Treatments to promote colonic hydration: enteral fluid therapy versus intravenous fluid therapy and magnesium sulphate

Although large intestine impactions are commonly treated with i.v. fluids combined with the osmotic laxative MgSO4, enteral fluids are less expensive and also appear to be efficacious for impactions. Therefore, this study was conducted to compare the systemic and gastrointestinal effects of enteral fluids with the changes produced by i.v. fluids combined with MgSO4. Four horses with a fistula in the right dorsal colon alternately received both treatments in 2 periods one week apart. Sixty litres of fluids were administered continuously (10 l/h) through a venous catheter or a nasogastric tube. Magnesium sulphate (1 g/kg bwt) was administered via nasogastric tube before i.v. fluid therapy. Two horses had mild abdominal discomfort at the end of enteral fluid therapy. Pollakiuria, hypostenuria, increased bodyweight, increased faecal and ingesta hydration, and decreased PCV, plasma protein and plasma magnesium were produced by both treatments. Abdominal distention and more pronounced changes in bodyweight and ingesta hydration were seen with enteral fluids. Intravenous fluids plus MgSO4 produced hypocalcaemia and more pronounced changes in plasma protein. These results indicate that enteral fluid therapy is more effective in promoting ingesta hydration and produces less pronounced systemic effects than i.v. fluid therapy plus MgSO4.     

The duodenum: An uncommon site of surgical lesions

It is fortunate for the horse that duodenal lesions requiring surgical correction occur infrequently. Despite being an uncommon site of obstruction, palpation of the duodenum should be part of a complete surgical abdominal exploration. Horses with proximal obstruction typically have large volumes of reflux following passage of a nasogastric tube. Biochemistry abnormalities may include hypochloraemia and hyperglycaemia particularly with a complete or strangulating obstruction. Early surgical treatment of a duodenal volvulus may result in a favourable outcome.     

Use of a carbonated beverage to disintegrate a phytobezoar obstructing the intrathoracic portion of the oesophagus of a horse

This report describes the treatment of a 17-year-old American Quarter Horse gelding for an oesophageal obstruction of approximately 24 h’ duration. An intraluminal oesophageal mass resembling a phytobezoar and located close to the cardia, was observed during endoscopic examination of the oesophagus of a horse showing signs of oesophageal obstruction. An intrathoracic oesophageal diverticulum, filled with fluid, was observed about 40 cm proximal to the obstruction. The end of a nasogastric tube was guided beyond the diverticulum, using gastroscopic observation, so that its tip rested close to the obstruction. The obstruction failed to disintegrate or move into the stomach despite vigorous, prolonged lavage. With the nasogastric tube left in place, and the horse's head elevated, 0.5 L cola was administered adjacent to the obstruction through the nasogastric tube. The head was maintained in the elevated position for an hour, after which time the head was lowered and oesophageal lavage resumed. The nasogastric tube was passed into the stomach within 3 min of re-instituting lavage. The successful use of a carbonated beverage to treat human patients for oesophageal or gastrointestinal obstruction caused by a phytobezoar is well documented. Carbonated beverages have also been reported to be effective in treating horses for gastric and enteric impactions caused by persimmon seeds. Administering cola into the oesophagus may help resolve oesophageal obstruction of horses caused by a phytobezoar or impacted feed material when horses are refractory to other treatments.     

Surgical management of small intestinal incarceration through the gastrosplenic ligament: 14 cases (1994-2006)

OBJECTIVE: To determine prevalence, clinical findings, and long-term survival rate after surgery associated with incarceration of the small intestine through the gastrosplenic ligament (ISIGL) in horses. DESIGN: Retrospective case series. ANIMALS: 14 horses with ISIGL. PROCEDURES: Medical records of horses with ISIGL examined between January 1994 and December 2006 were reviewed. Signalment, initial physical examination findings, results of abdominal fluid analysis, and clinical laboratory values were recorded, along with surgical findings, including segment of incarcerated intestine and surgical procedures performed. Long-term survival data were obtained through client interviews. RESULTS: Clinical findings included small intestinal distention identified via rectal palpation (10/14 horses) or transabdominal ultrasonography (8/11), nasogastric reflux (4/14), and abnormal abdominal fluid (9/9). All horses required intestinal resection and anastomosis. Postoperative complications included adynamic ileus (5/14 horses), incisional infection (4/14), diarrhea (3/14), and laminitis (1/14). No breed or age predilection was detected, although geldings were at increased risk for ISIGL. Long-term survival rate was 79% (11/14 horses). CONCLUSIONS AND CLINICAL RELEVANCE: ISIGL was an uncommon cause of colicin this hospital population. With appropriate surgical intervention and postoperative management, the long-term prognosis for surgically treated horses was fair to good.     

