A case of idiopathic eosinophilic pneumonia in a Quarter Horse gelding

A 16-year-old Quarter Horse gelding was presented to the Kansas State Veterinary Health Center for acute onset of diffuse, nonpruritic, generalised and coalescing urticaria. A single dose of dexamethasone resulted in resolution of the urticaria within 24 h; however, 48 h after discharge, he presented with mild colic. The patient was febrile and thoracic ultrasound was abnormal, evidenced by bilateral pleural echogenic irregularities, mild pulmonary consolidation and slight unilateral pleural effusion. Thoracic radiographs also revealed caudoventral soft tissue opacity in the same region of the ultrasonographic abnormalities. Transtracheal wash was performed and broad spectrum antimicrobials initiated. Poor clinical response to therapy and marked peripheral eosinophilia resulted in the necessity for bronchoalveolar lavage, which revealed a predominance of pulmonary eosinophils. A diagnosis of acute idiopathic eosinophilic pneumonia was made. Treatment included a tapering dose of dexamethasone over 4 weeks. Due to incomplete disease resolution, the patient was moved to an alternate environment which resulted in disease resolution.     

Congenital hypoplasia of the dorsal colon in a Quarter Horse filly with chronic,intermittent colic

Congenital colonic anomalies are rare in the horse and, to the authors' knowledge, no cases have been reported that include measurements of each segment of the large colon to confirm which section is abnormal. This case report describes chronic, intermittent colic in a Quarter Horse filly that had been attributed to chronic idiopathic hepatitis prior to an exploratory laparotomy. A colonic anomaly discovered at surgery became the primary differential for aetiology of the intermittent colic. Euthanasia of the filly and necropsy allowed further examination of the anomaly, where it was determined that the dorsal colon was short compared to the ventral large colon. In addition, the diagnosis of chronic idiopathic hepatitis was confirmed.     

Otopathy secondary to trigeminal schwannoma in a Quarter Horse

Otitis media secondary to trigeminal nerve (CN-V) paralysis is described in dogs and humans but not in horses. An 18-month-old Quarter Horse colt was presented with history of mastication difficulties and a nonhealing corneal ulcer. Clinical findings were consistent with paralysis of the right CN-V. Computed tomography imaging showed otopathy media and a mass at the root of the CN-V. The colt was euthanised due to poor prognosis. Post-mortem magnetic resonance imaging showed enlargement of the right CN-V which was slightly hyperintense on T2W. Histopathology of the mass revealed fusiform tumoural cells, positive on vimentin- and S100 immunohistochemistry, consistent with a schwannoma. Otitis media was presumed secondary to CN-V paralysis and denervation of the right tensor veli palatini muscle involved in opening of the Eustachian tube. This is the first case of trigeminal schwannoma and secondary otopathy media described in a horse, which highlights the importance of imaging in investigating trigeminal nerve paralysis.     

Ossifying fibroma as a cause of blindness in a 5-year-old Quarter Horse gelding

A 5-year-old Quarter Horse gelding presented to Texas A&M University Veterinary Medical Teaching Hospital with a several week history of bilateral blindness. Neurological deficits included an absent menace response and severe atrophy of the optic nerve head in the left eye (OS) as well as decreased vision in the right eye (OD). Advanced imaging consisting of computed tomography (CT) and magnetic resonance imaging (MRI) confirmed a large mass in the base of the skull invading the sinuses and asymmetrically compressing the optic nerves rostral to the optic chiasm. Due to the size and location of the mass as well as severity of associated neurological signs, humane euthanasia was elected. Necropsy examination identified a large mass effacing the sphenopalatine sinuses and compressing the optic nerves. Histologically, the mass was identified as an ossifying fibroma (OF) and degeneration of the optic nerves was confirmed. As an OF in this location has never been described in a horse, this case demonstrates a new differential for blindness in horses.     

