Subconjunctival voriconazole for the treatment of mycotic keratitis in a horse

Fungal keratitis in the horse is a common but challenging disease. This report describes the successful treatment of Fusarium keratitis with both topical and subconjunctival voriconazole 1%. Voriconazole is a new triazole antifungal that has demonstrated efficacy against common fungal pathogens. Topical voriconazole is able to penetrate the intact corneal epithelium making it a good choice for superficial or deep mycotic keratitis. Reports of subconjunctival use of antifungal drugs are sparse in the veterinary literature. We found subconjunctival voriconazole was well tolerated and easy to safely administer.     

Clinical aspects of mycotic keratitis in the horse.

Several manifestations of equine corenal ulcers caused by mycotic agents are discussed. Antifungal therapy is reviewed. Mycotic keratitis should be suspected when routine corneal ulcer therapy is nonproductive.     

Use of conjunctival pedicle grafts in the management of feline keratitis nigrum

Feline keratitis nigrum (necrosis, sequestrum or sequestration) usually presents as a black plaque in the axial or paraxial cornea. Most cats can be treated by excision of the lesion and covering the defect with a third eyelid flap. This technique did not provide satisfactory results in some cases. This paper describes microsurgery using conjunctival pedicle grafting following keratectomy to provide a one step technique to manage recurrent feline keratitis nigrum, feline keratitis nigrum with full thickness lesions of corneal stroma and eyes also affected with keratoconjunctivitis sicca.     

Listeria keratitis in a horse

Listeria monocytogenes is ubiquitous in the environment but is rarely reported as a cause of keratitis in animals. In this case, a mare was presented with epiphora and evidence of pain in the right eye. Listeria monocytogenes was isolated from a corneal lesion, and bacteria were also seen in the cytologic evaluation. This is the first reported case of ulcerative keratitis associated with L. monocytogenes in a horse.     

Eosinophilic keratitis in a horse

In this case report a 20-year-old horse with unilateral eosinophilic keratitis is presented. The occurrence, clinical symptoms, histological findings and treatment of this ocular disorder are described and discussed against the background of relevant literature. Local administration of 0.1% dexamethason was successful.     

Gutteral pouch mycosis and mycotic encephalitis in a horse

A case of mycotic encephalitis in a horse with guttural pouch mycosis is described. A liquid pellet feed binder contaminated with Aspergillus sp. and erroneously mixed in a feed concentrate was a possible source of infection.     

Outcome of superficial keratectomy without conjunctival graft as a surgical technique for immune-mediated keratitis in horses: Four cases

This case report describes four horses with unilateral superficial or mid-stromal immune-mediated keratitis (IMMK) treated with a superficial keratectomy (SK) without a conjunctival graft. In two horses, the surgery was performed under general anaesthesia, and in two horses standing with sedation and local blocks. Results of this report show that SK is a viable treatment option in horses with chronic superficial and/or mid-stromal IMMK that can even be performed in the standing, sedated horse. When sufficient corneal tissue is removed, no recurrence is to be expected in the long-term follow-up (up to 31 months). In two horses, healing occurred without complications. Two horses developed a secondary bacterial infection post-operatively (Enterococcus faecalis and Staphylococcus aureus). In one case, this resulted in a pre-perforating melting corneal ulcer necessitating conjunctival pedicle graft surgery 13 days post keratectomy. In three horses, there was no recurrence of the IMMK with a long-term follow-up of 6–31 months. One case showed recurrence of IMMK in the cornea region surrounding the keratectomy 9 months after surgery.     

Treatment of mycotic tracheitis in a horse with fluconazole and systemic iodine

Fungal infections of the equine trachea have been rarely reported. This case report describes the successful treatment of a mare with fungal infection of the trachea that had severe diffuse granulomatous thickening, erosions and haemorrhage of the proximal half of the trachea. The horse was treated with oral fluconazole and systemic iodine therapy. Serial endoscopic examinations confirmed rapid resolution of the condition.     

Treatment of left laryngeal hemiplegia in standardbreds, using a nerve muscle pedicle graft

The efficacy of a nerve muscle pedicle (NMP) graft in restoring upper airway function was evaluated in exercising horses with induced left laryngeal hemiplegia. The NMP graft was created from the first cervical nerve and the omohyoideus muscle and transplanted into the left cricoarytenoideus dorsalis muscle. Seven adult Standardbreds were trained to exercise on a treadmill inclined at 6.38 degrees. With the horses at rest and exercising at 4.2 and 7.0 m/s, the following variables were recorded: peak inspiratory and expiratory transupper airway pressures (defined as the pressure difference between a lateral tracheal catheter and a mask catheter), peak inspiratory and expiratory air flow, inspiratory and expiratory impedance, tidal volume, minute ventilation, heart rate, and respiratory frequency. Measurements were made before left recurrent laryngeal neurectomy (LRLN), 28 days after LRLN, and 12, 24, and 52 weeks after the NMP graft (n = 5) or sham operation (n = 2). Before LRLN, exercise increased inspiratory and expiratory air flow and transupper airway pressure, whereas the impedance was unchanged. After LRLN, transupper airway inspiratory pressure and impedance were significantly greater and inspiratory air flow was significantly less than baseline values at 7.0 m/s. The sham operation did not improve airway function. Twelve weeks after insertion of the NMP graft, inspiratory impedance and inspiratory air flow were significantly different (improved) from LRLN values. Twenty-four weeks after insertion of the NMP graft, inspiratory impedance was not significantly different from LRLN values.(ABSTRACT TRUNCATED AT 250 WORDS)     

Reconstruction of the parotid duct in a horse using an interposition polytetrafluoroethylene tube graft

A Thoroughbred gelding was referred for treatment of a parotid duct fistula. This had developed after the referring veterinarian had excised a portion of the duct, and ligated the proximal end, as a means of treating a recurring sialocoele. This report describes the successful surgical reconstruction of the excised 15 cm portion of the parotid duct using an interposition polytetrafluoroethylene tube graft.     