Bypass Surgery for the Treatment of Small Intestinal Ileus in the Horse A Report of Three Cases

The medical management of three horses with simple and strangulating small intestinal obstructions was unsuccessful and was therefore supported by surgical bypasses. Jejunocecostomies were used to treat horses with postoperative paralytic ileus that was unresponsive to medical management. These horses had abdominal pain, gastric distention, heart rate elevations greater than 60/minute, and small intestinal distention on rectal palpation. Two horses experienced weight loss which responded to bypass removal. The bypass effectively decreased the need for intravenous fluid administration and repeated nasogastric intubation.     

Use of a nasogastric tube for gastric and esophageal decompression in the dog and cat

Distension of the stomach with air and fluid was treated successfully in 9 of 10 dogs by use of an indwelling nasogastric tube. A nasogastric tube was used to remove swallowed air and gastric fluid after surgery, as a precautionary measure to prevent recurrence of gastric distention in 2 dogs. A nasoesophageal tube was used to remove retained barium sulfate and saliva in a cat with megaesophagus and esophageal obstruction caused by gastroesophageal intussusception. Passage of the tube through the nose into the esophagus or stomach was easily accomplished in 10 of the 13 animals, requiring only mild restraint and an anesthetic instilled locally into the nostril. Moderate restraint and more than one attempt at passage of the tube through the nose (ventral meatus) were required in the other 3 animals. In one of these, passage through the ventral meatus and into the pharynx could not be accomplished. Of the 12 animals in which the tube was inserted successfully, 11 tolerated it. The tubes remained inserted from 5 minutes to 48 hours (average, 18.5 hours) without clinically detected complications. This technique offers an alternative to orogastric, gastrostomy, or pharyngostomy tubes for initial and continuous intubation and decompression of the stomach and/or esophagus in the dog and cat. It was found to be practical and effective for the removal of air or fluid, but not the removal of coarse food particles.     

Effect of an indwelling nasogastric tube on gastric emptying rates of liquids in horses

OBJECTIVE: To evaluate the effect of an indwelling nasogastric tube on gastric emptying of liquids in horses. ANIMALS: 9 healthy adult horses. PROCEDURE: A randomized block crossover design was used. For treatment group horses, a nasogastric tube was placed and 18 hours later, acetaminophen was administered; the nasogastric tube remained in place until the experiment was complete. For control group horses, a nasogastric tube was passed into t stomach, acetaminophen was administered, and the nasogastric tube was removed immediately. Serial blood samples were collected 15 minutes before and after administration of acetaminophen. Serum concentration of acetaminophen was determined by use of fluorescence polarization immunoassay. The variables, time to maximum acetaminophen concentration (Tmax) and the appearance constant for acetaminophen (Kapp), were determined. The values for Kapp and Tmax in horses with and without prolonged nasogastric tube placement were compared. RESULTS: No significant difference was found in Kapp between horses with and without prolonged nasogastric tube placement; the median difference in Kapp was 0.01 min(-1) (range, -0.48 to 0.80 min(-1). No significant difference was found in Tmax between horses with and without prolonged nasogastric tube placement; the median difference in Tmax was 5 minutes (range, -30 to 50 minutes). Reanalysis of data following the removal of possible outlier values from 1 horse resulted in a significant difference in Tmax between horses with and without prolonged nasogastric tube placement. CONCLUSIONS AND CLINICAL RELEVANCE: Although no clinically important impact of 18 hours of nasogastric intubation was found on gastric emptying in healthy was found among horses.     

Predictive values,sensitivity and specificity of abdominal fluid variables in determining the need for surgery in horses with an acute abdominal crisis

