Isabelle Kilcoyne

Incidence, management, and outcome of complications of castration in equids: 324 cases (1998–2008)

OBJECTIVE To determine the incidence of complications and identify risk factors associated with development of complications following routine castration of equids. DESIGN Retrospective case series. Animals-311 horses, 10 mules, and 3 donkeys. PROCEDURES Medical records of equids undergoing routine castration were reviewed. Age, breed, surgical techniques (closed vs semiclosed castration and use of ligatures), anesthesia method (general IV anesthesia vs standing sedation with local anesthesia) and repeated administration of IV anesthetic agents, administration of antimicrobials and anti-inflammatory drugs, and details regarding development, management, and outcome of complications were recorded. Odds ratios and 95% confidence intervals were determined. Associations between additional doses of anesthetic agents during surgery and development of complications were analyzed with a Jonckheere-Terpstra test. RESULTS 33 of 324 (10.2%) equids developed a complication after surgery; 32 recovered and 1 was euthanized because of eventration. Equids that underwent semiclosed castration had significantly higher odds of developing a complication (OR, 4.69; 95% confidence interval, 2.09 to 10.6) than did those that underwent closed castration. Equids that received additional doses of anesthetic agents to maintain adequate general anesthesia developed complications more frequently than those that did not require this treatment. CONCLUSIONS AND CLINICAL RELEVANCE Incidence of complications was low, and most evaluated variables were not significantly associated with development of complications following castration in equids. However, findings suggested that the choice of surgical technique (closed vs semiclosed) is an important factor in this regard. Future studies should investigate whether duration of surgery is associated with complications following castration in equids.

Frequency of Corynebacterium pseudotuberculosis infection in horses across the United States during a 10-year period

OBJECTIVE To quantify the number of horses with Corynebacterium pseudotuberculosis infection identified in the United States from January 2003 through December 2012. DESIGN Cross-sectional study. SAMPLE State veterinary diagnostic laboratory records of 2,237 C pseudotuberculosis culture-positive samples from horses. PROCEDURES 44 state veterinary diagnostic laboratories throughout the United States were invited by mail to participate in the study. Data requested included the number of C pseudotuberculosis culture-positive samples from horses identified per year, geographic location from which the C pseudotuberculosis culture-positive sample was submitted, month and year of sample submission, breed and age of horses, and category of clinical manifestation (ie, internal infection, external infection, or ulcerative lymphangitis). RESULTS Of the 44 invited laboratories, 15 agreed to participate and provided data on affected horses from 23 states. The proportion of C pseudotuberculosis culture-positive samples submitted during 2011 through 2012 (1,213/2,237 [54%]) was significantly greater than that for the period from 2003 through 2010 (1,024/2,237 [46%]). Corynebacterium pseudotuberculosis was recovered from horses in states where the disease has not been previously recognized as endemic. Affected horses were identified year-round. The greatest proportion of C pseudotuberculosis culture-positive samples was identified during November, December, and January (789/2,237 [35%]). No significant association between the clinical form of disease and age or breed of horse was observed. CONCLUSIONS AND CLINICAL RELEVANCE The occurrence of C pseudotuberculosis infection in horses increased during the 10-year period, and affected horses were identified throughout the United States. Further studies to determine changes in annual incidence and to identify potential changing climatic conditions or vector populations associated with disease transmission are warranted to help control the occurrence and spread of C pseudotuberculosis infection in horses.

