Ponies, miniatures, and younger equids are at higher risk of fecalith obstruction compared to a general colic population.

OBJECTIVE: To determine breed, age, and sex predispositions for fecalith obstruction and to evaluate short-term survival and prognostic factors following surgical treatment of fecalith intestinal obstruction in equids. ANIMALS: 151 equids. METHODS: Medical records of equids undergoing surgery for fecalith obstruction from 2000 to 2020 were reviewed. Signalment, history, presenting clinicopathological data, surgical findings, complications, and short-term survival were recorded and compared between survivors and nonsurvivors. Signalment of the fecalith population was compared to a contemporaneous colic population. Clinical factors were assessed for association with outcome. RESULTS: 64 females, 53 castrated males, and 31 intact males were included. Three equids presented twice. Miniature horses, ponies, and miniature donkeys/mules represented 48% (71/148) of fecalith population and full-sized breeds represented 52% (77/148). Miniature horses and ponies were overrepresented and equids ≤ 1 year of age were overrepresented in the fecalith population compared to the colic population. One hundred thirty-nine equids (92%) survived to discharge, 6% (9/148) were euthanized intraoperatively, and 2% (3/148) were euthanized during hospitalization. Nonsurvivors showed more severe colic signs on admission, tachycardia on admission, and hyperlipemia. Equids with postoperative colic (P = .01) and complications (P = .002) were less likely to survive. CLINICAL RELEVANCE: Miniature horses and ponies were overrepresented compared to the colic population; however, full-sized breeds were also affected. Surgical treatment had an excellent short-term prognosis. Severe colic signs, tachycardia, hyperlipemia, postoperative colic, and surgical complications negatively affected short-term survival.

Effects of a 10% dimethyl sulfoxide solution on radiocarpal joint amikacin pharmacokinetics during intravenous regional limb perfusion in standing sedated horses.

OBJECTIVE: To determine the effect of a 10% dimethyl sulfoxide (DMSO) solution on the peak concentration (CMAX ) of amikacin in the radiocarpal joint (RCJ) during intravenous regional limb perfusion (IVRLP) compared with 0.9% NaCl. STUDY DESIGN: Randomized crossover study. ANIMALS: Seven healthy adult horses. METHODS: The horses underwent IVRLP with 2 g of amikacin sulfate diluted to 60 mL using a 10% DMSO or 0.9% NaCl solution. Synovial fluid was collected from the RCJ at 5, 10, 15, 20, 25, and 30 minutes after IVRLP. The wide rubber tourniquet placed on the antebrachium was removed after the 30 min sample. Amikacin concentrations were quantified by a fluorescence polarization immunoassay. The mean CMAX and time to peak concentration (TMAX ) of amikacin within the RCJ were determined. A one-sided paired t-test was used to determine the differences between treatments. The significance level was p < .05. RESULTS: The mean ± SD CMAX in the DMSO group was 1361.8 ± 593 µg/mL and in the 0.9% NaCl group it was 860 ± 481.6 µg/mL (p = .058). Mean TMAX using the 10% DMSO solution was 23 and 18 min using the 0.9% NaCl perfusate (p = .161). No adverse effects were associated with use of the 10% DMSO solution. CONCLUSION: Although there were higher mean peak synovial concentrations using the 10% DMSO solution no difference in synovial amikacin CMAX between perfusate type was detected (p = .058). CLINICAL SIGNIFICANCE: Use of a 10% DMSO solution in conjunction with amikacin during IVRLP is a feasible technique and does not negatively affect the synovial amikacin levels achieved. Further research is warranted to determine other effects of using DMSO during IVRLP.

Prevalence of and risk factors associated with Salmonella shedding among equids presented to a veterinary teaching hospital for colic (2013-2018).

