Surgical repair of a full-thickness ear pinna defect in a horse

A 5-year-old gelding used for showing was presented for surgical repair of a full-thickness 15 mm diameter defect in the right pinna, which had occurred as a delayed complication following laser excision of a sarcoid. The defect had resulted in progressive deformity of the ear, and the horse was considered at risk of further injury if the defect became entrapped on a fixed object. Two artificial dermis meshes were inserted to encourage the formation of granulation tissue across the defect, and a commercially available skin expander was implanted adjacent to the site. Eighteen days later, a second surgery was performed to remove the skin expander and to mobilise a local rotational skin flap to close the defect. Both surgeries were performed under standing sedation and local anaesthesia. The site healed well, avoiding further potential trauma to the ear and deformity due to tissue contracture at the site, although some deformation of the lateral aspect of the cartilage remained.     

Resection of a premaxilla and rostral portion of the maxilla in a horse

A 5‐year‐old, 520 kg Standardbred mare was admitted for an osteosarcoma of the right premaxilla. Two horizontal incisions of the labial mucosa and lingual surface were made 1 cm around the ulceration from the canine tooth to the premaxillary symphysis. The premaxilla and rostral portion of the maxilla were transected 1 cm caudal to the canine tooth with an oscillating saw. The maxillary symphysis was transected using an oscillating saw and a hammer. The wound was closed by primary intention and healed without complication. The cosmetic appearance of the mare was good. The mare was able to prehend hay and grain and grazed without difficulty and the tongue did not protrude. The neoplasm had not recurred 18 months after the surgery. A premaxilla and rostral portion of the adjacent maxilla can be resected to treat horses for a unilateral lesion of the premaxilla but care must be taken to avoid the palatine and incisive arteries which lie within the interincisive canal.     

Ocular manifestations of a metastatic adenocarcinoma in a horse

A 10‐year‐old German Warmblood gelding was referred to the Equine Department of the Vetsuisse Faculty, University of Zurich, Switzerland, for an iris mass OD, lethargy, intermittent fever, and coughing. Ophthalmic examination revealed a 7 × 9 mm raised, fleshy, whitish to pinkish, vascularized iris mass at the 2 o`clock position OD. Fundic examination showed multifocal round, brown to black, slightly raised lesions with indistinct margins and a surrounding hyperreflective zone OU. Physical examination revealed a temperature of 39.2 °C, sinus tachycardia, preputial and ventral edema, and an enlarged right mandibular lymph node. Results of a complete blood count and plasma biochemical profile showed mild anemia, leukocytosis, and thrombocytopenia. Severe splenopathy, moderate splenomegaly, and severe pulmonary pathology with nodules and large areas of consolidated lung parenchyma were observed on abdominal ultrasound and thoracic radiographs, respectively. Fine needle aspirates of the enlarged mandibular lymph node showed malignant epithelial neoplastic cells. The horse was euthanized because of the poor prognosis and subsequently underwent postmortem examination. Macroscopic necropsy and histopathology revealed an adenocarcinoma of suspected pulmonary origin with involvement of eyes, heart, liver, kidneys, spleen, diaphragm, skeletal muscles, mandibular, pulmonary, and internal iliac lymph nodes. Metastatic adenocarcinoma should be considered as a differential diagnosis in horses with iris masses, multifocal chorioretinal infiltrates, and clinical signs that conform to a paraneoplastic syndrome.     

Acute hindlimb paresis caused by extension of a peripheral nerve sheath tumour into the spinal canal of a horse

A 10-year-old Quarter Horse gelding presented for a large, slowly growing mass in the right thoracic region caudal to the withers (approximately at the level of thoracic vertebrae 10 to 16). The mass was surgically removed, the horse returned to normal riding activity, and no external regrowth was observed. Two years after surgery, the horse developed progressive signs of hindlimb weakness, ataxia and adopting a dog-sitting stance. Post-mortem examination confirmed spinal canal infiltration and spinal cord compression (at the level of the 12th thoracic vertebra) by a similar soft tissue sarcoma as diagnosed previously. Immunohistochemistry confirmed the tumour as a peripheral nerve sheath tumour (PNST) likely originating from the twelfth thoracic spinal nerve. This report demonstrates that with incomplete tumour resection, local recurrence and extension of a PNST into the central nervous system can occur even years after initial tumour removal. Immunohistochemistry to differentiate the type of soft tissue sarcoma in cases with close association to the nervous system may prove beneficial to anticipate this uncommon complication. Early surgical resection with adjunctive therapies should be considered in these cases.     

