Caecal intussusceptions and typhlocolitis in horses with severe Gastrodiscus aegyptiacus infestation

The intestinal trematode Gastrodiscus aegyptiacus (G. aegyptiacus) has been recognised in equids around the world for many years, but its pathogenicity is yet to be confirmed. This report describes seven cases of severe G. aegyptiacus infestation, including six cases of caecal intussusception.     

Caecal lipomatosis as a cause of colic in a 9‐year‐old gelding

Lipomatosis is an uncommon cause of colic. This case report details the pre‐ and intraoperative findings of a 9‐year‐old gelding, presented with acute abdominal pain. Exploratory laparotomy revealed a massive fatty infiltrate involving an extensive portion of the base and mid‐body of the caecum. To the authors' knowledge, this is the first report of an infiltrative lipomatous lesion of the equine caecum.     

Caecal intussusceptions in horses and the significance of Anoplocephala perfoliata

A caecocaecal intussusception in a pony and a caecocolic intussusception in a horse, both infected with Anoplocephala perfoliata, are described and the relevance of tapeworms in such intestinal disease of horses is reviewed.     

Surgical management of sand colic impactions in horses: a retrospective study of 41 cases

OBJECTIVE: A retrospective review of the medical records of 41 horses requiring abdominal surgery for sand colic. RESULTS: The diagnosis of sand colic was made when sand was found to be the cause of impaction of the gastrointestinal tract during surgical exploration. The most common clinical signs at presentation were abdominal pain, abdominal distension and diarrhoea. A statistically significant association was found between the respiratory rate on arrival and short-term survival. Sand impaction at multiple locations was detected in one-third of the horses. Concurrent pathology was detected in half of the horses. Four horses were euthanased during surgery; of those that recovered from surgery, 35/37 (95%) were discharged from hospital. Short- and long-term complications were similar to those previously reported. Long-term (1 year) survival of the horses discharged was 100%. CONCLUSION: The good prognosis for horses undergoing surgery for the treatment of sand impaction supports early surgical intervention in cases where large amounts of sand are suspected.     

Atypical presentation of caecal perforation in two horses

This case report describes retroperitoneal and subserosal emphysema as the primary indication of a caecal perforation associated with an episode of colic. Feed contamination was not noted on repeated peritoneal fluid samples or within the peritoneal cavity at the time of surgery; however, subserosal and retroperitoneal emphysema at the base of the caecum was identified during surgical exploration, which later corresponded to retroperitoneal caecal perforation at necropsy examination.     

Caeco-caecal and caeco-colic intussusception in two half-sibling Standardbred horses

This report describes caecal intussusception in two young half-sibling Standardbred horses. Both horses presented showing signs of low-grade abdominal pain. The horses remained haemodynamically stable despite signs of abdominal pain and associated tachycardia. Exploratory celiotomy was undertaken in both horses due to persistent abdominal pain and a poor response to administration of analgesic medications. Exploration of the abdomen revealed caeco-caecal intussusception in one horse and caeco-colic intussusception in the other horse. An underlying cause for caecal dysfunction and subsequent intussusception was not identified in either patient. Manual reduction of the intussusception was successful in both cases. The horses recovered uneventfully from surgery.     

Morphometry and abnormalities of the feet of Kaimanawa feral horses in New Zealand

Objective The present study investigated the foot health of the Kaimanawa feral horse population and tested the hypotheses that horses would have a large range of foot morphology and that the incidence of foot abnormality would be significantly high. Procedures Abnormality was defined as a variation from what the two veterinarian assessors considered as optimal morphology and which was considered to impact negatively on the structure and/or function of the foot. Fifteen morphometric variables were measured on four calibrated photographic views of all four feet of 20 adult Kaimanawa feral horses. Four morphometric variables were measured from the lateromedial radiographs of the left forefoot of each horse. In addition, the study identified the incidence of gross abnormality observed on the photographs and radiographs of all 80 feet. Results There was a large variation between horses in the morphometric dimensions, indicating an inconsistent foot type. Mean hoof variables were outside the normal range recommended by veterinarians and hoof care providers; 35% of all feet had a long toe conformation and 15% had a mediolateral imbalance. Abnormalities included lateral (85% of horses) and dorsal (90% of horses) wall flares, presence of laminar rings (80% of horses) and bull-nose tip of the distal phalanx (75% of horses). Both hypotheses were therefore accepted. Conclusions The Kaimanawa feral horse population demonstrated a broad range of foot abnormalities and we propose that one reason for the questionable foot health and conformation is lack of abrasive wearing by the environment. In comparison with other feral horse populations in Australia and America there may be less pressure on the natural selection of the foot of the Kaimanawa horses by the forgiving environment of the Kaimanawa Ranges. Contrary to popular belief, the feral horse foot type should not be used as an ideal model for the domestic horse foot.     

