Duodenal volvulus as a cause of gastric rupture in a 15‐year‐old Warmblood gelding

Duodenal volvulus is an unreported cause of colic in the horse. This case report describes a 15‐year‐old Warmblood gelding evaluated for acute abdominal discomfort. Exploratory celiotomy revealed duodenal volvulus and gastric rupture resulting in severe, acute, septic peritonitis. To the authors' knowledge, this is the first report of a volvulus of the equine duodenum.     

Atypical histopathological findings in a 15‐year‐old Warmblood gelding diagnosed with anhidrosis in a temperate climate

This case report describes the atypical histopathological findings in a horse with anhidrosis that presented for evaluation of suspected respiratory disease during autumn/winter in a temperate climate. Anhidrosis in this horse was associated with mononuclear infiltration of T lymphocytes around sweat glands, a finding not previously reported in cases of equine anhidrosis. This report highlights the importance of considering anhidrosis as a differential diagnosis in the investigation of respiratory disease and illustrates that the condition can occur in horses residing in temperate climates.     

Carcinoma of an accessory genital gland in a 23‐year‐old Camargue gelding

This report describes the case management, histopathological and post mortem findings in a 23‐year‐old gelding with a peri‐rectal mass. The mass was debulked surgically and submitted samples revealed it to be a poorly differentiated carcinoma. In the post operative period the horse developed signs of abdominal pain and dysuria and was subjected to euthanasia. Post mortem examination revealed a large infiltrative mass located between the rectum and urethra, consistent with a carcinoma of an accessory genital gland, most likely the seminal vesicle.     

Cutaneous habronemiasis in a 9‐year‐old Arab gelding in the United Kingdom

Cutaneous habronemiasis causes ulcerative granulating lesions in the skin of equids. Dramatic exuberant tissue may be seen, which becomes traumatised by the horse. To the authors' knowledge, cutaneous habronemiasis has not previously been documented on the distal limb of horses in the UK. Cutaneous habronemiasis should be considered as a potential differential diagnosis for ulcerative granulating skin lesions on the distal limb of the horse.     

Histopathological Characteristics of an Ossifying Fibroma Formed in the Maxilla of a Racehorse

A 1-year-old male thoroughbred racehorse experienced swelling of the left upper lip. The swelling was attributable to enlargement around the incisive bone of the interdental space posterior to the third incisor in the left maxilla. Even after two operations to reduce the bulk of the mass, it continued to increase in size. Dyspnea caused by stenosis of the nasal cavity forced us to perform euthanasia, and a pathological examination was conducted. Macroscopic examination of a section of the mass revealed the formation of multiple areas of solid fibrous tissue, and trabeculae within the incisive bone which had displaced the cortical bone. On histology, the mass was composed of trabecular bone-like structures due to the proliferation and aggregation of fibroblasts. Therefore, we diagnosed it as an ossifying fibroma. Equine ossifying fibroma is characterized by development in the mandible, but was formed in the maxilla in this case. Equine ossifying fibroma has not been reported previously in Japan. This is the first case of equine ossifying fibroma identified in Japan.     

Treatment of an 18‐year‐old mare for bilateral,branchial remnant cysts

This report describes the treatment of an aged mare for bilateral, branchial remnant cysts by marsupialisation and sclerotherapy the cysts. Treatment to resolve the cysts was prolonged, but the mare had no long‐term complications.     

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.     

Thoracotomy for repair of a large dorsal diaphragmatic hernia in an 18‐year‐old mare

An 18‐year‐old Arabian‐mix mare was presented with a history of severe colic. Emergency exploratory celiotomy revealed diaphragmatic hernia, with a large rent in the left dorsal aspect of the diaphragm and large colon volvulus. Attempts to close the defect in the diaphragm in dorsal recumbency were unsuccessful. Therefore, a thoracic approach through lateral thoracotomy was elected, and a mesh was attached to the diaphragm using skin staples. While in dorsal recumbency, the mare suffered from significant respiratory acidosis. Thus, the mare was tilted into reverse Trendelenburg (30° head upward) and ventilation improved markedly. The mare recovered uneventfully, and was doing well 5 years after surgery.     

