Treatment of right dorsal ulcerative colitis in a horse

Excessive administration of phenylbutazone was associated with development of right dorsal ulcerative colitis. The clinical signs of right dorsal colitis include chronic colic and weight loss. The laboratory abnormalities include panhypoproteinemia and a high WBC count in the abdominal fluid. Medical management of the chronic colic and protein-losing enteropathy associated with the ulcerative lesions in the right dorsal colon and surgical bypass of the right dorsal colon did not result in long-term resolution of clinical signs. Resection of the ulcerated right dorsal colon through a right lateral approach at the 16th rib resulted in resolution of intestinal protein loss and colic. The results of this case suggest that surgical resection of the ulcerated right dorsal colon may be the recommended treatment for right dorsal ulcerative colitis.     

Ulceration and stricture of the right dorsal colon after phenylbutazone administration in four horses

Four cases of ulceration and stricture of the right dorsal colon were encountered. Ulceration of the right dorsal colon is generally associated with nonsteroidal anti-inflammatory drug (NSAID) toxicosis but there are few reports of stricture following ulceration. All four horses had recent phenylbutazone use: three had been given doses well in excess of the recommended dose and in one the dose was marginally above those recommended but was combined with administration of other NSAIDs. All four horses presented with intermittent low-grade colic, weight loss and ventral oedema. Diarrhoea was also seen in three of them. All had hypoproteinaemia due to severe hypoalbuminaemia, and hyperfibrinogenaemia. Hypoalbuminaemia was less severe in one horse and this horse was successfully managed medically. Two cases were definitively diagnosed at exploratory celiotomy and two at necropsy. Exploratory celiotomy was performed in two horses: one was euthanased at surgery and one was managed successfully with medical treatment and remained normal 1 year after surgery. Medical management included feeding of a low-roughage pelleted ration, corn oil, psyllium mucilloid, and discontinuation of NSAID administration.     

Medical Management of Right Dorsal Colitis in 5 Horses: A Retrospective Study (1987–1993)

Right dorsal colitis in horses has been associated with administration of phenylbutazone. Although reports of right dorsal colitis in this species have described surgical treatment associated with a poor prognosis, we have had success treating this condition medically. This report describes 5 horses with right dorsal colitis confirmed during celiotomy that were initially managed medically. All horses had a history of intermittent abdominal pain; weight loss was noted in only 1 horse. The doses (2.0 to 4.6 mg/kg PO bid) and duration (5 to 30 days) of administration of phenylbutazone were not unusually high relative to those recommended (4.4 mg/kg PO bid). Hypoproteinemia and hypoalbuminemia were observed in all horses at the time of admission; packed cell volume was low in 4 horses, and hypocalcemia was also observed in 4 horses. Three of 5 horses (60%) appeared to respond to dietary management and discontinuation of administration of nonsteroidal anti-inflammatory drugs. Dietary management consisted of feeding pelleted feed, and restricting or eliminating roughage for a period of at least 3 months. Two horses developed strictures of the right dorsal colon. One horse that developed a colonic stricture, possibly because its owners did not comply with recommendations for management, was subsequently treated surgically. The remaining horse that developed a stricture of the right dorsal colon was euthanized. These data indicate that some horses with right dorsal colitis can be successfully managed with medical treatment.     

Nonsteroidal anti‐inflammatory drug associated right dorsal colitis in the horse

Right dorsal colitis in horses is a disease characterised by mucosal ulceration and oedema that is localised to the right dorsal colon. It is considered one of the more severe adverse effects associated with the use of nonsteroidal anti‐inflammatory drugs (NSAIDs), particularly phenylbutazone. Diagnosis is typically made based on a history of NSAID administration, the presence of hypoproteinaemia and hypoalbuminaemia, as well as ultrasound evidence of thickening and oedema of the right dorsal colon wall. Definitive diagnosis is made at surgery or necropsy. Treatment involves discontinuation of NSAID therapy, dietary management, and mucosal protectants such as misoprostol and sucralfate. Prognosis is dependent upon early recognition and appropriate treatment. Horses on prolonged courses of NSAIDs should have frequent monitoring of serum total protein and albumin concentrations, as this is one of the earliest and most consistent clinicopathological findings.     

