Vestibulovaginal leiomyosarcoma in a mare

A 14-year-old Quarter Horse mare presented for a mass within the vestibule and vagina resulting in external compression and incomplete occlusion at the external urethral opening with subsequent difficulty urinating. Examination revealed an approximately 15 × 10 cm lobulated mass within the vestibule and caudal vagina attached via a broad base dorsally. Histopathology of the mass identified a low-grade leiomyosarcoma. Complete resection was not possible, and surgical debulking of the mass was performed during standing sedation using a vessel-sealing and dividing device. The mare was discharged 3 days post-operatively without any complications. Recheck examinations performed at 1 month and 8 months’ post-surgery revealed excellent healing of the surgical site and no apparent tumour regrowth.     

Congenital Osteoma of the Frontal Bone in an Arabian Filly

Congenital frontal osteoma has not been previously described in horses. This report records—for the first time—a congenital osteoma of the frontal bone in a 4-month-old Arabian filly. The filly had a frontal hard mass that was present at birth and then showed a slow and continuous growth. This mass appeared as a solitary, painless, oval dense tumor of compact bone, about 2 cm in diameter and 3 cm in length. The tumor was asymptomatic, and the skin over the mass was normal. Radiography revealed a well-defined oval, radio-dense mass projecting from the surface of the right frontal bone with no local invasion. The tumor had a broad-based attachment to frontal bone with normal frontal sinus. The mass caused disfigurement; therefore, it was removed at the owner’s request. The mass was diagnosed histopathologically as osteoma. The surgical excision of the osteoma was successful without any complications, and the filly adapted remarkably well after surgery. No recurrence was reported 20 months after the surgery. In conclusion, osteoma should be listed during the differential diagnosis of the congenital craniofacial masses in horses. Early diagnosis of the frontal osteoma guarantees a successful surgical treatment and consequently prevents the future complications.     

Lameness caused by plate‐like osteoma cutis in a Thoroughbred colt

This report describes a case of osteoma cutis diagnosed by physical examination, surgery and histopathological examination. A 2‐year‐old Thoroughbred colt with hindlimb lameness was brought to our facility. Physical examination showed a well‐circumscribed, large plate‐like mass covered with normal haired skin in the right thigh region. Ultrasonography revealed a subcutaneous linear mass. After surgical removal, histopathological examination showed thin mature bone surrounded by fibrocollagenous tissues. To the authors' knowledge, this is the first report of spontaneous idiopathic osteoma cutis in horses.     

Treatment of haemoperitoneum secondary to ruptured granulosa cell tumours in two mares

This report describes two cases of successful surgical management of granulosa cell tumours (GCT) in mares presenting with haemoperitoneum (HP). Controlled abdominal drainage was initially attempted in Case 1 but was not successful. A ventral midline exploratory laparotomy allowed removal of a haemorrhaging 13 kg GCT. The mare made a full recovery and returned to normal work as a driving pony 11 months post-operatively. In Case 2 controlled abdominal drainage was followed by standing left flank laparoscopic visualisation of the bleeding ovary and transection of the ovarian pedicle by electrocautery. The GCT was then removed via a ventral midline incision due to its large size. Haemoperitoneum can be associated with GCTs and in some cases is severe enough to prompt emergency treatment. Stabilisation of the patient and removal of the haemorrhaging GCT can lead to a successful outcome.     

Removal of a metallic foreign body from the tongue of three horses

The objective of this case report is to describe the diagnostic and surgical techniques for removal of a metallic foreign body in the tongue of three adult horses. The three horses were presented for evaluation and treatment of dysphagia and marked hypersalivation of 3–5 days duration. Radiographs of the head revealed the presence of a metallic foreign body in the tongue of each horse. The foreign bodies could be precisely localised under general anaesthesia using palpation and lingual ultrasonography and/or lingual radiography in combination with a forceps as a marker. The foreign bodies were successfully removed using laparoscopic instruments creating minimal soft tissue trauma. The use of long (43 cm) small laparoscopic (5 mm) instruments enabled good visualisation of the surgical field, providing optimal conditions for successful minimally invasive surgical treatment of horses with foreign bodies in the tongue. The three horses made uneventful recoveries and 12 months after surgery were eating normally and could be ridden with a bit as per usual routine. It was concluded that using long laparoscopic instruments in combination with palpation, ultrasonography and/or radiography allowed removal of the foreign body creating minimal soft tissue trauma and allowing optimal conditions for a fast recovery.     

Sclerosing odontogenic carcinoma in the mandible of a horse

A 15-year-old Cob mare was presented for investigation of a mandibular mass. Radiography identified an oval-shaped mass occupying the intramandibular space, with a heterogeneous osseous opacity throughout the left hemimandible. Histopathology combined with immunohistochemistry was consistent with a diagnosis of sclerosing odontogenic carcinoma, which to date has only been described, rarely, in human patients. The mass was removed using a mandibular-sparing surgical technique allowing preservation of the dental arcade. Follow-up 5 years after surgery confirmed no signs of regrowth. This case report describes the successful treatment of a previously unreported mandibular neoplasm in the horse.     

