Septic pleuritis and abdominal abscess formation caused by Rhodococcus equi in a foal

A 3-month-old female Arabian horse was evaluated because of fever, respiratory distress, lethargy, and decreased appetite of 5 days' duration. Pleural effusion was diagnosed on the basis of ultrasonographic and radiographic examinations. Cytologic examination of pleural fluid collected via thoracocentesis revealed septic inflammation; bacteriologic culture of a sample of that fluid yielded Rhodococcus equi. A large intra-abdominal mass adjacent to the body wall was identified ultrasonographically. A specimen of the mass was collected via aspiration; the specimen was identified cytologically as purulent exudate that contained large numbers of rod-shaped bacteria, which confirmed abdominal abscess formation. Bacteriologic culture of a sample of the exudate also yielded R. equi. The foal was treated with azithromycin (10 mg/kg [4.5 mg/lb], PO, q 24 h for 5 days then q 48 h) and rifampin (5 mg/kg [2.3 mg/lb], PO, q 12 h) for 8 weeks and metronidazole (15 mg/kg [6.8 mg/lb], PO, q 8 h) for 3 weeks. Clinically, the foal responded to antimicrobial treatment within 2 weeks. At 8 weeks after the initial evaluation, ultrasonographic examination of the foal revealed resolution of the pleural effusion and abdominal abscess. In foals, R. equi infection typically results in pyogranulomatous pneumonia, and pleural effusion is an uncommon clinical sign. The combination of azithromycin and rifampin appears to be an effective treatment for R. equi infection in foals.     

Splenectomy in a foal to control intra‐abdominal haemorrhage caused by splenic rupture

Intra‐abdominal haemorrhage in horses can be due to rupture of the spleen and may result in severe blood loss. The assessment and resuscitation of a foal that collapsed due to intra‐abdominal haemorrhage is presented. Diagnosis of the source of the blood loss required exploratory laparotomy and confirmed splenic capsular rupture and haemorrhage. Splenectomy using a 17th rib resection approach was used to control the haemorrhage. Complications included acute cardiac muscle damage, which was monitored using echocardiography and troponin I levels. The successful surgical management of the ongoing blood loss in this foal suggests that splenectomy should be considered an option to control severe blood loss due to splenic rupture.     

Hematuria and a complex congenital heart defect in a newborn foal

A 16-hour-old foal was referred for evaluation of hematuria. A pansystolic heart murmur and left thoracic thrill were detected; laboratory diagnostics and ultrasonography identified a complex congenital heart defect. The diagnosis was confirmed at postmortem.     

Intracranial abscess caused by Rhodococcus equi infection in a foal

CASE DESCRIPTION: A 4-month-old Missouri Fox Trotter colt was examined for a 5-week history of head tilt after treatment for suspected pulmonary Rhodococcus equi infection. CLINICAL FINDINGS: Computed tomography revealed osteolysis of the occipital, temporal, and caudal portion of the parietal bones of the left side of the cranium. A soft tissue mass compressing the occipital region of the cerebral cortex and cerebellum was associated with the osteolytic bone. TREATMENT AND OUTCOME: A rostrotentorial-suboccipital craniectomy approach was performed to remove fragmented occipital bone, debulk the intracranial mass, and obtain tissue samples for histologic examination and bacterial culture. All neurologic deficits improved substantially within 3 days after surgery. Bacterial culture of the resected soft tissue and bone fragments yielded R equi. CLINICAL RELEVANCE: Intracranial surgery in veterinary medicine has been limited to dogs and cats; however, in select cases, extrapolation of surgical techniques used in humans and small animals can assist with intracranial procedures in horses.     

Protein-losing enteropathy caused by Lawsonia intracellularis in a weanling foal

A 5-month-old Morgan filly was presented to the Atlantic Veterinary College with a history of lethargy, fever, depression, anorexia, and dependent ventral edema. Diagnostic tests revealed severe inflammation, hypoproteinemia, and thickened small intestinal loops. Protein-losing enteropathy caused by Lawsonia intracellularis was diagnosed and treated successfully with erythromycin-rifampin.     

Hemorrhagic diathesis caused by multiple myeloma in a three-month-old foal

Multiple myeloma was diagnosed in a 3-month-old Quarter Horse foal with chronic weight loss, chronic bronchopneumonia, and epistaxis. The foal had pancytopenia, thrombocytopenia, and monoclonal beta-globulinemia. Bone marrow aspirates contained between 80 and 90% plasma cells.     

Hemorrhagic enteritis caused by Clostridium perfringens type C in a foal

A 4-day-old foal died with bloody diarrhea. Using a mouse neutralization test, Clostridium perfringens type C was isolated from intestinal contents, and alpha and beta toxins were identified. About 4 m of the jejunum had severe necrohemorrhagic enteritis. Microscopically, large, rod-shaped, gram-positive bacteria were seen on necrotic intestinal villi by use of Brown and Hopp's stains.     