Treatment and resolution of zilpaterol hydrochloride toxicity in a Quarter Horse gelding

Zilpaterol hydrochloride is a β‐2 agonist utilised as a repartitioning agent in cattle. In recent years, it has also been used illicitly among human athletes and body builders, and administered to racehorses. While there are numerous anecdotal reports of the effects of zilpaterol in horses, this is the first documented clinical case of equine zilpaterol toxicity. The horse presented with marked tachycardia, profuse sweating and generalised muscle fasciculations. Ultimately, treatment was initiated with propranolol and the horse made a complete recovery.     

Standing biceps brachii tenectomy to treat chronic bicipital tendinopathy associated with bursal fibrosis and humeral adhesions in a Quarter Horse gelding

Chronic biceps brachii (BB) tendinopathy is a rare cause of lameness in horses that can be challenging to diagnose and treat successfully. This pathology is typically insidious in onset and unresponsive to conservative treatment. A 12-year-old Quarter Horse gelding presented for chronic severe lameness of the left forelimb that was localised to the left shoulder area. The horse was unresponsive to conservative management and surgical exploration revealed a grossly enlarged proximal BB tendon, a thickened fibrotic bicipital bursa and adhesions between the tendon, humerus and bursa. With standing sedation and local anaesthesia, the adhesions were debrided and 10 cm of the affected tendon was excised. Immediately post-operatively, the left forelimb lameness dramatically decreased. The horse recovered well and after rehabilitation returned to the previous level of athletic performance without evidence of lameness or gait abnormality. In this case, tenectomy of the chronic unresponsive BB tendinopathy, with associated bursal fibrosis and humeral adhesions, was successful and resulted in a return to previous athletic performance without complications. Standing excision of the BB tendon may be a viable treatment option for chronic BB tendinopathy and associated conditions when there is significant compromise to the integrity of the BB tendon.     

Urinothorax in a Quarter Horse filly

An 18 h old Quarter Horse filly, while being treated for diarrhoea, was evaluated for a distended abdomen and electrolyte abnormalities. Peritoneal and pleural fluid was detected by ultrasound and a presumptive diagnosis of a ruptured bladder was made. Intravenous fluid therapy was instituted to correct the electrolyte abnormalities prior to surgical repair of the bladder tear. Anaesthetic complications included hypoxaemia and decreased compliance secondary to the pleural effusion; therefore, a thoracocentesis was performed. Analysis of the pleural fluid revealed a pleural fluid to serum creatinine ratio of >1.0, indicative of urinothorax. The filly recovered from anaesthesia and was discharged on systemic antimicrobials. Urinothorax should be considered in cases of uroperitoneum with concurrent pleural effusion. Early detection may decrease patient morbidity and anaesthetic complications.     

Preputial fibroma in a gelding

An 11‐year‐old gelding presented with a large mass located in the dermis of his preputium that surrounded the penis completely. This mass was first noted years ago but did not increase in size. Histological examination diagnosed a fibroma. No treatment was initiated since no signs of discomfort were noticed and the gelding was performing at a high level in competitive showjumping. Next to skin tumours, tumours of the penis and preputium are most common. Most frequently, squamous cell carcinomas and sarcomas are diagnosed. Although fibromas can develop anywhere in connective tissue, a preputial location of a fibroma in a gelding is rare. Differential diagnosis and possible treatment options are discussed.     

Haemolytic anaemia and bilateral uveitis associated with leptospirosis in a 6‐year‐old Quarter Horse gelding

A 6‐year‐old Quarter Horse gelding was presented for bilateral uveitis resulting in vision loss as well as icterus. Anaemia with autoagglutination was consistent with a presumptive immune‐mediated haemolytic anaemia. Urinary PCR was positive for Leptospira spp. and microscopic agglutination test (MAT) titres were elevated to multiple serovars supportive of a diagnosis of leptospirosis. Treatments included broad spectrum antibiotics and aggressive anti‐inflammatory medications. While the horse was hospitalised, the development of bilateral corneal ulcers precluded the use of topical ophthalmic anti‐inflammatories for a number of days. The corneal ulceration resolved, vision returned in both eyes and the immune‐mediated haemolytic anaemia resolved. After 9 days of hospitalisation, oral minocycline was administered for 2 weeks at home as well as low dose oral flunixin meglumine and topical ophthalmic diclofenac and atropine. This case represents the first published case of haemolytic anaemia associated with leptospirosis in a horse.     

