BEVA primary care clinical guidelines: Wound management in the horse

BACKGROUND

There are currently no evidence summaries on wounds in the horse.

OBJECTIVES

To develop evidence-based guidelines on wound management in the horse.

STUDY DESIGN

Evidence review using the GRADE framework.

METHODS

Research questions were proposed by a panel of veterinarians, and developed into PICO format. Evidence in the veterinary literature was evaluated using the GRADE evidence-to-decision framework. Searches for human evidence summaries were conducted in the NICE, Cochrane and JBI databases. Final recommendations were based on both veterinary and human evidence.

RESULTS AND RECOMMENDATIONS

The research questions were categorised into three areas: A. Wound lavage and topical treatments; B. Wound debridement and closure; C. Therapeutics for wound healing. Three hundred and six veterinary publications were identified across thirteen different topics. Fourteen papers were assessed using the GRADE criteria. Twenty-five human evidence summaries were reviewed. The results were developed into recommendations: Wound lavage and topical treatments: (i) Tap water should be considered instead of saline for lavage; (ii) Povidone iodine lavage should be considered for contaminated wounds; (iii) Topical silver sulfadiazine may not be suitable for acute wounds; (iv) Optimal lavage pressures are around 13 psi. Wound debridement and closure: (i) Debridement pads should be considered for wound preparation; (ii) Larvae debridement should be considered in selected cases; (iii) Hydrosurgery should be considered in acute contaminated wounds. Therapeutics for wound healing: (i) Honey may reduce duration of some phases of wound healing. There was insufficient evidence to draw conclusions on the use of chemical debridement, therapeutic ultrasound, laser therapy, wound closure with staples compared to sutures, or identify optimal concentrations of antiseptic lavage solutions.

MAIN LIMITATIONS

Low quality evidence in veterinary literature; majority of recommendations were based on human evidence.

CONCLUSIONS

These findings should be used to inform decision-making in equine primary care practice.

Ex Vivo Biomechanical Comparison of 4 Suture Materials for Laparoscopic Bladder Closure in the Horse

OBJECTIVE

To compare a knotless, barbed suture to standard suture using laparoscopic suturing methods in an ex vivo model of equine bladder repair.

STUDY DESIGN

Cadaveric study.

SAMPLE POPULATION

Equine cadaver bladders (n=42).

METHODS

A 5-cm incision was created and repaired in a laparoscopic training box with 4 different suture materials. Groups 1 and 2 used 2-0 poliglecaprone and 2-0 glycomer knotless, barbed suture, respectively, placed using laparoscopic instruments. Groups 3 and 4 used 0 and 2-0 polyglyconate knotless, barbed suture, respectively, placed using an automated laparoscopic suturing device. All groups used a double-layer inverting pattern. Time for suture placement was recorded. Bladders were inflated with water and bursting strength pressures recorded, including a control group of intact bladders. Statistical analysis using a linear model and taking into account the unequal variances was followed by a post-hoc Tukey's test. Significance was set at P<.05.

RESULTS

Bursting strength did not vary significantly between treatment groups, but was significantly decreased compared to the control group (P<.001). Time to place the sutures with the 2 automated suture device groups (groups 3 and 4) was significantly faster than those in which the suture was placed using laparoscopic needle holders and forceps (groups 1 and 2; P=.001).

CONCLUSION

Knotless, barbed suture may be a viable alternative to standard suture material for laparoscopic closure of the urinary bladder in horses. Further cyclic and in vivo testing should be performed before use in clinical cases.

Clinical features and management of equine post operative ileus (POI): Survey of Diplomates of the American Colleges of Veterinary Internal Medicine (ACVIM), Veterinary Surgeons (ACVS) and Veterinary Emergency and Critical Care (ACVECC)

REASONS FOR PERFORMING STUDY

A recent survey of European Colleges (European College of Equine Internal Medicine [ECEIM] and European College of Veterinary Surgeons [ECVS]) revealed the different strategies implemented by, and some of the challenges facing, European clinicians presented with cases of post operative ileus (POI). It was concluded that further comparative analysis of opinions, canvassed from additional colleges of equine veterinary specialism worldwide, would provide valuable additional insight into current POI knowledge on a more global scale.

OBJECTIVES

To report and compare the current strategies favoured by American veterinary specialists when managing POI in horses that underwent emergency colic surgery.

STUDY DESIGN

Cross-sectional survey.

METHODS

Electronic invitations were sent to 814 Large Animal specialists, including 3 colleges: the American College of Veterinary Internal Medicine (ACVIM), American College of Veterinary Surgeons (ACVS) and the American College of Veterinary Emergency and Critical Care (ACVECC).

RESULTS

The response rate was 14% (115/814). The majority of respondents (68%) reported an estimated prevalence range of POI of 0-20%. The presence of reflux on nasogastric intubation was the main criterion used to define POI. A lesion involving the small intestine was considered the main risk factor for POI. Anti-inflammatory drugs, intravenous (i.v.) fluids and antimicrobial drugs were the primary strategies used when managing POI. Flunixin meglumine and i.v. lidocaine were the drugs most commonly used in the treatment of horses with POI. Supplementary management strategies targeted mainly the prevention of post operative adhesions, infection and inflammation.

