Survey of the large animal diplomates of the American College of Veterinary Internal Medicine regarding percutaneous lung biopsy in the horse

A survey designed to obtain information on the indications, contraindications, complications, and methodology of percutaneous lung biopsy in the horse was sent to large animal diplomates of the American College of Veterinary Internal Medicine. Sixty-five of 190 diplomates returned the survey (response rate: 34%) and 59 of these 65 respondents (91%) indicated that they worked with horses. Forty-four diplomates had performed a percutaneous lung biopsy in 1 or more horses (i.e. 75% of those diplomates working with horses and 68% of total respondents). Clinical and radiologic diagnoses that prompted diplomates to perform percutaneous lung biopsy in the horse included a pulmonary miliary pattern (93%), suspicion of pulmonary infiltrative disease (91%), suspicion of pulmonary neoplasia (91%), suspicion of chronic obstructive pulmonary disease (COPD) (20%), and suspicion of exercise-induced pulmonary hemorrhage (EIPH) (7%). Only one of the respondents reported the use of percutaneous lung biopsy in the diagnostic workup if pneumonia was suspected, but 11% of respondents reported that suspicion of pulmonary abscessation would prompt them to perform a percutaneous lung biopsy. In contrast, a variable percentage of respondents felt there were contraindications to performance of this technique, which included neonatal septicemia (68%), pulmonary abscessation (65%), pleuropneumonia (55%) and pneumonia (42%), EIPH (41%), and COPD (26%). No respondent indicated that suspicion of neoplasia was a contraindication to percutaneous biopsy. Most common complications observed by respondents were epistaxis (68% of respondents), putative pulmonary hemorrhage (52%), tachypnea (39%), and respiratory distress (32%). Ten of 44 respondents (23%) had not seen any complications with percutaneous lung biopsy. Forty-two of 44 respondents (96%) warned owners about possible complications before performing percutaneous lung biopsy. All respondents to this question reported that they would perform percutaneous lung biopsies in horses in the future, but 4 of 41 would use the procedure only as a last resort.

Monitoring and detection of acute viral respiratory tract disease in horses

OBJECTIVE

To develop a system to monitor and detect acute infections of the upper respiratory tract (i.e., nares, nasopharynx, and pharynx) in horses and to assess the association among specific viral infections, risk factors, and clinical signs of disease.

DESIGN

Prospective study.

ANIMALS

151 horses with clinical signs of acute infectious upper respiratory tract disease (IURD) from 56 premises in Colorado.

PROCEDURE

Health management data, blood samples, and nasal or nasopharyngeal swab samples were obtained for 151 horses with clinical signs of acute IURD. Of these horses, 112 had an additional blood sample obtained during convalescence and were considered to have complete sample sets. Samples were tested for evidence of respiratory tract infection by use of ELISA, virus isolation, and serologic testing of paired serum samples.

RESULTS

Viral infections were identified in 65 horses with complete sample sets; influenza virus infection was identified in 43 horses, equine herpesvirus (EHV) infection in 18, and mixed influenza virus and EHV infections in 4. On 14 premises, samples were obtained from more than 1 affected horse. Viral infections were identified in horses on 11 of 14 premises. Equine herpesviruses were isolated from 10 horses. A relationship was not found between vaccination history and identification of EHV or influenza virus infections. An infection with EHV was less likely to be identified in horses with initial (acute) antibody titers > 1:16 to EHV.

CLINICAL IMPLICATIONS

Influenza virus (specifically, A/equine/2) was the most common virus associated with acute IURD. Use of multiple diagnostic tests and obtaining samples from more than 1 horse in an outbreak may improve detection of viral infections.

Enterocolitis associated with Clostridium perfringens infection in neonatal foals: 54 cases (1988-1997)

OBJECTIVE

To identify clinical signs, physical examination findings, results of diagnostic tests, treatments administered, and clinical outcome of neonatal foals with enterocolitis associated with Clostridium perfringens infection.

DESIGN

Retrospective study.

ANIMALS

54 neonatal foals.

RESULTS

Most foals had acute onset of obtunded mentation, colic, or diarrhea and developed leukopenia, neutropenia, an abnormally high number of band neutrophils, toxic WBC, and hypoproteinemia within 24 hours after admission, despite high serum IgG concentrations (> 800 mg/dl). Abdominocentesis and abdominal radiography of some foals revealed exudative peritonitis and gaseous distention of the small and large intestine, respectively. Cytologic examination of feces revealed spores or gram-positive rods in 8 of 10 foals. The most common genotypes of C perfringens isolates were type A and C, alone or in combination. Treatment did not alter mortality rate for most foals that had a positive culture for C perfringens type C. Of 54 foals, 29 (54%) that had C perfringens-associated enterocolitis died. Foals that had a culture that yielded C perfringens had higher sepsis scores, IgG concentrations, and mortality rates, compared with the overall hospital population of neonatal foals.