Surgical treatment of a rostral mandibular complex odontoma in a 3‐year‐old horse

Complex odontomas are rare odontogenic tumours in horses comprised of a combination of mesenchymal and epithelial tissues. Examination, radiographic and histopathological findings in this patient all represent the typical behaviour of a complex odontoma. Oral tumours in horses may have treatment limitations due to tumour size and location. Similar to treatment in other species, surgical enucleation was curative for this type of tumour.     

Fibro‐osseous tumour of the fourth metacarpal bone in a horse: Clinical,radiographic and long‐term post operative findings

This case study describes a rare case of a fibro‐osseous tumour in the distal part of the fourth metacarpal bone of a 13‐year‐old horse. The tumour was surgically removed and wound healing occurred without complications. A specific diagnosis was reached by considering the clinical and histological features of the mass. However, the process was complicated by the different classification systems for this type of tumour. When classified according to the veterinary literature, ossifying fibroma is the appropriate diagnosis, whereas in human medicine this term has been replaced.     

Caecal duplication in a 13‐year‐old Thoroughbred

A 13‐year‐old Thoroughbred gelding was presented for evaluation of recurrent colic of 4 weeks duration. These colic episodes were mild and responsive to medical therapy. Episodes of colic became more frequent and more painful. Exploratory laparotomy revealed a large intestine duplication with a cystic structure located at the caecocolic junction that was unable to be exteriorized and therefore not amenable to surgical correction. Thirty‐six hours following surgery, the horse became acutely painful, sweaty, and febrile suggesting gastrointestinal rupture. Post mortem examination showed a 0.6 × 1 m duplication and a 0.5 × 0.6 m cystic dilation that was probably associated with the caecum. There was a 10 × 30 cm area of rupture located within the duplication. Histological evaluation confirmed the presence of a true duplication.     

Anaerobic peritonitis caused by Clostridium septicum as a complication of routine castration in a 2‐year‐old Warmblood horse

This case report describes an unusual case of anaerobic peritonitis in a 2‐year‐old horse following castration. The horse was evaluated 2 weeks following castration for signs of acute, severe abdominal pain and swelling surrounding a previous castration site. Physical examination revealed marked scrotal and ventral abdominal oedema that was cool and crepitant upon palpation. Ultrasonographic evaluation was unrewarding because gas shadowing distributed throughout the subcutis prevented imaging of the abdominal cavity. Ventral midline celiotomy revealed a copious amount of malodorous, serosangious, cloudy peritoneal fluid that was submitted for culture. Abdominal exploration revealed the gastrointestinal tract to be in its anatomically correct position. There was diffuse petechiation of the small intestine and large intestine, oedema and crepitant swelling surrounding the left inguinal ring and body wall. The abdomen was lavaged with 10 l of sterile saline prior to closure of the celiotomy and the left castration incision was opened digitally, releasing a large volume of serosanguinous fluid and gas that flowed freely from the incision site and deeper inguinal tissues. The horse was placed in the recovery box where it suffered cardiac arrest. Culture of the peritoneal fluid revealed heavy growth of Clostridium septicum. This case of anaerobic peritonitis represents an unusual complication following castration not previously reported in the horse.     

Cerebellar abiotrophy in a 6‐year‐old Arabian mare

Cerebellar abiotrophy (CA) is an uncommon neurological disease that most commonly affects Arabian horses. Affected horses are typically identified within the first 6 months of life. Intention tremor, wide based stance and ataxia are common clinical signs observed in affected individuals. No treatment is available for resolution of clinical signs. Definitive diagnosis is based on histopathological examination of cerebellar tissue, which is characterised by loss of Purkinje cell layer. This report describes a case of cerebellar abiotrophy that had a delayed diagnosis until 6 years of age.     

