ophthalmic and cutaneous habronemiasis in a horse: case report ...

ISRAEL JOURNAL OF VETERINARY MEDICINE 

87 WEBSITE: www.isrvma.org VOLUME 63 (3) 200 

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, Isra 

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: Steinman@agri.huji.hu 

INTRODUCTION 

Hospital (KSVM-VTH). The horse presented skin lesions aro 

Habronemiasis is a parasitic disease of equids (horses, donkeys, the medial canthus of the right eye and on the lateral b 

mules and zebras) caused by the nematodes Habronema musca, the heel of the right front leg. The lesions were first not 

H. majus andDraschia microstoma (1,2). The adult worms live weeks previously and the referring veterinarian had suspe 

on the wall of the stomach of the host without internal migration. habronemiasis. The horse was treated with ivermectin 1.8 

Embryonated eggs are excreted in the feces to the environment per os (Eqvalan Veterinary® 200 ug/kg, Merial B.V., Haar 

where they are ingested by the larvae of intermediate hosts, such Netherlands), and dexamethasone intramuscularly (Dexacort 

as houseflies and stable flies. Most cases of gastric habronemiasis Forte®, 20 mg/ml Teva Pharmaceut. Works Private Ltd. 

do not show clinical signs (3), however heavy worm infestation Hungary), twice every second day. This treatment was repe 

can result in gastric perforation (4). Development of the parasite 3 times with a seven days interval between treatments. A 

is synchronous with the development of the intermediate host, of 30 ml penicilin-streptomycin (Pen-Strep 20/25 Veterinary 

and infectious larvae (L3) are deposited on the host when 200/250 the mg/ml respectively, Eurovet Animal Health B.V. 

flies are feeding. When a fly lands near the horse's lips, the L3 Netherlands) is was given intramuscularly 2 days before the h 

liberated and is swalowed by the horse, resulting in completion was referred to the KSVM-VTH. In addition, the referring 

of its life cycle (5). Larvae which are deposited on mucous veterinarian performed two minor surgical procedures un 

membranes or on injured tissue will not complete their life cycle sedation for debridement of the lesions.. Following these 

but will induce a local inflammatory reaction causing cutaneous procedures, the lesion around the eye continued to expa 

("summer sores") and/or ophthalmic habronemiasis (2). and it was decided to refer the horse for further diagnosis 

treatment. 

The cutaneous type of habronemiasis,"summer sore", is often 

seen in areas of the world with a tropical or temperate climate The horse was routinely vaccinated against tetanus and 

(1, 3). However, little is known about the prevalence of the rabies and the last deworming before the current treatmen 

disease mainly because of diagnostic limitations (1,2). Clinical performed 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 canthu 

cell carcinoma, fungal granulomas, pyogranulomas and foreign around the puncta lacrimalia of the right eye (Fig 1). The 

body granulomas. Differential diagnoses for ophthalmic had a bloody and purulent discharge and contained num 

habronemiasis include ocular neoplasia, foreign body granuloma, caseous granules. The ventral eyelid was swolen and pa 

ocular onchocerciasis and phycomycosis (5, 6). Confirmation of Ophthalmic examination revealed no pathological changes 

the clinical diagnosis should be performed by histopathology the to eyebal itself, but there was an evident purulent disch 

identify the larvae. 

A few minor skin granulomatous lesions were noted above 

In this report a case of ophthalmic and cutaneous habronemiasis dorsal eyelid, and an ulcerative lesion was visible on the 

in a horse in Israel is described with special attention to bulb of the heel of the right front leg above the coronary 

confirmation of the clinical diagnosis, surgical treatment and with bloody and purulent discharge and evident edema. T 

aftercare. 

horse showed some pain at palpation and was 1/5 lame (d 

as mild lameness observed while the horse is trotted in a s 

Clinical details 

line. Also, when the lame forelimb strikes a subtle head 

History: 

was observed, which may be inconsistent at times) (7). A 

granulomatous lesion was also noted on the skin on the 

A 4 year old 600 kg warm-blood, cross gelding was referred hind leg at the region of the M. semitendinosus. No fu 

to the Koret School of Veterinary Medicine, Veterinary Teaching abnormalities were found on physical examination.