CLINICAL IMPLICATIONS

Foals less than 7 days old that have enterocolitis associated with C perfringens infections, especially type C, have a guarded prognosis. Cytologic examination of feces to determine spore counts and detect rods may be a means for early identification of C perfringens infections. Polymerase chain reaction assays to determine genotype are important for designing preventive treatment regimens.

Outbreak of Salmonella infantis infection in a large animal veterinary teaching hospital

During the past 11 years, there have been numerous reports of outbreaks of salmonellosis involving horses in veterinary teaching hospitals. Some of these outbreaks have been associated with Salmonella serotypes not commonly associated with infection of horses. Salmonella infantis is among the more common Salmonella serotypes isolated from human beings, and is an important pathogen in the broiler chicken industry. However, it was not commonly isolated from horses or cattle on a national basis between 1993 and 1995. In this report, we describe an outbreak of S infantis infection among large animals, primarily horses, in a veterinary teaching hospital and the control measures that were implemented. Factors that appeared to be key in control of this outbreak in this hospital included providing biosecurity training sessions for hospital personnel, adopting a standard operating procedure manual for biosecurity procedures, installing additional handwashing sinks throughout the facility, painting the interior of the facility with a nontoxic readily cleanable paint, replacing the dirt flooring in 4 stalls with concrete flooring, and removing noncleanable surfaces such as rubber stall mats, wooden hay storage bins, and open grain bins. Our experience with this outbreak suggests that although it is virtually impossible to eliminate Salmonella organisms from the environment, minimizing contamination is possible. Prevention of nosocomial infection must be approached in a multifaceted manner and care must be taken to search out covert sources of contamination, especially if standard intervention procedures do not prevent spread of the disease.

Field study of the safety, immunogenicity, and efficacy of an inactivated equine rotavirus vaccine

OBJECTIVE

To determine safety, immunogenicity, and efficacy of an inactivated equine rotavirus vaccine.

DESIGN

Prospective randomized controlled trial.

ANIMALS

316 pregnant Thoroughbred mares during the first year of the study and 311 during the second year.

PROCEDURE

During the first year, mares received 3 doses of vaccine or placebo, IM, at 8, 9, and 10 months of gestation. Serum neutralizing antibody titers were measured before vaccination and 1 and 35 days after foaling. Antibody titers were measured in foals 1, 7, 35, 60, 90, and 120 days after birth. During the second year, mares that had been vaccinated the previous year received a single booster dose of vaccine approximately 1 month prior to parturition. Mares that had received the placebo the previous year and mares new to the study received 3 doses of vaccine or placebo. Serum neutralizing antibody titers were measured in samples taken from mares approximately 1 day after foaling and from foals approximately 1 and 60 days after birth.

RESULTS

Adverse reactions were not observed. Antibody titers were significantly increased at the time of foaling and 35 days after foaling in vaccinated, compared with control, mares and for 90 days after birth in foals born to vaccinated, compared with foals born to control, mares. Incidence of rotaviral diarrhea was lower in foals born to vaccinated, compared with foals born to control, mares, but the difference was not significant.

CLINICAL IMPLICATIONS

Results suggest that the equine rotavirus vaccine is safe and immunogenic and that reasonable efficacy under field conditions can be expected.

Rattlesnake venom poisoning in horses: 32 cases (1973-1993)

OBJECTIVE

To determine the clinical manifestations, morbidity, mortality, and treatment methods for rattlesnake venom poisoning in horses.

DESIGN

Retrospective analysis of medical records.

ANIMALS

27 horses with acute venom poisoning attributable to prairie rattlesnakes, and 5 with chronic problems subsequent to a rattlesnake bite.