BACKGROUND: Gastrointestinal disease has been associated with shedding of Salmonella with previous studies demonstrating that horses with colic have a higher risk of acquiring and shedding Salmonella organisms. OBJECTIVES: The purpose of this study was to determine the prevalence of and risk factors associated with Salmonella shedding in a colic population at a referral clinic. STUDY DESIGN: Retrospective case-control study. METHODS: For each colic case that was positive for Salmonella (n = 56), two colic cases (n = 112) that tested negative for Salmonella, were enrolled as controls. Associations between variables and Salmonella shedding were identified using logistic regression. Univariate and multivariable models were developed pertaining to (1) presenting clinicopathological data and (2) clinical variables that developed during hospitalisation. RESULTS: Of the equids presenting with colic, 1585/1917 had a sample submitted for Salmonella testing. Of these, 56 were positive for Salmonella yielding a prevalence of 3.5%. Equids shedding Salmonella were more likely to present in July (odds ratio [OR] = 7.2; 95% confidence interval [CI] = 1.63-32.13; p = 0.009) and present with a history of fever (OR = 53.5; 95% CI = 2.57-1113.03; p = 0.01), increased lactate (OR = 1.6; 95% CI = 1.14-2.29; p = 0.007) and/or neutropenia (OR = 0.79; 95% CI = 0.65-0.97; p = 0.02). Hospitalised equids shedding Salmonella were more likely to be febrile (OR = 4.8; 95% CI = 1.47-15.8; p = 0.01) and 10 times more likely to develop reflux (OR = 10.1; 95% CI = 1.67-61.43; p = 0.01) compared to colic controls. MAIN LIMITATIONS: Retrospective nature of the study and bias inherent to the retrieval of data from medical records cannot be discounted. Classifying Salmonella status based on a single sample may have resulted in misclassification bias. CONCLUSIONS: The prevalence of Salmonella shedding in this colic population was low compared to earlier reports. Certain predictors such as the development of a fever or reflux in hospitalised colic cases were associated with Salmonella shedding and may help the clinician to promptly identify horses likely to shed; thus, helping institute effective use of barrier nursing precautions.

Orthopedic Infections-Clinical Applications of Intravenous Regional Limb Perfusion in the Field.

For the equine veterinarian, orthopedic emergencies are a common occurrence in clinical practice, with traumatic wounds of the distal limb and penetrating injuries of the hoof being some of the most common medical conditions to affect horses. Intravenous regional limb perfusion is a technique widely used for the treatment of orthopedic infections in horses. The objectives of this review are to discuss some of the clinical applications for this treatment modality in the field and to review the technique for the practitioner.

Castration Complications: A Review of Castration Techniques and How to Manage Complications.

Castration is one of the most common surgical procedures performed in equine practice. Open, closed, and semiclosed techniques are described for castration of horses, and the procedure may be performed in a standing, sedated animal or in a recumbent animal under general anesthesia. Although a relatively routine procedure, complications can occur, with reported complication rates ranging from 10.2% to 60%. Most complications are mild and resolve rapidly with appropriate treatment, but more serious or life-threatening complications can also occur. A thorough knowledge of male reproductive anatomy combined with good surgical technique is imperative to help reduce the rate of complications.

In vitro efficacy of a 0.2% polyhexamethylene biguanide-impregnated gauze dressing against pathogenic bacterial isolates found in horses.