CONCLUSIONS

There is a lack of consensus on the clinical definition of POI. Prospective and objective clinical assessment of the effectiveness of the different strategies contained within this and the European survey is necessary in order to identify a standardised approach to the management of equine POI.

Evaluation of survival rate and athletic ability after nonsurgical or surgical treatment of cleft palate in horses: 55 cases (1986-2008)

OBJECTIVE

To determine survival rate and athletic ability after nonsurgical or surgical treatment of cleft palate in horses.

DESIGN

Retrospective case series.

ANIMALS

55 horses with cleft palate.

PROCEDURES

13 of the 55 horses died or were euthanized without treatment and were not included in all analyses. Medical records were reviewed for signalment, history, method of diagnosis, soft or hard palate involvement, type of surgical procedure performed, postoperative complications, and survival to hospital discharge. Information on athletic ability was acquired from race records and follow-up conversations with owners, trainers, or referring veterinarians.

RESULTS

The predominant reason for initial evaluation was milk or feed in the nostrils (60%). The diagnosis was confirmed by means of videoendoscopy of the upper portion of the airway in all cases. Most cases involved the soft palate only (92.7%). Twenty-six of the 55 (47.3%) horses underwent surgical repair, and 12 of these had dehiscence at the caudal edge of the soft palate. Among potential racehorses, 14 of 33 had surgery. Of these, 12 of 14 survived to discharge and 2 horses raced. Among potential racehorses, 10 of 33 were discharged without surgery and 2 of these raced. Among nonracehorses, 12 of 22 underwent surgery and 11 survived to discharge. All horses that were discharged and for which follow-up information was available survived to 2 years of age or older without ill thrift despite dehiscence at the caudal edge of the soft palate and continued mild nasal discharge.

CONCLUSIONS AND CLINICAL RELEVANCE

Horses with cleft palate had a higher survival rate than previously reported.

Expression of cyclooxygenase-1 and -2 in naturally occurring squamous cell carcinomas in horses

OBJECTIVE

To assess expression of cyclooxygenase (COX)-1 and -2 in naturally occurring squamous cell carcinomas (SCCs) and the analogous normal tissues in horses.

SAMPLE POPULATION

Tissue samples collected from 3 conjunctival, 2 vulvar, 4 preputial, and 5 penile SCCs during surgical excision in 14 horses and from corresponding body regions (conjunctiva [n = 5 horses], vulva [2], prepuce [3], and penis [3]) in 5 horses euthanized for reasons unrelated to neoplasia.

PROCEDURES

Tissue samples were snap frozen in liquid nitrogen and stored at -80 degrees C until analysis. Protein was extracted from the frozen tissues, and western blot analyses were performed. Nonneoplastic and abnormal tissues from each body region were run on the same blot, and blots were run in triplicate. Molecular-weight markers and COX-1 and 2 ovine standards (positive control samples) were run concurrently on the gels; negative control samples were not used.

RESULTS

All tissues, including the nonneoplastic and SCC tissues, expressed both COX-1 and -2 proteins.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that the expression of COX proteins in both nonneoplastic and SCC-affected tissues in horses is markedly different from that in other species. The reason for the potential benefit of COX-2 inhibitors in horses and other species is unknown. Further research needs to be performed to evaluate the efficacy of COX-2 inhibitors as cancer treatments in horses. Investigation of the mechanisms of tumor development in horses should be performed to increase understanding of this disease and ascertain how the mechanisms differ from those in other animals.

Infections in the Equine Abdomen and Pelvis: Perirectal Abscesses, Umbilical Infections, and Peritonitis

This article addresses the pathophysiology, diagnosis, management, and prognosis of several different infections within the equine abdomen and pelvic region. The latest advances in the diagnosis and treatment of perirectal abscesses, umbilical infections, and local and diffuse peritonitis are discussed. Emphasis is placed on recent advances in diagnostics and therapeutics with reference to human literature that may be useful in equine practice.

Ex vivo comparison of a novel tapered-sleeve and traditional full-limb transfixation pin cast for distal radial fracture stabilization in the horse

Distal radial fractures in adult horses are examples of long-bone fractures that are not always amenable to internal fixation. These fractures are often open, contaminated, severely comminuted, and located adjacent to the antebrachiocarpal joint. There have been few studies to improve upon the methods of stabilization of this type of fracture. External coaptation incorporating transfixation pins is one method that has been used to stabilize distal radial fractures in horses (1-3). The purpose of this preliminary study was to compare the load to failure in simulated weight-bearing of a novel tapered-sleeve transfixation pin cast (TSTPC) (4) with the traditional transfixation pin cast (TPC) in an ex vivo distal radial fracture model. Ten adult equine cadaveric forelimbs were randomly placed into a TPC group (n = 5) or a TSTPC group (n = 5). An oblique distal radial osteotomy was created prior to application of fibreglass cast material. The limbs were loaded in a single cycle to failure in simulated weight-bearing using an axial load. The mean load to failure for the TSTPC group (35,814 N) was significantly greater than in the TPC group (22,344 N) (p = 0.003). Tapered sleeves in conjunction with TPC warrant further investigation because they may prolong the life of the fixation, prevent or diminish fractures through the pin sites, and increase the load capacity of external coaptation used to stabilize equine fractures.