Penetrating injuries to the frog (cuneus ungulae) and collateral sulci of the foot in equids: 63 cases (1998-2008)

Objective-To determine the outcome of penetrating injuries to the central region of the foot in equids and identify factors that may affect treatment and outcome. Design-Retrospective case series. Animals-63 equids (61 horses, 1 pony, and 1 mule). Procedures-Records of equids incurring puncture wounds through the frog (cuneus ungulae) or collateral sulci of the foot between 1998 and 2008 were reviewed. Evaluated factors that were hypothesized to affect outcome included signalment, degree of lameness, foot affected, duration between injury and admission, and treatment. Injuries were graded from 1 (< 1 inch; involving superficial corium only) to 4 (involving a synovial structure) on the basis of severity of penetration as determined by radiographic evidence or findings on synoviocentesis at the time of admission. Results-Overall, 60% (38/63) of equids returned to soundness. Thirteen equids were euthanized on the basis of synovial structure involvement and financial constraints. Of 35 equids that were treated conservatively, which may have included undergoing a surgical procedure with the horse standing, 32 (91.4%) returned to their previous level of soundness. Fifteen equids underwent surgical treatment under general anesthesia, of which 6 (40%) became sound for intended use. Ten of 34 (29%) equids with synovial structure involvement regained soundness. Equids treated earlier after injury had a better prognosis. Equids with a hind foot injury had a more favorable outcome than those with a forefoot injury. Conclusions and Clinical Relevance-Results suggested that penetrating injuries located centrally in the foot of equids without involvement of a synovial structure have a favorable prognosis, especially if managed early. Penetration of a synovial structure provided a poor prognosis.

A Preliminary Study of Silver Sodium Zirconium Phosphate Polyurethane Foam Wound Dressing on Wounds of the Distal Aspect of the Forelimb in Horses

OBJECTIVE To determine if application of silver sodium zirconium phosphate polyurethane semi-occlusive foam (SPF) dressing would improve measures of wound healing and decrease bacterial contamination compared with a non-adherent, absorbent dressing applied to wounds created on the distal aspect of the equine limb. STUDY DESIGN Controlled randomized experimental study. ANIMALS Adult Quarter Horse and Thoroughbred horses (n = 5). METHODS One 6.25 cm(2) wound was created on the dorsomedial aspect of the proximal metacarpus on each forelimb. A SPF dressing was applied to 1 randomly assigned limb as a treatment and a non-adherent, absorbent dressing was applied to the opposite limb as control. Bandages were changed every 3 days for 60 days. Granulation tissue was scored every 3 days, wound area measured every 6 days, and wound bed was cultured every 12 days. RESULTS SPF-treatment wounds had significantly decreased wound area and decreased granulation tissue scores when evaluated <30 days and over the 60 day study, although complete wound healing times were not significantly different. Bacteria were cultured from all wounds at varying times throughout the study. CONCLUSIONS The SPF wound dressing improved some measures of wound healing compared with the control dressing, most significantly during the first 30 days. This suggests that the SPF wound dressing may be useful in the early management of wounds on the equine lower limb. Further studies using the SPF dressing are needed to characterize the temporal and cellular effects on wound healing and evaluate this dressing in a clinical environment.Objective To determine if application of silver sodium zirconium phosphate polyurethane semi-occlusive foam (SPF) dressing would improve measures of wound healing and decrease bacterial contamination compared with a non-adherent, absorbent dressing applied to wounds created on the distal aspect of the equine limb. Study Design Controlled randomized experimental study. Animals Adult Quarter Horse and Thoroughbred horses (n = 5). Methods One 6.25 cm2 wound was created on the dorsomedial aspect of the proximal metacarpus on each forelimb. A SPF dressing was applied to 1 randomly assigned limb as a treatment and a non-adherent, absorbent dressing was applied to the opposite limb as control. Bandages were changed every 3 days for 60 days. Granulation tissue was scored every 3 days, wound area measured every 6 days, and wound bed was cultured every 12 days. Results SPF-treatment wounds had significantly decreased wound area and decreased granulation tissue scores when evaluated <30 days and over the 60 day study, although complete wound healing times were not significantly different. Bacteria were cultured from all wounds at varying times throughout the study. Conclusions The SPF wound dressing improved some measures of wound healing compared with the control dressing, most significantly during the first 30 days. This suggests that the SPF wound dressing may be useful in the early management of wounds on the equine lower limb. Further studies using the SPF dressing are needed to characterize the temporal and cellular effects on wound healing and evaluate this dressing in a clinical environment.

