Extension large colon resection in 12 horses

Extensive resection (50-75%) of the large colon was performed in 12 horses. Indications for resection were: loss of viability due to large colon volvulus (seven), thromboembolic episode (three), impairment of flow of ingesta due to adhesions (one), or congenital abnormalities (one). The time required to correct the primary cause of abdominal pain and complete the resection ranged from 2.5 to 4.75 hours. Three horses had severe musculoskeletal problems postoperatively and were euthanized in the recovery stall. Four other horses were euthanized early in the postoperative period because of: further large colon infarction (two), ileus (one), or small intestinal problems (one). Five horses survived with no apparent nutritional or metabolic problems during two to three weeks of hospitalization. Clinical data were obtained from these horses from nine months to eighteen months postoperatively and revealed no clinical or clinicopathological abnormalities in four of them; the fifth horse exhibited diarrhea and weight loss four months postoperatively but responded to diet change.     

Large colon resection and anastomosis in horses

Large colon resection and anastomosis was performed in 11 horses at various levels of the colon, using several surgical methods. The level of resection ranged from the pelvic flexure to the cecocolic ligament. Nine of 11 horses survived and at follow-up (4 months to 7 years) were free of clinical signs referable to disease of the gastrointestinal tract. Seven horses could be evaluated as to athletic or reproductive function and all returned to original potential.     

Minimally invasive laser treatment of arytenoid chondritis in horses

Arytenoid chondritis is a performance-limiting condition in horses. The underlying problem is a primary infection in the body or corniculate process of 1 or both arytenoid cartilages of the larynx. When chronic inflammation or abscessation may deform and permanently immobilize the affected cartilages, partial arytenoidectomy is indicated. Before that point, the process can be arrested by local debridement or drainage of the lesions, which has traditionally been accomplished by laryngotomy with the horse under general anesthesia. Infections of the arytenoid cartilages with granulomas and abscesses can be effectively treated in the standing horse by using the diode laser administered by an endoscopically guided ventral stab incision in the cricothyroid membrane.     

Review of injection techniques targeting the sacroiliac region in horses

Local anaesthetic techniques and diagnostic imaging tools are currently used in conjunction with thorough physical and lameness examinations to diagnose sacroiliac disease (SID) in the horse. The deep and inaccessible location of the sacroiliac joint (SIJ), however, often renders diagnostic imaging modalities, such as radiography, nuclear scintigraphy and ultrasonography, unreliable in identifying sacroiliac problems. The equine clinician therefore often has to rely on positive results of local anaesthetic techniques to confirm a diagnosis of SID. Regional infiltration techniques have been described but result in a diffuse distribution of large volumes of local anaesthetic solution throughout the entire lumbosacroiliac region, which is nonspecific to the SIJ and has the potential to produce false positive results. Several periarticular injection approaches to the SIJ have recently been described. A combination of periarticular SIJ injections with the use of modest amounts of local anaesthetic solution provides increased SIJ specificity, but may lead to false negative results in cases where the pain originates from surrounding soft tissues. This article clarifies terminology related to sacroiliac injections, reviews current injection techniques, highlights the advantages and disadvantages of each approach, and investigates injectate volume considerations.     

A technique for resection of invasive tumors involving the trigone area of the bladder in dogs: preliminary results in two dogs

Objective— To describe a surgical technique for resection of the entire bladder neck, including the trigone and proximal urethra in dogs with invasive tumors causing life-threatening urinary tract obstruction.
Study Design— Clinical case reports.
Animals— Dogs (n=2) with bladder tumors.
Methods— Circumferential excision of the bladder neck and proximal urethra with preservation of the neurovascular pedicles was performed to remove a rhabdomyosarcoma (dog 1) and a transitional cell carcinoma (dog 2) involving the trigone and bladder neck that were causing urinary tract obstruction. Reconstruction of the bladder and proximal urethra included bilateral ureteroneocystostomy. Adjuvant chemotherapy was administered postoperatively to both dogs.
Results— Postoperatively, dogs 1 and 2 were continent after 7 and 17 days, respectively, and regained normal urinary function after resolution of a transient pollakiuria. Dog 1 had no evidence of local or regional recurrence; however, a large solitary pulmonary metastatic lesion was diagnosed 8 months later. The dog was euthanatized despite a lack of clinical signs. Dog 2 had at least 1 metastatic lesion in the abdominal wall 6 months later and was euthanatized at 580 days because of renal failure.
Conclusion— En-bloc removal of the bladder neck and proximal urethra with preservation of the dorsal vascular and nervous pedicles, although a technically challenging procedure, can be performed without associated urinary incontinence or bladder wall necrosis.
Clinical Relevance— In dogs with invasive bladder tumors causing life-threatening urinary tract obstruction, resection of the bladder neck and proximal urethra should be considered as a promising surgical alternative to urinary diversion.     