Standing laparoscopic castration in an equine male pseudohermaphrodite

This report describes the surgical anatomy and successful removal of the internal gonads in a 6-year-old male pseudohermaphrodite Friesian horse by standing laparoscopy. Gonads could not be identified by physical or ultrasonographic examination and bilateral standing flank laparoscopy revealed the presence of intra-abdominal gonads suspended from the dorsal aspect of the abdominal cavity by 10–15 cm long vascular pedicles. No evidence of female internal genitalia such as a uterus was found and bilateral gonadectomy was performed laparoscopically. Histological analysis of the excised gonads confirmed the diagnosis of male pseudohermaphroditism. Minor cosmetic surgery of the external genitalia to correct urinary misdirection was successfully performed 3 months after laparoscopic castration. Standing flank laparoscopic examination was excellent for identification and surgical removal of internal genitalia. Standing flank laparoscopy should be considered for inspection and removal of internal genitalia in intersex horses.     

SURGICAL MANAGEMENT OF PANCREATIC NODULAR HYPERPLASIA BY PARTIAL PANCREATECTOMY IN A BLACK-TAILED PRAIRIE DOG (CYNOMYS LUDOVICIANUS)

A 7.5-year-old male black-tailed prairie dog was presented for diarrhea of 3 weeks’ duration. Clinical examination revealed a multinodular mass in the left cranial quadrant of the abdomen that was confirmed with ultrasound. An exploratory laparotomy was performed and the majority of the mass and adherent spleen were removed. Histological diagnosis was severe pancreatic nodular hyperplasia associated with secondary pancreatitis and passive splenic congestion. The prairie dog recovered without complications. Three weeks following the surgical procedure, follow-up ultrasound showed no evidence of abnormal tissue in the pancreaticoduodenal area. Two months postsurgery, a follow-up computed tomographic scan revealed no significant abnormalities. No recurrence was noted 13 months following the mass removal. This article describes the diagnosis of pancreatic nodular hyperplasia in a prairie dog and successful treatment of complications arising from the condition by partial pancreatectomy.     

Laparoscopic Removal of a Large Abdominal Testicular Teratoma in a Standing Horse

Objective— To describe laparoscopic removal of a large testicular teratoma in a standing horse.
Study Design— Clinical report.
Animals— Thoroughbred horse (11 months) with a testicular teratoma.
Methods— A unilateral cryptorchid testicle could not be removed by an inguinal approach under general anesthesia because of it s large size. After recovery from general anesthesia, ultrasound evaluation revealed a 24 × 19 cm fluid-filled testicular mass. The mass was removed by paralumbar fossa laparoscopy with the horse in a standing position. After fluid aspiration of the mass, the mesorchium and ductus deferens were ligated with extracorporeal knots and the mass retrieved inside a laparoscopic specimen pouch. Morphologic features were consistent with a teratoma.
Results— Laparoscopic-guided aspiration of fluid from the teratoma decreased mass size and increased ease of manipulation and retrieval. Retrieval of the teratoma in a laparoscopic specimen pouch prevented loss of abdominal insufflation, helped reduce fluid leakage, and potential seeding of neoplastic cells.
Conclusion— Use of laparoscopy for removal of neoplastic cryptorchid testicles offers many advantages including minimal invasiveness and increased safety associated with good visibility of structures.
Clinical Relevance— Standing laparoscopic surgery should be considered for removal of testicular neoplasms in horses.     

Aryepiglottic lymphoma in a 19-year-old Paint gelding treated with excision and adjunctive radiotherapy

This case report describes the diagnosis and treatment of an aryepiglottic tumour in a 19-year-old Paint gelding. Diagnostic work-up included physical examination, endoscopic evaluation of the upper airway, and histopathology of the mass following removal. Treatment consisted of surgical excision of the aryepiglottic mass under endoscopic guidance followed by a 100 Gy dose of radiation delivered with strontium-90 plesiotherapy to the surgical bed at 72 h post-operatively. The radiation applicator was passed through the left nostril and the application area was confirmed via endoscopic evaluation. Histopathology, including immunohistochemistry, confirmed that the aryepiglottic tumour was T cell lymphoma. Recheck examination, including physical examination and upper airway endoscopy, was performed 1, 3 and 6 months following treatment and local recurrence was not observed. Local control with minimal morbidity can be achieved with surgical excision of equine lymphoma followed by strontium-90 plesiotherapy.     