Right dorsal colitis in the horse: minireview and reports on three cases in Ireland

: Right dorsal colitis (RDC) is an ulcerative inflammatory bowel disorder of the horse that has been associated with the administration of non-steroidal anti-inflammatory drugs (NSAIDs), particularly in horses treated when dehydrated or toxaemic. The acute form of RDC may result in profuse diarrhoea, severe colic, dehydration, endotoxic shock and even death; the chronic form may be manifest by mild to moderate intermittent colic, ventral oedema and weight loss with or without diarrhoea. The most consistent laboratory findings are anaemia, hypoproteinaemia, hypoalbuminaemia and hypocalcaemia. Medical management of RDC requires avoidance of NSAIDs, of stressful experiences and of large-volume diets. Specific medications such as sucralfate and metronidazole have been used to treat RDC in the horse. The use of dietary additions such as psyllium and corn oil has been mentioned in the literature.RDC has not been reported previously in Ireland or Britain; here we report that the condition was diagnosed in three horses in Ireland on the bases of a history of phenylbutazone therapy, clinical signs, clinical pathology and ultrasonography. In two of the three horses the diagnosis was confirmed by direct inspection of the affected colon at celiotomy.     

THE APPLICATION OF TECHNETIUM-99m HEXAMETHYLPROPYLENEAMINE OXIME (99mTc-HMPAO) LABELED WHITE BLOOD CELLS FOR THE DIAGNOSIS OF RIGHT DORSAL ULCERATIVE COLITIS IN TWO HORSES

The application of 99mTc-HMPAO labeled white blood cells to support the diagnosis of right dorsal ulcerative colitis was studied in two horses with a history and clinical signs consistent with phenylbutazone toxicity. These images were compared to a reference horse unaffected by right dorsal ulcerative colitis. Blood was collected aseptically in heparinized syringes from the patients for in vitro white blood cell (WBC) radiolabeling. The buffy coat was separated out and radiolabeled with 99mTc-HMPAO. The radiolabeled blood was re-injected i.v. and four images of the right and left side of the patient's abdomen were acquired at 4 hours and 20 hours post-injection. Results of the nuclear study revealed no abnormal findings in the abdomen at the four-hour post-injection images in any horse. Images obtained 20 hours post-injection revealed a linear uptake of radiolabeled WBCs in the right cranioventral abdomen in the region of the right dorsal colon in both horses with right dorsal ulcerative colitis. The reference horse had no radiopharmaceutical uptake in this region. This nuclear imaging study was a rapid, non-invasive method to identify right dorsal colon inflammation. These findings not only supported the diagnosis of right dorsal ulcerative colitis, but also facilitated appropriate medical management of each horse.     

Determination of the acid-base status in 50 horses admitted with colic between December 1998 and May 1999

The purpose of the present study was to investigate the acid-base status and the concentration of organic acids in horses with colic caused by various disorders. Blood samples were collected from 50 horses with colic and from 20 controls. No intravenous fluids had been given prior to sample collection. Identified causes of colic included gastric ulceration, small intestinal volvulus, cecal intussusception, cecal rupture, colonic impaction, left dorsal colon displacement, right dorsal colon displacement, colonic volvulus, colitis, peritonitis, and uterine torsion. Thirty-seven horses recovered from treatment of colic, 8 horses were euthanized, and 5 died. Most cases were not in severe metabolic acidosis. In previous studies, most horses presented for diagnosis and treatment of colic were in metabolic acidosis and in shock.     

Effectiveness of administration of phenylbutazone alone or concurrent administration of phenylbutazone and flunixin meglumine to alleviate lameness in horses