Caecal impactions: Diagnosis,management and prognosis

A caecal impaction can be caused by an accumulation of dry ingesta (type I) or abnormal caecal motility resulting in a feed impaction of fluid consistency (type II). Horses that develop a caecal impaction have often been administered a nonsteroidal anti-inflammatory drug (NSAID) during hospitalisation for treatment of a painful condition such as an ocular or orthopaedic disease. Clinical signs of caecal impaction can be mild, and progress to more moderate to severe signs of abdominal pain as the impaction enlarges. Since an impacted caecum has a high risk of rupture, early diagnosis and treatment are important. Horses with a caecal impaction can be treated medically or surgically, and treatment decisions are based on clinical signs, results of transrectal palpation, character of peritoneal fluid and response to medical management. For type I caecal impaction, medical management consists of aggressive fluid therapy, both intravenous and enteral, to soften ingesta. Fluid therapy can be combined with laxatives, motility-enhancing drugs and analgesic drugs. Surgery is indicated if results of transrectal abdominal examination indicate that the impaction is unchanged or has enlarged, signs of abdominal pain increase, or if there is cardiovascular deterioration. Horses with type II caecal impaction have a greater chance of survival if managed surgically. Using a ventral mid-line celiotomy approach, a caecal impaction can be resolved via a typhlotomy. When caecal motility is poor, or there are signs of chronic caecal dysfunction, a caecal bypass procedure (jejunocolostomy or ileocolostomy) should be considered. Although the prognosis for horses with a caecal impaction is claimed to be fair to good, choice of treatment is controversial and may influence prognosis. If the affected horse survives to discharge from the hospital, the long-term prognosis is generally good. Many retrospective studies of cases of caecal impaction are weakened by failure to distinguish between types I and II.     

Factors associated with mortality and morbidity in small intestinal volvulus in horses

OBJECTIVE: To determine historical, physical, and clinical factors that may affect morbidity and mortality in horses with small intestinal volvulus unrelated to other causes (e.g., incarceration, lipoma, etc.). STUDY DESIGN: Retrospective study. ANIMALS: Client-owned horses (115), aged 1 month to 21 years. Methods: Data were obtained from medical records, identified by computer search and manual review. Continuous variables were compared between affected and non-affected horses with Mann-Whitney U-tests and non-continuous variables with Fisher's exact test (2 x 2 tables) or chi(2)-tests (larger tables). Stepwise logistic regression analysis was used to develop a multivariable model of the risk factors, taking account of confounding and interaction. RESULTS: Eighty percent of horses recovered from surgery survived to hospital discharge. Neither age, breed, nor sex was related to mortality. Survivors had a significantly lower heart rate, shorter capillary refill time, and better mucous membrane color. Variables associated with worsening cardiovascular status, increased hemoconcentration, and exudation of cells and protein into peritoneal fluid were significantly associated with non-survival. After recovery from surgery, the most serious complication was colic, which was significantly associated with non-survival (P=.028) as was a second celiotomy (P<.01). Both of these complications were associated with a jejunocecostomy during the first surgery. CONCLUSIONS: Significant differences in the clinical and clinicopathologic signs were identified between survivors and non-survivors. CLINICAL RELEVANCE: These findings can be used to make a scientific assessment of prognosis in the pre-operative, operative, and post-operative management of horses with small intestinal volvulus.     

Colic after swimming exercise in racehorses: an investigation of incidence, management, surgical findings and outcome

The incidence of colic following swimming exercise (SC) in a racehorse population examined over 3 years was 0.08%. Following 167,977 swims, 136 cases were reported. Colic resolved spontaneously in 2 horses, medically in 129 or surgically in 5. In a separate study, 21 horses were subject to exploratory laparotomy for SC. Findings included non-strangulating displacements in 7 horses, strangulating displacements in 7, a combination of non-strangulating and strangulating displacements in 1, prominent gaseous intestinal distension in 5 and no abnormalities in 1 horse. A poor response to analgesia prompted surgery in all cases. Rectal palpation and/or abdominal ultrasound was performed in 16 of 21 cases and abnormalities were found in 14 of these. Of the 21 surgical cases, 20 (95.2%) survived to discharge and 18 (90%) raced postoperatively.     