Endobronchial polyp derived from a myxosarcoma in the lung of a dog

An endobronchial polyp was visible radiographically and bronchoscopically in an 11-year-old, mixed-breed dog with a persistent cough. The polyp was removed by traction. Initial histological examination suggested it was a myxomatous fibroma. The cough resolved but recurred with polyp regrowth. Two additional lung masses became visible radiographically. The polyp was removed twice more at 6-month intervals. Euthanasia was performed 15 months after first presentation when coughing recurred soon after the final bronchoscopy. Histological examination revealed that the mass was a myxomatous sarcoma. The lung contained two other unrelated tumors: a bronchioloalveolar carcinoma and a carcinoma of unknown origin.     

Subconjunctival nodule due to Setaria equina erratic migration in a horse: First case report

An 18‐month‐old Arabian‐English filly resident in southwest France was referred for evaluation of a conjunctival mass in the right eye (OD). A pink, solid, and mobile nodular formation, measuring approximately 1.2 × 0.8 cm was found under the superior nasal bulbar conjunctiva during an ophthalmic examination that was otherwise normal. The mass was surgically removed using a standing procedure. Cytological examination of fine‐needle aspirates from the mass revealed a mixed eosinophilic‐lymphocytic inflammation. Histological examination confirmed the dense and diffuse eosinophilic‐lymphocytic infiltrate of the mass, and it revealed several cross sections of a parasitic nematode. The morphometric diagnosis identified an immature form of a filarial worm, and molecular analysis of the mitochondrial cytochrome c oxydase subunit 1 (cox1) and 12S rRNA gene sequences led to further identification of the specimen as Setaria equina. Microfilaremia was not observed on fresh blood smears. There have been no signs of local recurrence after 18 months, nor any evidence of intraocular involvement. To the authors’ knowledge, this is the first documented case of subconjunctival setariasis due to S equina in a horse.     

Dermatophilus chelonae in a king cobra (Ophiophagus hannah).

A mass was removed from the left flank of a 10-yr-old male king cobra (Ophiophagus hannah), and histologic examination revealed granulomatous dermatitis with intralesional gram-positive cocci and filamentous bacteria. Fourteen months later, a histologically similar subcutaneous mass was removed from a different site. One year later, a large subcutaneous mass at the first surgical site was removed, and histopathologic examination revealed multiloculated granulomas with intralesional gram-positive cocci. An organism was cultured and identified by 16S ribosomal RNA gene sequencing as Dermatophilus chelonae. After a course of antibiotic therapy, no further lesions were seen for 5 mo.     

Successful surgical management of a medial humeral epicondyle fracture in a Thoroughbred foal

A 2-week-old 75 kg Thoroughbred filly was presented for the investigation of an acute forelimb lameness. Radiographs revealed a fracture of the medial epicondylar physis of the left humerus (Salter–Harris type II fracture). The fragment was removed via arthrotomy under general anaesthesia. Two months post-operatively, the foal was sound and at 2 years had resumed normal turn out. This case report describes a previously unreported surgical treatment for a fracture of the medial epicondylar physis in a foal.     

Acrylic cranioplasty and axial pattern flap following calvarial and cerebral mass excision in a dog

A 4 kg Chihuahua was presented with seizures and a large mass on his dorsal cranium. The mass had regrown after two previous attempts to remove it. Histological examination had shown the mass to be a multilobular osteochondroma (osteochondrosarcoma). A CT scan revealed destruction of the dorsal cranial bones by the mass and compression of cerebral cortex. A craniotomy was performed to excise the mass and attached skin, leaving a large deficit of calvarial bone and skin. A cranioplasty was performed in situ, using polypropylene mesh and polymethyl methacrylate. A caudal auricular axial pattern flap was placed directly over the cranioplasty to fill the skin defect. This unusual reconstruction resulted in good recovery, function and cosmetic effect, although tumour regrowth was seen within the cerebral cortex.     

Standing repair of a proximal,incomplete, articular fracture of the third metatarsal bone

A 5-year-old National Hunt Thoroughbred mare presented with sudden onset left hindlimb lameness after race training on the gallops. Clinical examination revealed a marked painful reaction over the proximal metatarsal region but no other obvious abnormalities were detected. Survey radiographs at the yard did not reveal any abnormalities. Nuclear scintigraphic examination 3 days after injury revealed focal marked increased radiopharmaceutical uptake in the proximal metatarsal region. Subsequent radiography revealed an incomplete, articular fracture of the proximal left third metatarsal bone. Repair of the fracture using 3 × 4.5 mm cortical screws placed in lag fashion was performed under standing sedation following perineural analgesia. Follow-up radiographs demonstrated progressive healing of the fracture. The mare returned to race training 8 months after the fracture was repaired and raced successfully 12 months post injury.     

