Multimodal therapy including electroacupuncture for the treatment of facial nerve paralysis in a horse

This Case Report describes a 5‐year‐old Standardbred gelding that was referred to the Equine Hospital of ONIRIS Veterinary School of Nantes, France for a surgical procedure under general anaesthesia. Anaesthesia was induced and maintained intravenously and the horse was placed in left lateral recumbency with a padded halter. On post operative Day 1, a post anaesthetic distal facial nerve branch paresis was diagnosed based on clinical signs. The horse was discharged on post operative Day 2 with medical treatment based on anti‐inflammatory drug administration locally and systemically. The horse was re‐examined 2 weeks after the surgery; the left partial facial paralysis was still present and associated with amyotrophy of the muscles supplied by the buccal branches of the facial nerve. In accordance with the owner, the horse was hospitalised to start an electrostimulation treatment. The horse was treated every day for the first 4 days, then every 2 or 3 days during the following 3 weeks, for a total of 11 sessions. At the end of the second week of treatment, the horse was able to normally prehend the food and atrophy seemed reduced. The horse was discharged from hospitalisation at the end of the third week of treatment with specific recommendations. One month after discharge from the hospital just a slight asymmetry could be noticed at rest. Six months later, the training season began and the horse was able to perform. Facial paralysis due to nerve compression is a well‐known complication of anaesthesia. Gradual recovery of function over the weeks of treatment suggests that electroacupuncture may promote recovery and may hasten time of recovery.     

Lateral canthoplasty for facial nerve paralysis and exposure keratitis in a mouse

An 11-month old entire male mouse was presented with mucopurulent discharge and corneal scarring of the left eye. This mouse previously had a history of ear mites that responded to therapy, and had undergone surgery to remove a large discharging mass from the left side of the neck. The eye problem was noted prior to surgery, but after the ear mite infection. Examination revealed absence of a palpebral reflex in the left eye, and no spontaneous movements of the left ear or lip and whiskers. Examination of the left eye revealed extensive corneal vascularisation and pigmentation. Intraocular structures were not visible. A diagnosis of facial nerve paralysis and secondary exposure keratitis was made. Surgery was performed to close the lateral canthus and reduce corneal exposure. Following surgery the eye discharge ceased and corneal vascularisation resolved, however corneal pigmentation persisted.     

Congenital odontogenic keratocyst in a filly

This report describes a congenital odontogenic keratocyst in the left mandible of a filly. A definitive diagnosis was only made after histopathological examination. Mandibular cysts of odontogenic and osteogenic origin have been reported in the past but a case of a keratocyst has not been previously reported in the horse.     

Magnetic resonance imaging features of a benign peripheral nerve sheath tumour with ‘ancient’ changes in the tongue of a horse

A 12‐year‐old Selle Français mare was presented because of inspiratory stridor, hypersalivation and dysphagia. A mass at the base of the tongue could be visualised by upper airway endoscopy, oral cavity examination and radiographs of the head. The exact localisation, extent of the mass and extent of tissue infiltration could only be defined by magnetic resonance imaging (MRI). This Case Report illustrates the usefulness of MRI to assess the characteristics and extent of such a lesion and describes the appearance of peripheral nerve sheath tumour in the tongue of a horse.     

Congenital occipitoatlantoaxial malformation in a Warmblood mare

A 3-year-old Warmblood mare was presented with spinal ataxia of 3 months’ duration. Clinically, reduced mobility of the neck and a prominent atlas were identified. Neurological evaluation revealed hypermetria, circumduction and reduced proprioception, predominantly in the hindlimbs. Occipitoatlantoaxial malformation (OAAM) was diagnosed based on radiography and computed tomography, and confirmed on post-mortem magnetic resonance imaging and pathological examination. Both the atlas and axis were hypoplastic and dysplastic, and a fusion of the atlanto-occipital joint was found. A dynamic compression of the spinal cord was present at the first and second cervical vertebrae. Histologically, the spinal cord was degenerated due to compression. Furthermore, there were muscular malformations including a fibrotic obliquus capitis cranialis muscle, aplasia of parts of the rectus capitis muscles and presence of additional abnormal muscle. Such muscular abnormalities associated with OAAM have not been reported yet and this is the first report of a case of OAAM in a Warmblood horse.     