OBJECTIVE: To determine the ability of 0.2% polyhexamethylene biguanide (PHMB)-impregnated gauze to inhibit the growth of bacteria isolated from equine infected sites. STUDY DESIGN: In vitro study. METHODS: Nine bacterial isolates were obtained from cultures submitted from equine patients presenting with penetrating injuries of the hoof (n = 4), septic osteitis (n = 1), synovial sepsis (n = 1), wounds (n = 2), and incisional infection following laparotomy (n = 1). Two standardized strains were also included. A standard inoculum of each isolate was placed on 12 Muller-Hinton agar plates. Squares (2.5 cm × 2.5 cm) of 0.2% PHMB-impregnated (n = 6) and nonimpregnated control gauze (n = 6) were placed on inoculated agar plates. Bacterial growth under each gauze square was assessed after a 24-h incubation period and areas of inhibition were measured to a standardized scale, using image-processing software. Mean ± SD growth inhibition (%) using 0.2% PHMB-impregnated gauze was compared to the nonimpregnated gauze for each isolate using Student's t test (p < .05). RESULTS: The 0.2% PMHB-impregnated gauze inhibited the growth of Staphylococcus spp. (n = 4) by 33%-83.1% and that of Escherichia coli spp. (n = 4) by 6.5%-37%. There was no inhibition of growth of Pseudomonas aeruginosa or either Enterococcus spp. CONCLUSION: The 0.2% PHMB-impregnated dressing tested here inhibited the growth of staphylococcal and E. coli isolates, but the magnitude of inhibition varied between strains. CLINICAL RELEVANCE: These results justify in vivo studies to evaluate the ability of the dressing to reduce the bacterial growth of common equine bacterial pathogens in clinical practice.

Clinical and diagnostic findings, treatment, and short- and long-term survival in horses with peritonitis: 72 cases (2007-2017).

OBJECTIVE: To identify etiology, clinical findings, diagnostic results, treatment, and short- and long-term survival and to report factors associated with nonsurvival and survival in horses with peritonitis. STUDY DESIGN: Retrospective study. ANIMALS: Horses (n = 72). METHODS: Medical records at William R. Pritchard Veterinary Medical Teaching Hospital from 2007-2017 were reviewed for horses diagnosed with peritonitis. The essential inclusion criterion was a peritoneal nucleated cell count of ≥25 000 cells/µL. Gastrointestinal rupture and cases in which peritonitis occurred after abdominal surgery or castration were excluded. Information retrieved from medical records included signalment, history, clinicopathological and peritoneal fluid variables, diagnostic imaging findings, inciting cause, treatment, and short- and long-term survival. Data were analyzed by using Fisher's exact test, Wilcoxon rank sum test, and χ2 test (P < .05). RESULTS: Colic was the most common presenting complaint (34/72 [48%]). A definitive diagnosis could be made in 44 (44/72 [61%]) cases. The most common cause of peritonitis was infectious agents (31/72), followed by trauma (8/72), gastrointestinal thickening (3/72), and eosinophilic peritonitis (2/72). Idiopathic peritonitis was identified in 28 (28/72 [39%]) cases. Sixty (83%) horses survived to hospital discharge. Long-term follow-up was available for 49 horses, with 43 (88%) horses alive 1 year after discharge. Significant differences between nonsurvivors and survivors were history of colic, positive peritoneal fluid culture, and several hematological/peritoneal fluid variables. CONCLUSION: Peritoneal fluid analysis was essential for a definitive diagnosis of peritonitis, and certain variables were useful for predicting outcome. CLINICAL SIGNIFICANCE: Results of this study provide evidence of the value of peritoneal fluid analysis for identification of peritonitis, prediction of outcome, and successful treatment.

Do allogeneic bone marrow derived mesenchymal stem cells diminish the inflammatory response to lipopolysaccharide infusion in horses? A pilot study.

Endotoxemia is a leading cause of morbidity and mortality in the equine industry, with colic being the most common cause of endotoxemia in horses. The objective of this study was to evaluate the safety and potential efficacy of a single dose of allogeneic equine bone marrow derived mesenchymal stem cells (BM-MSCs) in horses after the IV administration of lipopolysaccharide (LPS). Six horses were administered an IV infusion of 30 ng/kg LPS (O55:B5 Escherichia coli) in 500 ml saline over 30 min. Immediately after infusion test horses (n = 3) were administered 100 × 106 allogeneic BM-MSCs diluted in saline IV and control horses (n = 3) were administered saline. Clinicopathological data, pro-inflammatory cytokine measurements and sCD14 concentrations were compared between groups. No adverse reactions were observed in horses administered BM-MSCs intravenously. There were no significant differences between test and control horses with regard to clinicopathological values or pro-inflammatory cytokine production. At no time point did concentrations of sCD14 exceed the reference range in any horse. Results suggest that administration of a single IV dose of freshly cultured MSCs is safe and well-tolerated in horses with induced endotoxemia. Further study to evaluate their efficacy as a potential therapeutic in a larger number of horses with clinical disease is required.

