Epithelial inclusion cysts of the frontal bones in three horses

In this article, development of a fluctuating swelling in the middle of the frontal region is reported in 3 horses. Clinical and radiological examinations showed them to be palpably soft, nonpainful, well circumscribed and homogeneous. The diagnosis of a cyst‐like lesion is based on centesis and histology. This report describes the clinical features, surgical treatment, outcome and histological findings in all 3 cases.     

Study of laryngopharyngeal pathology in Thoroughbred horses in southern California

Reasons for performing study: There is increasing anecdotal evidence among horse owners, trainers and equine clinicians of a high prevalence of subepiglottic ulcers, suggested to have a negative effect on racing performance. Objectives: To provide a prevalence study and pathological characterisation of laryngopharyngeal lesions with emphasis in the subepiglottic area and, in particular, subepiglottic ulcers. Methods: The study was carried out on 91 Thoroughbred racehorses received for post mortem examination from 4 major Southern California racetracks. The most common reason for submission was catastrophic musculoskeletal injury, but others include sudden death, laminitis, colic, colitis, neurological disorders, pleuropneumonia and arytenoid chondropathy. Laryngopharyngeal specimens were collected and examined grossly; selected cases were also examined histopathologically. Results: Thirteen horses (14.3%) had at least one type of laryngopharyngeal abnormality, 7 horses (7.7%) had lesions in the subepiglottic soft tissues, including 4 subepiglottic ulcers, 2 soft palate ‘kissing lesions' and one 'subepiglottic scar’. Eight horses (8.8%) had lesions elsewhere in the laryngopharynx, including mucosal ulcerations, arytenoid chondropathy, epiglottic entrapment and partial absence of arytenoid cartilage. Conclusions and potential relevance: Lesions in the subepiglottic area were among the most prevalent in this study, suggesting that an important percentage of laryngopharyngeal abnormalities may be missed during routine endoscopy of the standing horse, which often does not include the examination of subepiglottic tissues. Pathologically, subepiglottic ulcers were chronic‐active with viable hyperplastic epithelial margins, suggesting that proper healing and re‐epithelialisation should occur with appropriate treatment. In most cases, the lesions observed do not necessarily indicate a clinical problem and more extensive prevalence studies and correlation between abnormalities found and performance are needed to assess the clinical relevance of subepiglottic soft tissue lesions accurately.     

Branchial remnant cysts of mature and juvenile horses

This clinical report describes 8 cases of branchial remnant cysts (BRC) in the horse. The horses presented with bimodal age distribution, with 5 cases in mature horses (age 8–21 years) and 3 in foals (age 1, 6 and 10 months). Mature cases presented for dysphagia or intermittent oesophageal obstruction (2/5), and retropharyngeal swelling (3/5), whereas respiratory stridor and visible mass were presenting complaints in the foals. Presence of a right‐sided (5/8) or dorsally located (2/8) palpable retropharyngeal mass of 3–35 cm diameter was noted clinically; one left‐sided mass was identified as an incidental finding at necropsy. Ultrasonography typically revealed a thick‐walled cyst containing hypoechoic fluid with dependent hyperechoic masses consistent with blood clots. Radiographs and upper airway endoscopy were also consistent with a retropharyngeal mass. Fluid cytology revealed chronic haemorrhage in 6/8 cases, and squamous epithelial cells in one case. Histopathology in all cases demonstrated an epithelium‐lined cyst with no smooth muscle or thyroid tissue. Two cases was subjected to euthanasia; one due to concurrent laryngeal anomalies and one due to financial constraints. The remaining 5 cases were treated via surgical excision. Post operatively, right laryngeal hemiplegia was observed in 4/5 cases. All previous reports of BRC in the horse have described juvenile individuals. Brachial remnant cyst should be considered a differential diagnosis for mature horses with masses of the throatlatch area and can be definitively diagnosed by the presence of squamous epithelium in aspirated fluid or by histopathology of the excised mass. Right recurrent laryngeal nerve damage is a common complication of surgery.     

