although final cTnl concentrations were significantly increased over their baseline values in horses that failed to finish competition, the degree of increase was not greater than the increase over baseline seen in the horses that successfully completed competition. The clinical significance of increased cTnl in exercising horses could not be ascertained from the results of this study. Potential relevance: These data indicate that cardiac stress may occur in horses associated with endurance exercise. Future studies utilising echocardiograpy to assess cardiac function in horses with increased cTnl are warranted. [source] Transmission of Ehrlichia risticii, the agent of Potomac horse fever, using naturally infected aquatic insects and helminth vectors: preliminary reportEQUINE VETERINARY JOURNAL, Issue 4 2000J. E. Madigan Summary Ehrlichia risticii, the agent of Potomac horse fever (PHF), has been recently detected in trematode stages found in snail secretions and in aquatic insects. Based on these findings, horses could conceivably be exposed to E. risticii by skin penetration with infected cercariae, by ingestion of infected cercariae in water or via metacercariae in a second intermediate host, such as an aquatic insect. In order to test this hypothesis, horses were challenged with infectious snail secretions and aquatic insects collected from a PHFendemic region in northern California. Two horses stood with their front feet in waterharbouring E. risticii -infected cercariae, 2 horses drank water harbouring E. risticii -infected cercariae, and 6 horses were fed pools of different aquatic insects harbouring E. risticii -infected metacercariae. In this preliminary study, only the one horse infected orally with mature caddisflies (Dicosmoecus gilvipes) developed the clinical and haematological disease syndrome of PHF. The agent was isolated from the blood of the infected horse in a continuous cell line and identified as E. risticii by characterisation of the 16S rRNA gene. Therefore, E. risticii is maintained in nature in a complex aquatic ecosystem and transmission to horses can occur through accidental ingestion of insects such as caddisflies containing infected metacercariae. At present, the small number of horses used in this study does not exclude other insects and free trematode stages as potential sources of infection. [source] Wounds of the pastern and foot region managed with phalangeal casts: 50 cases in 49 horses (1995,2006)AUSTRALIAN VETERINARY JOURNAL, Issue 9 2009KM Ketzner Objective Describe the use of a phalangeal cast as treatment for wounds in the pastern and foot region of horses. Secondly, to evaluate the healing and soundness of horses treated with phalangeal casts. Design Retrospective study of 49 horses. Procedures Medical records of 49 horses that were treated with a phalangeal cast for 50 cases of wounds in the pastern and foot region at equine referral hospitals from 1995 to 2006 were reviewed and follow-up information was obtained. Results Treatment consisted of wound debridement, lavage, wound closure (28 wounds), cast application and antibiotics (84%). At follow-up, the majority of horses were sound (42 of 47 wounds, 89.4%), three horses were still lame and one horse was euthanased because of persistent lameness. Three horses were lost to follow-up. There was no statistical difference between the outcomes of horses treated acutely (<24 h) or after a 24-h delay. Similarly, the involvement of synovial structures in the wound did not significantly influence outcome. Conclusions In this study, wounds involving the pastern and foot that were treated with a phalangeal cast carried a good prognosis for soundness (89.4%) and cosmetic healing (89.5%). The phalangeal casts were well-tolerated and effective. [source] Detection of viruses in nasal swab samples from horses with acute, febrile, respiratory disease using virus isolation, polymerase chain reaction and serologyAUSTRALIAN VETERINARY JOURNAL, Issue 1-2 2007K Dynon Objective To examine the association of viruses with acute febrile respiratory disease in horses. Design Nasal swab and serum samples were collected from 20 horses with acute febrile upper respiratory disease that was clinically assessed to have a viral origin. Methods Each of the samples was inoculated onto equine fetal kidney, RK13 and Vero cell cultures, and viral nucleic acid was extracted for polymerase chain reaction (PCR) or reverse transcription PCR. PCR primers were designed to amplify nucleic acid from viruses known to cause or be associated with acute febrile respiratory disease in horses in Australia. A type specific ELISA was used to measure equine herpesvirus (EHV1 and EHV4) antibody, and serum neutralisation assays were used to measure equine rhinitis A virus (ERAV) and equine rhinitis B virus 1 and 2 (ERBV1 and ERBV2) antibody titres in serum samples. Results Virus was isolated from 4 of 20 nasal swab samples. There were three isolations of EHV4 and one of ERBV2. By PCR, virus was identified in the nasal swab samples of 12 of the 20 horses. Of those that were positive, 17 viruses were detected as follows: one triple positive (EHV4, EHV2, and EHV5), three double positives (EHV4, ERBV and EHV2, EHV5 in two horses) and eight single positives (EHV4 in two horses, EHV2 in one horse, EHV5 in six horses and ERBV in six horses). Conclusion By virus isolation and PCR, 17 viruses were identified in nasal swab samples from 12 of 20 horses that had acute febrile respiratory disease consistent with a diagnosis of virus infection. Initial PCR identification and subsequent virus isolation led to the isolation of ERBV2 for the first time in Australia and the second time anywhere of ERBV2. [source] | ||||||||||