VOLUME 63 (3) 2008 WEBSITE: www.isrvma.org 88 

Clinical pathology 

Ind. Ltd., Holon, Israel) for 10 days. After the cessation o 

Cytologic examination of a direct smear taken from the lesion intravenous administration of flunixin meglumine the horse w 

around the medial canthus of the eye showed eosinophilia. treated A orally twice a day with lgr phenylbutazone (Vetma 

complete blood count (CBC) and biochemical analysis were not Marketing ltd.) for 2 weeks. The nasolacrimal catheter wa 

performed. Packed cell volume (PCV) was 26% (reference range flushed daily with sterile isotonic saline. The stent bandage 

32-52%), total solids (TS) was 7 g/dl (reference range 5.7-7.9 removed g/ after three days and the hoof bandage was cha 

dl), and serum urea was 42 mg/dl (reference 10-40 mg/dl). every three days. 

Casemanagement 

The horse was discharged 12 days post-operatively. The 

sutures were removed and the wounds were healed by pr 

The presence of eosinophils in the direct smear and the location intention. The lesions around the medial canthus of the ey 

of the lesion supported the suspicion of habronemiasis. Due at to the lateral heel bulb of the hoof showed progress of h 

the risk of deterioration and damage to the eye it was decided by secondary intention with a normal aspect of the granu 

to perform an extensive debridement under general anesthesia tissue. The horse did not show any lameness at the tim 

rather than treating it medicaly. 

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 epide 

benzylpenicillin sodium (Penicillin G sodium 10 m.u.®, 10 erosion and focal ulceration with dermal necrosis and ev 

m.uYvial, Sandoz GmbH, Austria), 4 gr gentamycin (Gentaveto- bacterial 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 

mg flunixin meglumine (Flunixin Veterinary®, 50 mg/ml, smal cross-section of a degenerating larva was also seen 

Norbrook Laboratories Ltd, Ireland). Following these preoperative 

medications, the horse was sedated intravenously that larvae were not seen. 

2). The lesion on the hind leg revealed similar findings, e 

with 1000 mg xylazine (Chanazine®, 100 mg/ml, Chanele 

Pharm. Manufacturing Ltd., Ireland) and subsequently induced 

The lesion on the front leg revealed epidermal hyperp 

with 2000 mg ketamine (Ketaset®, 100 mg/ml, Fort Dodge 

with hyperkeratosis and extensive ulceration, moderate to 

laboratories, USA) and 20 mg diazepam (Assival®, 10 ml/2 

marked fibrosis and diffuse eosinophilic infiltration. 

ml, Teva Pharmaceut. Works Private Ltd. Co, Hungary). The The lesion above the eye revealed irregular, epidermal 

horse was positioned in left lateral recumbency, anaesthesia was hyperplasia and mild perivascular eosinophilic infiltration. 

maintained with isoflurane (100%, Nicolas Piramal (I) Ltd., UK) The lesions near the eye and on the hind leg were com 

and 10 ml/kg/h of intravenous lactated Ringer's solution was with Habronema infestation. Severe eosinophilic dermatitis 

given. A catheter was inserted into the orifice of the nasolacrimal was seen in the sample colected from the right front leg, 

duct in the right nostril in order to flush the duct daily after might be the result of larval infection. The lesion above th 

surgery with the aim to keep the puncta lacrimalia patent during may represent a hypersensitivity reaction against an unident 

wound healing. An extensive debridement of the lesion around agent, but which is probably also Habronema considering 

the medial canthus of the right eye was performed. Electrocautery histopathology of the other lesions. 

was used to stop haemorrhage and after debridement, a stent 

was sutured over the debrided lesion using nylon 0 (Monosof®, Folow up 

Nylon (Polyamide), Tyco Healthcare Group LP, USA) in a One month after discharge from the hospital, the wound a 

Lembert pattern to control and prevent bleeding. One skin the eye had healed but there was some degree of ectropion 

lesion on the ventral eyelid, two skin lesions on the dorsal contraction of the scar (Fig 3). The lesion in the hoof had re 

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 was DISCUSSION 

also performed on the lesion on the bulb of heel of the right front In this report, confirmed case of ophthalmic and cutan 

hoof, proximal to the coronary band. The hoof was bandaged habronemiasis to in a horse has been described. Previously, 

control and prevent the bleeding. Samples from the lesion of number the of similar cases were suspected and treated accord 

eye, hoof and hind leg were sent for histopathology. by veterinarians clinicians (Haik R. personal communicatio 

Anesthesia was uneventful and the horse recovered well. 

but most cases were not confirmed by histopathology. 