Arthroscopic treatment of meniscal cysts in the horse

Reasons for performing study: To describe the clinical symptoms, treatment, and outcome of meniscal cysts in horses. These structures have not been previously described in the literature as a potential cause of lameness in the horse. Hypothesis: Meniscal cysts are an uncommon condition of the femorotibial joint but can be a significant cause of lameness. Symptoms can be resolved by arthroscopic excision. Methods: Records of horses diagnosed with meniscal cysts and treated by cyst excision and meniscal debridement at 2 surgical practices were reviewed. Clinical outcome was determined by repeat veterinary examination and contact with owner. Results: Seven cases of meniscal cyst were treated with arthroscopic cyst excision and meniscal debridement. Five of 7 horses had lameness attributable to femorotibial joint pathology, while the remaining 2 horses had meniscal cysts found incidentally during diagnostic arthroscopy for the treatment of osteochondritis dissecans of the lateral trochlear ridge of the femur. Five of 6 horses with long‐term follow‐up were sound and a 7th horse was improved 11 months after surgery. Conclusions and potential relevance: Meniscal cysts, while uncommon, can be associated with progressive lameness in the horse. Surgical excision of the cysts results in resolution or improvement of symptoms, without evidence of recurrence on follow‐up examination.     

Subchondral cyst‐like lesions in the talus of four horses

Subchondral cyst‐like lesions (SCLs) of horses have been found in various locations, but SCLs of the talus have been reported rarely. In this report, we describe 4 horses affected with a SCL of the talus. Each SCL was identified using digital radiography, and each horse was treated by intralesional injection of triamcinolone acetonide. Case details, history, findings during clinical and radiographic examination, treatment, and outcome of each horse are discussed.     

A clinical case of a subepiglottic cyst in a Japanese Black calf

A 36-day-old Japanese Black calf exhibited wheezing associated with dyspnea from birth. Arterial blood gas analysis revealed a low oxygen partial pressure of 51 mmHg, low oxygen saturation of 83%, and high carbon dioxide partial pressure of 58.8 mmHg. Computed tomography, endoscopy, and ultrasonography showed cyst formation under the epiglottis. When the cyst was aspirated under ultrasonic guidance to secure the airway, 30 ml of viscous white turbid content was aspirated. The cyst shrank immediately after aspiration, but the wheezing and respiratory symptoms resumed 7 days after aspiration. Therefore, the cyst was surgically removed from the ventral side of the neck. No cyst remodeling was observed 30 days after surgical removal.     

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.     

Surgical enucleation of unilateral mandibular radicular cysts in an 11-year-old Thoroughbred mare

An 11-year-old Thoroughbred broodmare was diagnosed with extensive radicular cysts that affected the left horizontal mandibular ramus. A left mandibular swelling was present clinically, and mandibular lesions appearing cystic in nature were identified with successive radiographic and ultrasonographic examinations. Surgical enucleation of the cysts was performed under a standing sedation protocol and the excised cystic structures submitted for histopathological analysis. Histological examination of the cystic structures confirmed a diagnosis of multiple radicular cysts.     

Bilateral dentigerous cysts (heterotopic polyodontia) in a yearling Standardbred colt

This article describes the occurrence of bilateral dentigerous cysts in a 1‐year‐old entire male Standardbred horse. Computer tomography (CT) with a positive contrast CT fistulogram was used to accurately define the anatomy of the cysts preoperatively. Conventional surgical techniques were used to remove the cysts under general anaesthesia. The CT studies were able to precisely define the margins of the cysts and facilitated uncomplicated surgical excision. Follow‐up examination of the animal revealed excellent cosmesis at the surgical site. Histology was used to confirm the diagnosis of bilateral dentigerous cysts. Preoperative CT studies are invaluable to precisely define the anatomical locations of the dental anomalies associated with dentigerous cysts and thereby allow confident and uncomplicated excision. Dentigerous cysts may occur bilaterally in horses.     

