Difference in incisional complications following exploratory celiotomies using antibacterial-coated suture material for subcutaneous closure: Prospective randomised study in 100 horses.

REASONS FOR PERFORMING STUDY: Incisional complications are a major post operative challenge following ventral midline exploratory celiotomy for abdominal pain in horses. They lead to discomfort, prolonged hospitalisation, longer recovery times and increased cost; therefore, investigation of preventative procedures are warranted. OBJECTIVES: To determine the clinical effect of antibacterial (triclosan) coated 2-0 polyglactin 910 suture material on the likelihood of incisional infections when used for closure of subcutaneous tissue following ventral midline celiotomies in horses. METHODS: One hundred horses undergoing exploratory celiotomy assigned at random to one of 2 groups. In the control group coated 2-0 polyglactin 910 (Vicryl) was used for apposition of the subcutaneous tissue in a simple continuous pattern and, in the study group, antibacterial (triclosan) coated 2-0 polyglactin 910 suture material (Vicryl Plus) was used. Post operatively an elastic adhesive abdominal bandage was applied, changed and the incision was inspected by a clinician blinded to the study protocol at 24-36 h and 6-9 days post operatively. Outcomes of interest were evidence of incisional pain, incisional oedema, sheath/udder oedema, incisional drainage, hernia formation and dehiscence. RESULTS: Antibacterial-coated suture material did not decrease the likelihood of incisional complications in 100 horses. CONCLUSIONS: A beneficial effect on ventral midline incisions in 100 horses was not evident by using antibacterial-coated suture material. POTENTIAL RELEVANCE: Lack of effectiveness of antibacterial-coated suture material in equine ventral midline closure after exploratory celiotomy and the observed potential adverse effects suggest that further clinical investigations are needed before using such material routinely on horses.

Large colon resection and anastomosis in horses: 52 cases (1996-2006).

REASONS FOR PERFORMING STUDY: Large colon resection and anastomosis (LCRA) is the most aggressive method of surgical management of a colon with questionable viability. Currently, published studies are comprised mostly of broodmares and discuss short-term survival. OBJECTIVES: To determine the prognosis for survival after LCRA in a diverse population of horses, report the incidence of post operative complications, and determine if associations between analysed variables and survival rate exist. METHODS: The medical records of 52 horses that underwent LCRA were evaluated. Data were used to identify univariable associations with survival as well as complications related to LCRA. Chi-square, odds ratio with 95% confidence interval, Mann-Whitney or Kruskal-Wallis tests were used, with significance set at P<0.05. RESULTS: Forty-four horses (84.6%) survived anaesthesia and recovery, 30 (57.7%) survived to be discharged from the hospital. Of the variables analysed, heart rate 24 h after recovery was significantly associated with mortality, as were endotoxaemia, ileus and peritonitis experienced post operatively. CONCLUSIONS: Heart rate 24 h after recovery may be a more reliable prognostic indicator than other analysed variables. Survival rate and complications after LCRA were similar to those previously reported.

Thoracoscopy in horses.

With the recent development of video-assisted thoracic surgery, visual inspection of the thoracic cavity has been used to provide a more accurate diagnosis and prognosis of thoracic diseases and to better manage these diseases. Equipment, techniques, and complications for standing thoracoscopy in horses are described.

In vitro effects of holmium. YAG laser on caprine stifle retinacular restraints.

This study was designed to evaluate the efficacy of the Holmium:YAG laser for performing lateral release and medial joint capsular tightening intracapsularly and to compare the efficacy of the laser versus a scalpel blade for performing a lateral release by performing arthroscopic surgery on 29 caprine patellofemoral joints. Specimens were divided into six treatment groups and treatments consisted of lateral release alone, medial capsular tightening alone, or both treatments, and the effect of each treatment on patellar tracking was evaluated using video analysis of optical markers. Each treatment caused significantly different magnitudes of medial patellar displacement throughout a 75 degrees range of motion: medial tightening followed by lateral release (1.5 +/- 0.10 mm, mean +/- standard error of the mean); lateral release followed by medial tightening (1.1 +/- 0.11 mm); medial tightening alone (0.73 +/- 0.10 mm); lateral release alone (0.36 +/- 0.09 mm); and sham (-0.15 +/- 0.05 mm). There were no significant differences between performing the lateral release using the laser (1.5 +/- 0.10 mm) versus a scalpel (1.4 +/- 0.11 mm). This study shows that lateral release can be performed as effectively with the laser as with a scalpel and that the laser is an effective tool for performing lateral release and medial joint capsular tightening procedures intracapsularly in this caprine model.