Clinical findings and management of 153 horses with large colon sand accumulations

Objective To determine the influence of radiographic quantification of sand accumulation on the medical versus surgical management of large colon sand accumulations. To compare short- and long-term outcomes and complications associated with medical and surgical management of these horses. Study design Retrospective. Sample population A total of 153 horses. Methods Medical records and abdominal radiographs of horses presented for colic between 2004 and 2014 were reviewed. Severity of sand accumulation was quantified by tracing and measuring a region of interest with a commercial software program. Breed, weight, amount of sand, presence of diarrhea at presentation, treatment, and the development of complications were recorded. Results Records from 153 horses were reviewed. The mean cross-sectional area of sand accumulation was 692.9 cm2 (median = 658.7 cm2, 84.6-1780.7 cm2). Increased accumulation of gas on radiographs and abnormal transrectal examination findings were associated with an increased likelihood of surgery. The most common complication was the development of diarrhea (20.3%) with only 4 (2.6%) horses positive for Salmonella spp. Horses had a favorable prognosis, with 94.8% of horses treated medically and 94.7% of those treated surgically surviving to discharge. Conclusion Increased accumulation of gas on radiographs and transrectal palpation of impaction or intestinal gas distension increase the likelihood of surgery. Both medical and surgical treatments carry a good prognosis. Clinical relevance The sheer quantity of sand is not a factor when determining surgical intervention. Attention should be paid to the presence of increased gas accumulation on rectal or radiographic examination.OBJECTIVE To determine the influence of radiographic quantification of sand accumulation on the medical versus surgical management of large colon sand accumulations. To compare short- and long-term outcomes and complications associated with medical and surgical management of these horses. STUDY DESIGN Retrospective. SAMPLE POPULATION A total of 153 horses. METHODS Medical records and abdominal radiographs of horses presented for colic between 2004 and 2014 were reviewed. Severity of sand accumulation was quantified by tracing and measuring a region of interest with a commercial software program. Breed, weight, amount of sand, presence of diarrhea at presentation, treatment, and the development of complications were recorded. RESULTS Records from 153 horses were reviewed. The mean cross-sectional area of sand accumulation was 692.9 cm2 (median = 658.7 cm2 , 84.6-1780.7 cm2 ). Increased accumulation of gas on radiographs and abnormal transrectal examination findings were associated with an increased likelihood of surgery. The most common complication was the development of diarrhea (20.3%) with only 4 (2.6%) horses positive for Salmonella spp. Horses had a favorable prognosis, with 94.8% of horses treated medically and 94.7% of those treated surgically surviving to discharge. CONCLUSION Increased accumulation of gas on radiographs and transrectal palpation of impaction or intestinal gas distension increase the likelihood of surgery. Both medical and surgical treatments carry a good prognosis. CLINICAL RELEVANCE The sheer quantity of sand is not a factor when determining surgical intervention. Attention should be paid to the presence of increased gas accumulation on rectal or radiographic examination.

Evaluation of 10 minute versus 30 minute tourniquet time for intravenous regional limb perfusion with amikacin sulfate in standing sedated horses

The objective of the article is to determine the synovial fluid concentrations of amikacin sulfate (AS) after performing an intravenous regional limb perfusion (IVRLP) with the tourniquet in place for 10 minutes and compare this with 30 minutes. This is a randomised crossover experimental design. Animals were seven healthy adult horses. Horses underwent two IVRLP procedures in a randomised, crossover design. The horses received IVRLP with 2 g AS diluted to 60 ml using 0.9% saline in the cephalic vein of alternate limbs with the tourniquet in place for either 10 or 30 minutes, with a washout period between procedures. Movement of the horses was recorded. Synovial fluid was collected from the radiocarpal and metacarpophalangeal joints at five minutes and 24 hours after IVRLP, and amikacin concentration was compared between groups. Amikacin was quantified by a fluorescence polarisation immunoassay. There was no significant difference between the synovial amikacin concentrations noted between 10 minute and 30 minute IVRLP. Horses in the 30 minute tourniquet application group demonstrated more movement than the 10 minute tourniquet group. There was a significant difference between groups with regard to the systemic venous blood concentration of amikacin one minute after tourniquet release with mean systemic venous blood concentrations of AS being higher (P=0.001) in the 10 minute group. Ten minute application of a wide elastic tourniquet may be sufficient when performing IVRLP in standing sedated horses.