Non-strangulating intestinal infarction in horses in the UK: A review of 15 cases

The clinicopathological features of 15 horses diagnosed with non-strangulating intestinal infarction (NSII) based on identification of focal areas of intestinal necrosis without mesenteric strangulation were reviewed. The mean age at presentation was 16.3 years, median 13 years, and there was no age, sex, or breed predilection. The major presenting clinical signs included: acute colic ≤ 24 h duration in nine horses; diarrhoea, depression, and inappetence in four horses; and low-grade chronic or recurrent colic, depression, and inappetence in two horses. One horse presented with both acute colic and diarrhoea. Predisposing diseases included colitis or typhlocolitis in five horses and an initial strangulating small intestinal obstruction in three horses, but in seven horses no underlying or predisposing disease was identified. Four cases were managed medically and 11/15 were managed surgically. The most useful diagnostic test was exploratory celiotomy and the only successful treatment was complete resection of the necrotic intestine. Prognosis for survival was poor with a survival rate of only 1/15 (7%). Among the 15 horses, both single and multiple NSII lesions were seen, and they occurred in both the small intestine and large intestines. There was no evidence of Strongylus vulgaris infestation in any of the affected horses.     

Osseous cyst‐like lesions/subchondral bone cysts of the phalanges

In the horse, the phalanges are the second most common location for the occurrence of osseous cyst‐like lesions (OCLLs) after the medial femoral condyle of the stifle. Phalangeal OCLLs occur in a variety of locations, most of which are adjacent to, if not communicating with, a joint. The aetiology of these lesions is considered to be multifactorial by most authors. Horses with OCLLs demonstrate lameness of varying severity. Diagnostic analgesia should be used to localise the lameness. After localisation of the lameness, standard radiographic views of the isolated area should be performed. The radiographic characteristics of OCLLs are dependent on the stage of development of the OCLL; OCLLs may first be identified as a small lucent flattening or depression in the articular surface; however, they may progress to a circular, oval or conical single or multi chambered radiolucency within the bone. There may be a rim of radiodense sclerosis around the lucency. Diagnosis of some OCLLs may only be achieved using nonstandard radiographic views or may require advanced diagnostic imaging modalities such as computed tomography or magnetic resonance imaging. Treatment of phalangeal cysts may be conservative or surgical. Surgical treatment options generally aim to prevent cyst enlargement and promote filling of the lesion with osseous material. Depending on the cyst, this can be performed arthroscopically or via an extra‐articular approach. Occasionally, the severity of proximal interphalangeal joint OCLLs warrants surgical arthrodesis. Overall the prognosis for return to performance for horses with OCLLs ranges from 30–90% but is dependent on the breed, age and intended use of the horse, surface area of weightbearing cartilage affected, concurrent osteoarthritis within the joint and treatment administered.     

Evaluation of the use of an endotracheal tube as a novel method of short-term haemostasis in post-operative paranasal sinus surgery in three horses

This case series describes placement of an endotracheal tube (ETT) with an air-inflated cuff within surgically created sinonasal windows as a technique of post-operative haemostasis. A frontonasal bone flap and a sinonasal window were performed routinely in three standing horses with paranasal sinus disease. In Case 1, the fistula was initially gauze packed, which controlled haemorrhage until concerns of gauze dislodgement necessitated removal 8 h post-operatively. Severe haemorrhage ensued, requiring emergency passage of an ETT and cuff inflation for control. In Cases 2 and 3, the ETT was placed electively intraoperatively for post-operative haemostasis. The ETT was easy to use in the standing horse and no discomfort or complications were recorded. It adequately controlled haemorrhage post-operatively by application of controlled pressure to the nasal and sinus vasculature. ETT cuff placement and inflation over surgically created sinonasal windows has the potential to provide simple and reliable haemostasis following standing sinus-flap surgery without the reported complications of conventionally used methods.