Rhodococcus equi pneumonia in an adult horse

A 20‐year‐old, Thoroughbred mare in the fifth month of gestation was examined for weight loss, pyrexia and lethargy. Physical examination, ultrasonography and radiography revealed a severe abscessing pneumonia and a dead fetus. The mare did not respond to symptomatic treatment and died suddenly. Necropsy revealed multifocal pulmonary abscessation. Rhodococcus equi was isolated from the lungs, liver and kidneys. Specific immune function of the mare and presence of the virulence associated protein A (VapA) of the R. equi isolated was not determined. It is likely that immunosuppression is required for systemic R. equi infections in adult horses; however, it is unknown if VapA is necessary to produce disease in adult horses.     

Tracheal trauma and pneumonia secondary to endotracheal intubation in a horse undergoing general anaesthesia,computerised tomography and myelography

Endotracheal intubation is commonly performed in horses undergoing general anaesthesia to avoid fluid aspiration and provide mechanical ventilation and inhalational anaesthetic agents. Secondary laryngeal and tracheal trauma following intubation is not rare. This case report describes the successful treatment of a horse with laryngeal and tracheal trauma secondary to intubation during myelography. Based on other clinical reports and clinical experience, movement of the endotracheal tube during myelography was considered the most likely cause of the damage. This case underscores the importance of monitoring horses for development of respiratory signs after general anaesthesia for computerised tomography and myelography.     

Rhodococcus equi pleuropneumonia in an adult horse

A 10-year-old warmblood gelding was evaluated for intermittent pyrexia, dullness, weight loss, and progressive respiratory disease. Multifocal necrotic pneumonia and pleuritis due to Rhodococcus equi infection was diagnosed. Case management is discussed, as well as factors that may have led to this rare cause of pleuropneumonia in an adult horse.     

Idiopathic gastroesophageal reflux disease in an adult horse

Chronic gastroesophageal reflux disease was diagnosed in a 22-year-old female Tennessee Walking Horse that had signs of bruxism and ptyalism. Esophageal ulceration was detected via endoscopy. Compared with the damage to the proximal portions of the esophagus, the severity of the ulceration increased toward the gastroesophageal junction. Esophageal ulceration attributable to chronic gastric acid reflux is usually secondary to pyloric outflow obstruction in horses. In the horse of this report, there was no evidence of either a chronic pyloric or duodenal obstruction that could have resulted in esophageal ulceration. Esophageal ulceration in this horse was attributed to gastroesophageal reflux disease, a common condition in humans in which the underlying abnormality is functional incompetence of the gastroesophageal junction. Treatment is directed at decreasing gastric acidity and protecting the ulcerated mucosa. In the horse of this report, treatment was unsuccessful and the horse was euthanatized; a physical cause of gastroesophageal reflux disease was not identified during an extensive postmortem examination.     

Repair of an open radial fracture in an adult horse

An open radial fracture in an adult horse (450 kg) was repaired by internal fixation, using two 18-hole 4.5-mm broad dynamic compression plates and 5.5- and 4.5-mm bone screws. The fracture healed completely, but when evaluated 9 months after surgery, the horse was lame on the fractured limb at a trot. Local infiltration of anesthesia along the distal half of the bone plates greatly ameliorated the lameness, suggesting that the plates were irritating the soft tissues and extensor tendons along the cranial and lateral aspects of the antebrachium. Both bone plates were removed simultaneously with no complications, and the horse became sound.     

Right subclavian artery anomaly in an adult Friesian horse

This report describes an unusual vascular ring anomaly (VRA) that resulted in repeated oesophageal obstruction in an adult horse. Oesophagoscopy identified a luminal obstruction with secondary mucosal sloughing. Post mortem findings revealed oesophageal and tracheal stenosis secondary to an aberrant right subclavian artery. The presence of the VRA may have resulted in repeated oesophageal impactions in an adult horse and the hereditary potential for this defect should be considered.     

Bilateral third eyelid ectopic cilia in an adult horse

A 15‐year‐old Cob mare presented with a 4‐month history of chronic epiphora and intermittent blepharospasm in the right eye. On ophthalmic examination, two translucent aberrant hairs were identified at the third eyelid margin corresponding to an area of corneal fibrosis and neovascularization. Partial excision of the third eyelid was performed, and histopathology confirmed ectopic hair follicles. Two weeks later, clinical signs recurred in the same eye. Examination revealed another pair of aberrant hairs on the bulbar surface of the third eyelid near its leading edge. This portion of the third eyelid was also excised, and histopathology confirmed two additional ectopic hair follicles. Eight months later, the horse developed similar clinical signs in the left eye. Ophthalmic examination showed a single aberrant translucent hair at the third eyelid margin associated with focal fibrosis and neovascularization of the ventromedial cornea. Partial excision of the third eyelid was performed, and histopathology confirmed an ectopic hair follicle within the third eyelid conjunctiva. Excision was curative at 4 years postoperatively with no further recurrence in either eye.     