Large pituitary adenoma in an 8‐year‐old Arabian stallion

An 8‐year‐old Arabian stallion weighing 361 kg presented to Louisiana State University Veterinary Teaching Hospital with a 3‐month history of weight loss, exercise intolerance, long hair coat and recent history of seizures and aimless wandering in the pasture. An initial presumptive diagnosis of pituitary pars intermedia dysfunction (PPID) was made based on clinical signs. The initial examination revealed weight loss and loss of body condition (BCS 3/9), hypertrichosis, muscle wasting and reluctance to move when prompted. A neurological examination revealed dull mentation with no evidence of proprioceptive deficits in the limbs. Mild hyperglycaemia and a stress leucogram were noted on initial biochemical panel and haematology, respectively. Plasma adrenocorticotrophic hormone (ACTH) concentrations before and after thyrotropin releasing hormone (TRH) stimulation were markedly increased. Rapid slice computed tomography (CT) scan of the head before and after contrast revealed a large mass in the region of the pituitary gland suggestive of macroadenoma causing PPID. Prior to imaging, treatment consisted of supportive nursing care. Due to size of the pituitary gland (measuring 4.6 × 4.6 × 3.8 cm) and the presence of seizure‐like activity and dull mentation, the stallion was subjected to euthanasia. A necropsy was not performed. Pituitary macroadenomas in horses affected with PPID, who show neurological signs such as seizure‐like activity, dull mentation and aimless wandering, might have a poor prognosis and treatment with pergolide mesylate might not reduce pituitary gland size or relieve clinical signs. A CT scan is indicated in horses with neurological signs suspected of PPID to further evaluate pituitary gland size and surrounding structures and rule out other causes to better assess prognosis.     

Direct preputial hernia associated with a ventral abdominal wall defect in a two‐year‐old gelding

The case of a 2‐year‐old gelding with acute onset of preputial swelling and prolapse is presented. After initiating conservative management using a penile repulsion device, the horse repeatedly displayed signs of mild abdominal discomfort with sudden deterioration to an episode of violent colic after 5 days of hospitalisation. Ultrasonographic examination of the preputial swelling at that time demonstrated the presence of small intestine between the internal and external laminae of the prepuce and led to the diagnosis of a direct preputial hernia. The contents of the hernia were readily reduced through a defect in the ventral abdominal wall after the anaesthetised horse was placed in dorsal recumbency. The historical information, clinical progression and surgical findings were supportive of an acquired ventral abdominal wall defect. To the authors' knowledge, this is the first reported case of a direct preputial hernia associated with an acquired ventral abdominal wall defect.     

Bone biomarkers and risk of fracture in two‐ and three‐year‐old Thoroughbreds

The aim of this study was to determine whether bone biomarkers (osteocalcin, PICP, ICTP and CTX‐I) could be used to identify 2‐ and 3‐year‐olds at increased risk of fracture in the subsequent flat racing season. It was concluded that these bone biomarkers cannot be used to identify 2‐ and 3‐year‐olds that sustain a fracture. Whether bone biomarkers have better predictive value in older horses or when measured serially in the same animal remains to be determined.     

Hindlimb lameness associated with a focal osseous metaplasia in an 18‐year‐old Welsh Section D mare

This report describes a case of chronic lameness secondary to an extraskeletal osseous mass located in the plantaromedial aspect of the right hind pastern in a mature Welsh Section D mare. The lesion was confirmed to represent metabolically active osseous tissue in close apposition with the adjacent plantar digital neurovascular bundle and digital flexor tendons. Surgical resection of the mass resulted in a complete resolution of lameness and return to previous level of activity. Histopathological examination classified the mass as a focal osseous metaplasia, which was most likely to be the result of previous trauma causing local haemorrhage, which resulted in subsequent dystrophic mineralisation and eventually osseous metaplasia. Similar lesions have been described in man, but have not been previously reported in the horse.     

Lawsonia intracellularis proliferative enteropathy in a 3.5‐year‐old miniature horse

A 3.5‐year‐old miniature horse gelding was evaluated for signs of colic and decreased faecal production. Initial clinical pathology showed severe hypoproteinaemia with an albumin concentration <10 g/l. Abdominal ultrasound identified multiple loops of small intestine with significantly increased wall thickness. Diagnosis of equine proliferative enteropathy was based on clinical and laboratory findings, as well as a positive faecal polymerase chain reaction and positive antibody titre (>1:240) to Lawsonia intracellularis. Treatment with intravenous oxytetracylcine and additional supportive care gradually resolved the clinical and laboratory abnormalities.     

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.     

Mandibular squamous cell carcinoma in a 5‐year‐old Tennessee Walking Horse

Squamous cell carcinoma (SCC) is the second most common neoplasm reported in the horse, but occurs rarely in the oral cavity. Clinical signs may be insidious in onset and mimic other non‐neoplastic processes, thus delaying appropriate treatment. Timely evaluation and advanced diagnostic imaging may offer the opportunity to initiate definitive treatment. This report describes a young gelding with mandibular SCC that was evaluated for mandibular swelling failing to respond to symptomatic therapy.