Factors associated with development of ileal impaction in horses with surgical colic: 78 cases (1986-2000)

Deal impaction is prevalent in the south-eastern USA, where feeding of Coastal Bermuda hay has been implicated as a risk factor. Alternatively, infection with the tapeworm Anoplocephala perfoliata has been identified as a risk factor for ileal impaction in the UK. We hypothesised that feeding Coastal Bermuda hay and failure to administer routinely an anthelmintic with efficacy against tapeworms would place horses at risk of developing ileal impaction in the USA. Seventy-eight horses, with surgically confirmed ileal impaction and 100 horses admitted for colic that did not have an ileal impaction, were selected retrospectively for logistic regression analysis. Using odds ratios (OR) as an index of risk, feeding Coastal Bermuda hay (OR = 2.9) and failure to administer a pyrantel salt within 3 months of admission (OR = 3.1) placed horses at risk of development of ileal impaction. This study confirms the belief that feeding Coastal Bermuda hay places horses at risk of ileal impaction, although the quality of the hay may also play a role. Periodic administration of anthelmintics with efficacy against tapeworms should be considered to reduce risk of ileal impaction.     

Extraperitoneal incisional abscess formation after colic surgery in 3 horses

In this article we report 3 horses that developed an extraperitoneal abscess after colic surgery at the incision site. All 3 horses presented with nonspecific clinical signs and extraperitoneal abscess was diagnosed from ultrasound evaluations and cytological examination of abscess aspirates. One horse developed dehiscence of the incision after drainage of the abscess through the incision. In 2 cases a small standing paramedian incision was performed through which the abscess was drained and lavaged; complete resolution of the abscess and healing of the incision was achieved in both cases. Extraperitoneal abscess is a previously unreported incisional complication after colic surgery in horses. Early and careful ultrasonographic examination of the abdominal incision is required for diagnosis in cases with nonspecific clinical signs. A paramedian incision through the rectus abdominis muscle into the abscess cavity permitted adequate drainage and debridement of the abscess in 2 cases.     

Sternothyrohyoideus myectomy in horses: 17 cases (1984-1985)

Review of medical records of 78 horses admitted to the George D. Widener Hospital for Large Animals with dorsal displacement of the soft palate revealed 94% of these horses to have evidence of an intermittent abnormal "gurgling" respiratory noise at the time of exercise. Sternothyrohyoideus myectomy was used as a primary treatment for 17 of these horses, with a success rate of 58%. Anatomic dissection of 30 horses indicated that the midcervical region is the optimal site for sternothyrohyoideus myectomy to alleviate dorsal displacement of the soft palate.     

Aflatoxicosis in Iowa swine: eight cases (1983-1985)

During 1983, 1984, and 1985, aflatoxicosis was diagnosed in 8 Iowa swine herds after the herds were fed corn from the 1983 corn crop. As a result of the diagnosis, the associated environmental conditions, clinical signs of aflatoxicosis, macroscopic and microscopic lesions, aflatoxin concentrations detected in feeds, and management of affected swine were reviewed. Concentrations of aflatoxin in shelled corn and complete feed were as high as 2,020 ng and 1,200 ng of aflatoxin (B1 and B2)/g of feed, respectively. Clinical signs of aflatoxicosis included decreased feed consumption and weight loss. Some pigs died acutely, but death often was preceded by a period of clinical disease. Greater morbidity and mortality were observed in swine herds that consumed greater concentrations of aflatoxin.     

Cutaneous vasculitis in horses: 19 cases (1978-1985)

The medical records of 19 horses with cutaneous vasculitis were reviewed. Most (73.7%) affected horses were between 3 and 10 years old, and there were significantly more mares (14) than stallions or geldings (5) (P less than 0.01). Subcutaneous edema of the limbs, body, and/or head was the predominant clinical sign (18/19 horses; 94.7%). The single most prevalent laboratory abnormality was neutrophilia (greater than 7,000 neutrophils/microliter), which was detected in 10 horses (52.6%). Leukocytoclastic vasculitis was evident in skin biopsy specimens from 12 of 14 horses (85.7%). All horses were treated with corticosteroids and supportive care, and the overall survival rate was 63.1% (12/19). The mean duration of treatment with corticosteroids in surviving horses was 14 (+/- 5.3) days. Of the 7 horses that died, 5 failed to respond to treatment (4 were euthanatized, 1 died), and 2 others had persistent debilitating sequelae (euthanatized). The only significant clinical or laboratory abnormality predictive of poor prognosis was fever (odds ratio, 17.81; P less than 0.05). Seven horses had history of, or were exposed to horses with, abscessed peripheral lymph nodes and likely were suffering from equine purpura hemorrhagica. In spite of histopathologic evidence of hypersensitivity-vasculitis and/or the clinical suspicion that the cause for vasculitis was immune mediated, 7 of 19 horses (36.8%) had no history of bacterial or viral infection nor a history of current drug administration.     