Sidewinder gait in horses.

BACKGROUND: Sidewinder gait in horses is poorly understood and characterized by walking with the trunk and pelvic limbs drifting to 1 side. HYPOTHESIS/OBJECTIVES: To report causes, clinical and diagnostic features. ANIMALS: Horses examined at 2 institutions. MATERIALS AND METHODS: Retrospective study (2000-2019). Cases with sidewinder gait, neurological and orthopedic examination, and diagnostic work up or postmortem evaluation were included. Descriptive statistics were performed. RESULTS: Twenty-four horses (mean age 18.9 years) of various breeds and both sexes were included. Onset was acute (N = 10), subacute (N = 6), and insidious (N = 8). Electromyography and muscle biopsy supported neurologic disease and further aided in localizing site of lesion (N = 9/9). Neurologic causes included dynamic thoracolumbar spinal cord compression (N = 5), equine protozoal myeloencephalitis (N = 4, confirmed and presumed [2 each]), thoracic myelopathy of unknown etiology (N = 4), gliosis (N = 2), and thrombosis of thoracic spinal cord segments (N = 1). Non-neurologic causes included osteoarthritis of the coxofemoral joint (N = 4), multiple displaced pelvic fractures (N = 2), bilateral rupture of the ligamentum capitis ossis femoris (N = 1), and severe myonecrosis of multiple pelvic limb muscles (N = 1). Case fatality was 79%. CONCLUSION AND CLINICAL IMPORTANCE: Sidewinder gait is usually observed in older horses and can have neurologic or musculoskeletal etiologies. Electromyography can be used as a diagnostic aid to determine neurologic versus non-neurologic disease and further localize those of neurologic origin. The condition often has a poor prognosis for function and life.

Diagnostic value of plasma and peritoneal fluid procalcitonin concentrations in horses with strangulating intestinal lesions.

OBJECTIVE: To assess the diagnostic value of plasma and peritoneal fluid procalcitonin concentrations for identification of horses with strangulating intestinal lesions. ANIMALS: 65 horses with signs of colic of intestinal origin and 10 healthy (control) horses. PROCEDURES: For each horse, plasma and peritoneal fluid samples were obtained for a CBC and determination of total protein, procalcitonin, and lactate concentrations. Signalment and clinicopathologic findings were compared among control horses and horses with strangulating and nonstrangulating intestinal lesions. RESULTS: Mean ± SD plasma (274.9 ± 150.8 pg/mL) and peritoneal fluid (277 ± 50.6 pg/mL) procalcitonin concentrations for horses with colic were significantly greater than the mean ± SD plasma (175.5 ± 46.0 pg/mL) and peritoneal fluid (218.8 ± 48.7 pg/mL) procalcitonin concentrations for control horses. Mean procalcitonin concentration in peritoneal fluid, but not plasma, differed significantly between horses with strangulating lesions and those with nonstrangulating lesions. A peritoneal fluid procalcitonin concentration ≥ 281.7 pg/mL had a sensitivity of 81%, specificity of 69%, positive predictive value of 56.7%, and negative predictive value of 87.9% for detection of strangulating lesions. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that peritoneal fluid procalcitonin concentration, when evaluated in conjunction with other clinicopathologic results, might be a sensitive indicator of intestinal ischemia and facilitate early identification of horses that require surgery to address a strangulating lesion.

