Equine veterinary journal. Supplement最新文献

Reasons for performing study: Maggot debridement therapy is a long-established tool to promote wound healing.

Objectives: To describe and assess the results of this technique in equids with various lesions.

Methods: Retrospective analysis performed on cases in which, depending on clinical case, type, size and location of the wound, maggots were applied either in direct or indirect contact with the wound.

Results: Treated cases (n = 41) included horses with foot pathology (n = 9), laceration of the limbs (n = 15), other soft tissue abscesses or wounds (n = 6), fistulous withers (n = 5), other musculoskeletal infection (n = 2) and dehiscence of the linea alba (n = 4). In 5 cases, a second maggot application was necessary to reach the desired level of wound healing. In 38 cases a favourable outcome was reached in less than one week. In one individual with a sequestrum, healing was uneventful after its removal. In 2 other horses, squamous cell carcinoma and melanoma were involved in chronic infected wounds and complete healing was not achieved because of recurrence of underlying tumours. Some discomfort was recorded in 7 individuals between 24 and 72 h of treatment.

Conclusions: Maggot debridement therapy can be recommended in equids for debridement and enhanced healing and its potent antibacterial action. Maggot debridement therapy is not recommended on wounds invaded with a tumour and if bone sequestration is suspected.

Potential relevance: Maggot debridement therapy can be an integral part of modern wound care in equids.

Reasons for performing study: Definitive ante mortem diagnosis of pancreatitis in horses is difficult. Reports summarising the most common clinical signs, clinicopathological features and concurrent disorders in horses with a definitive diagnosis of pancreatitis that may aid in the recognition of disease are lacking.

Objectives: To describe case details, clinical signs, clinicopathological data and necropsy findings in horses with a definitive diagnosis of pancreatitis.

Methods: This was a retrospective study (1986-2011) and inclusion criteria consisted of horses with a definitive diagnosis of pancreatitis. A medical records database search was performed and data extracted included case details, clinical signs, clinical laboratory data and post mortem findings. Pancreatitis was defined as acute, active chronic or chronic and presumed primary or secondary, based on postmortem findings.

Results: Pancreatitis was diagnosed in 43 horses (acute pancreatitis in 34, active chronic in 4 and chronic in 5). A presumed diagnosis of primary pancreatitis was made in 6 horses. Pancreatitis was associated with gastrointestinal disorders in 28 horses (14 large colon, 10 small intestine and 4 gastric ruptures) and primary hepatic disease in 3 horses. Six horses had pancreatitis associated with other disorders: multiple endocrine neoplasia syndrome (one horse), strychnine toxicosis (one horse) and compromised immune system (4 horses).

Conclusion: Pancreatitis is an uncommon disorder that can occur as a primary problem or secondary to gastrointestinal, hepatic or immunocompromising disorders, and when it occurs it affects adult horses more commonly.

Potential relevance: Unexplained abdominal pain, gastric dilation or rupture, peritonitis and/or the presence of white fibrinous plaques and fat necrosis in the peritoneum and mesentery or mass-like structures in the root of the mesentery during an exploratory celiotomy should raise a suspicious of pancreatitis.

Reasons for performing study: Osseous resorption of the flexor surface of the distal phalanx of the horse has been identified previously using magnetic resonance (MR) imaging; however, little is known about the prevalence and characteristics of this lesion.

Objectives: To establish the MR prevalence of resorptive lesions in the flexor surface of the distal phalanx and identify concurrent lesions associated with this finding and associations between the MR and radiographic findings.

Methods: Horses with distal extremity MR and radiographs performed within 2 weeks of each other were included in the study. The flexor surface of the distal phalanx was graded independently on both modalities for the presence of osseous resorption. The sensitivity and specificity of radiography for identifying osseous resorption was calculated using MR as the gold standard.

Results: Eighty-two MR studies met the inclusion criteria, 8 of which included osseous resorption of the flexor surface of the distal phalanx. Concurrent injury to the deep digital flexor tendon and the navicular bone was a common finding. An association between MR and radiographic grades was identified. Radiography had a high specificity (0.96) but lower sensitivity (0.45-0.55) for detecting osseous resorption.

Conclusions: Osseous resorption of the flexor surface of the distal phalanx can be observed both on MR and radiographic examinations of horses with lameness localised to the foot. This lesion is most often associated with other pathological changes in the podotrochlear apparatus.

Potential relevance: Focal radiolucency of the flexor surface of the distal phalanx is a newly recognised radiographic sign associated with pathological changes of the podotrochlear apparatus.

Reasons for performing study: Serum amyloid A (SAA) in synovial fluid has recently been used as a marker for septic arthritis in horses but the effects of repeated intra-articular (IA) administration of amikacin on synovial SAA concentrations are unknown.

Objectives: To report the effect of repeated IA administration of amikacin on SAA, total protein (TP), nucleated cell count (NCC) and differential NCC in synovial fluid of healthy equine joints.

