Post anaesthetic colic in horses: a preventable complication?

REASONS FOR PERFORMING STUDY: There is little information on the prevalence of, and risk factors associated with, post anaesthetic colic (PAC) in horses undergoing nonabdominal operations. OBJECTIVES: To undertake the first prospective study of prevalence of PAC and identify risk factors in its development in nonabdominal procedures. METHODS: A multicentre prospective case-control study was conducted, on every horse undergoing anaesthesia for a nonabdominal procedure between April 2004 and June 2005. Colic cases were defined as any horse with recognised signs of abdominal pain within 72 h of general anaesthesia that could not be attributed to any concurrent disease. Five control horses per case were selected randomly from the study population at all hospitals. Multivariable logistic regression analysis was used to examine the relationship between predictor variables and the risk of developing PAC. RESULTS: The estimated mean prevalence of PAC in the study population was 5.2% (95% CI, 2.8, 8.0). However, the prevalence of colic varied between each centre. The most commonly diagnosed cause of colic was impaction. Multivariable analyses showed that the centre involved and the type of surgery performed were associated with an increased risk of PAC. Preoperative food deprivation and the use of opioid drugs were confounding factors. CONCLUSIONS: Prevalence of PAC varied significantly between the 4 hospitals studied; there may be hospital-related covariates that account for this. The type of surgery performed influenced the risk of PAC. POTENTIAL RELEVANCE: Identifying the risk factors for PAC is a prerequisite for its prevention. This study indicates horses at increased risk of PAC that might benefit from a more critical evaluation of post anaesthetic gastrointestinal function and/or the provision of preventative measures. Further investigation is required to explain the variation in prevalence of PAC between centres.     

Do horses suffer from irritable bowel syndrome?

Irritable bowel syndrome (IBS) in man is not a single entity but has several causes. One of the most common forms has similarities with colic and laminitis in horses. Undigested food residues may pass from the small intestine into the colon where bacterial fermentation produces chemicals that lead to disease. In horses the consequences may be disastrous, but in healthy humans such malabsorption may not be harmful. After events such as bacterial gastroenteritis or antibiotic treatment, an imbalance of the colonic microflora with overgrowth of facultative anaerobes may arise, leading to malfermentation and IBS. It is not known whether such subtle changes may likewise be present in the microflora of horses who are susceptible to colic and laminitis. Metabolomic studies of urine and faeces may provide a suitable way forward to identify such changes in the horse's gut and thus help to identify more accurately those at risk and to provide opportunities for the development of improved treatment.     

Is a single force plate adequate for stabilographic analysis in horses?

Reasons for performing study: Postural balance can be quantified using stabilographic variables derived from force plate data that describe movements of the horse's centre of pressure (COP) in the horizontal plane. Most force plates are not large enough to accommodate all 4 limbs of a standing horse, so the study was designed to assess whether representative stabilographic data could be collected from the forelimbs or hindlimbs. Objective: To determine whether stabilographic data from either the forelimbs or the hindlimbs were representative of data for the total body. Methods: Stabilographic data (960 Hz) were collected from 17 sound horses standing with the forelimbs and the hindlimbs on separate force plates. To increase variability in the data, horses were of different sizes, the recording duration was varied (15–60 s) and data were collected under sighted and blindfolded conditions. Results: Correlation matrices indicated that total body stabilographic variables were highly significantly correlated with both forelimb and hindlimb data but correlation coefficients were higher for forelimb data. Forward stepwise regression selected forelimb data for inclusion in the model for 15/16 variables, the exception being mean absolute mediolateral velocity. Conclusions: Ground reaction force data from a pair of limbs, preferably the forelimbs, can be used to measure variables that represent total body postural balance in sound standing horses. Potential relevance: Stabilographic data from either the forelimbs or hindlimbs may be useful for detecting and quantifying deficiencies in postural balance in ataxic horses.     

Larval cyathostominosis in horses in Ontario: an emerging disease?

From 1991 to 2003, 24 cases of larval cyathostominosis were diagnosed at postmortem in equids, 15 (63%) from 2001 to 2003. Cases occurred from September to May, the majority from October to December. Median age was 12 mo. Diarrhea, colic, and weight loss were common clinical signs. Hypoalbuminemia and microcytosis were consistent findings.     

Strongylus vulgaris (Looss, 1900) in horses in Italy: is it still a problem?

A post-mortem survey was carried out on 46 Sardinian horses to evaluate the presence of Strongylus vulgaris and associated pathology. Horses were from local farms and had been treated with broad-spectrum anthelmintics at least 3 times a year. Examination of the cranial mesenteric arterial system (CMAS) showed parasite-induced lesions in all horses. S. vulgaris larvae were found in 39% of examined arteries, while their detection rate in coprocultures was 4%. Histology, carried out on 26 horses, showed mainly chronic and chronic-active lesions. Histometry showed a significant increase in thickness of the arterial wall, in particular of the intima tunic and adventitia tunic of the ileocolic artery and its colic branch. MCV, MCHC and alpha2, beta and gamma globulins were increased in horses with S. vulgaris larvae in the arteries, while the albumin/globulin ratio was decreased. Horses that were positive on faecal examination showed decreased values for RBC, PCV and the albumin/globulin ratio. Although several studies have shown a dramatic decrease of S. vulgaris infection worldwide, our data show that this parasite continues to exert its pathogenic role, even when its detection rate is quite low within the strongyle population infecting horses.     