Scapula fracture secondary to metastatic pulmonary carcinoma in a horse: Clinical, sonographic, radiographic, computed tomographic, and pathologic findings.

A 20-year-old Quarter horse gelding was referred for evaluation of an acute onset non-weight-bearing right forelimb lameness. Marked soft tissue swelling was apparent over the right scapula and shoulder region; no crepitus was palpable. A complete transverse fracture of the scapular neck was suspected based on ultrasonography and radiographs were obtained to confirm the presumptive diagnosis. A complete, oblique fracture of the right scapular neck with mild cranial and proximal displacement of the distal fragment was detected. Computed tomography of the upper right forelimb was performed post-mortem; lytic bony destruction of the scapular neck with a secondary pathologic fracture was observed. The lesion was considered most likely neoplastic. At necropsy a complete, comminuted fracture of the right scapula was confirmed, secondary to neoplastic invasion of the bone. A solitary, dorsally located, neoplastic mass was also observed within the parenchyma of the right caudal lung. Histopathologically, the lung and scapula lesions were similar, characteristic of a well-differentiated pulmonary carcinoma.

Fracture de l'omoplate secondaire à un carcinome pulmonaire métastasique chez un cheval : trouvailles cliniques, échographiques, radiographiques, par tomodensitométrie et pathologiques. Un cheval hongre Quarter horse âgé de 20 ans fut référé pour évaluation d'une boiterie de non-appui de la patte avant droite d'apparition aiguë. Une enflure marquée des tissus mous était apparente par-dessus l'omoplate droite et la région de l'épaule; aucun crépitement n'était palpable. Une fracture transverse complète du col de l'omoplate était suspectée sur la base de l'échographie et des radiographies furent obtenues pour confirmer le diagnostic présomptif. Un examen par tomodensitométrie de la portion supérieure du membre droit fut effectué post-mortem; une destruction osseuse lytique du col de l'omoplate avec une fracture pathologique secondaire fut observée. La lésion fut considérée comme fort probablement néoplasique. Lors de la nécropsie, une fracture comminutive complète de l'omoplate droite fut confirmée, secondaire à l'invasion néoplasique de l'os. Une masse néoplasique solitaire, localisée dorsalement fut également observée dans le parenchyme du poumon caudal droit. À l'examen histopathologique, les lésions du poumon et de l'omoplate étaient similaires, caractéristiques d'un carcinome pulmonaire bien différencié.(Traduit par Dr Serge Messier).

Evaluation of the risk of incisional infection in horses following application of protective dressings after exploratory celiotomy for treatment of colic.

OBJECTIVE To assess incidence of incisional infection in horses following management with 1 of 3 protective dressings after exploratory celiotomy for treatment of acute signs of abdominal pain (ie, colic) and determine the risk of complications associated with each wound management approach. DESIGN Prospective, randomized, controlled study. ANIMALS 85 horses. PROCEDURES Horses were assigned to 3 groups. After standardized abdominal closure, a sterile cotton towel (group 1) or polyhexamethylene biguanide-impregnated dressing (group 2) was secured over the incision site with 4 or 5 cruciate sutures of nonabsorbable monofilament, or sterile gauze was placed over the site and secured with an iodine-impregnated adhesive drape (group 3). Demographic and clinicopathologic data, intraoperative and postoperative variables, and development of complications were recorded and compared among groups by statistical methods. Follow-up information was collected 30 and 90 days after surgery. Incidence and odds of incisional complications were calculated. RESULTS 75 horses completed the study. Group 3 typically had dressing displacement necessitating removal during anesthetic recovery; dressings were in place for a mean of 44 and 31 hours for groups 1 and 2, respectively. Purulent or persistent serosanguinous incisional discharge (ie, infection) was detected in 11 of 75 (15%) horses (2/24, 0/26, and 9/25 from groups 1, 2, and 3, respectively). Odds of incisional complications were significantly greater for group 3 than for groups 1 or 2. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that risk of infection after celiotomy for treatment of colic is lower for incisions covered with sterile towels or polyhexamethylene biguanide-impregnated dressings secured with sutures than for incisions covered with gauze secured with iodine-impregnated adhesive drapes.