RESULTS

Most horses were bitten on or near the muzzle while on pasture, resulting in head swelling, dyspnea, and epistaxis. Additional manifestations of acute poisoning included fever, tachycardia, tachypnea, cardiac arrhythmia, hemolytic anemia, thrombocytopenia, hemorrhage, thrombosis of venipuncture sites, colic, diarrhea, and prehensile and masticatory dysfunction. Chronic problems included cardiac disease, pneumonia, laminitis, pharyngeal paralysis, and wound complications. The most common chronic problem was cardiac disease. The most commonly used treatments were antibiotics, nonsteroidal anti-inflammatory drugs, tetanus prophylaxis, and airway support. Mortality in the 27 acutely affected horses was 18.5%; the overall mortality was 25%.

CLINICAL IMPLICATIONS

Horses bitten by prairie rattle-snakes may develop multiple, often severe, acute or chronic manifestations of poisoning involving various organ systems. Thorough clinical evaluation, effective treatment, supportive care, and close observation are indicated in horses with rattlesnake venom poisoning.

Toxicity of field bindweed (Convolvulus arvensis) to mice

The effects of feeding high and low doses of field bindweed (Convolvulus arvensis) to mice were investigated. Bindweed contains several alkaloids, including pseudotropine, and lesser amounts of tropine, tropinone, and meso-cuscohygrine. Mice fed bindweed exclusively died or were euthanized after 4-7 d and had severe hepatic necrosis and gastritis with ulceration or erosions. Mice fed low doses of bindweed along with standard laboratory mouse diet for 6 or 8 w had no clinical disease or gross lesions on necropsy examination but did have histologic lesions of mild multifocal hepatitis and gastritis.

Neonatal isoerythrolysis in mule foals

Four mule foals received anti-RBC antibody from their dam's colostrum. Two foals developed anemia, 1 developed severe thrombocytopenia, and 1 did not develop any clinical or laboratory abnormalities. All foals had the same donkey sire. Seven mares, including the dams of foals 1 to 4, bred to the donkey sire produced anti-RBC antibody. Two mares produced anti-RBC antibody to the donkey RBC on the first mating. The donkey sire and 18 of its offspring were found to have an RBC antigen unique to mules and donkeys. Thus, all matings of this donkey to horse mares were incompatible. The reason for the high rate of sensitization of mares bred to this donkey is unknown.

Ventricular tachycardia and myocardial dysfunction in a horse

Ventricular tachycardia develops less frequently than supraventricular dysrhythmias and generally is more indicative of cardiac disease. The horse in this report had clinical signs of lethargy and hypophagia and was determined to have sustained ventricular tachycardia. Echocardiography was a valuable diagnostic tool and revealed an echodense area in the left ventricle that had subnormal ventricular performance. A primary heart problem of an inflammatory nature was suspected. The horse responded favorably to treatment with lidocaine, antimicrobials, and aspirin, as well as stall rest. The horse was used successfully as a sire and hunter-jumper after treatment, but subsequently died 2.2 years later of massive hemoperitoneum. Necropsy revealed an extensive area in the left ventricle that appeared thin and fibrotic.

Multifocal myositis associated with Sarcocystis sp in a horse

Multifocal myositis was diagnosed in a 7-year-old Quarter Horse gelding on the basis of history and findings on physical examination, serum biochemical analysis, electromyography, and microscopic examination of frozen sections of muscle biopsy specimens. Histologic examination of the muscle specimen revealed multifocal accumulations of histiocytes, lymphocytes, and plasma cells, with attendant myofiber degeneration and necrosis. Parasitic cysts with morphologic characteristics of Sarcocystis sp were found in regions of myocyte degeneration and necrosis, and in regions of normal muscle. Based on a tentative diagnosis of Sarcocystis sp-induced myositis, the horse was treated with trimethoprim/sulfamethoxazole and pyrimethamine for 28 days, phenylbutazone for 5 days, and paddock rest for 30 days. At the end of treatment, the horse had gained 35 kg, its appetite had returned to normal, and muscle mass was returning to normal. Sarcocystis fayeri is the only Sarcocystis sp reported in equine muscle in the United States and is rarely associated with acute myositis or muscle atrophy. The development of clinical signs in this horse could have been the result of an underlying immunosuppression or infection with a particularly pathogenic strain or large infective dose of S fayeri.