Cellulitis and subcutaneous abscesses caused by Rhodococcus equi infection in a foal

Cellulitis and subcutaneous abscess formation was diagnosed in a 3-month-old Thoroughbred filly. Clinical signs consisted of a large ulcerated plaque, with satellite pustules on the medial aspect of the right hock and subcutaneous abscesses in the right inguinal and mammary gland areas. Laboratory analysis revealed mature neutrophilia. Rhodococcus equi was isolated from the cellulitis and the subcutaneous abscess. Oral administration of erythromycin and rifampin for 35 days resulted in a clinical cure.     

Vertebral osteomyelitis caused by Rhodococcus equi in a three-and-half-month-old Dutch Warmblood foal

Rhodococcus equi infection occurs worldwide and is especially a problem in foals, where it often causes colitis or pneumonia. Other organs are seldom affected, and their involvement is regarded as a complication of pneumonia and/or colitis. Vertebral osteomyelitis is one such rare complication and is probably caused by haematogenous spread from inflammatory lesions in the lungs and/or intestine. In rare cases, osteomyelitis can be caused by contamination of a wound. This case study describes a foal with vertebral osteomyelitis due to R. equi in which there were only minor inflammatory changes in a mesenteric lymph node.     

Intra‐abdominal cystic lymphangiomatosis in a Thoroughbred foal

Cystic lymphangiomas are rare malformations of the lymphatics that result in the formation of a cystic mass. Where multiple cysts are seen, the condition is termed cystic lymphangiomatosis. This case describes the diagnosis and unique management of cystic lymphangiomatosis in a 10‐day‐old Thoroughbred foal. Ultrasonography, histopathology and laparoscopy were essential for diagnosis and appreciation of the extent of disease. Ultimately, the cystic lymphangiomatosis was so extensive in this foal that complete surgical excision was considered impossible and the presence of adhesions within the abdomen indicated a very poor long‐term prognosis; the owners elected for euthanasia at age 14 weeks. Although rare, lymphangioma and lymphangiomatosis should be considered as a differential diagnosis for an intra‐abdominal mass in a young horse.     

Medical management of a large intra-abdominal mass caused by Rhodococcus equi in a foal

A 4-month-old Thoroughbred filly presented with pyrexia, inappetence and diarrhoea. Abdominal ultrasonography revealed a multilobulated abdominal mass that was determined to be associated with the caecum using computed tomography. Computed tomography also identified mesenteric lymphadenopathy and a pulmonary mass in the left caudal lung lobe. Percutaneous aspiration of the abdominal mass yielded pure growth of Rhodococcus equi. The filly responded in a positive fashion to the administration of clarithromycin, rifampin and gallium maltolate. Follow-up computed tomography revealed complete resolution of the abdominal mass and lymphadenopathy. Extrapulmonary disorders associated with R. equi should be considered even when thoracic ultrasonography reveals no evidence of pulmonary pathology. Although intra-abdominal abscesses have a grave prognosis, successful treatment is possible. Gallium maltolate can be safely administered to foals and may improve patient outcomes.     

Surgical repair of a congenital lateral abdominal wall hernia in a neonatal foal

A 16‐hour‐old Quarter Horse filly presented for evaluation of a soft mass in the right caudoventral lateral abdominal wall. Radiography and ultrasonography confirmed the presence of a nonreducible lateral abdominal wall hernia with small intestine located between the skin and body wall. The size of the defect itself could not be imaged and the filly was taken to surgery. A 4 cm vertical defect that appeared congenital was found in the transverse abdominal muscle and was repaired by primary apposition. This case report describes the repair and outcome of this unusual type of congenital hernia.     

Pulmonary embolism as a complication after abdominal surgery and colitis in a foal

This report describes a fatal pulmonary embolism in a foal, as a sequela of septic thrombophlebitis of the right jugular vein and/or a generalised hypercoagulable state. The foal underwent abdominal surgery and suffered from severe and prolonged colitis. Despite intense supportive care, the colt developed venous thrombophlebitis and subsequently died suddenly 12 days after discharge from the hospital, following an initial improvement. On post‐mortem examination, a large pulmonary embolism was discovered. Pulmonary thromboembolism is a potentially fatal sequelae of thrombus formation. It is difficult to detect and therefore likely to be underdiagnosed.     

Successful surgical management of abdominal abscessation secondary to Strongylus edentatus migration

This report describes the successful surgical management of abdominal abscessation secondary to Strongylus edentatus migration. Abdominal abscesses are a relatively common source of recurrent fever in the horse and are primarily managed with long‐term antimicrobial administration. However, identification of the definitive cause, extent of the abscesses and successful resolution in this case were not possible without an exploratory celiotomy to facilitate surgical resection.