Post-operative process 

Common sites for infestation by Habronema larvae are lim 

ventral aspect of the abdomen, prepuce, external genitalia 

Benzylpenicillin sodium at a dose of 10 m.u. four-times a males day (penis, urethral process), ocular and peri-ocular are 

and gentamycin at a dose of 4 gr once a day were administered (conjunctiva, medial canthus, nasolacrimal duct) and commiss 

intravenously for 3 days, and 300 mg flunixin meglumine was of the lips (3,5). In a study conducted in 18 horse farms i 

administered intravenously twice a day for 2 days. The horse 20 years ago, the prevalence of gastric habronemiasis was 

was also treated with hydrocortisone acetate 1.5% and neomycin (8). The prevalence of habronemiasis justifies the need to inc 

sulphate 0.5% ophthalmic ointment (Hycocine®, Rekah Pharm. it in the differential diagnosis of lesions on these body par


89 WEBSITE: www.isrvma.org VOLUME 63 (3) 2008 

A retrospective study was performed at Davis Veterinary 

Teaching Hospital on 63 horses diagnosed with ocular or 

cutaneous habronemiasis to identify epidemiological features 

of the disease (5). According to this study Arabians were 

overrepresented, Thoroughbreds were underrepresented, no sex 

predisposition was noticed, the median age was 7.3 years, and 

none of the horses was less than 1 year old. Of the 63 horses, 

only 8 had recurrent infections in the following years. 

In Western Europe, cutaneous habronemiasis has not 

been reported so far (3). However, the occurrence of gastric 3. Gasthuys, F. M. R., Van Heerden, M. and Vercruysse, J 

habronemiasis has been reported in a number of surveys. In Conjunctival habronemiosis in a horse in Belgium. Vet. 

Sweden 1.2% of 461 horses were found positive (9), in France Rec. 154: 757-758,2004. 

8.5%o of 410 horses were found positive (10) and in Belgium 

55% of 11 ponies were reportedly positive (11). 

The exact pathogenesis of habronemiasis is unknown but it 

is highly probable that the disease involves a hypersensitive 

reaction to dead or dying larvae because of the eosinophilia 

seen in direct smears and in histopathological sections. The 

lesions usualy appear during spring and summer, probably 

related to a high fly activity, and regress in wintertime. Although 

it is a rather sporadic disease, certain horses show an annual 

6. Rebhun, W. C, Mirro, E. J, Georgi, M. E. and Kern, T. 

recurrence (2, 5).Diagnosis is chalenging, but based on the Habronemic Blepharoconjunctivitis in horses. J. Am. Ve 

history, clinical signs and location of the lesions, habronemiasis Med. Assoc. 179: 469-472, 1981 

should be diagnosed. Histopathological examination of a biopsy, 7. Ross, M. W: Movement. In: Ross, M. W. and Dyson, S. 

although less sensitive, is currently the method of choice for (Eds.): Diagnosis and management of lameness in the hors 

confirming the diagnosis. Characteristic histological lesions Saunders, Philadelphia, pp. 60-73, 2003. 

consist of eosinophilic dermatitis and coagulative necrosis with 8. Sharir, B., Pipano, E., Markovics, A. and Danieli, Y.: Fie 

or without degeneration of nematode larvae in the centre, as was studies on gastro-intestinal infestation in Israeli horses. I 

seen in this case, and as reported previously (2,5). Molecular J. Vet. Med. 43: 223-227, 1987. 

diagnosis is being developed, but is not commercialy available 

yet. A PCR assay has been reported for the diagnosis of gastric 9. Hoglund J., Ljungstrom, B. L., Nilsson, O., Lundquist, H 

habronemiasis (1, 12), cutaneous habronemiasis (2), and in Osterman, E. and Uggla, A.: Occurence of Gasterophilus 

epidemiological studies (13). 

intestinalis and some parasitic nematodes of horses in 

Sweden. Acta. Vet. Scand. 38: 157-165, 1997. 