A retrospective study of vein thrombosis in horses treated with intravenous fluids in a veterinary teaching hospital

The medical records of 68 horses treated with IV fluids for 24 hours or more were reviewed to determine the risk of vein thrombosis and to determine which factors were associated with the occurrence of vein thrombosis in these horses. Three factors were positively associated with vein thrombosis including use of locally produced fluids and presence of fever and diarrhea. Two factors, having general anesthesia or having surgery, were negatively associated with vein thrombosis. One continuous variable, duration of treatment, was positively associated with vein thrombosis. Factors not associated with vein thrombosis included breed, age, sex, type of catheter, outcome (lived or died), laminitis, colic, other drugs via the catheter, and type of surgery. One type of catheter was used in the majority of horses (57) making it difficult to detect effect of catheter type. Preparation of the catheter site, the person placing the catheter, and technique of catheter maintenance were not evaluated. Like all retrospective studies, this study has limitations to the conclusions that can be made; however, the strong association between source of fluids, fever, diarrhea, anesthesia/surgery, and the occurrence of vein thrombosis merits consideration in the clinician's therapeutic plan.

Clostridia-associated enterocolitis in adult horses and foals

A review of the literature describing clostridia-associated enterocolitis is presented. The bacteria, their toxins, and possible factors that interact to contribute to the pathogenesis of enterocolitis are described. Clinical signs associated with clostridia-associated enterocolitis, methods of diagnosis, treatments, and preventive strategies are discussed.

Evaluation of clinical signs of disease, bronchoalveolar and tracheal wash analysis, and arterial blood gas tensions in 13 horses with chronic obstructive pulmonary disease treated with prednisone, methyl sulfonmethane, and clenbuterol hydrochloride

We evaluated the efficacy of 3 treatments for chronic obstructive pulmonary disease in horses: prednisone (400 mg/horse, PO, daily; n = 7), methyl sulfonmethane (10 g/horse, PO, q 12 h; n = 6), and clenbuterol hydrochloride (0.4 mg/horse, PO, q 12 h; n = 7). A fourth group acted as controls (n = 6) and was not treated. The treatment period lasted 10 days. Each horse was a member of 2 different groups for 10 days, separated by an 18-day interval of no treatment. All horses were housed together in an outdoor pen without bedding. Horses were fed alfalfa/grass hay mix ad libitum from a large feeder. The same batch of hay was fed throughout the study. Multiple physical and laboratory variables were monitored prior to, during, and at the end of each 10-day trial period. Changes in lung sounds, respiratory effort, degree of anal movement, nasal discharge, temperature, respiratory rate, or heart rate were not significant. Changes in arterial blood gas tensions, tracheal wash or bronchoalveolar lavage cytologic findings, or phagocyte function were not significant. All horses were tachypneic and most were tachycardic. The median value for PaO2 was below normal for all horses. All tracheal wash and most bronchoalveolar lavage cytologic findings represented a suppurative response. Negative linear correlation was observed between PaO2 and degree of respiratory effort in these horses (eg, as PaO2 decreased, the degree of respiratory effort increased).

Intestinal fibrosis with partial obstruction in five horses and two ponies

Fibrosis of the small intestine led to recurrent colic and weight loss in 2 ponies and 5 horses. There was a reduction in the length of the small intestine to one-half normal in horses 4 to 7. Histologic examination revealed substantial small intestinal submucosal fibrosis and arteriole sclerosis. The cause was not determined, but an environmental factor was suspected because 3 horses were from the same farm and the other animals were from within a 10-mile radius of the farm. The submucosal fibrosis appeared to be secondary to sclerosis of arterioles in the submucosa and mesentery, with low blood flow state or altered vessel permeability.

Respiratory stridor associated with polymyopathy suspected to be hyperkalemic periodic paralysis in four quarter horse foals

Four Quarter Horse foals ranging in age from 6 days to 2 months were determined to have upper airway stridor secondary to polymyopathy suspected to be hyperkalemic periodic paralysis. Electromyography revealed spontaneous muscle activity in all muscles examined. Electromyographic findings were similar in the dams of 3 foals (No. 1, 3 and 4). Hyperkalemia was found in foals 1 and 4. Endoscopically, the upper airway stridor in foals 1 and 3 was confirmed to be attributable to laryngeal and pharyngeal collapse or spasm. Foals 1, 2, and 3 were treated with acetazolamide. Foal 4 was not treated, at the owner's request. Foals 2 and 3 improved with treatment, foal 4's condition was static, and foal 1 required a tracheostomy and laryngeal surgery to manage its upper airway stridor.

Medical problems of adult horses, as ranked by equine practitioners

This paper reports the results of a survey conducted among members of the American Association of Equine Practitioners, concerning medical problems of adult horses. A one-page questionnaire listing 36 medical problems grouped by body system was completed by 1,149 veterinarians. The top-ranked disease was colic, followed by viral respiratory tract disease, endometritis, dermatitis, and parasitism. When responses were evaluated by type of practice, location of practice, and number of veterinarians in the practice, ranking of the top 2 diseases was the same for the total respondents. Ranking of diseases 3 through 5 varied when these criteria were taken into consideration.

