Extreme eosinophilia with disseminated eosinophilic granulomatous disease in a horse

Extreme eosinophilia with disseminated eosinophilic granulomatous disease is described in a 4-year-old Arabian mare. Clinical signs included weight loss, coughing, jugular distention, and ventral edema. Cutaneous lesions were not observed. Eosinophilic inflammation was observed in cytologic specimens from the respiratory tract, body cavities, and lymph nodes. At necropsy, a 20-cm diameter intrathoracic mass was observed. Smaller nodules were present in the lymph nodes, liver, spleen, adrenal glands, pancreas, and skeletal muscle. Histologically, these masses and nodules were characterized by infiltrates of eosinophils, macrophages, and multinucleated giant cells, reactive fibroplasia; and multifocal eosinophilic coagula. Microscopically, mild eosinophilic infiltrates were observed in sections of stomach, small intestine, colon, and pleura; however, gross lesions were not observed in these tissues at necropsy. The etiology of the extreme eosinophilia and disseminated eosinophilic granulomatous disease in this horse was not determined.     

Surgical treatment of sacral fracture in a horse

An 8-year-old Arabian stallion had signs of severe tailhead pruritus and slowly progressive loss of tail tone for 3 months. Palpation per rectum and radiography of the sacrocaudal region revealed a transverse, ventrally displaced fracture of the caudal portion of the sacrum. Surgical decompression and tail amputation resulted in complete recovery of athletic and reproductive function. Evidence of cauda equina neuritis was not seen on histologic examination of nerve roots obtained at surgery.     

Umbilical cord remnant abscess in a yearling colt

An abscess of the external umbilical remnant and umbilical vein remnant was diagnosed in a 16-month-old colt, using ultrasonography. Because of the colt's size, primary closure of the surgical incision after umbilical cord resection was not complete. Vertical mattress stainless steel sutures and stents were used, and healing was by second intention. Intervening gas-filled viscera made it impossible to visualize ultrasonographically the bladder of umbilical artery remnants in a colt of this age.     

Testicular seminoma associated with torsion of the spermatic cord in two cryptorchid stallions

Two adult horses had colic attributable to spermatic cord torsion and strangulation of abdominally retained neoplastic testes. Both horses had caudal abdominal soft tissue masses palpable per rectum. One horse was treated successfully by surgical removal of the testis, and the other was euthanatized without treatment. Histopathologic diagnosis of the involved testes was testicular seminoma. Spermatic cord torsion of an abdominally retained testis should be considered in the differential diagnosis of signs of abdominal pain in cryptorchid stallions, especially those with a palpable caudal abdominal mass.     

Hypoperfusion of the small intestine during slow infusion of a low dosage of endotoxin in anesthetized horses

The effects of intravenous infusion of endotoxin for 30 minutes at a cumulative dosage of 0.03 micrograms/kg on average carotid arterial pressure, and on average arterial pressure, capillary pressure, venous pressure, total vascular resistance, precapillary resistance, postcapillary resistance, and capillary filtration coefficient in the jejunum were compared to the effects of intravenous infusion of 0.9% sodium chloride solution in 6 anesthetized horses. Endotoxin significantly reduced intestinal venous blood flow by inducing vasoconstriction. Increased vascular resistance resulted from increased precapillary resistance. The capillary filtration coefficient was unchanged by endotoxin. These results suggest that intestinal vasoconstriction occurs during the compensatory stages of endotoxemia.     

Clinical, ultrasonographic, and surgical findings in foals with umbilical remnant infections

Infection of umbilical arteries, umbilical vein, and/or urachus was diagnosed ultrasonographically in 33 foals 1 to 90 days old (mean, 17.7 +/- 17.3 days). In these foals, the most common initial problems were umbilical abnormalities, septic arthritis, and/or neonatal septicemia. In 16 foals, abnormalities of the external umbilical stalk were noticed on admission. Abnormalities of the internal umbilical structures were identified when enlargement and echogenic material (fluid and/or gas) were imaged ultrasonographically within these structures. Multiple structures were affected in 23 foals, with the urachus the most commonly affected structure. Surgical findings confirmed ultrasonographic identification of infected umbilical structures in 23 foals. Twenty-two samples from affected umbilical remnants submitted for culture at surgery were positive for bacterial growth. Multiple organisms were isolated in 15 cultures. Escherichia coli and beta-hemolytic streptococci were the most common isolates. Two foals died of late complications associated with surgical resection, 1 foal treated surgically and 3 foals treated medically died or were euthanatized because of other complications, and the remaining 27 foals lived.     