OBJECTIVE: To determine the predictive values, sensitivity and specificity of abdominal fluid variables associated with the need for surgery in horses with an acute abdominal crisis. DESIGN: Retrospective study. ANIMALS: Two-hundred and thirty-six horses examined for signs of abdominal pain between January 1993 and June 1999. METHODS: Breed, age and gender of the horse and colour, total protein concentration and total nucleated cell count of an abdominal fluid sample were recorded. Colour of the abdominal fluid was classified as normal if it was yellow and transparent. Turbid fluid or fluid that was serosanguinous or other colours was classified as abnormal. Protein concentration < or = 20 g/L and a total nucleated cell count < or = 5 x 10(9) cells/L were considered normal and values above these were considered abnormal. An abdominal fluid sample was classified as abnormal if one or more of the three variables were considered abnormal. Cases were defined as surgical when lesions identified at surgery or necropsy examination would not have resolved with medical treatment alone. Cases were defined as medical in horses that survived without surgical intervention, and those with a lesion found at surgery or necropsy that would have resolved with medical treatment alone. A third category was identified during the study as those diagnosed with Actinobacillus equuli--induced peritonitis. These horses were included in the study but not in the data analysis. DATA ANALYSIS: The association between the sensitivity, specificity and positive and negative predictive value of colour, total protein, and total nucleated cell count in the abdominal fluid and the need for surgery was calculated. RESULTS: There were 100 females and 136 males of mixed breeds, ranging from 3 days to 26 years of age that had an abdominocentesis performed during the specified period. There were 97 horses with a lesion classified as surgical, 91 horses with a lesion classified as medical and 48 horses with a diagnosis of A equuli-induced peritonitis. Colour of the abdominal fluid was recorded in all horses, protein concentration was recorded in 194 horses and total nucleated cell count was recorded in 179 horses. Abnormal abdominal fluid colour had a sensitivity, specificity, positive and negative predictive value of 92%, 74%, 79% and 89% respectively, associated with the need for surgery. Sensitivity, specificity, positive and negative predictive values for a serosanguinous abdominal fluid sample associated with the need for surgery were 48%, 99%, 98% and 64% respectively. Abnormal abdominal fluid protein concentration had a sensitivity, specificity, positive and negative predictive value of 86%, 75%, 77% and 85% respectively, associated with the need for surgery. The sensitivity, specificity, positive and negative predictive value associated with the need for surgery in horses with an abnormal total nucleated cell count in the abdominal fluid were 59%, 75%, 67% and 67%, respectively. An abdominal fluid sample classified as abnormal had a sensitivity, specificity, positive and negative predictive value of 92%, 74%, 79% and 89% respectively, associated with the need for surgery. CONCLUSION: Results of this study suggest that abdominal fluid sample analysis contributes to the decision to proceed to surgery, but is not a diagnostic panacea. Colour and protein concentration of abdominal fluid were the most useful variables in abdominal fluid for differentiating medical and surgical lesions. Colour and protein had a greater value in horses with a disease likely to respond to medical treatment (negative predictive value) than those with a lesion requiring surgery (positive predictive value) except when the fluid was serosanguinous. Abdominal fluid colour and protein are clinically relevant and easily measured in the field, providing immediate information without the need for sophisticated laboratory techniques.     

Maxillary-mandibular wiring for the management of caudal mandibular fractures in two cats

Maxillary-mandibular wiring was used for mandibular immobilisation and maintenance of proper dental occlusion in two cats with caudal mandibular fractures. Alimentation was provided to one cat via a gastrostomy tube and to the other cat via a nasogastric tube during the seven day period the maxillary-mandibular wires were maintained. Both cats had normal occlusion and mandibular function at the time of discharge from the hospital and at follow-up examination.     

The effect of oxytocin on contractility of the equine oesophagus: a potential treatment for oesophageal obstruction

This study was performed to determine the effect of administration of i.v. oxytocin on the contractility of the musculature associated with the equine oesophagus. Nine clinically normal horses were fitted with a nasogastric tube modified with inflatable latex cuffs. These cuffs were connected to piezoelectric pressure recording devices. Oxytocin in 3 different doses or saline controls were administered i.v. in a randomised block pattern. Systolic blood pressure, ECG, heart rate and nasogastric tube cuff pressures were then measured for 60 min. Administration of oxytocin i.v. at 0.11 and 0.22 iu/kg bwt, resulted in a short-term statistically significant relaxation of the musculature of the equine oesophagus. When oxytocin was administered at 0.11, 0.22 and 0.44 iu/kg bwt, no clinically significant cardiovascular changes were seen. In approximately 5% of the oxytocin administrations, signs of mild short-term abdominal discomfort were observed. In clinical cases of noncomplicated oesophageal obstruction, it is suggested that reduction in tone of oesophageal musculature may result in passage of oesophageal obstructions with reduced risk of oesophageal injury when compared to other traditional treatments.     

