Ectoparasites in a Pigeon Colony

James R. Owiny and Elisa D. French

Forty retired White Carneaux breeder pigeons (Columbia ing organs called halteres on the metathorax, except for mem- liva), weighing 400 to 500 g and approximately 5 years old, were bers of the family Hippoboscidae, which usually lack wings or purchased (Palmetto Pigeon Plant, Sumter, SC). The pigeons have only temporary ones. Diptera contain blood-sucking spe- were going to be used for teaching in a psychology class and for cies that act as vectors (3). Hippoboscidae are relatively perma- behavioral studies, both approved by the institutional animal nent ectoparasites of birds and some mammals. care and use committee. The pigeons were housed in banks of Pseudolynchia canariensis is found on pigeons in tropical and stainless steel cages on a 12-hour light/12-hour dark cycle. Tem- subtropical regions throughout the world, and is common in perature and relative humidity were maintained at 201 C southern United States and California. It is about 6.5 to 7.5 mm and 605%, respectively, with 10 to 12 air changes/h, in an As- long, with a pair of well developed transparent wings and sociation for Assessment and Accreditation of Laboratory Ani- strong spurred claws. The female deposits mature larvae in mal Care, Inc.-approved facility. Non-contact paper bedding (CB crevices near the host or directly on the host from which it falls ZORB X 20, Bunzl, Cincinnati, OH) was changed twice weekly; off into the bedding. The pupal stage lasts 1 month, and adults a full cage change was performed every two weeks. All pigeons live for 45 days. Adults are blood suckers causing painful were fed pigeon chow (Mad Jack’s Wild Bird Mix, Econo Pigeon wounds and considerable annoyance as they feed. In squabs, Chow, Northern Colorado Feeder Supply, Fort Collins, CO) once this feeding habit may retard development, cause anemia, and a day to maintain 80% of the free feeding weight, with ad libi- result in death in heavy infestations. Klei and DeGuisti (4) have tum access to water and grit (Red Cross Grey Pigeon Health described the bionomics of the pigeon ked. The fly is also a vec- Grit, J. W. Williamson CO., Glassboro, NJ). tor for Hemoproteus columbae (1, 2, 5). Seasonal occurrence of Twenty days after pigeons arrived, the investigator reported H. columbae has been linked to P. canariensis in feral pigeons to the veterinary staff that there was a fly in the pigeon room. (6). Pseudolynchia canariensis may also carry the slender pi- On entering the room, the veterinarian saw two diminutive fly- geon louse (Columbicola columbae) between birds (2), and may like insects resting on a wall near the bird cages. Both insects occasionally bite humans (7). were captured and subsequently preserved in 70% ethanol. Pigeon keds are usually hard to see on the host, as they move Other flying insects were not seen in the room or on the birds. rapidly, but can often be found resting head down motionless on Examination of several birds revealed excess dander, and frayed nearby inanimate objects. We found the keds resting near the feathers with tiny yellowish brown moving objects. Similar bird cages, but not on the birds themselves. Newly arrived pi- moving objects were also seen on shed feathers. There was in- geons should be examined and treated if infested. Dusting the creased shedding of feathers. The birds otherwise looked nor- birds and cages with 1% pyrethrins is effective. Weekly or semi- mal. Investigator records indicated no change in food intake, monthly cleaning of cages will eliminate the pupal stages (1, 5). body weight, or performance during the previous 20 days. Two kinds of small ectoparasites were seen. One was long The flying insects and the small motile organisms were sub- and slender (2.5 mm long x 0.5 mm wide) with prominent claws mitted to an entomologist for identification. On consultation on its legs (Figure 2) and was identified as the slender pigeon with the investigator, all birds were treated with 0.25% louse (C. columbae) (2, 7–9). The other was more oval (1.5 mm permethrin dust (Horse Lice Duster™ III, Farnam Companies, long x 0.75 mm) with a pronounced dome-shaped head and Inc., Phoenix, AZ). Birds were then moved to clean cages imme- prominent claws (Figure 3) and was identified as the fluff louse diately after treatment. Treatment was repeated after two of chicken and guinea fowl (Goniocotes gallinae) (1, 7, 9). These weeks. Ectoparasites were not seen at time of the second appli- lice belong to the order Mallophaga or biting lice, suborder cation of permethrin dust. The dander had disappeared, and Ischnocera, family Pediculidae. Most of the biting lice are yellow feather shedding markedly decreased, with few frayed feathers with chewing mouth parts adapted for feeding on epithelial skin evident. A month after treatment, the feathers looked normal. debris or on feathers of birds. Some members have mouth parts The flying insects (Figure 1) were approximately 7 mm long, adapted for feeding on host tissue fluids. The mesothorax and with a pair of transparent wings, 7 mm long, biting mouthparts, metathorax are fused to form one piece, whereas the prothorax short thorax, and short round abdomen with a semicircular pale is a separate segment. The thoracic spiracles are located ven- yellow band dorsally and extending to the ventral abdominal trally on the mesothorax. The tarsi of species parasitic on birds surface. The insects were identified as pigeon keds have two claws, and those parasitic on mammals have one claw. (Pseudolynchia canariensis) (1, 2). This fly belongs to the order They have filiform antennae visible at the sides of the head, ver- Diptera, family Hippoboscidae (louse flies, keds). Diptera have tical biting mandibles, and 11 abdominal segments. functional mesothoracic wings and a pair of club-shaped balanc- Mallophaga spend their entire life on the host and are fairly common in pigeon lofts. Eggs are laid in clusters on the feather Laboratory Animal Resources, Painter Center, Colorado State University, Fort shafts, and hatch in 4 to 7 days. Nymphs require 3 molts and Collins, Colorado. about 3 weeks to mature. Adults live several months on the 229 Vol 50, No 2 Comparative Medicine April 2000