Ultrasonographic detection of chronic epididymitis in a stallion

Clinical signs of chronic epididymitis in a stallion included recurrent signs of inguinal pain--retraction of the right testis into the inguinal area, resentment of palpation of the right testis, and right-sided scrotal swelling. The tail of the right epididymis was firm and seemed to be adhered to the testis. The tail of the left epididymis felt firmer than normal. Ultrasonographically, the diameter of the head of the epididymis was considered larger than normal, was hyperechoic in relation to the right testis, and had an irregular border. Several bright 1- to 5-mm-diameter echogenic areas that alternated with less echogenic areas were seen in the head of the right epididymis. Ultrasonographic findings were interpreted as fibrosis attributable to chronic inflammation. Unilateral castration (right-sided) was performed, but the prognosis was guarded because of presumed involvement of the left epididymis.

Bacterial pneumonia

Bacterial pneumonia in the horse often occurs secondary to viral respiratory infection; however, primary infections can occur. A diagnosis of bacterial pneumonia is made on the basis of history, physical examination, and laboratory and radiographic findings. Treatment consists of appropriate antimicrobial therapy for at least 7 to 10 days; further therapy may be needed in more severe cases. Prevention of bacterial pneumonia includes attempting to prevent viral respiratory infections and appropriate management to prevent stress to the respiratory tract.

Epidemiologic study of salmonellae shedding in the feces of horses and potential risk factors for development of the infection in hospitalized horses

A study was designed to identify epidemiologic factors associated with the development and spread of salmonellae in horses in a veterinary teaching hospital, through a case-control study and a longitudinal follow-up prospective study. In the case-control study, 44 horses shedding salmonellae in feces were compared with 99 control horses not shedding salmonellae in feces; regarding breed, sex, age and initial diagnosis, none of the odds ratios for study factors was significant. The factors found to be associated with fecal shedding of salmonellae in the prospective study included diarrhea at the time of admission to the hospital, fever while hospitalized, and a change in diet while hospitalized. Horses identified to be shedding salmonellae in feces were not limited to those with clinical signs of salmonellosis; however, spread of salmonellae from a shedder without clinical signs of disease to other hospitalized horses was not identified. The most common serovars of Salmonella isolated were oranienburg and newport.

Diarrhea associated with sand in the gastrointestinal tract of horses

Four horses with diarrhea had radiographic evidence of large quantities of sand in the gastrointestinal tract. Initially, none of the horses had sufficient fecal sand quantity to suggest sand enteropathy. Diarrhea resolved in all horses within 2 days of oral administration of psyllium hydrophilic mucilloid. Historically, all 4 horses had lost weight or had difficulty maintaining weight. After treatment was administered, the horses either gained weight or were easier to maintain in good condition.

Adjunctive methods of examination of the urogenital tract

Included in this article are descriptions of adjunctive methods of examination of the urogenital tract, including ultrasonography of the kidneys, urinary bladder, ovaries and uterus; endoscopy of the urethra, urinary bladder, and uterus; contrast radiography of the urinary tract; kidney biopsy; and laparoscopy of the abdomen, emphasizing examination of the mare's reproductive tract.

Effect of transportation stress on bronchoalveolar lavage fluid analysis in female horses

Four bronchoalveolar lavages were performed sequentially on 9 control and 8 transport-stressed female horses. Alterations in results of fluid cytologic analyses, microbial content, and phagocyte function of recovered pulmonary macrophages in all horses were determined. Seemingly, absolute and relative increase in the number of inflammatory cells detected in the second bronchoalveolar lavage fluid of control horses was the result of irritation of the first lavage. This increased response was not observed in transport-stressed horses until 5 days after transport (third lavage; 10 days after initial lavage). Seemingly, delayed inflammatory response was the result of the transport stress. Microbial content and macrophage function were not significantly different between the 2 groups (P greater than 0.05).

Hemorrhagic necrotizing enterocolitis associated with Clostridium difficile infection in four foals

Severe hemorrhagic necrotizing enterocolitis was determined to be the cause of death for 4 foals. Toxigenic Clostridium difficile was isolated form the intestine of each foal, and large, gram-positive, rod-shaped bacteria lined the surface of necrotic villi. This finding of toxigenic C difficile associated with enteritis in foals adds another possible cause to the list of infectious agents that should be considered when evaluating foals with enteritis. Definitive diagnosis requires a thorough diagnostic evaluation, including procedures that will identify the organism and demonstrate its toxigenicity.

