ISRAEL JOURNAL OF VETERINARY MEDICINE OPHTHALMIC AND CUTANEOUS HABRONEMIASIS IN A HORSE: CASE REPORT AND REVIEW OF THE LITERATURE Yarmut Y., Brommer H., Weisler S., Shelah M., Komarovsky O., and Steinman A*. a Koret School of Veterinary Medicine, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100, Israel. b Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University. Yalelaan 114, NL-3584 CM, Utrecht, The Netherlands. c Kfar Shmuel 13, 99788, Israel. * Corresponding author. A. Steinman Tel.: +972-54-8820-516; Fax: +972-3-9604-079. E-mail address: [email protected] Hospital (KSVM-VTH). The horse presented skin lesions around INTRODUCTION the medial canthus of the right eye and on the lateral bulb of Habronemiasis is a parasitic disease of equids (horses, donkeysth,e heel of the right front leg. The lesions were first noticed 3 mules and zebras) caused by the nematodes Habronema musca,week s previously and the referring veterinarian had suspected H. majus andDraschia microstoma (1,2). The adult worms livhabronemiasise . The horse was treated with ivermectin 1.87 % on the wall of the stomach of the host without internal migrationper .os (Eqvalan Veterinary® 200 ug/kg, Merial B.V., Haarlem, Embryonated eggs are excreted in the feces to the environmenNetherlands)t , and dexamethasone intramuscularly (Dexacort where they are ingested by the larvae of intermediate hosts, sucForte®h , 20 mg/ml Teva Pharmaceut. Works Private Ltd. Co, as houseflies and stable flies. Most cases of gastric habronemiasiHungary)s , twice every second day. This treatment was repeated do not show clinical signs (3), however heavy worm infestatio3n time s with a seven days interval between treatments. A dose can result in gastric perforation (4). Development of the parasitoef 30 ml penicillin-streptomycin (Pen-Strep 20/25 Veterinary®, is synchronous with the development of the intermediate host200/25, 0 mg/ml respectively, Eurovet Animal Health B.V., and infectious larvae (L3) are deposited on the host whenNetherlands the ) was given intramuscularly 2 days before the horse flies are feeding. When a fly lands near the horse's lips, the Lwa3s is referred to the KSVM-VTH. In addition, the referring liberated and is swallowed by the horse, resulting in completioveterinarian n performed two minor surgical procedures under of its life cycle (5). Larvae which are deposited on mucousedatios n for debridement of the lesions.. Following these membranes or on injured tissue will not complete their life cyclprocedurese , the lesion around the eye continued to expand, but will induce a local inflammatory reaction causing cutaneouans d it was decided to refer the horse for further diagnosis and ("summer sores") and/or ophthalmic habronemiasis (2). treatment. The cutaneous type of habronemiasis,"summer sore", is often seen in areas of the world with a tropical or temperate climatThe e horse was routinely vaccinated against tetanus and (1, 3). However, little is known about the prevalence of thrabiee s and the last deworming before the current treatment, was disease mainly because of diagnostic limitations (1,2). Clinicaperformel d one year previously. diagnosis is unreliable as there is a range of equine skin diseases that should be considered as differential diagnoses. These Clinical examination include proliferative granulation tissue, sarcoids, squamous An ulcerative lesion was present around the medial canthus and cell carcinoma, fungal granulomas, pyogranulomas and foreignaroun d the puncta lacrimalia of the right eye (Fig 1). The lesion body granulomas. Differential diagnoses for ophthalmic had a bloody and purulent discharge and contained numerous habronemiasis include ocular neoplasia, foreign body granulomacaseou, s granules. The ventral eyelid was swollen and painful. ocular onchocerciasis and phycomycosis (5, 6). Confirmation oOphthalmif c examination revealed no pathological changes of the clinical diagnosis should be performed by histopathology thtoe eyeball itself, but there was an evident purulent discharge. identify the larvae. A few minor skin granulomatous lesions were noted above the dorsal eyelid, and an ulcerative lesion was visible on the lateral In this report a case of ophthalmic and cutaneous habronemiasibuls b of the heel of the right front leg above the coronary band in a horse in Israel is described with special attention to with bloody and purulent discharge and evident edema. The confirmation of the clinical diagnosis, surgical treatment andhors e showed some pain at palpation and was 1/5 lame (denned aftercare. as mild lameness observed while the horse is trotted in a straight Clinical details line. Also, when the lame forelimb strikes a subtle head nod was observed, which may be inconsistent at times) (7). A small History: granulomatous lesion was also noted on the skin on the right A 4 year old 600 kg warm-blood, cross gelding was referrehindd leg at the region of the M. semitendinosus. No further to the Koret School of Veterinary Medicine, Veterinary Teachinabnormalitieg s were found on physical examination. 