Small intestinal adenomatous polyposis resulting in protein-losing enteropathy in a horse

A 4-year-old Quarter Horse gelding was presented with a history of weight loss of 6 months duration, along with extensive ventral subcutaneous edema. Clinicopathologic findings included a markedly low serum total protein (2.9 g/dl) and a low packed cell volume (24%). The mucosal surface of the distal jejunum and entire ileum were carpeted with numerous polypoid, papillary, and glandular masses comprised of pseudostratified tall columnar cells and large numbers of interspersed goblet cells. Neoplastic change was diffuse throughout the mucosa of each mass, but abrupt demarcation occurred between neoplastic masses and adjacent mucosa. Immunohistochemical staining for protein of the p53 tumor suppressor gene revealed only occasional cytoplasmic reactivity within polyps and normal mucosa. Nuclear staining for papillomavirus antigens was not observed. Electron microscopic examination revealed features of well-differentiated intestinal epithelial cells, including apical tight junctions and microvilli, desmosomes, and the presence of numerous goblet cells. Microorganisms were not detected. Small intestinal polyposis should be considered as a rare differential diagnosis for protein-losing enteropathy in the horse.     

Soft tissue sarcomas in the pharyngeal region of a 5‐year‐old Quarter Horse mare

This case report describes the identification of multiple soft tissue sarcomas in the pharyngeal region of a 5‐year‐old Quarter Horse mare. Diagnostic work‐up included physical examination, radiography, ultrasonography, endoscopic examination of upper airways and guttural pouch, and post mortem examination with histopathology. Humane euthanasia was indicated due to the chronicity of the condition, prognosis and financial constraints.     

An abdominal teratoma in a yearling Irish Cob with a strangulating obstruction of the small intestine

A yearling Irish Cob stallion was presented to De Morette Equine clinic for severe acute abdominal pain, nonresponsive to analgesics and sedatives. Rectal palpation and a limited transabdominal ultrasonographic examination led to the presumptive diagnosis of a strangulated obstruction of the small intestine. The painful behaviour of the pony did not allow conservative treatment and surgical exploration was denied by the owners for financial considerations. On necropsy, a large cystic mature teratoma was adhered to the ventral body wall, the mesenteric root, omentum and intestines. Teratomas are rare in man and animals, and an extragonadal intraperitoneal location has not previously been reported in the equine species.     

Small colon obstruction by an ovarian pedicle as an acquired condition in a foal

This report describes the clinical course and the surgical findings in a 7‐day‐old foal referred for signs of abdominal pain. The foal underwent abdominal celiotomy due to the degree of pain unresponsive to medical treatment and, upon exploration, an ovarian pedicle was found to be wrapped around the small colon. The lesion was corrected, the foal recovered well from anaesthesia, and a 4 month follow‐up revealed no other signs of abdominal pain or complications.     

Lumbar fractures in a 5-year-old Warmblood cross gelding

This case report describes multiple lumbar vertebral fractures in a 5-year-old Warmblood cross gelding used for low-level exercise, with no known history of trauma. Clinical signs included intermittent severe pain, distress and unwillingness to move. When the horse was in less severe pain, he tilted the pelvis to one side when walking and also when trotting. Fracture of the 6th lumbar vertebral body was diagnosed by transrectal ultrasonography and confirmed by post-mortem computed tomography. Post-mortem examination also revealed a complete fracture of the 3rd lumbar vertebral body. Previously, lumbar fractures have only been reported in racing breeds and ante mortem diagnosis has been limited to scintigraphy.     