Comparison of clinical findings and short-term survival between horses with intestinal entrapment in the gastrosplenic ligament and horses with intestinal entrapment in the epiploic foramen

OBJECTIVE To compare clinical findings and short-term outcome for horses with intestinal entrapment in the gastrosplenic ligament (GLE) with those of horses with intestinal entrapment in the epiploic foramen (EFE). DESIGN Retrospective case-control study. ANIMALS 43 horses with GLE (cases) and 73 horses with EFE (controls). PROCEDURES Medical records of horses examined because of colic at a veterinary teaching hospital between 1992 and 2012 were reviewed. Signalment was extracted from medical records for all horses with colic (colic population), and additional information regarding colic history, clinical findings, treatments, and outcome was extracted from the records of horses in which GLE or EFE was diagnosed during surgery or necropsy. Signalment was compared between the colic population and the case and control populations. Clinical findings and short-term outcome were compared between the cases and controls. RESULTS The proportions of middle-aged horses and geldings in both the case and control groups were greater than those in the colic population. Mean heart rate and blood and peritoneal fluid lactate concentrations in horses with EFE were significantly greater than those for horses with GLE. The proportion of horses that underwent surgery and were discharged from the hospital (short-term survival rate) did not differ between the GLE (22/25 [88%]) and EFE (29/34 [85%]) groups. CONCLUSIONS AND CLINICAL RELEVANCE Compared with the colic population, results suggested middle-aged geldings might be predisposed to GLE and EFE. The short-term survival rate was similar between the GLE and EFE groups even though horses with EFE had more severe systemic derangements than did horses with GLE.

Complications associated with perineal urethrotomy in 27 equids.

Objective To report the clinical findings, incidence of complications, and outcome associated with perineal urethrotomy in equids. Study Design Retrospective case series. Animals Equids (n = 27). Methods Medical records (January 2000 to December 2010) of equids that had a perineal urethrotomy were reviewed. Data retrieved and evaluated were breed, age, surgical technique, use of general anesthesia, complications, time from surgery to development of complications and their management, and outcome. Results Perineal urethrotomy was performed for urolithiasis (n = 22), for treatment of urethral rents (3), severe balanoposthitis (1), and bladder atony caused by equine protozoal myeloencephalitis (1). The incidence of complications was 52%, including recurrence of urolithiasis in 5 (23%) equids. Horses that had postoperative cystoscopy and bladder lavage were significantly less like likely to have recurrence of urolithiasis (P = .039). Of equids that had postoperative indwelling urinary catheters, 75% developed complications. Conclusions Perineal urethrotomy can be an effective for treatment of urolithiasis, hematuria, and urethral trauma. Postoperative cystoscopy and bladder lavage significantly reduced the incidence of postoperative recurrence of urolithiasis.OBJECTIVE To report the clinical findings, incidence of complications, and outcome associated with perineal urethrotomy in equids. STUDY DESIGN Retrospective case series. ANIMALS Equids (n = 27). METHODS Medical records (January 2000 to December 2010) of equids that had a perineal urethrotomy were reviewed. Data retrieved and evaluated were breed, age, surgical technique, use of general anesthesia, complications, time from surgery to development of complications and their management, and outcome. RESULTS Perineal urethrotomy was performed for urolithiasis (n = 22), for treatment of urethral rents (3), severe balanoposthitis (1), and bladder atony caused by equine protozoal myeloencephalitis (1). The incidence of complications was 52%, including recurrence of urolithiasis in 5 (23%) equids. Horses that had postoperative cystoscopy and bladder lavage were significantly less like likely to have recurrence of urolithiasis (P = .039). Of equids that had postoperative indwelling urinary catheters, 75% developed complications. CONCLUSIONS Perineal urethrotomy can be an effective for treatment of urolithiasis, hematuria, and urethral trauma. Postoperative cystoscopy and bladder lavage significantly reduced the incidence of postoperative recurrence of urolithiasis.

