Abstract
Parasitic conjunctivitis is an uncommon finding in avian species. An adult 15-year-old female ostrich (Struthio camelus) presented with a two-week history of blepharospasm and epiphora. On examination a follicular conjunctivitis was diagnosed, characterized by a mild heterophilic inflammation which responded well to 0.3% ciprofloxacin and 0.1% diclofenac sodium ophthalmic drops along with parenteral enrofloxacin (Baytril 100, 8.5 mg/kg q 24 h). Three days after the cessation of therapy, the conjunctivitis returned. Subconjunctival triamcinolone OU (Kenalog-10, 10 mg/ml, 2.5 mg OU) proved ineffective. On subsequent examination, a carpet of 1.4–5-mm long, pink organisms, tentatively identified as Philophthalmus megalurus (based on geographic distribution and morphologic characters of adults and eggs)1,2 were seen attached to the conjunctiva. The closely related fluke, P. gralli, has been diagnosed in ostrich in Zimbabwe and Brazil.3-5 Philophthalmus megalurus transmission involves a freshwater snail and ingestion of metacercariae encysted on solid surfaces (e.g., vegetation, crustaceans). Initial treatment consisted of hypertonic saline ophthalmic drops and manual removal. Despite repeated treatments, heavy infestation persisted. Treatment was altered to levamisole injectable (137.5 mg/ml solution, 80 mg), topically OU along with manual removal q 1 week.3 After three weeks of treatment, clinical signs had resolved completely and flukes were only occasionally seen on the conjunctiva, but during treatments large numbers were found to be coming out from under the nictitating membrane. After seven weeks of treatment, no flukes could be seen during examination and only a rare, non-motile, discolored fluke was removed after topical treatment with levamisole. Two months after treatment there has been no recurrence of clinical signs.
Acknowledgments
The authors thank all of the keepers, veterinary and laboratory technicians who made diagnosis and treatment of this case successful.
Literature Cited
1. Krygier, B. B., R. W. Macy. 1969. The eye fluke Philophthalmus megalurus (Cort) (Trematoda: Philophthalmidae) in the dipper, Cinclus mexicanus, in Oregon. J. Parasitol. 55: 78.
2. West, A. F. 1961. Studies on the biology of Philophthalmus gralli Mathis & Leger, 1910 (Trematoda: Digenea). Am. Midland Naturalist. 66: 363–383.
3. Mukaratirwa, S., M. Chimbwanda, N. Matakwe, and E. Matenga. 2008. A comparison of the efficacy of doramectin, closantel and levamisole in the treatment of the ‘oriental eye fluke’, Philophthalmus gralli, in commercially reared ostriches (Struthio camelus). J. S. Sfr.Vet. Assoc. 79: 101–103.
4. Mukaratirwa, S., T. Hove, Z.M. Cindzi, D. B. Maononga, M. Taruvinga and E. Matenga. 2005. First report of an outbreak of oriental eye-fluke, Philophthalmus gralli (Mathis & Leger 1910), in commercially reared ostriches (Struthio camelus) in Zimbabwe. Onderstepoort J. Vet Research 72: 203–206.
5. Verocai, G. G., L. N. Lopes, L. Burlini, T. R. Correia, C. P. deSouza, K. Coumendouros. 2009. Occurrence of Philophthalmus gralli (Trematoda: Philophthalmidae) in farmed ostriches in Brazil. Trop. Anim. Health Prod. 41: 1241–1242.