Nasopharyngeal cicatrices in horses: 47 cases (1972-1985)

Nasopharyngeal cicatrices were observed endoscopically in 47 horses examined because of abnormal respiratory noises and/or exercise intolerance. A review of these cases revealed a correlation between cicatrization and age, sex, and the presence of other upper airway abnormalities. The age of affected horses ranged from 6 to 21 years, with a mean age of 12.7 +/- 7.8 (+/- 2 SD) years. Females were affected 2.7 times more frequently than males. Abnormalities commonly observed with a nasopharyngeal cicatrix included chondritis of the arytenoid cartilage, epiglottic deformity, and deformity of the guttural pouch openings. The nasopharyngeal cicatrix was responsible for respiratory obstruction in only 3 horses. Treatment for the cicatrix was not performed on any horse in this series. Generalized nasopharyngeal and laryngeal inflammation were postulated as causes of the cicatrices and associated abnormalities.     

Ultrasonographic findings in horses with cholelithiasis: eight cases (1985-1987)

Cholelithiasis and/or obstructive biliary tract disease was diagnosed ultrasonographically in 8 horses, 5 to 15 years old. Ultrasonographic findings revealed greater than normal amount of hepatic parenchyma in the right side of the abdomen in 8 horses and in the left side in 3 horses. The echogenicity of the liver was greater than normal, and thick distended bile ducts were seen in all horses. Choleliths were imaged ultrasonographically in 6 horses. Subsequently, postmortem findings in 6 horses revealed periportal and intralobular fibrosis, moderate bile duct dilatation, proliferation, and cholestasis. One or more choleliths were found in all horses. Ultrasonographic findings accurately depicted the histologic changes in the hepatic parenchyma in horses with cholelithiasis.     

Positive end-expiratory pressure during colic surgery in horses: 74 cases (1986-1988).

Positive end-expiratory pressure (PEEP) was applied in 74 anesthetized, ventilated horses during colic surgery, to attempt to increase arterial oxygen tensions. In 28 horses with an initial PaO2 less than 70 mm of Hg, PEEP increased PaO2 values to a mean of 173 +/- 24 mm of Hg. Arterial oxygen content increased from 14.1 +/- 0.05 ml/dl to 17.2 +/- 0.05 ml/dl. In the remaining 46 horses, PEEP increased PaO2 from a mean value of 101 +/- 6 mm of Hg to 194 +/- 15 mm of Hg, and arterial oxygen content increased from 14.9 +/- 0.09 ml/dl to 16.9 +/- 0.07 ml/dl. Cardiovascular depression and decrease in arterial blood pressure was observed after the application of PEEP in 54 horses. These 54 horses required use of pressors (n = 8), inotropes (n = 32), or both (n = 14) to keep the mean arterial blood pressure greater than 60 mm of Hg. Combined with pharmacologic support of blood pressure, PEEP could be a useful clinical treatment of arterial hypoxemia in horses.     

Clostridial myonecrosis in horses (37 cases 1985-2000)