Problems associated with perioperative morphine in horses: a retrospective case analysis

Objective To identify the incidence of adverse effects caused by morphine 100–170 µg kg^?1 administration during surgery in horses. Design Retrospective case record analysis (1996–2000). Animals Eighty‐four healthy (ASA 1 or 2) horses, mean age 5.5 ± 3.1 (SD) years (2 months to 16 years), mean weight 524 ± 14 kg (100–950). Methods Physiological data and evidence of complications were collected from the anaesthetic records of all animals anaesthetized with romifidine, ketamine, diazepam and halothane and undergoing laryngeal surgery or orchiectomy at the Royal (Dick) School of Veterinary Studies. Cases were divided into those receiving (group M+; n = 18) and those not receiving morphine (M?; n = 29), and the data compared. Values for heart and respiratory rate and mean arterial pressure were compared at 15‐minute intervals between 30 and 120 minutes after induction using anova for repeated measures. The incidence of intraoperative problems was compared using Fisher's exact test. Recovery scores were compared using Student's unpaired t‐test. The records of a further 37 horses undergoing umbilical herniorrhaphy (n = 5), arthroscopy (n = 29) or tarsal arthrodesis (n = 3) were also studied but not analysed statistically due to disparate treatment distribution. Results There were no significant differences between the M+ and M? groups. The incidence of post‐operative complications such as box‐walking and colic were similar in each group. Conclusions Morphine doses of 100–170 µg kg^?1 do not increase the risk of problems when used to provide perioperative analgesia in horses anaesthetized with romifidine, ketamine, diazepam and halothane. Clinical relevance Morphine provides an acceptable and relatively inexpensive way to provide perioperative analgesia in horses.     

Caecal duplication in a 13‐year‐old Thoroughbred

A 13‐year‐old Thoroughbred gelding was presented for evaluation of recurrent colic of 4 weeks duration. These colic episodes were mild and responsive to medical therapy. Episodes of colic became more frequent and more painful. Exploratory laparotomy revealed a large intestine duplication with a cystic structure located at the caecocolic junction that was unable to be exteriorized and therefore not amenable to surgical correction. Thirty‐six hours following surgery, the horse became acutely painful, sweaty, and febrile suggesting gastrointestinal rupture. Post mortem examination showed a 0.6 × 1 m duplication and a 0.5 × 0.6 m cystic dilation that was probably associated with the caecum. There was a 10 × 30 cm area of rupture located within the duplication. Histological evaluation confirmed the presence of a true duplication.     

Post-anaesthetic pulmonary oedema in horses: a review

OBJECTIVES: To review information on the pathogenesis, diagnosis and treatment of post-anaesthetic pulmonary oedema in horses. DATABASES USED: Pubmed 1970-present, personal files.     

Incarceration of the caecum through a rent in the gastrosplenic ligament

A 3-year-old Thoroughbred gelding presented with acute signs of colic and tachycardia. Transabdominal ultrasonography revealed a viscus visible on the left and right sides of the cranioventral abdomen with a mural thickness of up to 1.6 cm. Exploratory laparotomy was performed under general anaesthesia. This revealed that the caecum was incarcerated through a rent in the gastrosplenic ligament, and the caecal apex was in the left caudal abdomen. The ventral aspect of the gastrosplenic ligament was ligated and transected. The caecum was freed, and normal orientation confirmed. The horse recovered uneventfully from surgery. Caecal mural thickness was monitored using daily ultrasonography, until normal. The horse was discharged from the hospital 11 days post-operatively. Five months later, the horse returned to race training.     

Retrograde intussusception of the descending colon secondary to multiple colonic hamartomas in a neonatal foal

A neonatal Thoroughbred filly presented with a 3-h history of abdominal pain and distention that failed to respond to medical treatment. Diagnostic evaluation, including abdominal ultrasound, barium enema and proctoscopy, was suggestive of atresia coli. Exploratory laparotomy revealed a pedunculated mass in the wall of the diaphragmatic flexure of the ascending colon. The mass, subsequently diagnosed as a hamartoma, was attached to a smaller hamartoma by a fibrous pedicle originating from the descending colon. The descending colon had intussuscepted retrograde into the ascending colon along the fibrous band. The filly was euthanised due to poor prognosis.     

Jejunal myxoma as a cause for jejunoileo‐caecal intussusception in a horse

A 17‐year‐old gelding was presented with mild to moderate signs of colic. Exploratory laparotomy revealed an intussusception of ileum and jejunum into the caecum. The starting point of the intussusception was an intramural mass in the jejunum. Half a metre of jejunum was resected and the horse recovered without complications. Histopathology and immunohistochemistry revealed a myxoma with no myogenic or neurogenic origin.     