barb grooves, hatch in 6 to 7 days, and mature to adults in 3 to 4 weeks. The lice are transmitted by direct contact and possibly by P. canariensis (2). Goniocotes gallinae is distributed world- wide. It is pale yellow, about 1.5 mm long, and appears almost circular. The life cycle is unknown, but the louse may be transmitted by direct contact. It generally causes little irritation, but restlessness, damaged plumage, and weight loss sometimes ac- company heavy infestations (1, 7, 9). In contrast to mites, lice cause feather damage and associated secondary complications but have no appreciable effects on reproductive success of pigeons (10). We believe the keds and lice arrived at the facility on the birds; the colony had no contact with other birds and is not directly accessible to the outside. It is important that all birds ar- Figure 1. The pigeon ked Pseudolynchia canariensis. riving at a facility be properly examined for ectoparasites. The rigorous sanitation program in the pigeon room would have eventually eliminated the pigeon keds; the pupa need 1 month to mature, and adults live only 45 days. However, sanitation would have not eliminated the lice, which are permanent parasites on the birds. Although these parasites appear to be common in wild pigeons and in pigeon lofts, they appear to be rare in laboratory raised birds. We successfully eliminated both ectoparasites by application of pyrethrin dust and maintaining rigorous sanitation in the pigeon rooms.

Acknowledgment We are grateful to Duane Lassen, Department of Pathology for as- sistance with identification of the parasites.

Figure 2. The slender pigeon louse Columbicola columbae. References 1. Flynn, R. J. 1973. Flies, p. 358–375 and Lice, p. 376–397. In R. J. Flynn, Parasites of laboratory animals. Iowa University Press, Ames. 2. Tudor, D. C. 1991. External parasite infestations, p. 194–213. In D. C. Tudor, Pigeon health and disease. Iowa State University Press, Ames. 3. Bowman, D. C. 1995. Arthropods, p. 1–81. In D. C. Bowman, Georgi’s parasitology for veterinarians. 6th ed. W. B. Saunders Co, Philadelphia. 4. Klei, T. R. and D. L. DeGuisti. 1975. Observations on the bionomics of Pseudolynchia canariensis (Diptera: Hippoboscidae). Parasitology 70:195–202. 5. The Merck veterinary manual. 1998. 8th ed. Merck & Co., Inc., Whitehouse Station. 6. Klei, T. R. and D. L. DeGiusti. 1975. Seasonal occurrence of Hemoproteus and its vector Pseudolynchia canariensis Bequaert. J. Wildl. Dis. 11:130–135. 7. Soulsby, E. J. L. 1982. Arthropods, p. 357–504. In E. J. L. Soulsby, th Figure 3. The fluff louse of chicken and guinea fowl Goniocotes Helminths, arthropods and protozoa of domesticated animals. 7 gallinae. ed. Lea & Febiger, Philadelphia. 8. Schrag, L. 1981. Healthy pigeons, p. 181–183. Verlag L. Schrober, birds, but survive only 5 to 6 days off the bird (2). Columbicola Hengersberg. 9. Greiner E. C. 1994. Arthropods of veterinary importance in North columbae is found on domestic and wild pigeons (2, 7–9). It has America, p. 121–175. In Sloss, M. W., R. L. Kemp, and A..M. Zajac a slender body, 1.8 to 2.7 mm long and 0.3 mm wide. It feeds on (eds.), Veterinary clinical parasitology. 6th ed. Iowa University keratins, feather powder, and sprouting quills, resulting in Press, Ames. feather abrasion due to increased wear and tear and inadequate 10. Clayton, D. H., and D. M. Tompkins. 1995. Comparative effects of mites and lice on the reproductive success of rock doves plumage formation (8). Eggs are attached to feather shafts or (Columbia liva). Parasitology 110:195–206.

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