Temporohyoid osteoarthropathy and unilateral facial nerve paralysis in a horse

A 13-year-old broodmare was referred for weight loss and left facial nerve paralysis. Bilateral temporohyoid osteoarthropathy was diagnosed based on proliferation of the temporohyoid joints and stylohyoid bones on radiographs and guttural pouch endoscopy. The left side was more severely affected. Treatment resulted in little or no improvement.     

Advanced imaging of an incomplete fracture and exostosis of the third metacarpal bone in a young Warmblood horse

A 5-year-old Hanoverian gelding with acute moderate right forelimb lameness underwent nuclear scintigraphy, which identified marked increase in radiopharmaceutical uptake of the proximomedial aspect of the right metacarpus. Ultrasonography and radiography identified sclerosis and exostosis of the proximomedial aspect of the metacarpal bone III in-between the suspensory ligament and the second metacarpal bone, and presence of a suspected fracture. The owner requested euthanasia of the gelding, and post-mortem computed tomography and magnetic resonance imaging identified marked bone sclerosis and thickening of the palmar cortex of the metacarpal III (McIII), presence of an incomplete fracture in the palmar cortex of McIII and expansive exostosis from McIII extending in a palmar direction between the suspensory ligament and the second metacarpal bone. Histopathological examination confirmed the imaging findings of sclerosis and led to final diagnosis of a fracture of the palmar cortex of the McIII associated with an exostosis encroaching the medial aspect of the suspensory ligament. No abnormalities were present in the suspensory ligament or metacarpal bone II (McII).     

Reoccurrence of a paranasal osteoma following surgical removal in a 6-month-old Warmblood filly

A 6-month-old Warmblood filly presented for evaluation of a left sided unilateral mucopurulent discharge of 5 weeks' duration. Upper airway endoscopy revealed a large, smooth mass in the region of the ethmoturbinates. Dorso-ventral and lateral radiographs of the head revealed a large osseous mass in the left paranasal area. A biopsy was performed under general anaesthesia and an osteoma was diagnosed. A computed tomography (CT) examination was performed to guide surgical removal. Surgery was performed under general anaesthesia and a large mass was removed ~15 × 9 cm. A CT examination 3 months following surgery revealed three small areas of mineralisation. It was difficult to differentiate if these were areas of regrowth or portions of the original mass that were not entirely removed. A CT examination 8 months later revealed one of the areas had increased moderately in size. A second surgery was performed standing to remove the growth. A final CT 8 months later revealed no further evidence of a bone growth. This report describes the successful removal of an osteoma regrowth following initial surgical removal and, to the best of the authors’ knowledge, is the first to describe the reoccurrence of an osteoma after surgical intervention. It also describes a successful rhinotomy in the standing equine patient. This case highlights the importance of serial follow-up imaging after surgical removal as osteoma regrowth occurred in this case.     

Peripheral nerve sheath tumour of the equine maxillary sinus

This case report describes an 8‐year‐old Belgian Warmblood mare that was initially diagnosed and treated for a dental sinusitis. Despite removal of the diseased teeth and appropriate treatment, the sinusitis did not resolve. Over time, growth of a peripheral nerve sheath tumour of the left maxillary sinus became apparent, with recurrence after surgical removal. The clinical, radiographic, computed tomography, magnetic resonance imaging and pathological (gross and histological) findings of the first reported peripheral nerve sheath tumour of the equine paranasal region are described and illustrated.     

Traumatic neuroma of the medial palmar nerve as a possible cause of a severe gait abnormality in a Warmblood riding horse

This paper describes the history, examination and clinical findings in a riding horse with a gait abnormality. The lesion was localised to the carpal area of one of the forelimbs, but could not be properly characterised until post mortem examination, when a diagnosis of a traumatic neuroma of the medial palmar nerve could be reached. Thus, the most plausible explanation for the gait abnormality of the horse was found in the peripheral nervous system.     

Treatment and ophthalmic sequelae in a horse with facial cellulitis and orbital abscess

A 22‐year‐old Quarter Horse gelding with a history of dental (107) extraction 2 weeks previously was presented with facial cellulitis and an orbital abscess. The abscess was drained surgically dorsally and ventrally to the zygomatic arch and the horse was treated with parenteral antimicrobial and anti‐inflammatory drugs. The affected eye was protected with a temporary tarsorrhaphy and treated via a subpalpebral catheter. Six months after presentation, the horse was in excellent general condition and returned to previous level of exercise but showed blindness on the affected side. Pallor of the optic disc and severe attenuation of the retinal vessels, suggestive of optic disc atrophy, were present.     