Methods: A controlled, 2 period crossover study was performed on 5 clinically healthy horses. Each intercarpal joint received one of 2 treatments every 48 h for 5 consecutive times: arthrocentesis alone (control group) or arthrocentesis combined with IA administration of 500 mg of amikacin (treatment group). Clinical and lameness examinations were performed daily. Serum SAA and synovial SAA, TP, NCC and differential NCC were measured and statistically compared. Significance level was set at P < 0.05.

Results: Horses remained healthy and nonlame throughout the study. Baseline values for all variables were not significantly different between groups. Values for TP in the treatment group were significantly higher than in the control group after the first sample (P < 0.05). In both groups NCC increased significantly (P < 0.05) after the first sample. No significant changes were identified in differential NCC. In both groups, all synovial and most serum SAA concentrations remained below the lower limit of quantification.

Conclusions: Repeated IA administration of amikacin caused increased values of TP and NCC in synovial fluid, with some TP concentrations falling within the range reported for septic arthritis. In contrast, synovial SAA concentrations did not increase in either group.

Potential relevance: Synovial SAA could serve as a more reliable marker than TP and NCC when evaluating a joint previously sampled or treated with amikacin.

Reasons for performing study: Selenium and vitamin E deficiency have been associated with nutritional myopathy, more commonly known as white muscle disease (WMD) in horses. However, correlations between selenium concentrations and presenting clinical signs, age, breed, gender, serum vitamin E, creatine kinase (CK) and final diagnosis, have not previously been evaluated.

Objectives: To determine the number of hospitalised horses in 3 age groups that were selenium tested and the proportions of horses with categorised presenting clinical signs; the association/odds risk of final diagnosis with selenium deficiency and to examine the association between selenium status, vitamin E status and serum CK in adult horses.

Methods: Two hundred and seventy-one hospitalised horses with a selenium concentration evaluated between 1996 and 2011 were examined retrospectively. Records were examined in order to ascertain selenium and vitamin E concentrations, age, breed, gender, CK values, presenting clinical signs and final diagnosis. Data were analysed with proportions, Fisher's exact t test, odds ratios and multivariate linear regressions.

Results: Within the < 30 day old age group, 13/20 animals had low selenium concentrations. There were 18/42 horses in the 30 days to 2 years old age group with low selenium and 77/209 horses more than 2 years of age with low selenium. There was an association between low selenium and myopathy in the < 30-day-old animals (P = 0.017), all of which were classified as having WMD. No associations were identified between nutritional myopathy and selenium status in horses between 30 days and 2 years of age or in horses more than 2 years of age.

Conclusions and potential relevance: This study indicates that WMD occurs most commonly in foals < 30 days old and is associated with low selenium concentrations (7 out of 8 affected foals had blood Selenium levels < 1.26 microm/l). Low serum selenium concentrations are common in hospitalised adult horses while nutritional myopathy is rare in these animals.

Reasons for performing study: Acquired equine polyneuropathy (AEP, also known as 'Scandinavian knuckling syndrome'), is a serious disease of unknown aetiology, which emerged clustering in horse farms in Sweden, Norway and Finland in the 1990s. Clinical and epidemiological data regarding the syndrome are scarce.

Objectives: To describe the clinical and epidemiological findings and outcome in outbreaks of AEP and compare risk factors in affected and unaffected horses on affected farms in Norway and Sweden during 2007-2009.

Methods: Neurological examinations were performed and data collected regarding demography, usage, turning-out, feeding, prophylactic strategies and long-term outcome.

Results: Thirteen affected farms with 157 horses of various breeds, of which 42 were AEP cases, were studied. Typical digital extensor dysfunction and knuckling of pelvic limbs were noted in 34 definitive cases. Eight additional plausible cases had a severe, acute course of neurological disease. There were no signs of brain orcranial nerve dysfunction. Cases occurred from December to April, with new cases emerging within 100 days of the index case. Affected and unaffected horses were fed wrapped forage. Prevalence for AEP was 27% and case fatality 29%. The median duration of AEP in survivors was 4.4 months (1-17 months). Survivors returned to full work within 19 months (median 6.6 months). Acquired equine polyneuropathy was less prevalent in horses aged > 12 years and young horses had a higher chance of survival than older horses. Management factors did not differ between affected and unaffected horses.

Conclusions: Acquired equine polyneuropathy is a potentially fatal neurological disease characterised by pelvic limb knuckling. Surviving horses returned to normal function after a long period of rest. Cases were clustered in farms during the winter/spring season. Wrapped forage was used in all farms.

Potential relevance: The results provide valuable insights into the dinical examination, handling and prognosis of cases of AEP, an emerging neurological disease of unknown aetiology in horses.

Reasons for performing study: We wanted to investigate the visual outcome of horses presented with iris prolapse and treated with corneal transplantation.

Objective: To evaluate the visual outcome of horses with iris prolapse treated with penetrating keratoplasty alone and penetrating keratoplasty in combination with overlying conjunctival or amniotic membrane grafting.

Methods: A retrospective medical records study of horses presented to the University of Florida Veterinary Medical Center for iris prolapse and treated with penetrating keratoplasty in the period of 1998-2010. Data collected from the medical records included signalment, clinical descriptions of ocular lesions, treatments, and therapeutic outcome.