87 WEBSITE: www.isrvma.org VOLUME 63 (3) 2008 ISRAEL JOURNAL OF VETERINARY MEDICINE Clinical pathology Ind. Ltd., Holon, Israel) for 10 days. After the cessation of the Cytologic examination of a direct smear taken from the lesiointravenoun s administration of flunixin meglumine the horse was around the medial canthus of the eye showed eosinophilia.treate A d orally twice a day with lgr phenylbutazone (Vetmarket complete blood count (CBC) and biochemical analysis were noMarketint g ltd.) for 2 weeks. The nasolacrimal catheter was performed. Packed cell volume (PCV) was 26% (reference rangflushee d daily with sterile isotonic saline. The stent bandage was 32-52%), total solids (TS) was 7 g/dl (reference range 5.7-7.9remove g/ d after three days and the hoof bandage was changed dl), and serum urea was 42 mg/dl (reference 10-40 mg/dl). every three days. The horse was discharged 12 days post-operatively. The skin Case management sutures were removed and the wounds were healed by primary The presence of eosinophils in the direct smear and the locatiointentionn . The lesions around the medial canthus of the eye and of the lesion supported the suspicion of habronemiasis. Due atot th e lateral heel bulb of the hoof showed progress of healing the risk of deterioration and damage to the eye it was decidebyd secondar y intention with a normal aspect of the granulation to perform an extensive debridement under general anesthesitissuea . The horse did not show any lameness at the time of rather than treating it medically. discharge from the hospital. Surgery Histopathology and confirmation of the clinical diagnosis Preoperatively, the horse was given intravenously 10 m.u. The lesion adjacent to the eye revealed extensive epidermal benzylpenicillin sodium (Penicillin G sodium 10 m.u.®, 10erosio n and focal ulceration with dermal necrosis and evident m.uYvial, Sandoz GmbH, Austria), 4 gr gentamycin (Gentavetobacteria- l colonies. There was diffuse and heavy dermal 5 Veterinary® 50 mg/ml, V.M.D. N.V, Belgium) and 600 infiltration of numerous eosinophils and fewer neutrophils. A mg flunixin meglumine (Flunixin Veterinary®, 50 mg/ml, small cross-section of a degenerating larva was also seen (Fig Norbrook Laboratories Ltd, Ireland). Following these pre• 2). The lesion on the hind leg revealed similar findings, except operative medications, the horse was sedated intravenously that larvae were not seen. with 1000 mg xylazine (Chanazine®, 100 mg/ml, Chanelle Pharm. Manufacturing Ltd., Ireland) and subsequently induced The lesion on the front leg revealed epidermal hyperplasia with 2000 mg ketamine (Ketaset®, 100 mg/ml, Fort Dodgwite h hyperkeratosis and extensive ulceration, moderate to laboratories, USA) and 20 mg diazepam (Assival®, 10 ml/marke2 d fibrosis and diffuse eosinophilic infiltration. ml, Teva Pharmaceut. Works Private Ltd. Co, Hungary). TheTh e lesion above the eye revealed irregular, epidermal horse was positioned in left lateral recumbency, anaesthesia wahyperplasis a and mild perivascular eosinophilic infiltration. maintained with isoflurane (100%, Nicolas Piramal (I) Ltd., UK)Th e lesions near the eye and on the hind leg were compatible and 10 ml/kg/h of intravenous lactated Ringer's solution wawits h Habronema infestation. Severe eosinophilic dermatitis given. A catheter was inserted into the orifice of the nasolacrimawals seen in the sample collected from the right front leg, which duct in the right nostril in order to flush the duct daily aftemighr t be the result of larval infection. The lesion above the eye surgery with the aim to keep the puncta lacrimalia patent durinmagy represent a hypersensitivity reaction against an unidentified wound healing. An extensive debridement of the lesion arounagentd , but which is probably also Habronema considering the the medial canthus of the right eye was performed. Electrocauterhistopathology y of the other lesions. was used to stop haemorrhage and after debridement, a stent was sutured over the debrided lesion using nylon 0 (Monosof®Follo, w up Nylon (Polyamide), Tyco Healthcare Group LP, USA) in a One month after discharge from the hospital, the wound around Lembert pattern to control and prevent bleeding. One skin the eye had healed but there was some degree of ectropion due to lesion on the ventral eyelid, two skin lesions on the dorsacontractiol n of the scar (Fig 3). The lesion in the hoof had resolved. eyelid, and the lesion in the area of the M. semitendinosus were excised. The wounds were closed with nylon 2/0 (Monosof®) to achieve primary intention wound healing. Debridement waDISCUSSIOs N also performed on the lesion on the bulb of heel of the right fronIn tthi s report, a confirmed case of ophthalmic and cutaneous hoof, proximal to the coronary band. The hoof was bandagedhabronemiasi to s in a horse has been described. Previously, a control and prevent the bleeding. Samples from the lesion ofnumbe the r of similar cases were suspected and treated accordingly eye, hoof and hind leg were sent for histopathology.