Many treatments for habronemiasis have been reported, 

including corticosteroids for reducing the inflammatory 10. Colobert-Laugier, C, Lamidey, C, Brisseau, N., Moussu 

hypersensitivity reactions (5). Ivermectin has been used to kill 

the larvae and the adult worms in the stomach (5, 14). Topical 

combinations of anti-inflammatory, larvicidal, and antimicrobial 

ingredients are also recommended (5). In cases of lesions 

refractory to medical treatment, surgical intervention is indicated, 11. Dorny, P., Eysker, M., Demeulenaere, D., Smets, K. a 

as has been described for the horse in this report. Once surgery Vercruysse, J.: Study on the gastrointestinal metazoan paras 

is indicated, extensive debridement should be performed since fauna of ponies in Belgium, Vlaams Diergeneeskundig 

superficial debridement will usualy be insufficient, leading Tijdschrift, 68:173-178, 1999. 

to progression of the condition which is probably related to 

persistence of degenerated larvae in the lesion. Fly control, 

proper removal and disposal of manure and protecting existing 

wounds are essential for reduction of incidence and prevention 

of recurrence of habronemiasis (3, 5, 6). 

REFERENCES: 

1. Giangaspero, A., Traversa, D. and Otranto, D.: A new too 

for the diagnosis in vivo of habronemosis in horses. Equin 

vet. J. 37: 263-264, 2005. 

2. Traversa, D., Iorio, R., Petrizzi, L., De Amicis, I., Bran 

S., Meana, A., Giangaspero, A. and Otranto, D.: Molecula 

diagnosis of equid summer sores. Vet. Parasitol. 150: 1 

121,2007. 

4. Nadalian, M. Gh., Hosseini, S. H., Tavassoli, A. and Raouf 

A. : Gastritis and gastric perforation due to habronema sp 

in the horse. J. Equine Vet. Sci. 17: 385-386, 1997. 

5. Pusterla, N., Watson, J. L., Wilson, W. D., Affolter, V. K 

and Spier, S. J.: Cutaneous and ocular habronemiasis in 

horses: 63 cases (1988-2002). J. Am. Vet. Med. Assoc. 2 

978-982, 2003. 

C. and Hamet, N.:. Prevalence of stomach nematodes 

{Habronema spp, Draschia megastoma and Trichostrong 

axei) in horses examined post mortem in Normandy, Re 

de Medecine Veterinaire, 151: 151-156, 2000. 

12. Traversa, D., Giangaspero, A., Iorio, R., Otranto, D., Paole 

B. and Gasser, R. B.: Semi-nested PCR for the specific 

detection of Habronema microstoma or Habronema mus 

DNA in horse faeces. Parasitology. 129: 733-739, 2004. 

This case report confirms the presence of the cutaneous and 13. Traversa, D., Iorio, R., Capelli, G., Paoletti, B., Bartolini, R 

ophthalmic forms of habronemiasis in Israel. Thus abronemiasis Otranto, D. and Giangaspero, A.: Molecular cross-sectiona 

should be included in the differential diagnosis when encountering survey of gastric habronemosis in horses. Vet. Parasitol. 

typical lesions. The clinical diagnosis should be then confirmed 141:285-290,2006. 

and treated accordingly as described here. Studies to assess the 14. Herd, R. P. and Donham, J. C: Efficacy of Ivermectin aga 

current prevalence of Habronema spp are required in Israel to cutaneous Draschia and Habronema infection (summer 

evaluate its significance. 

sores) in horses. Am. J. Vet. Res. 42: 1953-1955, 1981.

VOLUME 63 (3) 2008 WEBSITE: www.isrvma.org 90 


Figure 1: Cutaneous and ophthalmic habronemiasis adjacent Figure to 2: Histopathology of the lesion adjacent to the eye. 

the right eye of the horse on referral to the hospital. There There is an is dermal necrosis and diffuse and heavy dermal infiltr 

ulcerated lesion along the nasolacrimal duct - from the medial of numerous eosinophils and fewer neutrophils. A smal cro 

canthus of the eye. It has progressed to a cutaneous lesion inferior section through a degenerated larva of Habronema can be 

to the ventral eyelid. In addition there are a few smal ulcerated 

lesions dorsal and medial to the eye. 

Figure 3: The right eye of the horse one month after discharge. 

The lesion around the eye has healed and a smal scar remains. There is some degree of ectropion due to contraction

ophthalmic and cutaneous habronemiasis in a horse: case report ...

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