Isolation of methicillin-resistant Staphylococcus aureus from a postoperative wound infection in a horse.

Methicillin-resistant Staphylococcus aureus (MRSA) was isolated from a postoperative wound infection in a horse. Methicillin-resistant S aureus infections in animals have been reported. In human beings, MRSA is an important cause of hospital-acquired (nosocomial) infections. Infections caused by MRSA respond poorly to beta-lactam treatment, and resistance of MRSA to multiple antimicrobials, including aminoglycosides, macrolides, clindamycin, and tetracyclines, is common. Identification of MRSA by routine susceptibility testing may be difficult; therefore, techniques for MRSA detection should be incorporated by clinicopathology laboratories. Because the number of hospital and community-acquired MRSA infections in human beings is increasing, it seems likely that MRSA infections in animals will also become more frequent.

Management of a transverse fracture in the distal phalanx of a horse.

A yearling horse was presented with a septic, transverse fracture in the frontal plane of the distal phalanx. The fracture fragment was surgically removed from the parent bone via the sole. The foot was managed by corrective farriery and the horse was able to be ridden for pleasure.

Use of diagnostic ultrasonography in horses with signs of acute abdominal pain.

OBJECTIVE: To evaluate the use of abdominal ultrasonography as a diagnostic tool in horses with signs of colic. DESIGN: Prospective study. ANIMALS: 226 horses with signs of acute abdominal pain were compared to 20 clinical normal horses. PROCEDURE: The following were performed in horses with signs of colic: physical examination, CBC, abdominal fluid analysis, placement of a nasogastric tube to obtain gastric reflux, abdominal palpation per rectum, and ultrasonography of the abdomen. Results of ultrasonography were compared with the surgical, necropsy, or medical findings. RESULTS: Ultrasonography of horses with primary small-intestine lesions revealed images of small intestine with a wall thickness of 0.2 to 1.8 cm and a diameter of 3.6 to 13.5 cm without evidence of motility. Horses with peritonitis did have evidence of small-intestine motility on ultrasonography with a wall thickness of 0.5 to 1.3 cm and a diameter of 2 to 5.1 cm. Horses with primary large-colon lesions or small-colon impactions had small-intestine diameters on ultrasonographic evaluation of 3 to 7.1 cm. In these horses, small-intestine motility was detected. If abnormal small intestine that lacked motility was detected by ultrasonographic evaluation, the sensitivity, specificity, and positive and negative predictive values for small-intestine stragulation obstructions were 100%. Detection of distended or edematous small intestine by abdominal palpation per rectum provided a sensitivity of 50%, specificity of 98%, positive predictive value of 89%, and negative predictive value of 89% for small-intestine strangulation obstructions. CLINICAL IMPLICATIONS: The use of abdominal ultrasonography. In horses with signs of colic is accurate for detecting small-intestine strangulation obstructions.

Laparoscopic repair of scrotal hernia in two foals.

Nonstrangulating indirect scrotal hernias were corrected in two 4-week-old Percheron foals by a laparoscopic technique. After laparoscopic reduction of herniated nonstrangulated small intestine each testes was retracted through the vaginal ring. The ligament of the tail of the epididymis was transected by electrocautery. The testicular vessels and nerves were isolated by cautery of the mesenteric portion of the mesorchium and then ligated. Staples were used to close the opening of the inguinal canal by apposing the peritoneal edges of the vaginal ring. Resection of umbilical stalk remnants via celiotomy performed in one foal after laparoscopic observation of enlargement of the right umbilical artery and urachus. No complications or recurrence of herniation had occurred 16 weeks after surgery.

Effects of potentiated chlorhexidine on bacteria and tarsocrural joints in ponies.