Severe polyuria and polydipsia as major clinical signs in a horse with unilateral renal adenocarcinoma

A 14‐year‐old Swiss Warmblood gelding was presented with chronic severe polyuria, polydipsia and weight loss. At the time of admission, water intake was 240 l/day. On rectal examination, a large mass was identified in the left dorsal abdominal quadrant, which was shown to originate from the left kidney by transabdominal ultrasonographic examination. Unilateral nephrectomy via flank incision was performed under general anaesthesia. Histopathological examination of the tumour revealed a papillary renal adenocarcinoma. Successful outcome and survival was documented 13 months after surgery. Severe polyuria and polydipsia should be considered as major clinical signs for renal carcinoma in horses, which can be successfully treated with unilateral nephrectomy if no signs of metastatic spread are evident.     

A modified surgical technique for penile amputation and preputial ablation in the horse

The aim of this study was to describe a modified surgical technique for treatment of severe penile pathology, and the long‐term outcome. The surgery consisted of subischial urethrostomy and penile amputation with preputial ablation, with the horse in dorsal recumbency. A redundant section of the penis root and body was left in situ, rather than being retroflexed as described elsewhere. Follow‐up was obtained using a structured owner telephone questionnaire. The 15 cases included: 11 squamous cell carcinomas (73.3%); 2 melanomas; one chronic preputial discharge with no associated neoplasia; and one paraphimosis following routine sedation. Length of survival ranged from 0.9 to 74.6 months (median 25.1 months). From the 14 horses with follow‐up, 9 survived >18 months (64.3%) [Correction added on 17 August 2015, after first online publication: The percentage in the preceding sentence was wrong and has been corrected to '64.3%' from '69.2%']. Four euthanasias were due to presenting or post operative complications, while 2 were unrelated to the procedure. This procedure presents a simplified, viable option for treatment of extensive mixed penile lesions; reducing surgical complexity and time in comparison to previously described techniques requiring retroversion.     

Comparison of bacterial organisms and their susceptibility patterns from otic exudate and ear tissue from the vertical ear canal of dogs undergoing a total ear canal ablation

The purpose of this prospective study was to compare bacterial organisms and their susceptibility patterns from otic exudate and ear tissue from the vertical ear canal of six dogs with end-stage otitis undergoing a total ear canal ablation. Twenty-six organisms, 13 from the exudate and 13 from the tissue, were morphologically and biochemically similar, and their susceptibility patterns were compared. There were discrepancies for only 5 antibiotics for 4 organisms from 3 dogs. Culture of otic exudate from the vertical ear canal of dogs with chronic end-stage otitis externa provides an accurate reflection of the bacterial species present and the antimicrobial susceptibility patterns of these infections.     

Phacofragmentation for morgagnian cataract in a horse

A 3‐year‐old Paint gelding was presented for sudden onset of cataract affecting the right eye. Ophthalmic examination revealed subtle to mild microphthalmia and a mature cataract affecting the right globe. The right eye was treated with an antibiotic‐corticosteroid ophthalmic ointment and phacofragmentation was recommended. On re‐examination 5 months later, resorption of the cortex of the right lens and a morgagnian cataract were evident. The nucleus was positioned ventronasally in the lens capsule. The right eye had light perception, and a menace response was present. Examination of the right fundus via binocular indirect ophthalmoscopy was not possible. Ophthalmic ultrasonography revealed that the right globe was 4 mm shorter in axial length when compared with the left globe. There was a marked reduction in the size of the right lens vs. the left lens, and the presence of a moderate amount of hyperechoic debris was identified within the vitreal compartment of the right globe. Phacofragmentation, irrigation and aspiration of the morgagnian cataract and an anterior vitrectomy were performed. On postoperative examination, the eye was comfortable and a menace response was present. The horse regained useful vision and continues to have a comfortable, visual eye 7 months postoperatively.     

A novel approach for palatal cyst ablation in a horse

An 18-month-old Welsh Cob was referred to a university teaching hospital for investigation of abnormal respiratory noise at rest. Video-endoscopy revealed persistent displacement of the soft palate with bilateral 2–3 cm diameter raised areas on either side of the midline. Neither trans-nasal nor oral approaches allowed sufficient visualisation of the caudal soft palate for diagnosis or treatment. Latero-lateral radiographs showed a blunted, thickened caudal edge of the soft palate consistent with a palatal cyst. Two palatal cysts were thermally ablated with a transendoscopic diode laser via temporary tracheotomy. The horse recovered uneventfully and resolution of the displacement was evident on follow-up endoscopy 11 months later. This report documents a novel surgical approach to the caudal aspect of the soft palate.     

Osteosarcoma of the middle phalanx in a horse

An 11‐year‐old Thoroughbred gelding was presented for lameness investigation following acute onset hindlimb lameness, which developed during a period of paddock turnout. Clinical examination revealed a swelling over the dorsolateral aspect of the pastern that was painful on digital palpation. Radiography of this area was consistent with an aggressive bone lesion involving both joint surfaces of the middle phalanx with pathological fracture and distal collapse of this bone. On this basis, the horse was subjected to euthanasia. Post mortem histopathological examination revealed presence of an osteosarcoma without involvement of the articular cartilage. This bone tumour is extremely rare in horses and has not been reported in this anatomical location.     