Small intestinal biopsy and resection in standing sedated horses

Diagnostic laparotomy and laparoscopy are surgical techniques commonly used for the investigation of chronic abdominal disease and weight loss. They can both be usefully carried out in the standing sedated horse, allowing a thorough examination of the dorsal abdominal cavity and biopsies to be harvested. Small intestinal disease is an important cause of weight loss and recurrent colic. Inflammatory or neoplastic bowel disease may not always be apparent grossly and histopathological assessment of full thickness biopsies may be required to provide a definitive diagnosis. Details of cases of 15 horses that underwent small intestinal biopsy or enterectomy while sedated and standing are presented. Three incisional infections occurred causing delayed wound healing. Three horses were subjected to euthanasia before hospital discharge: two had persistent gastric reflux and one had colitis. A further six were subjected to euthanasia in the first 4 months due to their underlying inflammatory bowel condition. One horse was subjected to euthanasia for severe laminitis that was presumed to be caused by treatment with a corticosteroid 4 years later, and one died of acute colic 2.3 years after successful resection and anastomosis. Five horses were alive at the time of review, median 2.7, range 1.2–4.3 years. Overall therefore, 3 (20%) horses died during hospitalisation and 5 (33%) were still alive at the end of the study. Results from this series suggest that minimising the number of intestinal biopsies may reduce morbidity, but the underlying pathological process appears to be the most important prognostic factor for survival. Resection and anastomosis in the standing sedated horse proved feasible.     

Digestion in horses after resection or ischemic insult of the large colon

The effect of 60% resection of the large colon vs ischemic insult without resection on the ability of horses to digest grass hay was investigated. Digestion trials were performed on 9 horses before surgery (base line) and 3 weeks, 6 weeks, and 6 months after surgery. The percentage of apparent digestion of crude protein, crude fiber, nitrogen-free extract, calcium, phosphorus, magnesium, manganese, copper, and zinc was calculated. Horses that had resection (n = 5) had decreased apparent digestion of crude protein, crude fiber, and phosphorus 3 weeks after surgery, compared with those in horses with ischemic insults (n = 4) and with base-line values. Horses with ischemic insults also had a decrease in crude protein digestion 3 weeks after surgery, compared with base-line values. All horses returned to base-line values of digestion at the 6-month trials, although horses that had resection had higher fecal concentrations of phosphorus and nitrogen-free extract than did horses with ischemic insult. During the study, all horses had maintained good body condition.     

Comparative serological diagnosis of toxoplasmosis in horses using locally isolated Toxoplasma gondii

A total of 420 serum samples collected from horses of different ages, sexes and breeds, located at some horse farms in Egypt, were used for serological studies. A crude antigen of the locally isolated Toxoplasma gondii tachyzoites from horse tissues (LA) was used for the detection of T. gondii antibodies in horses. It showed good diagnostic efficiency (38.1%) by Enzyme Linked Immunosorbent Assay (ELISA). To increase this efficiency, an affinity purification process was performed. Two fractions were obtained from LA by CNBr-Sepharose 4B affinity column chromatography named; unbound (LAunb) and bound (LAb). LAb showed the highest diagnostic potency (51.7%), while LAunb showed the lowest value (31.7%) using ELISA. The electrophoretic profile of LA (12 bands), LAb (6 bands) and LAunb (6 bands) showed molecular weights ranged from 25.1 to 184.3kDa. The immunoreactive bands of each of the three antigens were identified with infected horse sera by immunoblot assay. Four immunogenic bands of 155.8, 115.1, 83.2 and 66.2kDa were identified in LAb and probably were responsible for the highest diagnostic potency. Examination of horse sera by Indirect Fluorescence Antibody Test (IFAT) at a dilution of 1: 64 and Modified Agglutination Test (MAT) at a dilution of 1: 25 revealed that 170 (40.5%) and 202 (48.1%) had antibodies against T. gondii, respectively. The current research introduces crude and purified fractions (bound and unbound) obtained from the locally isolated tachyzoites (equine origin), which are utilized globally for the first time in detection of T. gondii antibodies in horses. Furthermore, this study recommended utilization of the bound fraction in diagnosis of toxoplasmosis using indirect ELISA which proved better diagnostic potency compared with IFAT and MAT.     