Septic sialoadenitis in equids: A retrospective study of 18 cases (1998–2010)

REASON FOR PERFORMING STUDY Septic sialoadenitis, although uncommonly reported in equids, is a significant cause of pain, inappetence, dysphagia and discomfort. There are currently few reported cases possibly as a result of its infrequent occurrence. OBJECTIVES To review cases presenting with sialoadenitis and describe the presenting complaints, results of diagnostic tests, treatment and outcome. STUDY DESIGN Retrospective case series. METHODS Records were reviewed for equids presenting to the UC Davis William R. Pritchard Veterinary Medical Teaching Hospital between 1998 and 2010 for salivary gland swelling. Equids were included if a diagnosis of septic sialoadenitis was made based on a combination of oral examination and/or ultrasonographic findings and/or microbial culture. Data collected included age, breed, presenting complaints, diagnostic results, treatment and outcome. RESULTS Eighteen equids were diagnosed with septic sialoadenitis affecting the parotid gland (11) or the mandibular salivary gland (7). Ultrasound was useful to differentiate whether the mandibular or parotid salivary gland was involved. Affected equids ranged in age from 4 to 30 years (mean 17.7 years). Fourteen of 15 (93.3%) equids that underwent a complete oral examination had dental or other oral abnormalities. Six of 18 cases had evidence of sialolithiasis. Culture of the infected salivary gland or secretions was performed in 9 equids and all yielded growth of Fusobacterium sp. along with other aerobic and anaerobic bacteria. Infection resolved in 15/18 cases (83.3%) and 2/18 (11.1%) were subjected to euthanasia. CONCLUSIONS Dental disease and sialolith formation may play important roles in the development of septic sialoadenitis in equids. Anaerobic infection should be assumed in all cases and affected horses should be treated for this until culture and sensitivity results are available. Prognosis is favourable (83.3%) with appropriate treatment.

Effect of Dose on Intra‐Articular Amikacin Sulfate Concentrations Following Intravenous Regional Limb Perfusion in Horses

OBJECTIVE To compare synovial concentrations of amikacin following intravenous regional limb perfusion (IVRLP) with two different doses, and to compare their ability to reach target concentrations for bacterial isolates from common orthopedic conditions. STUDY DESIGN Randomized crossover experiment. ANIMALS Six adult horses. METHODS Horses received IVRLP with 2 and 3 g of amikacin in the cephalic vein of alternate limbs (20 minutes tourniquet application and ≥14 days washout period). Amikacin concentrations were quantified in synovial fluid collected from the middle carpal and metacarpophalangeal joints at 25 minutes, and 24, 36, and 48 hours after IVRLP. Minimum inhibitory concentrations (MIC) were determined from equine bacterial isolates and ability to reach target amikacin concentrations were compared. RESULTS Overall, middle carpal joint amikacin concentrations were higher following IVRLP with 3 g amikacin compared to 2 g (P=.031), with significant differences at 25 minutes (P=.002) and 24 hours (P=.021). No differences were observed between doses in the metacarpophalangeal joint (P=.267). Target amikacin concentrations for Staphylococcus aureus and coagulase-negative staphylococci were achieved in middle carpal and metacarpophalangeal joints at 25 minutes with both dosages and for Escherichia coli and Actinobacillus spp. in the middle carpal joint at 25 minutes with 3 g. Target concentrations were not achieved for Enterococcus spp, Pseudomonas spp, or Streptococcus equi ssp. zooepidemicus. CONCLUSION A 3 g amikacin dose is not justified in the majority of distal limb injuries, but should be reserved for isolates with an MIC higher than that achievable with a 2 g dose. Daily IVRLP may be necessary based on our results.