Bilateral ureterocystostomy to correct left ureteral atresia and right ureteral ectopia in an 8-month-old standardbred filly

OBJECTIVES

To report the diagnosis and outcome after surgical correction of bilateral distal ureteral anomalies in a Standardbred filly.

STUDY DESIGN

Clinical case report.

ANIMAL

An 8-month-old, 310 kg Standardbred filly with left ureteral atresia and right ureteral ectopia.

METHODS

The filly was admitted for evaluation of incontinence since birth and severe urine scalding of the hindquarters. Diagnosis was made by both direct (cystoscopy and vaginoscopy) and indirect (intravenous pyelography, ultrasonography, and scintigraphy) evaluation of the ureters and bladder. The filly had left ureteral atresia, hydronephrosis, and decreased left-sided renal function and right ureteral ectopia before surgery. Surgical correction was performed on the left by an end-to-side stapled anastomosis technique and on the right by a side-to-side hand-sewn anastomosis technique.

RESULTS

Surgical correction was successful. The filly had no postoperative complications and remained continent 18 months after surgery. Left renal function improved.

CONCLUSION

Ureteral anomalies can be successfully repaired in larger (>300 kg) foals and some renal function may be restored after surgical correction.

CLINICAL RELEVANCE

Scintigraphy should be considered in diagnosis of ureteral anomalies, assessing renal function, and determining prognosis for horses with hydronephrosis caused by ureteral ectopia and atresia.

Unilateral thyroidectomy in 6 horses

OBJECTIVE

To describe the surgical technique, complications, and outcome of thyroidectomy in 6 horses.

STUDY DESIGN

Retrospective study.

ANIMALS

Six horses, 10 to 22 years of age, with unilateral, rapidly enlarging thyroid masses.

METHODS

Medical records between 1985 and 2000 were reviewed for horses that had unilateral thyroidectomy. Retrieved data included signalment, physical, clinical, and ultrasonographic examination findings, surgical technique, complications, and outcome. A minimum of 6 months follow-up was obtained.

RESULTS

Six horses were identified. Three horses had tracheal compression and 2 of these also had exercise intolerance. On ultrasonography (5 horses), the enlarged thyroid ranged from 125 to 990 cm(3), and had either a heterogeneous (1 horse), cystic (2), or homogeneous (2) appearance. En bloc, unilateral thyroidectomy under general anesthesia was performed in all horses. After surgery, 3 horses had ipsilateral laryngeal hemiplegia, but tracheal compression was resolved. Thyroid masses were adenoma (3), C-cell compact carcinoma (1), and adenocarcinoma (1). No tumor recurrence or metastatic disease was reported 6 to 14 months after surgery.

CONCLUSIONS

Unilateral thyroidectomy can be successfully performed in horses with large thyroid tumors, but laryngeal hemiplegia can be an important surgical complication. Ultrasonographic examination is useful to define thyroid enlargement and location but is seemingly not useful to characterize tumor type.

CLINICAL RELEVANCE

Thyroidectomy is an uncommon surgical procedure and has an attendant risk for recurrent laryngeal nerve damage. Laryngoscopic examination before and after surgery and careful isolation of the recurrent laryngeal nerve during surgery is recommended.

Arthroscopic removal of dorsoproximal chip fractures of the proximal phalanx in standing horses

OBJECTIVE

To report a technique for, and outcome after, arthroscopic removal of dorsoproximal chip fractures of a proximal phalanx in standing horses.

STUDY DESIGN

Retrospective study.

ANIMALS OR SAMPLE POPULATION

A total of 104 horses, 1 to 13 years of age, with a dorsoproximal chip fracture of a proximal phalanx.

METHODS

Horses were restrained in standing stocks and sedated with intravenous xylazine, detomidine, or a combination of both drugs. Local analgesia was achieved with 2% mepivacaine administered intra-articularly and by subcutaneous infiltration in a crescent-shaped block dorsal to the fetlock. Sterile drapes were placed on the surgical field, and impervious drapes were used on the hoof and floor. Arthroscopic portals were created in the dorsal pouch of the metacarpophalangeal or metatarsophalangeal joints to remove chip fractures. Statistical analysis was performed on race records for all Thoroughbred racehorses and compared with previously published studies. Operative and hospitalization times were compared with those of the general hospital population, and risks associated with general anesthesia were examined.

RESULTS

No major operative or postoperative complications occurred. Ninety-one percent of racehorses raced after surgery with 78% returning to race at the same or higher level.

CONCLUSION

Standing arthroscopic surgery can be performed successfully to remove dorsoproximal chip fractures of the proximal phalanx.

CLINICAL RELEVANCE

Standing arthroscopic surgery is a valid alternative treatment for experienced surgeons to avoid the expense and potential risks associated with general anesthesia.