Tumor Necrosis Factor and Interleukin-6 Activity and Endotoxin Concentration in Peritoneal Fluid and Blood of Horses with Acute Abdominal Disease

The purpose of this study was to evaluate the diagnostic and prognostic significance of tumor necrosis factor-alpha (TNF) and interleukin-6 (IL-6) activities and endotoxin concentration in blood and peritoneal fluid of 155 adult horses with acute abdominal disease (colic). Samples also were obtained from 20 healthy adult horses. Blood and peritoneal fluid supernatant TNF and IL-6 activities and endotoxin concentration were significantly greater in horses with colic, compared with healthy horses. In horses with colic, the peritoneal fluid endotoxin concentration and TNF and IL-6 activities were significantly greater than those in blood. Within the colic group, peritoneal fluid IL-6 activity was the analyte that was most frequently increased. Blood and peritoneal fluid supernatant TNF and IL-6 activities were significantly greater when endotoxin was detected in the same sample. Blood and peritoneal fluid IL-6 activity was significantly greater in horses with inflammatory or strangulating lesions, compared with horses having nonstrangulating or noninflammatory lesions. Compared with all other data categories, diagnostic accuracy for nonsurvival was greatest (80%) when blood IL-6 activity exceeded 60 units/mL. The results of this study indicate that endotoxin was present in the peritoneal cavity of at least one third of horses with any acute disease of the abdomen. In horses presented for colic, blood or peritoneal fluid IL-6 activity was more useful than either TNF activity or endotoxin concentration for distinguishing lesion type. Although diagnostic accuracy for the prediction of nonsurvival was good for all of the analytes, negative values were more useful in the prediction of a favorable outcome than were abnormally increased values in the prediction of mortality.     

Septicemia, atrial fibrillation, cardiomegaly, left atrial mass, and Rhodococcus equi septic osteoarthritis in a foal

A foal with vegetative bacterial endocarditis affecting the wall of the left atrium was treated successfully with cefotaxime, erythromycin, and rifampin. Bacterial isolates included Escherichia coli from blood and Rhodococcus equi from a P-type osteomyelitic lesion of the left third metatarsal bone and from synovial fluid from the left metatarsophalangeal joint. Cardiac complications included cardiomegaly and atrial fibrillation, which responded to treatment with digoxin and quinidine sulfate. Cardiac function was considered normal 18 months after treatment. Bacteriologic cure of osteoarthritis was achieved by use of surgical debridement, lavage, and local and systemic antimicrobial treatment; however, lameness developed 18 months after treatment when training for flat racing was begun. Radiography revealed chronic degenerative joint disease.     

Ultrasonography of umbilical structures in clinically normal foals

The umbilical arteries, urachus, and umbilical vein were scanned ultrasonographically in 13 clinically normal foals that ranged in age from 6 hours to 4 weeks. Sonograms were obtained using a 7.5-MHz sector scanner transducer placed across the midline of the ventral portion of the foal's abdominal wall. The umbilical vein was scanned from the umbilical stalk to its entrance into the hepatic parenchyma. The mean (+/- SD) diameter of the umbilical vein was 0.61 +/- 0.20 cm immediately cranial to the umbilical stalk, 0.52 +/- 0.19 cm midway between the umbilicus and liver, and 0.6 +/- 0.19 cm at the liver. The urachus and umbilical arteries were scanned from the umbilical stalk to the apex of the urinary bladder and had a mean total diameter of 1.75 +/- 0.37 cm at the bladder apex. The umbilical arteries also were scanned along either side of the bladder and had a mean diameter of 0.85 +/- 0.21 cm. These measurements and the ultrasonographic appearance of the internal umbilical structures from clinically normal foals can be used as references to diagnose abnormalities of the umbilical structures in neonatal foals.