OBJECTIVES: To evaluate the bactericidal properties of chlorhexidine diacetate (CHD) after potentiation with EDTA and Tris buffer (EDTA-Tris), and to find a potentiated CHD concentration that would achieve 90 to 100% killing for all bacteria tested. ANIMALS: 6 adult ponies. PROCEDURES: Serial dilutions of CHD, CHD in EDTA-Tris and EDTA-Tris alone were evaluated for bactericidal activity against Staphylococcus aureus, Escherichia coli, and Streptococcus zooepidemicus. The tarsocrural joints of 6 ponies were lavaged with either 1 L phosphate-buffered saline solution (control) or 1 L of 0.0005% CHD in EDTA-Tris. Synovial fluid was collected before lavage and on days 1,4, and 8. Synovia, cartilage, and bone with cartilage were collected on day 8 when the ponies were euthanatized. RESULTS: In vitro results indicated that 0.0005% CHD in EDTA-Tris was 90% lethal to all bacteria tested. Results of synovial fluid analysis, glycosaminoglycan analysis, and histologic examination of the synovial membrane and articular cartilage indicated that joint lavage with 0.0005% CHD in EDTA-Tris was not detrimental to the synovium or the articular cartilage of pony tarsocrural joints. Changes observed were a result of the actual lavage process, the phosphate-buffered saline solution, and hemarthrosis. CONCLUSIONS: A concentration of 0.0005% CHD in EDTA-Tris was 90% lethal to all bacteria tested. Pony tarsocrural joint lavage with 0.0005% CHD in EDTA-Tris was not detrimental to the synovium or the articular cartilage. The efficacy of 0.0005% CHD potentiated with EDTA-Tris as a potential joint lavage fluid for treatment of infectious arthritis needs to be evaluated in clinical patients.

Use of antimicrobial-impregnated polymethyl methacrylate beads for treatment of chronic, refractory septic arthritis and osteomyelitis of the digit in a bull.

A 6-year-old 895-kg Angus bull was evaluated for a 6-month history of left hind limb lameness that was refractory to antimicrobial treatment. On physical examination, there was soft-tissue swelling associated with the lateral digit. Radiography revealed septic arthritis of the distal interphalangeal joint and osteomyelitis of the distal and middle phalanges. Treatment included debridement and lavage. Bacteriologic culture of debrided tissues yielded aerobic and anaerobic organisms. Antimicrobials were administered parenterally and locally in the form of antimicrobial-impregnated polymethyl methacrylate beads. The limb also was placed in a cast to promote ankylosis. The bull recovered, and the digit was salvaged.

Atrophic nonunion can be predicted with dual energy x-ray absorptiometry in a canine ostectomy model.

This study demonstrated that dual energy x-ray absorptiometry can be used to distinguish between normal union and atrophic nonunion, with high sensitivity and high negative predictive value, by 8 weeks after surgery in a canine model. Eighteen adult mixed-breed dogs were divided into two equal groups: normal union and atrophic nonunion. In the normal union group, a 5 mm mid-diaphyseal transverse ostectomy was performed in the right tibia, and the bone was stabilized with a unilateral external fixator. In the atrophic nonunion group, a 5 mm mid-diaphyseal ostectomy was performed; the distal 1.5 cm of the bone ends, including the periosteum, were frozen twice to -20 degrees C using liquid nitrogen and thawed slowly twice; and the bone was stabilized with a unilateral external fixator. The members of the research team were blinded to the group assignments until after all dogs were killed and all data were acquired. Radiography and dual energy x-ray absorptiometry of both tibiae were performed at weeks 1, 2, 3, 4, 6, 8, 10, 12, 14, and 16 after surgery. All dogs were killed at 16 weeks, and the torsional stiffness and maximum torque of both tibiae of five dogs in each group were determined. Mechanically, the tibiae in the normal union group had significantly higher maximum torque (43-fold higher) and torsional stiffness (86-fold higher) than the tibiae in the atrophic nonunion group. The sensitivity and negative predictive value of dual energy x-ray absorptiometry for predicting nonunion were 100% by 8 weeks after surgery. The specificity and positive predictive value reached 78 and 82%, respectively, by 16 weeks. Radiographic scores were significantly higher for the union group than for the nonunion group beginning at 2 weeks after surgery. The earliest time after surgery that radiography classified an ostectomy as a nonunion was significantly later (4.6 +/- 1.2 weeks) than for dual energy x-ray absorptiometry (2.6 +/- 1.4 weeks). Before these results can be extrapolated to human applications, further animal studies must be performed to evaluate clinically or experimentally induced fractures, or both, rather than the well defined ostectomies that were performed in this study.