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.     

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.     

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.     

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.     

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.     

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.     

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.     

Septic funiculitis caused by Streptococcus equi subspecies equi infection with associated immune‐mediated haemolytic anaemia

A 2‐year‐old Quarter Horse gelding presented for anaemia, icterus, depression and intermittent colic 2 weeks after routine castration. Bilateral septic funiculitis with Streptoccocus equi ssp. equi with secondary immune‐mediated haemolytic anaemia were diagnosed. A blood transfusion was required to facilitate general anaesthesia for surgical excision of the septic funiculitis. Antibiotic therapy was provided initially with chloramphenicol and later enrofloxacin. Immunosuppressive therapy was provided with dexamethasone and later azathioprine. The horse responded well to treatment and was discharged 8 weeks after presentation. Streptococcus equi ssp. equi should be considered in cases with septic funiculitis and the potential for a secondary immune‐mediated haemolytic anaemia exists with this bacterial species.     

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.     

Successful management of multiple extrapulmonary complications associated with Rhodococcus equi pneumonia in a foal

This report describes the diagnosis and successful treatment of multiple extrapulmonary sequelae of Rhodococcus equi (R. equi) pneumonia in a 3‐month‐old filly. Bilateral uveitis and hyphaema, haemolytic anaemia and polysynovitis developed in this foal and were likely due to immune‐mediated mechanisms. The challenges associated with diagnosis and treatments of these extrapulmonary disorders are discussed. The filly was treated initially with clarithromycin and rifampin; however, a blood transfusion and immunosuppressive therapy with dexamethasone were required due to progressive haemolysis and for treatment of uveitis and polysynovitis. Bilateral hyphaema was successfully treated with intracameral injections of a recombinant tissue plasminogen activator. The development of antimicrobial resistance in R. equi was an additional challenge encountered in the management of this case and emphasises the importance of culture and in vitro antimicrobial susceptibility testing of isolates from foals with R. equi pneumonia. Extrapulmonary disorders associated with R. equi pneumonia are likely underdiagnosed and associated with a poor prognosis. This case highlights the importance of thorough and ongoing diagnostic assessment of foals with R. equi pneumonia and demonstrates that a successful outcome can be achieved with appropriate and directed treatment.     

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.     

Resection of the incisive bone and rostral maxillae for removal of an ossifying fibroma in an 18‐year‐old Warmblood gelding

A 510 kg, 18‐year‐old Warmblood gelding used for high level dressage was presented with a 6 week history of a growing mass at the rostral aspect of the incisive bone. Radiographic examination of the maxillae showed an osteolytic lesion between the left maxillary central and intermediate teeth spreading caudally into the hard palate. Biopsy of the mass was consistent with an aggressive oral fibrosarcoma. Diagnostic work‐up ruled out metastatic lesions. An amputation of the incisive bone and part of the rostral maxillae was performed with the intent of removing the mass in healthy margins. However, the neoplastic tissue extended to the rostral aspect of the ventral nasal conchae and a resection in healthy margins was not performed to avoid surgical complications due to communication with the nasal conchae. After surgery, the horse's appetite and food uptake were not impaired and cosmetic appearance was excellent. Active drains were used in order to prevent any submucosal collection of fluids. Histopathological examination of the surgical margins of the removed maxillae confirmed the presence of tumoural tissue. Even though excision of the tumour was not complete, no macroscopic local recurrence was reported post operatively at 36 months' follow‐up. Based on histological re‐evaluation of the removed tissue and the absence of recurrence a definitive diagnosis of ossifying fibroma was made.     

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.     

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.     

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.     

Diagnosis of Borrelia‐associated uveitis in two horses

Borrelia burgdorferi, the etiologic agent of Lyme disease is a tick born spirochetal infection. Clinical signs of Lyme borreliosis are uncommon in horses, but when present they are often vague and nonspecific. In horses, Lyme borreliosis has been implicated in musculoskeletal, neurological, reproductive, and ocular disorders, including uveitis, but definitive diagnosis can be challenging as the causative agent is rarely isolated and serologic tests can be unreliable and do not confirm active disease. Here, we report two cases of equine uveitis associated with B. burgdorferi based on the identification of spirochetes within ocular fluids and confirmed with PCR testing. The two cases illustrate some of the challenges encountered in the recognition and diagnosis of equine Lyme borreliosis. Although only one of many possible causes of equine uveitis, Lyme disease should be considered a differential diagnosis, especially in endemic areas. Given the possibility for false negative results of serum tests during uveitis associated with B. burgdorferi and the failure of such tests to confirm active infection, a combination of cytologic assessment, antibody, and/or PCR testing of ocular fluids may be worthwhile if the clinical suspicion for Lyme uveitis is high.     

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.     

Haemoabdomen and colitis following a colon displacement in a 9‐year‐old Thoroughbred mare

This report describes acute haemoabdomen following phenylephrine administration in a case treated for left dorsal displacement of the large colon. The horse also subsequently developed a severe colitis which was treated with aggressive medical therapy.     

True cementomas (cementoblastomas) associated with a nonvital left maxillary second premolar in an 11‐year‐old miniature horse

An 11‐year‐old miniature horse gelding presented for a left maxillary facial swelling and surgical removal of 2 ovoid mineralised masses located near the tooth roots of the left maxillary second and third premolars. Preoperative radiographs were performed to triangulate the location of the calcified masses for removal, and an oral examination revealed that the left maxillary second premolar was nonvital with multiple feed‐packed pulp exposures. Both the radiographs and oral examination indicated that the mineralised masses were associated with the nonvital second premolar. Therefore, the tooth was extracted intraorally, and the masses were removed via a maxillary trephine dorsal to the extracted tooth. Both masses were submitted for histopathology, which diagnosed the masses as true cementomas (cementoblastomas) with adenomatous hyperplasia of the surrounding nasal glandular tissue.