OBJECTIVE: To determine the effectiveness of administering multiple doses of phenylbutazone alone or a combination of phenylbutazone and flunixin meglumine to alleviate lameness in horses. ANIMALS: 29 adult horses with naturally occurring forelimb and hind limb lameness. PROCEDURES: Lameness evaluations were performed by use of kinematic evaluation while horses were trotting on a treadmill. Lameness evaluations were performed before and 12 hours after administration of 2 nonsteroidal anti-inflammatory drug (NSAID) treatment regimens. Phenylbutazone paste was administered at approximately 2.2 mg/kg, PO, every 12 hours for 5 days, or phenylbutazone paste was administered at approximately 2.2 mg/kg, PO, every 12 hours for 5 days in combination with flunixin meglumine administered at 1.1 mg/kg, IV, every 12 hours for 5 days. RESULTS: Alleviation of lameness was greater after administration of the combination of NSAIDs than after oral administration of phenylbutazone alone. Improvement in horses after a combination of NSAIDs did not completely mask lameness. Five horses did not improve after either NSAID treatment regimen. All posttreatment plasma concentrations of NSAIDs were less than those currently allowed by the United States Equestrian Federation Inc for a single NSAID. One horse administered the combination NSAID regimen died of acute necrotizing colitis during the study. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of a combination of NSAIDs at the dosages and intervals used in the study reported here alleviated the lameness condition more effectively than did oral administration of phenylbutazone alone. This may attract use of combinations of NSAIDs to increase performance despite potential toxic adverse effects.     

Ultrasonographic findings in horses with right dorsal colitis: five cases (2000-2001)

OBJECTIVE: To determine whether ultrasonography would be useful in the diagnosis of right dorsal colitis in horses. DESIGN: Retrospective study. ANIMALS: 5 horses with right dorsal colitis and 15 healthy adult horses. PROCEDURE: Mural thickness and appearance of the right dorsal colon were determined from ultrasonographic images obtained at right intercostal spaces 10, 11, 12, 13, and 14. RESULTS: The right dorsal colon could be imaged most consistently at the right 11th, 12th, and 13th intercostal spaces, below the margin of the lung and axial to the liver. Mural thickness measured from ultrasonographic images was significantly greater in horses with right dorsal colitis than in healthy horses. The right dorsal colon in affected horses had a prominent hypoechoic layer associated with submucosal edema and inflammatory infiltrates. Successful treatment of 1 horse with right dorsal colitis was associated with a decrease in mural thickness coincident with an increase in serum albumin and total protein concentrations and weight gain. A decrease in mural thickness was also observed in a second horse treated for right dorsal colitis that was not associated with healing of the right dorsal colon or an increase in serum albumin concentration but rather thinning of a segment of the right dorsal colon that eventually ruptured. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that ultrasonographic measurement of mural thickness and evaluation of the appearance of the right dorsal colon may be useful in the diagnosis of right dorsal colitis in horses.     

BEVA primary care clinical guidelines: Analgesia

Primary care guidelines provide a reference point to guide clinicians based on a systematic review of the literature, contextualised by expert clinical opinion. These guidelines develop a modification of the GRADE framework for assessment of research evidence (vetGRADE) and applied this to a range of clinical scenarios regarding use of analgesic agents. Key guidelines produced by the panel included recommendations that horses undergoing routine castration should receive intratesticular local anaesthesia irrespective of methods adopted and that horses should receive NSAIDs prior to surgery (overall certainty levels high). Butorphanol and buprenorphine should not be considered appropriate as sole analgesic for such procedures (high certainty). The panel recommend the continuation of analgesia for 3 days following castration (moderate certainty) and conclude that phenylbutazone provided superior analgesia to meloxicam and firocoxib for hoof pain/laminitis (moderate certainty), but that enhanced efficacy has not been demonstrated for joint pain. In horses with colic, flunixin and firocoxib are considered to provide more effective analgesia than meloxicam or phenylbutazone (moderate certainty). Given the risk of adverse events of all classes of analgesic, these agents should be used only under the control of a veterinary surgeon who has fully evaluated a horse and developed a therapeutic, analgesic plan that includes ongoing monitoring for such adverse events such as the development of right dorsal colitis with all classes of NSAID and spontaneous locomotor activity and potentially ileus with opiates. Finally, the panel call for the development of a single properly validated composite pain score for horses to allow accurate comparisons between medications in a robust manner.     