Results: Iris prolapses in this study were caused by corneal ulcers with keratomalacia (n = 37). All horses were treated medically for infection, hyperproteinase activity and iridocyclitis, and then surgically treated with either penetrating keratoplasty alone (n = 9) or penetrating keratoplasty with either a conjunctival pedicle flap (n = 22), amniotic membrane transplant (n = 5) or amnion membrane and conjunctival pedicle flap (n = 1). The eyes were visual postoperatively in a majority of the cases (n = 24; 64.9%). Limited vision was noted in 6 eyes (16.2%), 3 eyes became phthisical (8.1%) and 4 globes were enucleated (10.8%). Graft rejection manifested as some degree of donor corneal graft opacification in all cases. Anterior synechiae were present in 48.6% of the eyes. Wound dehiscence and aqueous humour leakage were also common as post operative problems.

Conclusion: Penetrating keratoplasty alone or in combination with an overlying graft of conjunctiva or amniotic membrane can achieve a successful visual outcome in a high percentage of horses with iris prolapse.

Reasons for performing study: A commonly used commercial extender (i.e. INRA 96) contains antimicrobials that may have limited effectiveness. Therefore, addition of ticarcillin-clavulanic acid to this extender is a widespread procedure in the equine breeding industry in the United States. However, such practice has not been critically evaluated.

Objectives: To evaluate the addition of ticarcillin-clavulanic acid to INRA 96 and different extender and antimicrobial storage conditions on sperm function and antimicrobial effectiveness.

Methods: Gel-free semen (42 ejaculates from 14 mature Quarter Horse stallions) was extended with INRA 96 and stored for 24 h in an Equitainer II. The effects of added ticarcillin-clavulanic acid and different extender storage procedures on sperm motion characteristics (by computer-assisted analysis), sperm membrane integrity (by fluorescence-based measurement) and suppression of bacterial growth (by aerobic and anaerobic culture methods) were evaluated using analysis-of-variance and Chi-square statistical methods. The P value for significance was set at < 0.05.

Results: Freezing and thawing of modified or unmodified extender prior to use for stallion semen resulted in reduced sperm quality post cooling for 24 h, as evidenced by a significant reduction in sperm motility (i.e. total and progressive) and sperm membrane integrity. Addition of ticarcillin-clavulanic acid to extender resulted in higher sperm velocity when the reconstituted antimicrobial was subjected to cooled storage, as compared with frozen storage, prior to use. Only 28 of 42 ejaculates (67%) yielded presence of bacteria in neat semen but addition of ticarcillin-clavulanic acid to INRA 96 was not different than INRA 96 alone for inhibiting growth of bacteria (98 vs. 94%, respectively).

Conclusions: Addition of ticarcillin-clavulanic acid (1 mg/ml) to INRA 96 did not adversely affect sperm quality in extended semen after cooled storage. Extender freezing and thawing prior to use had detrimental effects on sperm quality.

Potential relevance: These data suggest that INRA 96 should not be frozen and thawed prior to use. Addition of ticarcillin-clavulanic acid to INRA 96 did not impair sperm quality. All extender treatments effectively controlled the bacterial growth compared with neat semen.

Reasons for performing study: Management decisions on unilateral orchiectomy are often influenced by the potential for post operative return to successful breeding. The effects of 2 surgical methods (first intention [FI] vs. second intention [SI] incision healing) for unilateral orchiectomy on resulting semen quality and scrotal temperature were evaluated.

Objective: To evaluate the effects of 2 surgical unilateral orchiectomy techniques on scrotal healing, size of the remaining testis and post operative sperm quality.

Materials and methods: Unilateral orchiectomy was performed on mature Miniature Horse stallions. Semen was collected prior to and up to 60 days after, unilateral orchiectomy. Semen parameters, scrotal and body temperatures, testis volume and days to incision healing were evaluated.

Results: There was no effect of treatment or time on percent total sperm motility. Total sperm numbers were higher (P < 0.05) 60 days after unilateral orchiectomy compared with 14 and 30 days. Percent viable sperm were higher (P < 0.05) 30 and 60 days compared with pre- and 14 day post unilateral orchiectomy. Scrotal temperatures were lower after unilateral orchiectomy compared with preoperative values ( < or = 0.003). Higher scrotal temperatures were recorded in Group IF, as compared with Group IS, during recoveryfrom anaesthesia and at 1 and 2 h after surgery (P = 0.02). Mean time to incision healing was less in Group II (10.0 days) than in Group II (21.5 days; P = 0.05).

Conclusion: In this study, total sperm motility was maintained and size of the remaining testis, total sperm numbers and percent viable sperm increased after unilateral orchiectomy. Incision healing time was shorter in Group II; however, surgical technique did not have an effect on semen quality at 30 and 60 days post unilateral orchiectomy.

Potential relevance: These data suggest that surgical technique for unilateral orchiectomy may not dramatically influence function of the remaining testis.