Standing myotomy to treat fibrotic myopathy: 22 cases (2004-2016).

OBJECTIVE: To report the clinical and diagnostic findings associated with fibrotic myopathy, describe the surgical procedure for standing fibrotic myotomy and report postoperative outcomes. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Twenty-two horses. METHODS: Records were included if a clinical diagnosis of fibrotic myopathy was based on clinical and/or ultrasonographic examination and the horse was treated with myotomy of the affected muscle. Records were reviewed for signalment, preoperative findings, perioperative complications, and outcomes. Follow-up also included a phone survey of owners. RESULTS: Quarter horses represented 14 of 22 horses in this study. Ultrasonographic examination was performed in 14 of 22 horses. The semitendinosus muscle was affected in 17 of 22 horses. Other muscles affected included the semimembranosus, gracilis, and biceps femoris. Four of the 22 horses had a diagnosis of incisional postoperative complications. Eight of 12 formerly athletic horses returned to their intended athletic use. Ten of 16 owners were satisfied with the procedure. CONCLUSION: Prognosis for long-term comfort after standing fibrotic myotomy was fair with appropriate rehabilitation. Ultrasonographic examination was helpful in identifying the muscles affected and aided in surgical planning. CLINICAL IMPACT: Standing fibrotic myotomy is a technically straightforward procedure that yields a fair outcome in horses with minimal intraoperative and/or postoperative complications.

An atypical presentation of multi-systemic B-cell lymphoma in a horse.

This report describes an unusual presentation of multicentric B-cell lymphoma with central and peripheral nerve involvement in a horse that was presented with acute onset, severe, multiple limb lameness, and muscle atrophy. This case highlights the importance of including neoplasia in the differential list in horses presenting for severe limb lameness associated with muscle atrophy, muscle fasciculations, and weakness.

Présentation atypique d'un lymphome à cellules B multisystémique chez un cheval. Ce rapport décrit la présentation inhabituelle d'un lymphome à cellules B multicentrique avec une implication du nerf central et périphérique chez un cheval qui avait été présenté avec une boiterie aiguë et grave de plusieurs membres et de l'atrophie musculaire. Ce cas souligne l'importance d'inclure la néoplasie dans la liste des diagnostics différentiels des chevaux présentés pour une boiterie grave d'un membre associée à l'atrophie musculaire, aux fasciculations musculaires et à la faiblesse.(Traduit par Isabelle Vallières).

Preoperative factors associated with resection and anastomosis in horses presenting with strangulating lesions of the small intestine.

OBJECTIVE: To determine if preoperative and intraoperative clinical variables correlate with resection and anastomosis (RA) in horses presenting with strangulating small intestinal (SI) lesions. STUDY DESIGN: Retrospective case series. ANIMALS: Horses undergoing exploratory celiotomy for a strangulating SI lesion (n = 243). METHODS: The records of horses undergoing surgical correction for strangulating SI lesions from January 1, 2000 to December 31, 2017 were reviewed. Horses were categorized as treated with RA or not treated with RA. Obtained information included history, signalment, clinical findings, diagnostic test results, intraoperative findings, and survival to discharge. Univariable and multivariable analyses were used to compare data between horses treated with RA vs those not treated with RA (P = .05). RESULTS: In total, 172 SI lesions were resected, and 71 were not resected. Horses that had gastric reflux at admission to the hospital (odds ratio [OR] 5.56; 95% CI 1.76, 17.59) and horses with amotile SI according to abdominal ultrasonography (OR 9.69; 95% CI 3.09, 30.37) were more likely to undergo RA. Increased difference between peritoneal fluid and blood lactate was higher in horses that underwent RA (OR 1.55; 95% CI 1.12, 2.13). Survival to hospital discharge was lower in the group of horses that underwent RA compared with horses that did not undergo RA. CONCLUSION: Resection and anastomosis of strangulating SI lesions was associated with several preoperative variables. CLINICAL SIGNIFICANCE: This study highlights the value of preoperative diagnostic procedures in aiding intraoperative decision making and prognostication in horses presenting with strangulating SI lesions.