Ultrasonographic visualization of colonic mesenteric vasculature as an indicator of large colon right dorsal displacement or 180�� volvulus (or both) in horses

Visualization of colonic mesenteric vasculature during transabdominal ultrasonographic examination of horses with colic can be a predictor of right dorsal displacement of the large colon or 180° large colon volvulus, or both. Medical records of 82 horses having had surgical treatment of colic and having received a transabdominal ultrasonographic examination on admission were reviewed. Colonic mesenteric vessels were sonographically identified coursing laterally on the right side of the abdomen in 24 of the 82 cases. Horses with colonic vessels identified on ultrasound were 32.5 times more likely to be diagnosed at surgery with either large colon right dorsal displacement or 180° large colon volvulus than those in which vessels were not seen (P < 0.001). Visualization of colonic mesenteric vessels on ultrasound provided a sensitivity of 67.7%, specificity of 97.9%, positive predictive value of 95.8%, and negative predictive value of 81% for large colon right dorsal displacement or 180° large colon volvulus, or both.     

Experimental Large Colon Resection at the Cecocolic Ligament in the Horse

Ten normal horses had approximately 95% of the length of the large colon resected with a side-to-side anastomosis between right ventral and right dorsal colon performed with surgical stapling equipment. Four horses died shortly after surgery of colitis (1 horse) or failure of the TA 90 transection staple line (3 horses). Another horse died 4 months after surgery from disseminated streptococcal infection but had recovered well from the colon resection. Five horses survived long term (18 months) with no clinical evidence of adverse effects of the resection. Surviving horses had weight loss and soft fecal consistency for 3 to 12 weeks after surgery but returned to preoperative values within 12 months. At a second surgery 1 year later (5 horses) or at necropsy 4 months later (1 horse), fibrous omental adhesions were present over the transection staple line in four horses and over the anastomotic staple line in two horses. Omental adhesions to the everted staple line were moderate but not associated with any clinical sequellae. An incisional hernia was present in one horse. The anastomotic stomata measured between 8 and 9 cm, which was 60% of the size of the original surgically created stomata. Failure of the transection staple line occurred in the first three of five horses in which the procedure was attempted due to improper configuration of the staples or crushing of the tissue between the staples. Experience corrected this complication.     

Inflammatory bowel disease characterized by multisystemic eosinophilic epitheliotropic disease (MEED) in a horse in Saskatchewan,Canada

A 3-year-old Quarter Horse gelding was evaluated for chronic weight loss, diarrhea, and pruritus. Physical examination revealed several ulcerative lesions on the skin and mucosal membranes. Diagnostic imaging findings were consistent with enteritis, typhlitis, and colitis. Multisystemic eosinophilic epitheliotropic disease (MEED) was diagnosed upon necropsy. This disease may be considered a form of equine inflammatory bowel disease complex which can be challenging to diagnose, requiring histological assessment, and in some cases, the use of immunohistochemical markers.Key clinical message:Multisystemic eosinophilic epitheliotropic disease is challenging to diagnose but should be considered in horses with chronic weight loss that fail to respond to conventional treatment for concurrent diarrhea and skin lesions.     

In vitro investigation of the effect of prostaglandins and nonsteroidal anti-inflammatory drugs on contractile activity of the equine smooth muscle of the dorsal colon, ventral colon, and pelvic flexure

OBJECTIVES: To determine the in vitro effect of prostaglandin E2 (PGE2), PGF2alpha, PGI2; and nonsteroidal anti-inflammatory drugs (NSAID; ie, flunixin meglumine, ketoprofen, carprofen, and phenylbutazone) on contractile activity of the equine dorsal colon, ventral colon, and pelvic flexure circular and longitudinal smooth muscle. ANIMALS: 26 healthy horses. PROCEDURE: Tissue collected from the ventral colon, dorsal colon, and pelvic flexure was cut into strips and mounted in a tissue bath system where contractile strength was determined. Incremental doses of PGE2, PGF2alpha,, PGI2, flunixin meglumine, carprofen, ketoprofen, and phenylbutazone were added to the baths, and the contractile activity was recorded for each location and orientation of smooth muscle. RESULTS: In substance P-stimulated tissues, PGE2 and PGF2alpha enhanced contractility in the longitudinal smooth muscle with a decrease or no effect on circular smooth muscle activity. Prostaglandin I2 inhibited the circular smooth muscle response with no effect on the longitudinal muscle. The activity of NSAID was predominantly inhibitory regardless of location or muscle orientation. CONCLUSIONS AND CLINICAL RELEVANCE: In the equine large intestine, exogenous prostaglandins had a variable effect on contractile activity, depending on the location in the colon and orientation of the smooth muscle. The administration of NSAID inhibited contractility, with flunixin meglumine generally inducing the most profound inhibition relative to the other NSAID evaluated in substance P-stimulated smooth muscle of the large intestine. The results of this study indicate that prolonged use of NSAID may potentially predispose horses to develop gastrointestinal tract stasis and subsequent impaction.     