Occult metastatic intestinal adenocarcinoma resulting in pathological fracture of the proximal humerus

Intestinal adenocarcinomas are rare but have been described in the literature. The present case is unusual in both its clinical presentation and in the distribution of metastatic lesions. The sequestrum formation and pathological fracture present are most commonly associated with osteomyelitis in horses and the details of the case highlight the need for differential diagnosis in these particular circumstances and of which clinicians should be aware.     

An atypical case of recurrent cellulitis/lymphangitis in a Dutch Warmblood horse treated by surgical intervention

The case reported here describes an atypical presentation of cellulitis/lymphangitis in an 8‐year‐old Dutch Warmblood mare. The horse was presented with a history of recurrent episodes of cellulitis/lymphangitis and the presence of fluctuating cyst‐like lesions on the left hindlimb. These lesions appeared to be interconnected lymphangiectasias. Surgical debridement followed by primary wound closure and local drainage was performed under general anaesthesia. Twelve months post surgery, no recurrence of cellulitis/lymphangitis had occurred and the mare had returned to her former use as a dressage horse.     

Fine-needle biopsy of external ear canal masses in the cat: cytologic results and histologic correlations in 27 cases

BACKGROUND: The cytologic diagnosis of ear canal tumors is difficult or impossible by swab alone because cell exfoliation may be poor and neoplastic cells may be masked by associated inflammation. Fine-needle biopsy (FNB) can be used to obtain a higher yield of cells for diagnosis. OBJECTIVE: The purpose of this study was to assess the efficacy and diagnostic value of FNB and cytologic examination in providing an accurate diagnosis of masses growing in the external ear canal of cats. METHODS: Cytologic specimens from masses in the external ear canal, taken under inhaled, general anesthesia, were classified into 4 groups: 1) ceruminous gland hyperplasia or adenoma, 2) ceruminous gland adenocarcinoma, 3) inflammatory polyps, and 4) other neoplastic and non-neoplastic masses. Cytopathologic diagnoses were compared with the final histopathologic diagnoses, and indices of diagnostic test accuracy (sensitivity, specificity, likelihood ratios, diagnostic-odds ratios) were calculated. RESULTS: Twenty-seven masses (from 25 cats, including 2 cats affected bilaterally) were included in the study. The results showed good correspondence between cytologic and histologic diagnoses with an overall agreement index (kappa) of .74, a diagnostic odds ratio of 22, and 100% (27/27) agreement in the diagnosis of inflammatory polyps versus neoplasia (both benign and malignant). CONCLUSIONS: FNB cytopathology of external ear masses in the cat was sufficiently accurate for distinguishing inflammatory polyps from neoplasia. For differentiation of benign proliferation and malignant neoplasia, however, histopathologic confirmation is recommended.     

Cosmetic results of a ventrally based advancement flap for closure of total ear canal ablations in 6 cats: 2002-2003

OBJECTIVE: To report the outcome of a modified total ear canal ablation (TECA) technique to maintain normal ear carriage in cats. STUDY DESIGN: Case series. ANIMALS: Six cats with external ear canal disease. METHODS: Medical records were reviewed to identify cats in which a modified TECA using a single pedicle advancement flap was used to maintain normal ear carriage. Signalment, histopathologic diagnosis, complications, and outcome were retrieved. Owners were contacted to document long-term outcome. RESULTS: Modified TECA procedures (7) were performed in 6 cats. Normal ear carriage was present immediately after surgery and was preserved at follow-up interview. Owners were satisfied with cosmetic appearance. Histopathologic diagnosis of excised ear masses included ceruminous gland adenocarcinoma (2 cats), ceruminous gland adenoma (2 cats, 3 ears), and inflammatory polyp (2 cats). CONCLUSIONS: Modification of the TECA skin incision preserved normal ear carriage in all cats. Owners were satisfied with overall outcome and with cosmetic result. Rate and nature of complications were similar to previously published data. CLINICAL RELEVANCE: A simple modification of the TECA skin incision to create a single pedicle advancement flap maintains normal ear carriage in cats.     

Resection cystoplasty of a squamous cell carcinoma in a mare

A 22‐year‐old Arabian mare was examined for evaluation of haematuria of 2 months' duration. Complete blood cell count and chemistry revealed anaemia of chronic disease (i.e. normocytic, normochromic) and hypoproteinaemia. Cystoscopy revealed a haemorrhagic mass protruding into the lumen of the urinary bladder in the apical region. The mass was surgically removed by partial cystectomy performed through a caudal ventral midline laparotomy. Histological examination of the mass confirmed the diagnosis of squamous cell carcinoma. Tumours of the equine urinary bladder are rare, and when a partial cystectomy is indicated, a caudal ventral midline laparotomy may provide adequate surgical exposure even in adult horses.     