Oil Red O-positive lipid in peritoneal fluid from a horse with a rectal tear

A 4-year-old Quarter Horse mare was presented to the Texas A&M University Veterinary Medical Teaching Hospital for evaluation of a rectal tear. On initial evaluation, rectal palpation and colonoscopy revealed a grade IIIb rectal tear. Analysis of peritoneal fluid revealed a modified transudate. Preliminary supportive care included fluid therapy and mineral oil administration via nasogastric tube. Approximately 48 hours after presentation, a second abdominocentesis was performed, and cytologic examination of the fluid revealed a marked suppurative exudate. Round clear nonrefractile material observed within neutrophils and macrophages and in the background stained bright pink to red with Oil Red O, confirming the material as lipid, likely from leakage of mineral oil through the rectal tear. The condition of the mare deteriorated and euthanasia was elected due to the poor prognosis. At necropsy, gross and histologic findings included peritoneal effusion and a full-thickness rectal tear with transmural necrotizing pyogranulomatous colitis and fibrinous peritonitis. To the authors' knowledge, this is the first reported case of Oil Red O-positive lipid vacuoles in the peritoneal fluid of a horse from presumed leakage of mineral oil through a transmural rectal perforation. The frequency of this occurrence in horses is unknown, but it is important for cytopathologists to be familiar with the appearance and significance of lipid-type droplets in phagocytic cells in cytologic fluid analysis specimens.     

Surgical management of duodenal obstruction in an adult horse

A 3-year-old Standardbred stallion was admitted for treatment of acute enterocolitis. The horse improved in response to empiric treatment, but subsequently developed ventral edema, scrotal abscessation, and severe laminitis. Improvement again was seen, but on day 29 of hospitalization, the horse developed rapid heart rate and signs of abdominal pain. Exploratory celiotomy revealed complete obstruction of the descending portion of the duodenum, 20 cm caudal to the duodenal sigmoidal flexure. Three-tier duodenojejunostomy and jejunojejunostomy were performed to bypass the duodenal obstruction.     

Pneumopericardium associated with blunt thoracic trauma in an adult horse

Pneumopericardium, the presence of air in the pericardial space, is a rare condition that has been well documented in human medicine and associated with several different aetiologies, most commonly trauma. We report a case of pneumopericardium after blunt chest trauma in an adult horse. The horse responded well to conservative therapy and made a full recovery.     

Pseudomonas aeruginosa sepsis in an adult horse with enteric Salmonellosis

Objective: To report a case of enteric Salmonellosis and Pseudomonas aeruginosa bacteremia in an adult horse. Case summary: A 7‐year‐old mare presented for signs of acute abdominal pain. Exploratory laparotomy allowed surgical correction of right dorsal displacement of the large colon with a 180° volvulus at the cecocolic ligament. Postoperatively, the mare developed fevers, leukopenia, and diarrhea. Salmonella newport was cultured from the feces and P. aeruginosa from 2 consecutive blood cultures. The mare responded well to intensive medical therapy. New or unique information provided: Bacteremia associated with colitis is unusual in an adult horse, although the percentage of animals that may be bacteremic is unknown. The bacteria isolated, P. aeruginosa, a common pathogen of other sites in the horse, has not, to our knowledge, been previously reported as a cause of bacteremia and septicemia in an adult horse.     

Internal fixation of a fractured axis in an adult horse

Objective: To report internal fixation of a fractured axis with a dynamic compression plate (DCP). Study Design: Case report. Animals: A 7‐year‐old Warmblood gelding. Method: Surgery was performed under anesthesia in sternal recumbency. After fracture reduction the complete transverse fracture in the cranial third of the axis was stabilized with a 7‐hole 4.5 mm DCP. Optimal positioning of the plate and the length of the screws were facilitated by fluoroscopy. Recovery from anesthesia was supervised in a pool. Results: The horse had an excellent outcome and returned to its previous activity level. Conclusion: Surgical treatment with fracture reduction and plate fixation enables normal bearing of the head and neck and improves neck flexibility soon after surgery.     

Tracheal rupture following general anaesthesia in a horse

A Dutch Warmblood, with no other underlying clinical disease, presented for surgical excision of a sarcoid tumour on the distal right pinna under general anaesthesia. At the end of the procedure, immediately before being moved to recovery, the horse became light and made repeated attempts to move whilst attached to the hoist. Anaesthesia was deepened with intravenous thiopental sodium (Thiopentone)¹ and the horse was moved into the recovery room. The trachea was extubated with the cuff of the endotracheal tube inadvertently left partially inflated. Recovery was smooth and the horse stood uneventfully. The following day subcutaneous emphysema was noted along the neck and tracheoscopy revealed an abnormal dorsoventrally flattened trachea and a 5 cm tear in the dorsal aspect of the trachea. Symptomatic treatment resulted in progressive healing of the lesion and the horse recovered fully with no evidence of respiratory complications.     

Avian influenza A virus causing an outbreak of contagious interstitial pneumonia in mink

An outbreak of contagious respiratory disease in mink occurred in October 1984 on the south-east coast of Sweden. High morbidity with coughing, sneezing and dullness was reported. Post mortem examination showed interstitial pneumonia in most examined mink. An avian influenza A virus was isolated and shown to belong to serotype H10N4. Serological studies established that this virus was the most probable cause of the outbreak and also that this new viral infection seemed to be limited to the south-east coast of Sweden.