REASONS FOR PERFORMING STUDY: Previous reports of clostridial myonecrosis have either focused on individual case reports or have been small retrospective studies reporting very high mortality rates. OBJECTIVES: The objective of this study was to describe the outcome of cases of clostridial myonecrosis submitted to 2 referral equine hospitals in the United States over a 15 year period. METHODS: A retrospective study of case material selected on the basis of positive Clostridium spp. culture or the identification of Clostridium spp. by specific fluorescent antibody testing from soft tissue wounds was performed at Cornell and Wisconsin. RESULTS: 37 cases of clostridial myonecrosis were documented. Twenty-seven horses survived, 8 were subjected to euthanasia and 2 died during treatment for an overall survival rate of 73%. Twenty-five cases (68%) were associated with Clostridium perfringens alone, 6 cases (16%) with Cl. septicum alone, 4 cases with mixed clostridial infections (11%), 1 case with Cl. sporogenes and 1 with an unspeciated Clostridium spp. The highest survival rate of 81% was documented for those cases from which Cl. perfringens alone was isolated. The most common antecedent condition prior to referral was colic. The myonecrotic lesion occurred within 6-72 h of a soft tissue injection in 34 cases but was associated with a wound or laceration in the remaining 3 cases. Of the 34 cases associated with recent injections, 24 were associated with i.m. injections in the cervical region, 4 in the semimembranosus/semitendinosus region, 3 in the gluteal region, 2 with perivascular leakage of drugs administered into the jugular vein and 1 case developed simultaneously in the gluteal and neck region following injections at both sites. CONCLUSIONS: Clostridial myonecrosis can occur following the i.m. or inadvertent perivascular administration of a wide variety of commonly administered drugs. It is most common in the neck musculature. Aggressive treatment can be associated with survival rates of up to 81% for cases due to Cl. perfringens alone. Survival rates for other Clostridial spp. tend to be lower. POTENTIAL RELEVANCE: A combination of high dose i.v. antibiotic therapy and surgical fenestration/debridement is the best approach to cases of clostridial myonecrosis. With rapid diagnosis and therapeutic intervention, horses may have up to an 81% chance of survival.     

Strangulated umbilical hernias in horses: 13 cases (1974-1985)

The medical records of 13 horses with strangulated umbilical hernias were reviewed. Typical history included increased swelling, warmth, and firmness of the hernial sac. Enterocutaneous fistulas had developed in 2 horses. Four horses had signs of abdominal pain. Surgery was performed on all horses, and the hernia was reduced by an open reduction technique. Incarcerated tissue included omentum (1 horse), jejunum (5), ileum (4), cecum (1), and ventral colon (2). All horses survived and were discharged from the hospital. Follow-up information on 9 horses (5 to 52 months after discharge) revealed no complications in 6 horses. Of the remaining 3 horses, one horse was euthanatized 5 months after discharge because of laminitis. One horse had persistent drainage from the skin incision requiring removal of nonabsorbable suture material 8 months after discharge. One foal required a second surgery because of signs of abdominal pain 17 days after the initial surgery. The foal was euthanatized during surgery because of severe peritonitis secondary to anastomotic leakage.     

Acute small intestinal obstruction associated with Parascaris equorum infection in young horses: 25 cases (1985-2004)

AIMS: To retrospectively evaluate the medical and surgical records of horses with acute small intestinal obstructions associated with Parascaris equorum infection; to describe the gastrointestinal lesions; and to determine the outcome of cases with such lesions. METHODS: Records of 25 horses with acute small intestinal obstruction associated with P. equorum between 1985 and 2004 were reviewed to determine signalment, history, physical examination, surgical or post-mortem findings, and outcome. RESULTS: All horses except one were less than 12 months old. Standardbreds were over-represented in the population studied. Sixteen horses (72%) had been administered anthelmintics, including pyrantel (n=8), ivermectin (n=7), and trichlorphon (n=1), within 24 h prior to the onset of colic. Of the 25 cases reviewed, 16 had simple obstructive ascarid impactions (SOAIs), and nine had complicated obstructive ascarid impaction (COAI) including volvulus (n=6) or intussusception (n=3), both concurrent with ascarid impaction of the small intestine. Short-term survival (discharge from hospital) occurred in 79% of horses treated for SOAI, and was 64% for all horses. Long-term survival (>1 year) occurred in 33% of horses with SOAI, and the overall long-term survival was 27% for all horses. Formation of adhesions was the most frequent finding associated with death for horses that did not survive long-term. CONCLUSIONS AND CLINICAL RELEVANCE: The incidence of anthelmintic treatment within 24 h of the onset of colic in this study population (72%) was higher than that previously reported. Resistance of P. equorum to ivermectin recently reported in Ontario may be associated with increased ascarid burdens, predisposing horses to ascarid impaction. The long-term survival of these horses was better than that reported previously.     