Predictive value of plasma and peritoneal creatine kinase in horses with strangulating intestinal lesions.

OBJECTIVE: To determine the ability of plasma and peritoneal creatine kinase (CK) to predict the presence of a strangulating lesion in horses presented for colic. STUDY DESIGN: Prospective clinical study. ANIMALS: Ten healthy control horses and 61 clinical colic cases. METHODS: Creatine kinase activity was measured in peritoneal fluid and plasma of 10 healthy horses and 61 horses presenting for colic (40 horses with nonstrangulating lesions and 21 horses with strangulating lesions). Information on other blood and peritoneal fluid variables, signalment, results from the physical examination, outcome, requirement for surgery, and lesion location and type were retrieved from the medical records of horses presenting for colic. RESULTS: A peritoneal CK cutoff level of 16 IU/L yielded a sensitivity of 95.2% and a specificity of 84.6% (positive predictive value [PPV] = 76.9% and negative predictive value [NPV] = 97%, respectively) for predicting a strangulating lesion. A peritoneal lactate cutoff level of 3.75 mmol/L yielded a sensitivity of 81% and a specificity of 92% (PPV = 85% and NPV = 90%, respectively) for predicting a strangulating lesion. CONCLUSION: Peritoneal CK concentration was a sensitive indicator of the presence of a strangulating lesion in horses presenting with colic, whereas peritoneal lactate concentration was a more specific indicator. CLINICAL SIGNIFICANCE: Measuring CK in peritoneal fluid may be a useful adjunct to clinical case presentation to accelerate the diagnosis and definitive treatment of horses presenting with strangulating intestinal lesions, thereby improving their outcome.

Time required to achieve maximum concentration of amikacin in synovial fluid of the distal interphalangeal joint after intravenous regional limb perfusion in horses.

OBJECTIVE To determine the maximum concentration (Cmax) of amikacin and time to Cmax (Tmax) in the distal interphalangeal (DIP) joint in horses after IV regional limb perfusion (IVRLP) by use of the cephalic vein. ANIMALS 9 adult horses. PROCEDURES Horses were sedated and restrained in a standing position and then subjected to IVRLP (2 g of amikacin sulfate diluted to 60 mL with saline [0.9% NaCl] solution) by use of the cephalic vein. A pneumatic tourniquet was placed 10 cm proximal to the accessory carpal bone. Perfusate was instilled with a peristaltic pump over a 3-minute period. Synovial fluid was collected from the DIP joint 5, 10, 15, 20, 25, and 30 minutes after IVRLP; the tourniquet was removed after the 20-minute sample was collected. Blood samples were collected from the jugular vein 5, 10, 15, 19, 21, 25, and 30 minutes after IVRLP. Amikacin was quantified with a fluorescence polarization immunoassay. Median Cmax of amikacin and Tmax in the DIP joint were determined. RESULTS 2 horses were excluded because an insufficient volume of synovial fluid was collected. Median Cmax for the DIP joint was 600 µg/mL (range, 37 to 2,420 µg/mL). Median Tmax for the DIP joint was 15 minutes. CONCLUSIONS AND CLINICAL RELEVANCE Tmax of amikacin was 15 minutes after IVRLP in horses and Cmax did not increase > 15 minutes after IVRLP despite maintenance of the tourniquet. Application of a tourniquet for 15 minutes should be sufficient for completion of IVRLP when attempting to achieve an adequate concentration of amikacin in the synovial fluid of the DIP joint.

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.