Colopexy of the Left Large Colon to the Right Large Colon in the Horse

Three colopexy techniques were examined in 11 normal horses to determine which would prevent recurrence of targe colon displacement and volvulus. The medial free band of the left ventral colon was sutured to the medial free band of the right ventral colon (technique A). The free band of the left dorsal colon was sutured to the free band of the right dorsal colon (technique B). In technique C, both the ventral and dorsal colon were sutured as in techniques A and B, and the pelvic flexure was sutured to the mesocolon between the right dorsal and right ventral colon. Absorbable (surgical gut) and nonabsorbable (polypropylene) suture material were compared.
One horse from each group was euthanized 2 weeks and 6 months after surgery. The position of the colon and the integrity of the colopexy were examined. At necropsy, attempts were made to produce displacement and volvulus of the colon. In the remaining horses, exploratory celiotomy 1 year after surgery was used to examine the integrity of the colopexy.
Although all horses initially lost weight after surgery, all but one began gaining weight 2 to 4 weeks later and had attained their preoperative weight by 6 months. The horse that continued to lose weight was euthanized 2 months after surgery. Numerous small colon, omental, and large colon adhesions were found at necropsy.
For all colopexy techniques, the colopexy adhesion remained short and intact at polypropylene suture sites. At surgical gut sites, the adhesion had lengthened by 6 months and was absent at 1 year. At necropsy, all colopexies prevented manual displacement of the large colon and volvulus of the colon at the sternal and diaphragmatic flexures. The colopexies did not prevent manual creation of volvulus at the base of the colon. Technique A was the easiest to perform.     

Nutritional considerations for horses with colitis. Part 1: Nutrients and enteral nutrition

The equine colon is the primary site of fibre digestion and water absorption. It is therefore not surprising that colitis and associated colonic dysfunction can result in severe nutritional derangements, which can be exacerbated by reduced feed intake in affected horses. Dietary management of colitis is important for optimum recovery. In broad terms, it should prioritise provision of nutrients to horses that otherwise have reduced appetites. In some forms, such as right dorsal colitis, as well as those with chronicity, nutritional recommendations include restricting or eliminating long‐stem roughage from the diet and feeding a complete pelleted diet. Voluntary enteral nutrition is preferred, but horses that are not ingesting enough to meet the minimum recommended requirements as outlined, should be fed via nasogastric tube (if tolerated – no reflux, no ileus and no colic present; faecal output present). Parenteral nutrition may be necessary in some cases, as some colitis cases do not tolerate enteral feeding for reasons such as colic, intestinal dysmotility or abdominal distension. Timing and constitution of nutritional intervention is vital and should be tailored to the individual patient to prevent further complications of the disease process.     

A retrospective study of gastrointestinal disorders in a predominantly Austrian leisure horse referral hospital population

The aim of our retrospective study was to produce and analyse epidemiological data on gastrointestinal (GI) disorders of Austrian leisure horses. Case records of horses referred to the Equine Clinic of the Veterinary University of Vienna were collected from an electronic hospital information system using its search options. All cases reported to have suffered a GI disorder between March 2003 and February 2015 were selected. In this period of 4314 days, data of 1833 GI cases, mostly accompanied by colic signs, were analysed. The vast majority of our GI cases appeared in the abdominal parts of the GI tract 96% (1760/1833) while just 1.3% (24/1833) could be definitively attributed to oesophageal disorders, whereas in 2.7% (49/1833) of the cases a definitive diagnosis could not be made. The highest prevalence of GI disorders was seen in July and October/November. A breakdown of figures for cases clustered under the colic syndrome showed that colon impactions in left ventral large and/or pelvic flexure (35%) were the major problem followed by gastric disorders (18%), spasmodic colic (9%), enteritis (7%), caecal tympany (6%); caecal impaction (4%), colitis (3%), abnormal anatomical positions of large colon including complete and partial strangulation/volvulus, nephrosplenic entrapment of the left ventral and dorsal colon and right dorsal displacement of the large colon (3%) and small intestinal volvulus (2.7%). In 12% of the cases, the cause of the abdominal discomfort was likely idiopathic paralytic ileus. The searching tool of the electronic patient data also brought up cases with malabsorbtion/IBD syndrome and GI ruptures, both these contributed less than 1% of the referred GI cases. Results suggested that the causes of colic are diverse, but the major reasons for referred cases of colic in the east Austrian horse population are large colon impaction or displacements. Seasonal distribution and specific causes of gastrointestinal disorders should be considered essential components of the initial clinical assessment of horses presenting with colic.     