Leiomyoma of the third eyelid in a dog

A 14‐year‐old neutered male Dachshund presented for the evaluation of oculus dexter (OD) third eyelid elevation ongoing for approximately 2 months. Complete ophthalmic examination revealed a large, nonpainful, well‐demarcated, soft mass at the base of the right third eyelid causing elevation and mild hyperemia. The mass was freely moveable with the third eyelid, and no right globe deviation was noted. No other abnormalities were noted on physical examination, routine blood chemistry, complete blood count, serum T4, urinalysis, or urine cortisol/creatinine ratio. Ocular B‐mode ultrasonography showed an anechoic, well‐demarcated, homogenous, soft tissue mass at the base of the third eyelid with no orbital extension. A leiomyoma was diagnosed after multiple punch biopsies were obtained from the palpebral surface of the mass. The right third eyelid was excised surgically. Histopathology confirmed a completely excised, nodular, unencapsulated, expansile mass within the third eyelid. Positive smooth muscle actin and negative S‐100 immunohistochemistry confirmed a leiomyoma. Bundles of normal smooth muscle were also present adjacent to the mass. The mass was compressing the adjacent lacrimal gland and associated with moderate dacryoadenitis. Twelve months postoperatively, the right globe position and motility remain normal with no evidence of mass regrowth. To the author's knowledge, this is the first reported case of a leiomyoma of the third eyelid in any species. In this case, the mass was completely excised and no regrowth has occurred twelve months after surgery. This case along with independently reviewed canine third eyelids clearly demonstrates the presence of smooth muscle within the canine third eyelid.     

Orbito-nasal cyst in a young European short-haired cat

Purpose To describe a case of an orbito‐nasal cyst in a cat. Procedure An 18‐month‐old male European short‐haired cat was presented to the Ophthalmology service of the Vetsuisse Faculty, University of Zurich for a subcutaneous swelling in the medial canthal region of the right eye (OD). Ophthalmologic, ultrasound and CT examinations, and fine needle aspiration were performed. After lesion excision, the removed tissue was submitted for histopathology. CT examination was repeated 5 months after removal of the cyst. Results Ophthalmologic examination revealed a large fluctuant swelling inferonasal to OD. Despite patent lacrimal puncta, only the first few mm of the lacrimal canaliculi could be cannulated. A normal globe with moderate enophthalmos was present. Ultrasound examination showed a well‐defined lobulated cyst‐like structure in the right orbit, inferonasal and anterior to the eye. CT examination revealed extension of this lesion through the medial orbital wall into the right nasal cavity. Fine needle aspiration confirmed the cystic nature of the lesion. An orbito‐nasal cyst was diagnosed. The orbital part of the cyst was dissected from the surrounding tissue and excised from the periosteum in the medial orbital wall defect. Part of the maxillary bone was removed to allow removal of the cyst from the nasal cavity. Histologically, the cyst wall consisted of a single to multilayered, mostly cuboidal epithelium and surrounding connective tissue. Follow‐up revealed a good functional result and no recurrence 7 months after cyst removal. Conclusions Similar orbito‐nasal cystic structures were reported in dogs but not in cats.     

Surgical treatment of a mammary gland comedocarcinoma in an Arabian mare: Post-operative management,and histopathological and immunohistochemical features

A lactating 20-year-old, brown, Arabian mare, weighing about 300 kg, presented for bleeding from one teat and severe swelling of the entire mammary gland. The mare had untreated mastitis 10 months before. Consequently, a gangrenous teat developed after chronic bloody and purulent discharges. The teat was removed surgically by the field veterinarian. At that time, the mammary gland increased in size. Bloody and purulent discharges restarted 10 days previously. Under general anaesthesia, the entire mammary gland was removed. Comedocarcinoma was diagnosed by histopathological assessment. Immunohistochemical staining was performed for pan-cytokeratin and vimentin. Microscopic examination of immunohistochemical stained slides revealed expression of pan-cytokeratin. In conclusion, this report describes clinical, macroscopic, histopathological and immunohistochemical characteristics of comedocarcinoma that did not metastasise to regional lymph nodes. Reports in the field of equine oncology contribute to improved general knowledge in equine medicine, contributing to better diagnosis and treatment.     

Osteoma of paranasal sinuses of a horse

A 2-year-old Quarter Horse gelding was examined for torticollis, facial protuberances over the frontal and maxillary sinuses, and persistent nasal discharge unresponsive to antibiotics. Radiograph revealed an osseous mass in the right paranasal sinuses. Histologic examination of the biopsied mass led to a diagnosis of osteoma. The mass was removed surgically in sections from the right frontal and maxillary sinuses through separate bone flaps, and sinuses were irrigated with saline solution for 8 days after surgery. Two weeks after surgery, radiography revealed small osseous opacities in the right paranasal sinuses. These opacities remained unchanged in radiographs obtained up to 23 months after surgery.