Clinical application of multidetector computed tomography and magnetic resonance imaging for evaluation of cranial nerves in horses in comparison with high resolution imaging standards

Although horses are affected by cranial nerve disease, our understanding of these structures' imaging anatomy is limited, and the optimal modality for imaging of each of these nerves is unclear. The aim of this study was to describe the imaging appearance of the equine cranial nerves on high‐resolution 1.5T magnetic resonance imaging (MRI) and computed tomography (CT) scans of a cadaver head, and with these as standards, examine the utility of MRI and CT performed in clinical cases. High‐resolution MRI and CT images were prospectively acquired of the head of a normal Thoroughbred gelding following euthanasia. Ten clinical cases undergoing high‐field MRI under general anaesthesia and 10 clinical cases undergoing CT in the standing horse under sedation were retrospectively evaluated by three reviewers to assess cranial nerve visibility. On high‐resolution, thin‐slice, MRI scans of the normal cadaver head, each of the 12 cranial nerves and their topographic location could be appreciated. On high‐resolution cadaver CT, cranial nerves II, V and VII were clearly visible, but others were less easily identified; osseous structures were clearly visualised. Clinical MRI and CT allowed for variable visualisation of the cranial nerves, dependent on the sequence and the orientation of scan planes. High‐field MRI allowed excellent visualisation of equine cranial nerves, whereas CT allowed for more detailed visualisation of the osseous canals and foramina. In live horses, the ability to identify all 12 nerves is challenging with either MRI or CT; however, high‐field MRI enables better visualisation of the nerve bundles than CT.     

Multiple mandibular ossifying fibromas in a yearling Belgian Draught horse filly

A yearling Belgian Draught horse filly was presented with a history of bilateral, progressive, painful swelling of the mandible, fever and anorexia. Radiographs and computed tomographic images showed an expansile lesion with a coalescing, well‐defined cystic pattern at the level of the horizontal ramii of the mandible. The histopathological findings confirmed the diagnoses of bilateral, multiple ossifying fibroma. This report indicates that ossifying fibroma should be included in a differential diagnosis if multiple expansile lesions of the jaw are present.     

Heterotopic polydontia as a cause for a cystic lesion in the paranasal sinus of a Thoroughbred filly

A 1-year-old Thoroughbred filly with left bony facial distortion was diagnosed with a multilobar expansile mass within the caudal maxillary and frontal sinuses on computed tomography (CT). Typical findings associated with a sinus cyst, including expression of amber fluid from the mass and a thick lining that could be peeled from the sinus walls, were found on surgical exploration of the sinus under general anaesthesia. Histological examination of firm structures within the fluid-filled cyst contained all components of embryologically normal dental tissue. The filly recovered well and entered training to race as a 2-year-old, as remodelling of the bony distortion and narrowing of the nasal passage was sufficient for airflow. Previous reports of paranasal cystic lesions in horses suggest developmental abnormalities as a causative factor, especially in young horses. Furthermore, heterotopic polydontia is reported as the underlying aetiology in some human paranasal sinus cysts. While polydontia has been reported in the paranasal sinuses and nasal passages of horses, this is the first case report that finds them associated with a cystic lesion within the paranasal sinus.     

Subchondral bone cyst of the apical portion of the proximal sesamoid bone as a cause of severe lameness in a Warmblood filly

A 20‐month‐old Warmblood filly was evaluated for acute onset of a nonweightbearing lameness and swelling of the left hindlimb. Clinical and lameness evaluation and diagnostic intrasynovial anaesthesia isolated the lameness to the left hind metatarsophalangeal region. Radiography and ultrasonography revealed a subchondral cystic lesion of the apical portion of the lateral proximal sesamoid bone associated with oedema and synovial effusion of the metatarsophalangeal joint. Arthroscopic surgical debridement of the subchondral cystic lesion resulted in immediate post operative improvement in the lameness score. Rest and controlled exercise achieved complete resolution of the lameness with the filly being able to start training without apparent lameness. Subchondral cystic lesions of the proximal sesamoid bones can be a cause of nonweightbearing lameness. Surgical debridement resulted in complete resolution of the lameness with a favourable outcome in this case.