Cecocecal intussusception in a pony: A case report

A 14-year-old Welsh-cross gelding was referred to Texas Veterinary Medical Center's Teaching Hospital because of mild to moderate abdominal pain of 48 hours duration. The referring veterinarian rectally palpated a grapefruit-sized firm mass in the anterior ventral abdomen. The pony had been treated with flunixin meglumine^a (1.0 mg/kg, IV) and mineral oil (2 liters) via nasogastric tube.     

Successful treatment of a pancreatic pseudocyst by omentalisation in a dog

CASE HISTORY: A 3-year-old male Labrador retriever was presented with a history of dietary indiscretion followed by vomiting and abdominal pain. CLINICAL FINDINGS AND TREATMENT: Abdominal ultrasonography revealed the presence of a fluid-filled cystic structure in the region of the pancreas. Flocculent, dark fluid was drained from the cystic structure during exploratory celiotomy prior to resection of the lateral cystic wall. Omentum was sutured into the cystic cavity to provide drainage and enhance immune response. A jejunostomy feeding tube was placed. Post-surgical care consisted of antibiotic therapy. The dog was clinically normal at 1 and 7 months post-operatively and the pancreas appeared normal on final ultrasonographic examination. CLINICAL RELEVANCE: This case describes the use of omentum to provide physiological drainage of a pancreatic pseudocyst. This surgical technique may help clinicians manage patients with this condition in the future.     

Successful treatment of a pancreatic pseudocyst by omentalisation in a dog

CASE HISTORY A 3-year-old male Labrador retriever was presented with a history of dietary indiscretion followed by vomiting and abdominal pain.

CLINICAL FINDINGS AND TREATMENT: Abdominal ultrasonography revealed the presence of a fluid-filled cystic structure in the region of the pancreas. Flocculent, dark fluid was drained from the cystic structure during exploratory celiotomy prior to resection of the lateral cystic wall. Omentum was sutured into the cystic cavity to provide drainage and enhance immune response. A jejunostomy feeding tube was placed. Post-surgical care consisted of antibiotic therapy. The dog was clinically normal at 1 and 7 months post-operatively and the pancreas appeared normal on final ultrasonographic examination.

CLINICAL RELEVANCE: This case describes the use of omentum to provide physiological drainage of a pancreatic pseudocyst. This surgical technique may help clinicians manage patients with this condition in the future.     

Small colon intussusception in a broodmare

A 9-year-old pregnant Standardbred broodmare was evaluated for signs of mild abdominal pain, failure to defecate, and mild abdominal distention. Rectal examination revealed the leading edge of a small colon intussusception, and peritoneal fluid analysis indicated suppurative peritonitis. Surgical management, including reduction of the intussusception and small colon resection with end-to-end anastomosis, resulted in successful outcome (1-year follow-up evaluation). Postoperative complications including dehiscence of the ventral midline surgical incision and simple obstruction at the anastomosis site necessitated a second surgical procedure. Small colon intussusception is an uncommon cause of signs of abdominal pain and is similar to type-IV rectal prolapse.     

Effects of indwelling nasogastric intubation on gastric emptying of a liquid marker in horses

OBJECTIVE: To determine the effects of indwelling nasogastric intubation on the gastric emptying rate of liquid in horses. ANIMALS: 6 healthy horses. PROCEDURES: Horses were assigned to treatment and control groups in a prospective randomized crossover study with a washout period of at least 4 weeks between trials. Acetaminophen (20 mg/kg) diluted in 1 L of distilled water was administered via nasogastric tube at time points of 0, 12, 30, 48, and 72 hours to evaluate the liquid-phase gastric emptying rate. In control horses, nasogastric tubes were removed after administration of acetaminophen. In horses receiving treatment, the tube was left indwelling and maintained for 72 hours. A 10-mL sample of blood was collected from a jugular vein immediately before and 20, 40, 60, 80, 100, 120, and 180 minutes after acetaminophen administration. Serum acetaminophen concentrations were measured by use of a colorimetric method. RESULTS: Peak serum acetaminophen concentration was significantly higher in the control group (38.11 microg/mL) than in the treatment group (29.09 microg/mL), and the time required to reach peak serum acetaminophen concentration was significantly shorter in the control group (22.79 minutes) than in the treatment group (35.95 minutes). CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that indwelling nasogastric intubation has a delaying effect on the gastric emptying rate of liquids. Veterinarians should consider the potential for delayed gastric emptying when placing and maintaining an indwelling nasogastric tube for an extended period of time after surgery. Repeated nasogastric intubation may be better than maintenance of an indwelling tube in horses with ileus.     