Caecal disease in equids

Objective To review the breed, age, gender, clinical and laboratory findings, treatment and outcome of horses with caecal disease presented to a referral centre. Design Retrospective study of 96 cases. Procedure The breed, age, and gender of the study population were compared with the corresponding hospital population for the same period. The means (± SD) for clinical and laboratory findings were recorded for each caecal disorder. Treatment was categorised as medical or surgical, and outcome was recorded. Results Caecal diseases included impaction (40% of total cases), rupture associated with concurrent unrelated disease (13%), rupture with parturition (9%), rupture with no associated disease (5%), infarction (11%), torsion (9%), abscess or adhesion (7%), tumour (3%), and miscellaneous conditions (3%). The breed or gender of affected horses did not differ from the hospital population, although horses > 15 years were more frequently represented (P < 0.05). This age group was specifically more predisposed to caecal impaction (P < 0.05), as were Arabian, Morgan, and Appaloosa breeds (P < 0.05). In horses with caecal impaction transrectal examination was the most useful diagnostic procedure; 90% of affected horses treated medically were discharged while horses treated by typhlotomy alone, or typhlotomy and blind end ileocolostomy, had survival rates to discharge of 71% and 86%, respectively. Horses with caecal rupture associated with concurrent un-related disease showed no signs of impending rupture; all were receiving phenylbutazone, all were euthanased, and 50% had caecal ulceration at necropsy. Of horses with caecal rupture with parturition 56% had prior dystocia; in two-thirds the site of rupture was the ileocaecal junction and all were euthanased. Horses with caecal rupture with no associated disease died or were euthanased; rupture was idiopathic. Horses with caecal infarction usually had signs of abdominal pain and abdominal fluid changes consistent with peritonitis; transrectal examination was nonspecific, and typhlectomy was successful in seven of eight horses. Horses with caecal torsion had signs of severe, acute abdominal pain and typhlectomy was successful in three of five horses. Diagnosis of caecal adhesion or abscess was assisted by transrectal palpation in two of seven horses and surgical treatment was successful in two of five horses. A caecal tumour was diagnosed in three horses aged 20 years or older that presented with chronic weight loss. Other caecal diseases were uncommon. Conclusion Caecal disease is uncommon in equids but some specific features of the history and physical findings can alert the veterinarian to the possibility of caecal involvement in horses with gastrointestinal dysfunction. Medical or surgical therapy can be effective in horses where caecal rupture has not occurred.     

RESEARCH PAPER: Romifidine as a constant rate infusion in isoflurane anaesthetized horses: a clinical study

Objective To evaluate the effects of a constant rate infusion (CRI) of romifidine on the requirement of isoflurane, cardiovascular performance and recovery in anaesthetized horses undergoing arthroscopic surgery. Study design Randomized blinded prospective clinical trial. Animals Thirty horses scheduled for routine arthroscopy. Methods After premedication (acepromazine 0.02 mg kg^?1, romifidine 80 μg kg^?1, methadone 0.1 mg kg^?1) and induction (midazolam 0.06 mg kg^?1 ketamine 2.2 mg kg^?1), anaesthesia was maintained with isoflurane in oxygen. Horses were assigned randomly to receive a CRI of saline (group S) or 40 μg kg^?1 hour^?1 romifidine (group R). The influences of time and treatment on anaesthetic and cardiovascular parameters were evaluated using an analysis of variance. Body weight (t‐test), duration of anaesthesia (t‐test) and recovery score (Wilcoxon Rank Sum Test) were compared between groups. Significance was set at p < 0.05. Results All but one horse were positioned in the dorsal recumbent position and ventilated from the start of anaesthesia. End tidal isoflurane concentrations were similar in both groups at similar time points and over the whole anaesthetic period. Cardiac output was significantly lower in horses of the R group, but there were no significant differences between groups in cardiac index, body weight or age. All other cardiovascular parameters were similar in both groups. Quality of recovery did not differ significantly between groups, but more horses in group R stood without ataxia at the first attempt. One horse from group S had a problematic recovery. Conclusions and clinical relevance No inhalation anaesthetic sparing effect or side effects were observed by using a 40 μg kg^?1 hour^?1 romifidine CRI in isoflurane anaesthetized horses under clinical conditions. Cardiovascular performance remained acceptable. Further studies are needed to identify the effective dose of romifidine that will induce an inhalation anaesthetic sparing effect in anaesthetized horses.