A captive herd of six African elephants (Loxodonta africana) was diagnosed with a louse (Haematomyzus elephantis) infestation. Clinical signs of pediculosis included dry skin and pruritis. Infested elephants demonstrated pruritis by increased rubbing of their bodies on walls and objects. This led to pustular dermatitis along the dorsolateral truncal aspects in one elephant. Adult lice were primarily located along the dorsal surface of the pinna and base of the ears, while nits were found attached to hairs in various locations.
The Haematomyzus sp. of chewing louse has been reported in African elephants, Asian elephants (Elephas maximus), warthogs (Phacochoerus aethiopicus), and bush pigs (Potamochoerus porcus).1,2 Based on a published dosage for elephants, oral treatment with 0.07 mg/kg ivermectin (ProMectin 1% solution, Vedco, St. Joseph, MO, USA) was initiated.3 This treatment regimen, including repeat ivermectin doses, failed to eliminate the ectoparasitism. Higher doses of oral ivermectin along with topical 0.5% carbaryl baths (Mycodex shampoo with carbaryl, Veterinary Products Laboratories, Phoenix, AZ, USA) were then instituted. An oral ivermectin pharmacokinetic study was also undertaken to determine whether the dosage of ivermectin was reaching therapeutic blood levels. Other treatments, including fipronil (Frontline spray, Merial Animal Health, Duluth, GA, USA) and topical human delousing products, were considered, but deemed impractical. A dosage of 0.2 mg/kg ivermectin administered orally every 3 weeks for five treatments along with weekly insecticidal baths proved safe and effective in eliminating this irritating parasite from the elephant herd.
1. Emerson, K.C., and R.D. Price. 1988. A new species of Haematomyzus (Mallophaga: Haematomyzidae) off the bush pig, Potamochoerus porcus, from Ethiopia, with comments on lice found on pigs. In: Proc Entomol Soc Washington. 90(3):338–342.
2. Georgi, J.R. 1985. Parasitology for Veterinarians, 4th ed., WB Saunders, Philadelphia, Pennsylvania. 30.
3. Karesh, W.B., and P.T. Robinson. 1985. Ivermectin treatment of lice infestations in two elephant species. J Am Vet Med Assoc. 187:1235.