Surgical treatment of sand colic in equids: 48 cases (1978-1985)

Medical records of 48 equids (47 horses, 1 pony) with surgical sand colic were reviewed. The diagnosis of sand colic was made if a sand impaction(s) was palpated during exploratory abdominal surgery or if a large quantity of sand was found during colotomy. Most equids did not experience a previous episode of sand diarrhea or sand colic. Clinical findings and results of clinicopathologic determinations were not diagnostic. Rectal palpation findings in 40 of 46 horses were compatible with large-colon and/or cecal distention. Impactions were palpable per rectum in only 7 horses, but emergency abdominal surgery revealed one or more impactions in 46 of 48 equids. Single impaction most commonly was observed at the pelvic flexure. Twenty-six horses had concurrent large-colon torsion or displacement. Pelvic flexure colotomy was performed in 44 horses. Of 48 equids, 44 survived and were discharged.     

Factors associated with outcome following treatment of horses with septic tenosynovitis: 51 cases (1986-2003)

OBJECTIVE: To identify factors associated with outcome (ie, survival and return to function) following treatment of horses with septic tenosynovitis. DESIGN: Retrospective case series. ANIMALS: 51 horses with septic tenosynovitis. PROCEDURES: Information was obtained from medical records and through follow-up conversations with owners. Factors analyzed for an association with outcome included affected limb, etiology, duration of clinical signs prior to examination, presence of complications, primary treatment, secondary treatments, number of surgical procedures, and hospitalization time. RESULTS: Concurrent complications were identified in 41 (80%) horses. The primary treatment consisted of through-and-through lavage in 26 (51%) horses, tenoscopy in 20 (39%), and tenosynoviotomy combined with lavage in 5 (10%). Forty (78%) horses were discharged, and 37 (73%) survived at least 1 year after surgery; 21 of the 37 (57%) returned to their previous or a higher level of performance. Percentages of horses that survived 1 year after discharge and percentages that returned to their intended use did not vary significantly among treatments. Horses with tendon rupture or sepsis of an adjacent joint were significantly less likely to survive. Horses with tendon injury or pannus were significantly less likely to return to their intended use. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that various factors were associated with outcome in horses with septic tenosynovitis. However, surgical technique was not found to be associated with survival rate or rate of return to intended use.     

Septic tenosynovitis in horses: 25 cases (1983-1989).

The medical records of 25 horses with septic tenosynovitis treated over 7 years (1983 to 1989) were reviewed to determine clinical features of the disease and response to treatment. The median age of horses with septic tenosynovitis was 5 years (range, 1 month to 21 years). Fourteen fore limbs and 11 hind limbs were affected. Sepsis was located in the sheath of the digital flexor tendons of 22 horses. Sepsis was located in the sheath of the extensor carpi radialis tendon (1 horse), sheath of the long digital extensor tendon (1 horse), or sheath of the common digital extensor tendon (1 horse) in the remaining horses. Nine horses received only medical treatment, using a combination of broad-spectrum parenterally administered antimicrobial drugs (8 of 9 horses), nonsteroidal anti-inflammatory drugs (8 of 9 horses), or irrigation of the wound (4 of 9 horses). Fourteen horses were treated surgically with either transection of the palmar/plantar annular ligament of the metacarpo/metatarsophalangeal joint (5 of 14 horses), lavage of the sheath after insertion of drains into the sheath (7 of 14 horses), or both (2 of 14 horses). All horses treated surgically were concurrently treated parenterally with broad-spectrum antimicrobial drugs and nonsteroidal anti-inflammatory drugs. Two horses with septic tenosynovitis were not treated and were euthanatized at the owners' request. Five horses were euthanatized before discharge from the hospital. Two horses (both treated medically) were lost to follow-up. Follow-up information was obtained for 18 horses, 6 to 55 months after discharge from the hospital.(ABSTRACT TRUNCATED AT 250 WORDS)     

Survival and complication rates in 300 horses undergoing surgical treatment of colic. Part 4: Early (acute) relaparotomy