Effects of phenylbutazone alone or in combination with flunixin meglumine on blood protein concentrations in horses

OBJECTIVE: To assess effects of treatment with phenylbutazone (PBZ) or a combination of PBZ and flunixin meglumine in horses. ANIMALS: 24 adult horses. PROCEDURE: 13 horses received nonsteroidal antiinflammatory drugs (NSAIDs) in a crossover design. Eleven control horses were exposed to similar environmental conditions. Treated horses received PBZ (2.2 mg/kg, PO, q 12 h, for 5 days) and a combination of PBZ and flunixin meglumine (PBZ, 2.2 mg/kg, PO, q 12 h, for 5 days; flunixin meglumine, 1.1 mg/kg, IV, q 12 h, for 5 days). Serum samples were obtained on day 0 (first day of treatment) and day 5, and total protein, albumin, and globulin were measured. RESULTS: 1 horse was euthanatized with severe hypoproteinemia, hypoalbuminemia, and colitis during the combination treatment. Comparisons revealed no significant difference between control horses and horses treated with PBZ alone. There was a significant difference between control and treated horses when administered a combination of PBZ and flunixin meglumine. Correction for horses with values >2 SDs from the mean revealed a significant difference between control horses and horses administered the combination treatment, between control horses and horses administered PBZ alone, and between horses receiving the combination treatment and PBZ alone. Gastroscopy of 4 horses revealed substantial gastric ulcers when receiving the combination NSAID treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of results of the study indicates the need for caution when administering a combination NSAID treatment to horses because the detrimental effects may outweigh any potential benefits.     

Diagnosis and surgical treatment of functional obstruction of the right dorsal colon in a horse

Functional obstruction of the right dorsal colon was found at surgery in a 6-year-old American Saddlebred gelding with a history of anorexia, depression, weight loss, and intermittent colic. Side-to-side anastomosis of the right dorsal colon to the small colon was done to bypass the obstruction. Histopathologic findings of the right dorsal colon and regional colonic lymph nodes were unremarkable. Surgical treatment was successful.     

Right Dorsal Colon Resection and Bypass for Treatment of Right Dorsal Colitis in a Horse

Objective: To describe a novel surgical technique for management of right dorsal colitis in the horse. Study Design: Clinical report. Animals: 14‐year‐old Warmblood gelding. Methods: The horse was referred for treatment of a stromal abscess and signs of right dorsal colitis. Plasma chemistry revealed marked hypoproteinemia. Abdominal ultrasonographic examination showed a thickened right dorsal colon (RDC). Medical treatment was unsuccessful. With the horse in left lateral recumbency under general anesthesia, an approach to the right side of the abdomen through a 16th rib resection was made. The thoracic cavity was entered during the approach. Surgical resection of the RDC and side‐to‐side anastomosis of the diaphragmatic flexure to the small colon (bypass) was performed. The thoracic cavity was closed by attaching the diaphragm to the body wall and air was removed at the completion of surgery. Results: Resection of the RDC and bypass of the resected area was successfully performed. The colic signs and hypoproteinemia resolved. Complications of surgery included a deep surgical site infection with development of a large intrathoracic abscess. The abscess was managed with drainage and long‐term antimicrobial treatment. Conclusion: Right dorsal colitis can be treated successfully with resection and bypass of the RDC. In cases where the thoracic cavity is penetrated during the abdominal approach, the diaphragm should be sutured to the body wall at the beginning of surgery to avoid development of an infection within the thoracic cavity. Clinical Relevance: RDC resection and bypass may be an alternative approach for management of horses with right dorsal colitis.