Severe extrapyramidal syndrome in a dog caused by a Haloperidol (Serenase®) intoxication

Summary The case history of a one-year-old male mongrel dog intoxicated with 120 mg haloperidol is described. The dog showed a coma with a severe extrapyramidal syndrome and was treated with orphenadrine. Symptoms, occurrence, and therapy of the extrapyramidal syndrome are discussed. Emphasis is laid on the importance to differentiate this syndrome from epilepsy and other neurological disorders.     

Neurological trypanosomiasis in quinapyramine sulfate-treated horses—a breach of the blood–brain barrier?

Trypanosoma evansi infection typically produces wasting disease, but it can also develop into a neurological or meningoencephalitis form in equids. Trypanosomiasis in horses was treated with quinapyramine sulfate, and all the 14 infected animals were recovered clinically. After clinical recovery, four animals developed a neurological form of the disease at various intervals. Two of these animals treated with diminazene aceturate recovered temporarily. Repeated attempts failed to find the parasite in the blood or the cerebrospinal fluid (CSF), but all of the animals were positive in enzyme-linked immunosorbent assay. The calculation of the antibody index (AI) in the serum and the CSF and polymerase chain reaction (PCR) analysis of the CSF and brain tissue were carried out to confirm the neuro-infection. We found PCR and AI analyses of the CSF to be useful tools in the diagnosis of the neurological form of trypanosomiasis when the organism cannot be found in the blood or CSF. The increased albumin quotient is indicative of barrier leakage due to neuroinflammation. The biochemical changes in the CSF due to nervous system trypanosomiasis include increases in the albumin quotient, total protein, and urea nitrogen. It seems to be the first report on relapse of the nervous form of trypanosomiasis in equids even after quinapyramine treatment in endemic areas.     

Severe extrapyramidal syndrome in a dog caused by a Haloperidol (Serenase®) intoxication

Summary

The case history of a one‐year‐old male mongrel dog intoxicated with 120 mg haloperidol is described. The dog showed a coma with a severe extrapyramidal syndrome and was treated with orphenadrine.

Symptoms, occurrence, and therapy of the extrapyramidal syndrome are discussed. Emphasis is laid on the importance to differentiate this syndrome from epilepsy and other neurological disorders.     

Bad behavior or a physical problem? Rearing in a Dutch Warmblood mare

Behavior problems in horses are often thought to be due to the horse’s bad attitude, which commonly results in them being punished. However, when these cases are carefully worked up, there may be an underlying physical problem, and pain may play an important role. A 5-year-old Dutch Warmblood mare was presented for rearing and flipping over backward. The mare had been repeatedly examined by an equine veterinarian and a nonveterinarian equine dentist who found no abnormalities. Several different bits were tried, and side reins were used to keep her head down. The mare was whipped every time she reared. None of these measures helped. On presentation to our equine teaching hospital, no abnormalities were detected on routine physical examination. The behavior was observed when the mare was lunged; as soon as a small amount of tension was put on the lunge rein, the mare shook her head horizontally for approximately 1-2 seconds, reared, and flipped over onto her back. Neurological examination revealed that the mare was slow to resume a normal stance when her hind legs were placed in an abnormal position. Dental examination and endoscopy of the upper airways proved unremarkable. Radiography of the atlanto-occipital joint area revealed fractures of the first and second cervical vertebrae and fracture fragments, which are both suggestive for the presence of cervical instability and the possible presence of spinal cord compression. These suggestions were further supported by identification of delayed postural reflexes during neurological examination. The mare was deemed unfit for dressage and was successfully kept for breeding. Horses are frequently punished for “bad behavior.” These behaviors are frequently due to underlying physical problems and not a “nasty” horse. This case highlights the importance of careful history taking and a thorough veterinary examination with the use of further diagnostics (if necessary) when dealing with equine behavior problems.     

Pain control in horses: What do we really know?

Currently, approaches to pain control in horses are a mixture of art and science. Recognition of overt pain behaviours, such as rolling, kicking at the abdomen, flank watching, lameness or blepharospasm, may be obvious; subtle signs of pain can include changes in facial expression or head position, location in the stall and response to palpation or human interaction. Nonsteroidal anti‐inflammatory drugs (i.e. phenylbutazone, flunixin meglumine and firocoxib), opioids (i.e. butorphanol, morphine and buprenorphine) and α₂‐adrenergic agonists (i.e. xylazine, detomidine, romifidine and medetomidine) are the most commonly used therapeutic options. Multimodal therapy using constant‐rate infusions of lidocaine, ketamine and/or butorphanol has gained popularity for severe pain in hospitalised cases. Drugs targeting neuropathic pain, such as gabapentin, are increasingly used for conditions such as laminitis. Optimal strategies for management of pain are based upon severity and chronicity, including special considerations for use of intra‐articular or epidural delivery and therapy in foals. Strategies that aim to mitigate adverse effects associated with use of various analgesic agents are briefly discussed.     

Inflammatory bowel diseases in horses: What do we know?

Chronic inflammatory bowel diseases (IBDs) are a group of gastrointestinal (GI) disorders described in both humans and animals, but unlike in other species, in horses they are poorly defined and there is a lack of standardisation of the method of diagnosis. Although there is an impellent need of consensus on the nomenclature, diagnostic work-up, diet, treatment and management of horses with a suspected IBD, the aim of this review is to give initial guidelines for practitioners dealing with suspected cases. It provides a summary of the most relevant literature on the topic and presents the current knowledge on the clinical signs, diagnostic work-up, treatment and prognosis of IBDs in horses.