Osseous metaplasia in the conjunctiva of a horse presenting with recurrent ulcerative keratitis

A 13‐year‐old Thoroughbred gelding presented with a 6 month history of recurrent conjunctivitis, dacryocystitis and corneal ulceration affecting the left eye (OS). Treatment had included multiple topical antibiotic and anti‐inflammatory preparations, nasolacrimal system flushing and an injection of methylprednisolone acetate (MPA) (Depomedrone) ¹ administered subconjunctivally into the left lower eyelid. No mechanical cause for the ulcerative keratitis could be visualised but digital palpation revealed a firm linear structure in the central palpebral conjunctiva of the lower eyelid. An excisional biopsy was performed and histopathological examination revealed the lesion to be a region of osseous metaplasia. Following excision of the lesion, the corneal ulcer resolved and the eye remained disease free over a 4 year follow‐up period. A causal link between the osseous metaplasia and the recurrent ulcerative keratitis was therefore suspected. This report describes the management of this case and discusses the pathogenesis of osseous metaplasia and the use of subconjunctival corticosteroids.     

Treatment of hemangiopericytoma in a dog, using surgical excision, radiation, and a thoracic pedicle skin graft

A dog with hemangiopericytoma of the left forelimb underwent surgical excision followed by radiation therapy and thoracic pedicle skin grafting. Recurrence of the neoplasm was not observed 3.5 years after surgery. Hemangiopericytoma is an uncommon neoplasm that seldom metastasizes but has a high recurrence rate. In this dog, complete surgical excision was not possible because of the location and invasiveness of the neoplasm. The combination of surgery, radiotherapy, and skin grafting was a viable alternative to limb amputation.     

Necrotizing mycotic vasculitis with cerebral infarction caused by Aspergillus niger in a horse with acute typholocolitis.

An 18-year-old Morgan mare was presented to the Veterinary Medical Teaching Hospital, University of Illinois, with a 10-day history of watery diarrhea, depression, and dysphagia. On admission, the animal was severely dehydrated, depressed, and unable to swallow and had no clinical signs of diarrhea. The respiratory and heart rate and body temperature were within normal limits. Following fluid therapy, the mare developed severe watery diarrhea and continued to be depressed, incoordinated, and dysphagic. The animal died on the fourth day after admission and was sent to the Laboratories of Veterinary Diagnostic Medicine for necropsy. Gross postmortem findings were consistent with an acute cerebral infarction in the right cerebral hemisphere, an acute necrotizing typhlocolitis, multifocal petechial and ecchymotic hemorrhages, enlarged and congested pars intermedia of the pituitary gland, and marked bilateral adrenocortical hyperplasia with multifocal areas of necrosis and hemorrhage. Histologic evaluation of the affected brain demonstrated an area of coagulative necrosis of the gray matter, with hemorrhage, vasculitis, and thrombosis. There were many fungal hyphae 3.5-6.0 microm, pale basophilic, septate, and occasionally branching at 45 degrees present in the arterial walls and throughout the necrotic tissue. Immunohistochemical analysis revealed Aspergillus niger as the etiologic agent responsible for the mycotic vasculitis and infarction in the brain. Bacteria culture and immunohistochemical staining of the colon and cecum failed to demonstrate specific pathogens.     

Management of a keratoma in a horse: A case report

An 8-year-old Thoroughbred gelding presented with chronic intermittent lameness of the left forelimb. Keratoma was diagnosed based on history, clinical signs and the radiographic evidence of a radiolucent concavity of the third phalanx. The keratoma was removed by hoof wall resection and the foot was immobilized using a bar shoe with clips and a dorsal hoof wall plate positioned across the hoof wall defect. The hoof wall defect was completely filled with new hoof wall by 9 months postoperatively. The horse returned to normal athletic function and is performing successfully 18 months later.     

Treatment of a mandibular bone cyst by use of a corticocancellous bone graft in a horse.

A 1-year-old Appaloosa stallion had a mass on the right rostral hemimandible. The mass was firm, did not cause signs of pain, and was identified as a bone cyst by radiography and biopsy. Surgical correction included curettage of the cystic cavity and grafting the defect with both cortical and cancellous bone. By 5 months, the cystic cavity was ossifying; continued remodeling with an increase in bone density was apparent 22 months after surgery.     

Mycotic keratitis in a horse caused by Aspergillus fumigatus. The first reported case in Finland.

The first identified Finnish case of equine mycotic keratitis caused by Aspergillus fumigatus is described. The clinical picture, the sampling method, the macro- and micromorphology of the causative fungus and the therapy applied are reported in detail. Therapy with natamycin (Pimafucin 2.5% eyedrops. Gist-Brocades) was successful.