REASONS FOR PERFORMING STUDY: Early (acute) relaparotomy after surgery for equine colic is widely considered to be an acceptable treatment option for management of certain post operative complications. However, there is relatively little published information about resulting complication rates and short- and long-term outcomes. OBJECTIVES: To document the proportions, indications, complication rates and survival rates of horses undergoing acute relaparatomy following colic surgery. METHODS: History, clinical findings, surgical findings and procedures, post operative treatments and outcome of 300 consecutive surgical colic cases (1994-2001) were reviewed. Long-term follow-up information was retrieved from case records and telephone enquiries from owners. RESULTS: Acute relaparotomy was performed in 27/254 horses (10.6%) that recovered from initial general anaesthesia. The indications for relaparotomy included persistent pain, persistent ileus, peritonitis and wound breakdown. Of these 27 horses, 21 (77.8%) recovered from the second surgery, of which 8 (29.6%) died during the immediate post operative period. Thirteen of the 27 horses (48.2%) were discharged. Of these 13 horses, 5 (38.5%) were re-admitted to the hospital for surgical treatment of a subsequent bout of colic. The long-term survival rate for the 27 horses that underwent relaparotomy was 22.2%. Colic following discharge after relaparotomy was recorded in 69.2% of cases. CONCLUSIONS: Relaparotomy is necessary in approximately 10% of horses undergoing surgery for acute colic. Persistent pain and post operative ileus were the most common indications. The short-term survival rate for horses requiring relaparotomy was approximately 50% and the long-term survival rate 22%. Nearly 40% of horses surviving relaparotomy developed episodes of acute colic that necessitated further surgery. POTENTIAL RELEVANCE: Owners of horses requiring early (acute) relaparotomy should be advised of the high complication rates for this procedure.     

Risk factors associated with colic in horses

Many factors have been identified as risk factors for colic in horses in several epidemiological studies. The aim of our paper was to review the results of 12 epidemiological studies, in order to assess the impact of each risk factor for colic. According to the literature, the factors that increase the risk of colic are feeding practices (type and quality of food, type and changes of feeding), the intrinsic factors of horses (sex, age and breed), management (type and changes of housing and activity), medical history (a previous colic, administration of a medical treatment) and parasite control (the presence of worms and type of deworming program). Several individual factors were incriminated as risk factors by all the studies. Nevertheless, the different studies did not always agree on the role of other risk factors. The conclusions were tightly related to several criteria in the selection of the study population, like the type of the epidemiological study, the number and the origin of horses included and the location of the study.     

Ocular lesions associated with coccidioidomycosis in dogs: 35 cases (1980-1985)

Thirty-five dogs with ocular lesions associated with coccidioidomycosis were examined. Serologic and/or histologic evaluation confirmed the diagnoses of coccidioidomycosis. The disease most frequently associated with signs referable to the anterior segment of the eye, such as iritis and granulomatous uveitis. Histologic evaluation of the eye revealed a primary posterior segment disease, such as chorioretinitis or retinal separation, with an extension into the anterior segment of the eye.     

Cardiac arrhythmias identified in horses with duodenitis/proximal jejunitis: six cases (1985-1988)

During a 3 1/2-year period, cardiac arrhythmias were identified in 6 of 67 horses diagnosed with duodenitis/proximal jejunitis (DPJ). Arrhythmias were detected by auscultation of irregular cardiac rhythm and subsequently were characterized by electrocardiographic evaluation. Arrhythmias included frequent second-degree atrioventricular block, ventricular ectopic depolarizations, and atrioventricular conduction disturbance. In 4 horses, arrhythmias resolved with recovery from the primary problem. One horse died suddenly 66 hours after admission, and another was euthanatized at 72 hours after admission. Clinical and laboratory data from horses with DPJ and cardiac arrhythmias (group 1) were compared with findings for horses with DPJ and without arrhythmias (group 2). Group-1 horses had significantly (P less than 0.05) higher serum bicarbonate concentration and serum creatine kinase activity. Normal sinus rhythm returned in all 4 group-1 horses that recovered from DPJ, suggesting a causal relationship between DPJ and the arrhythmias. Two group-1 horses were necropsied, and both had myocarditis. The cause of these lesions was not determined.     

Use of phacofragmentation for cataract removal in horses: 12 cases (1985-1989)

The medical records of 12 horses that had cataracts removed by use of phacofragmentation were reviewed. Cataracts were removed from 16 eyes in horses ranging in age from 2 months to 15 years. Complications after surgery included corneal ulcers in 13 eyes, diffuse corneal edema in 5 eyes, and uncontrollable uveitis in 3 eyes. Follow-up information was obtained in all horses from 1 month to 3.5 years after surgery. Visual results were judged good by owners or veterinarians in 10 of the horses.