Survival after small intestine resection and anastomosis in horses

The authors examined factors influencing survival in 140 horses that recovered from anesthesia after small intestinal resection between 1968 and 1986, using Kaplan-Meier estimated survival curves and the Cox proportional hazards regression model. Seventy-two horses (51%) died during the initial postoperative period, 19 horses (14%) died after discharge from the hospital, 33 horses (24%) were alive, and 16 horses (11%) were classified as censored. Mean age at surgery was 8 years. Horses 15 years of age or older, Arabians and Stallions, were overrepresented in the hospital population. The most common reason for resection was strangulation of bowel through a mesenteric rent. The mean and 50% median survival times were 1540 and 27 days, respectively. Horses admitted after January 1, 1980, had a significantly longer survival than those admitted before that time. Survival was longer after anastomosis of two small intestinal segments than after anastomosis of a small intestinal segment to the cecum; however, the length of bowel resected and the method of anastomosis had no demonstrable influence on survival. Of the variables studied, the heart rates at presentation and 24 hours after surgery were the most accurate predictors of survival.     

Ileocecal intussusception corrected by resection within the cecum in two horses.

Irreducible ileocecal intussusceptions pose a difficult surgical problem. Strangulating ileocecal intussusceptions involving the ileum and jejunum were identified in 2 horses undergoing exploratory laparotomy because of colic. Surgical correction in both horses was achieved by amputation of the ileocecal intussusception from within the cecal lumen, via typhlotomy. The inverted ileal stump was blindly stapled near the ileocecal orifice after pulling the intussusceptum into the cecum. A jejunocecostomy was performed to reestablish intestinal continuity.     

Evaluation of a minimally invasive arthrodesis technique for the carpometacarpal joint in horses

Objective: To evaluate a minimally invasive technique for arthrodesis of the carpometacarpal (CMC) joint in horses. Study Design: Experimental study. Animals: Healthy horses (n=6). Methods: A 5.5 mm, 3‐drill tract arthrodesis technique was evaluated in 1 randomly selected CMC joint in each of 6 normal horses. Peak vertical ground reaction force (GRF) values were recorded before surgery and at 6, 8, and 12 months thereafter. Radiographic and clinical lameness scores were assigned at regular intervals until 12 months after surgery when the horses were euthanatized. Gross and histologic examinations were performed on the treated CMC joints. Results: After surgery, all horses were lame. Clinical resolution of lameness occurred in 2 by 12 months. Mean peak vertical GRF values significantly differed between treated and nontreated limbs at all recorded time points after surgery. Radiographic scores significantly differed from day 0 at all times after surgery, but did not change significantly after 4 months. Intraarticular bony ankylosis only occurred in 2 horses, based on gross, histologic, and microradiographic examination of sagittal sections of the operated CMC joints. Conclusion: The 5.5 mm, 3‐drill tract arthrodesis technique was considered successful in only 2 of 6 normal CMC joints treated. Greater articular damage may be necessary to achieve arthrodesis in normal horses. Better results may be achieved by technique modification or in horses affected by CMC osteoarthritis.     

Cross-sectional area of the tendons of the tarsal region in Standardbred trotter horses

Reasons for performing study: The assessment of a normal range for cross‐sectional area (CSA) of tendons in the tarsal region is important in order to use them as reference values in the identification of pathological changes of dimensions. Objectives: To provide normal reference values for the CSA of the tendons of the tarsus of Standardbred trotter horses (STH) by means of ultrasonography. Methods: Transverse echographic images of the tendons were obtained at different levels proximodistally; these images were digitised and CSA values (mean ± s.d.) were obtained for each structure. Results: The largest structure corresponded with the lateral digital flexor/caudal tibial tendon complex at Level 1 and the smallest was the medial digital flexor tendon at Level 4. Almost all tendons showed a slight decreasing in their CSA when crossing the tarsus. Conclusions: The normal CSA values of tendinous structures in the tarsal region of the STH are reported. These data could be used as anatomical references. Potential relevance: The establishment of reference values could serve as a tool to discriminate between normal and abnormal dimensions of tarsal tendons in STH. Other horse breeds should need their own reference values.