Surgical treatment of colic in the miniature horse: a retrospective study of 57 cases (1993-2006)

REASONS FOR PERFORMING STUDY: It has been suggested that the rate of post operative abdominal adhesions in miniature horses is higher than that for other breeds. However, few reports exist in the veterinary literature describing complications and long-term survival following surgical treatment of colic in these horses. OBJECTIVES: To determine the prevalence of surgical lesions in miniature horses with acute abdominal disease in terms of clinical signs, surgical management, post operative treatment and complications, as well as short- and long-term survival. METHODS: Medical records of 57 American Miniature Horses undergoing surgical treatment for acute abdominal pain at the Michigan State University Large Animal Veterinary Teaching Hospital 1993-2006 were evaluated for clinical information. Owners and trainers were contacted to gain information regarding long-term survival. RESULTS: The most common surgical lesion was a faecalith (38/57 cases) located primarily within the descending colon and most frequently diagnosed in horses age <6 months (19/38 cases). Short-term survival to hospital discharge for horses recovered from anaesthesia was 98% (55/56) with the most common post operative complications being diarrhoea and inappetance. Intra-abdominal adhesions were identified in 2/8 horses requiring a second celiotomy. Long-term follow-up was available for 45 horses and 87% (39/45) were alive at least 12 months after surgery. CONCLUSIONS: As previously reported, faecalith obstruction is a frequent surgical lesion in the miniature horse and is most common in miniature horses age <6 months. The incidence of adhesion formation may be lower than previously reported.     

Standing removal of the proximal aspect of an olecranon fracture in a mature horse

A 12‐year‐old 450 kg Argentine polo mare presented with a dropped elbow and an unwillingness to bear weight after being kicked by another horse on the lateral aspect of the upper left forelimb. The mare was subsequently diagnosed with a displaced olecranon fracture that did not readily conform to the standard classification systems. Referral for surgical treatment involving open reduction and internal fixation was declined due to financial constraints. Due to the mare being unsuitable for breeding, and conservative treatment of displaced olecranon fractures being deemed to have an overall poor prognosis for return to full athletic performance, another treatment option was sought. Given the fracture configuration, standing surgical removal of the large proximal fragment was performed. The mare returned to full athletic performance 12 months post operatively without lameness. This case report describes an alternative treatment option for selected olecranon fractures.     

Primary lacrimal gland adenocarcinoma of the third eyelid in a horse

A 5-year-old Draft Horse gelding presented for evaluation of a large, fleshy, ulcerated third eyelid mass OD of 3 weeks duration. Complete ophthalmic examination, ocular ultrasound and skull radiographs revealed a large soft-tissue mass involving the entire third eyelid OD and extending into the ventral right orbit to the level of the globe equator. No other abnormalities were noted on physical or ophthalmic examination. Surgical removal via exenteration was performed 3 months after initial presentation. A lacrimal adenocarcinoma of the third eyelid was diagnosed based on histopathology. Concurrent asymptomatic intra-ductal and intra-acinar Demodex caballi parasites were found in the eyelid sebaceous glands, likely as an incidental finding. No tumor recurrence or metastasis has occurred 12 months after excision. To the author's knowledge, this case is the first reported primary lacrimal adenocarcinoma in a horse. Complete surgical excision was curative.     

Cervical vertebral canal endoscopy in a horse with cervical vertebral stenotic myelopathy

A 3-year-old Thoroughbred gelding presented with a history of neurological signs, including incoordination in his hindlimbs, of about 7 months' duration. On initial examination, the horse exhibited ataxia and paresis in all limbs with more severe deficits in the hindlimbs. Cervical radiographs displayed severe osteoarthritis of the articular processes between C5 and C6. On subsequent cervical myelography the dorsal contrast column was reduced by 90% at the level of the intervertebral space between C5 and C6. Cervical vertebral canal endoscopy, including epidural (epiduroscopy) and subarachnoid endoscopy (myeloscopy), was performed under general anaesthesia. A substantial narrowing of the subarachnoid space at the level between C6 and C7 was seen during myeloscopy, while no compression was apparent between C5 and C6. Epiduroscopy showed no abnormalities. After completion of the procedure, the horse was subjected to euthanasia and the cervical spinal cord submitted for histopathological examination. Severe myelin and axon degeneration of the white matter was diagnosed at the level of the intervertebral space between C6 and C7, with Wallerian degeneration cranially and caudally, indicating chronic spinal cord compression at this site. Myeloscopy was successfully used to identify the site of spinal cord compression in a horse with cervical vertebral stenotic myelopathy, while myelography results were misleading.