Small intestinal segmental volvulus in horses after gastroscopy: Four cases (2011–2012)

Gastroscopy is the most common technique used in veterinary medicine to evaluate the stomach in horses and to date, no complications have been described associated with the procedure. This paper reports 4 cases developing a nonstrangulating segmental volvulus of the small intestine after gastroscopy at 3 referral institutions over a 2 year period. After performing diagnostic gastroscopy, all horses developed acute and severe clinical signs of colic unresponsive to medical management. Time range between gastroscopy and onset of colic signs varied from 10 min to 3 h. An exploratory laparotomy revealed a nonstrangulating segmental volvulus of the small intestine that was manually corrected without need for resection in all horses. In all cases, affected small intestine was severely gas distended. Three of those horses survived to discharge and were alive at follow‐up. One horse was subjected to euthanasia 2 days after surgery due to diffuse intestinal lymphoma.     

Chronic eosinophilic granulomatous tenosynovitis in a Quarter Horse mare

A 5-year-old Quarter Horse mare was presented to the Michigan State University Equine Surgery Service for evaluation of a right hind metatarsophalangeal joint injury. On presentation, the horse was a grade 4/5 lame. Radiographs and ultrasonography showed peritendinous ossification/mineralisation of soft tissue structures and digital flexor tenosynovitis with profound intracapsular mineralisation. A digital flexor tendon sheath tenoscopy was performed with a plantar annular ligament desmotomy and a manica flexoria ligament tenotomy. During surgery, a significant amount of tan granular material was found within the digital tendon sheath. Approximately 80% of this material was removed, and a sample was sent for histopathology. The horse was diagnosed with eosinophilic granulomatous tenosynovitis. Long-term follow-up revealed improvement with four treatments of intralesional triamcinolone given 2–4 weeks apart. The horse became serviceably sound (grade 1/5) and was beginning light work under the saddle approximately 5 months post-tenoscopy.     

Caecal lipomatosis as a cause of colic in a 9‐year‐old gelding

Lipomatosis is an uncommon cause of colic. This case report details the pre‐ and intraoperative findings of a 9‐year‐old gelding, presented with acute abdominal pain. Exploratory laparotomy revealed a massive fatty infiltrate involving an extensive portion of the base and mid‐body of the caecum. To the authors' knowledge, this is the first report of an infiltrative lipomatous lesion of the equine caecum.     

Small intestinal volvulus in 115 horses: 1988-2000

OBJECTIVE: To evaluate the historical data, signalment, clinical signs, results of laboratory analyses, treatment, and outcome of horses with small intestinal (SI) volvulus. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: One hundred and fifteen client-owned horses, aged 1 month to 21 years. METHODS: Clinical signs, laboratory data, surgical or necropsy findings, and outcome for horses with SI volvulus were obtained from medical records, identified by computer search and manual review. RESULTS: There was no statistical difference in signalment between cases and the hospital population. Seventy-four percent of horses were >/=3 years. There were considerable variations in clinical signs on admission; high heart rate and signs of severe pain were not consistent features. Examination per rectum identified distended small intestine in only 69% of horses. One hundred horses had surgery, and small intestine resection was performed in 25. Eighty-four horses were recovered from surgery, and 67 horses survived to hospital discharge (80% of horses recovered from surgery, 58% of 115 horses). Forty-eight percent that were ultimately discharged had a post-operative complication and these horses had a longer average stay than horses with no complication (11 days versus 8.9 days). CONCLUSIONS: We identified 115 horses with primary SI volvulus over a 12-year period. We found that the population of horses with this lesion was older than has previously been reported and that the prognosis for post-operative survival to hospital discharge is good (80%). Post-operative complications were common, and affected approximately half the horses that were ultimately discharged from the hospital. CLINICAL RELEVANCE: This information may aid diagnosis and prognosis and guide decision making for horses with this condition.