Epidemiologic survey of diarrhea in foals

Epidemiologic and etiologic data about diarrhea in foals were collected under a planned prospective recording and monitoring study. The survey and monitoring procedures included a survey to obtain an overview of current horse management practices on participating farms, a daily health record survey to obtain information on mares and their foals, and collection of feces from 19 of 144 diarrheic foals and 10 age-matched nondiarrheic foals for electron microscopy, ELISA for rotavirus, and bacteriologic culture. Coronavirus was detected in the feces of diarrheic as well as clinically normal foals. Rotavirus was detected in the feces of diarrheic foals only. With regard to agents found in the feces, there was no significant (P less than 0.05) difference between diarrheic and nondiarrheic foals. Half of the 297 foals on which data were available developed diarrhea. Most foals that developed diarrhea lacked other clinical manifestations of disease. Basic cleanliness at foaling was associated with a lower percentage of foals developing diarrhea. Prophylactic use of antibiotics and vitamins in newborn foals was associated with a higher percentage of foals developing diarrhea. A higher percentage of foals born to visiting mares developed diarrhea, compared with foals born to resident mares.

Chronic flunixin meglumine therapy in foals

Effects of a therapeutic dose of flunixin meglumine on gastric mucosa of horse foals were determined by endoscopy, double-contrast radiography, and gross and histologic examinations. Foals were administered 1.1 mg of flunixin meglumine/kg of body weight, PO/day for 30 days in an encapsulated form that was divided into 2 doses/day (group 1; n = 3) or by IM injection once a day (group 2; n = 7). Three control foals (group 3; n = 3) were administered capsules (n = 1) containing dextrose powder or IM injections (n = 2) of vehicle solution without flunixin meglumine. All 3 groups-1 foals given flunixin meglumine PO developed oral ulcers. Group-2 foals given flunixin meglumine IM did not develop oral ulcers. One control foal (group 3) developed 1 oral ulcer that healed during the study. Endoscopic examination revealed linear crease-like mucosal lesions in the glandular portion of the stomach in 2 group-2 foals. Radiographic evidence of gastric ulcers was observed in only 1 gastrogram of a group-1 foal. Foals were euthanatized, and necropsy revealed erosions and/or ulcers of the glandular portion of the stomach. Oral ulcers were observed in all 3 group-1 foals. Erosions of the glandular portion of the stomach developed in all 10 foals given flunixin meglumine, but did not develop in group-3 foals. Ulceration of the glandular portion of the stomach was present in 1 group-2 foal.

Monitoring the progression of renal failure in a horse with polycystic kidney disease: use of the reciprocal of serum creatinine concentration and sodium sulfanilate clearance half-time

Sequential reciprocals of serum creatinine concentration and sodium sulfanilate clearance half-times were used to monitor a horse with chronic renal failure. The horse was diagnosed as having polycystic kidney disease; at least one cyst was of distal tubular origin. Using the plots of the sequential data, a reasonably accurate prediction was made for complete renal decompensation to develop.

Atrial fibrillation in a pregnant mare: treatment with quinidine sulfate

Atrial fibrillation in a pregnant, lactating, 15-year-old mare nursing a 70-day-old foal was converted to normal sinus rhythm, using quinidine sulfate. The maximum concentration of quinidine was 4.3 mg/L in the mare's milk and was 2.6 mg/L in the mare's serum. Treatment with quinidine did not interrupt the pregnancy. Six months after treatment, the mare developed acute volvulus of the large colon and died. At necropsy, the mare did not have macroscopic or microscopic cardiac lesions. The fetus was macroscopically and histologically normal.

Isolation of piliated Escherichia coli from diarrheic foals

Escherichia coli was isolated from the feces and intestines of foals with and without diarrhea. Piliation of isolates was demonstrated by electron microscopy and agglutination in antisera having specificity for K88, K99, P987 and F41 pili. Piliation was also demonstrated by electron microscopy on organisms which did not react with any of the antisera.

Bilateral hypoplasia of the soft palate and aryepiglottic entrapment in a horse

Endoscopic examination of a 7-year-old gelding with weight loss indicated a palatal defect with a prominent tissue mass at the caudomedial margin of the defect. At necropsy, the condition was determined to be bilateral hypoplasia of the soft palate.