Oil Red O-positive lipid in peritoneal fluid from a horse with a rectal tear

A 4-year-old Quarter Horse mare was presented to the Texas A&M University Veterinary Medical Teaching Hospital for evaluation of a rectal tear. On initial evaluation, rectal palpation and colonoscopy revealed a grade IIIb rectal tear. Analysis of peritoneal fluid revealed a modified transudate. Preliminary supportive care included fluid therapy and mineral oil administration via nasogastric tube. Approximately 48 hours after presentation, a second abdominocentesis was performed, and cytologic examination of the fluid revealed a marked suppurative exudate. Round clear nonrefractile material observed within neutrophils and macrophages and in the background stained bright pink to red with Oil Red O, confirming the material as lipid, likely from leakage of mineral oil through the rectal tear. The condition of the mare deteriorated and euthanasia was elected due to the poor prognosis. At necropsy, gross and histologic findings included peritoneal effusion and a full-thickness rectal tear with transmural necrotizing pyogranulomatous colitis and fibrinous peritonitis. To the authors' knowledge, this is the first reported case of Oil Red O-positive lipid vacuoles in the peritoneal fluid of a horse from presumed leakage of mineral oil through a transmural rectal perforation. The frequency of this occurrence in horses is unknown, but it is important for cytopathologists to be familiar with the appearance and significance of lipid-type droplets in phagocytic cells in cytologic fluid analysis specimens.     

Decision for surgery

Based on the clinical impression and the current knowledge of the clinical variables (rectal examination, abdominal distention, abdominal fluid, intractable pain) most likely to differentiate between medical and surgical cases, three decision trees are provided as a guide to making the management decision in a horse with abdominal pain. Prior elimination of horses with limited life expectancy because of age or function or where financial constraints are present is understood. It must be emphasized that most of the information presently available originates from referral centers where the prevalence of surgical candidates is much higher than in general practice. This would influence the accuracy of the clinician in identifying horses with a surgical lesion or estimating survival (positive predictive value).     

Improved nasogastric intubation technique for administration of nutritional support in dogs.

Established procedures for nasogastric intubation are difficult to perform in dogs because of anatomic variation of nasal passages and turbinate structures. Twenty-five clinically normal dogs were used to improve and refine the technique of nasogastric tube placement, and 13 clinical patients at our teaching hospital were evaluated for malnutrition and were considered candidates for nutritional support by nasogastric tube feeding. An improved method for the placement of nasogastric tubes in dogs was used. By pushing the external nares dorsally while advancing the tube in a caudoventral, medial direction, the tube passed through the ventral meatus and into the oropharynx and esophagus easily. The procedure does not require chemical restraint, and the complication of epistaxis was not observed in any dog. Materials required to perform this technique are inexpensive, and the method can be used for the administration of nutritional support, fluids, drugs, or contrast material.     

Idiopathic focal eosinophilic enteritis associated with small intestinal obstruction in 6 horses

OBJECTIVE: To report the history, clinical findings, and outcome of horses with idiopathic focal eosinophilic enteritis associated with acute small intestinal obstruction. STUDY DESIGN: Retrospective study. ANIMALS: Six horses with idiopathic focal eosinophilic enteritis. METHODS: Retrospective review of medical records of horses with idiopathic focal eosinophilic enteritis, with acute abdominal pain and small intestinal obstruction, associated with a focal region of eosinophilic enteritis of unknown cause. Information retrieved from the medical records included signalment, physical examination, laboratory findings, surgical procedure, histologic diagnosis, and postoperative management. Outcome was determined by telephone communication with owners. RESULTS: Six horses met the selection criteria. Horses had persistent pain, distended small intestine, and nasogastric reflux. Idiopathic focal eosinophilic enteritis lesions associated with a small intestinal obstruction were treated surgically by intestinal resection and anastomosis or wedge resection. There were no observed complications associated with extension of the disease from the lesion site. Five horses were alive at follow-up 5 to 60 months after surgery. CONCLUSIONS: Although the cause of these focal eosinophilic enteritis lesions is unknown, the long-term outcome after lesion resection was favorable. CLINICAL RELEVANCE: Small intestinal obstruction associated with a focal eosinophilic enteritis lesion may be a cause of acute abdominal pain in horses. Horses apparently have a good prognosis after lesion resection.     

Removal of a nasogastric tube fragment from the stomach of a standing horse

An 82-cm fragment of nasogastric tube was removed from the stomach of an adult horse under standing sedation by use of an endoscope and electrocautery snare. This is the first report of successful non-surgical removal of a nasogastric tube fragment from the stomach of a horse.