Endoparasites Of Birds Of Prey
Endoparasites are parasites that live within the internal organs or tissues of the host. There are several classes of parasites that are of concern.
Nematodes
Capillaria
• can be very debilitating, causing lesions in the mouth, tongue, pharynx, crop, esophagus and small intestine. These lesions can be very similar to frounce.
Ascarids
• (round worms), develop and mature in the intestines. The eggs are passed in the feces. Transmission is usually fecal to oral contamination or possibly with the ingestion of earthworms. Heavy loads may cause obstruction.
Baylisascaris
• (raccoon roundworm) eggs are shed in the feces. The environment becomes contaminated with the eggs and may infect the raptor. Raptors are very susceptible to the larval migration of this parasite to the brain, causing progressive neurologic signs. Treatment is difficult once the larvae are migrating and often result in death of the raptor.
Spiruroids
• (stomach worm) are found in the proventriculus and ventriculus
Serratospiculum
• (filarial nematode) is responsible for airsac worm infections.All falcons are susceptible to this parasite, however it is very common in the prairie falcon. Eating infective prey infects the raptor. Some ivertebrates may also carry this parasite and act as a source of infection.
Microfilaria
• is a filarial nematode that can be found in the heart. This nematode is know to have aberrant migration and may be found under the skin or in joints.
Trematodes:
• Trematodes (flukes) are very common in many species of raptors and can be found in the liver, bile duct, intestines and kidney. The eggs are shed in the feces and birds become infected by eating infected prey or invertebrates
Cestodes (tapeworms)
• are long, flat worms that attach to the intestines and consist of multiple segments which appear as small flat worms in the feces. As they dry they look like grains of rice or seeds. Eating infected prey, insects, slugs, earthworms or spiders infects raptors.
Coccidia:
• Coccidian parasites include Eimeria sp, Caryospora sp., Isospora sp., Sarcocystis sp., and Toxoplasma sp. Specialty testing may be required to determine which coccidian parasite is present. The eggs are found in the feces and can cause debilitating disease. These classifications of parasites are often resistant to the sulfa drugs and require newer medications.
Protozoa:
• Trichomonas sp. (Frounce, Canker) inhabits the upper digestive tract, respiratory tract,liver and other organs.
• Giardia sp. inhabit the intestinal tract
Both can cause lethargy, poor appetite and intermittent diarrhea. Transmission is by eating infected prey or drinking contaminated water.
Treatment:
Nematodes:
• Ivermectin at 0.2 mg/Kg orally every 14 days for 2 or 3 treatments. The dose range is 0.2-1 mg/Kg
• Pyrantel Pamoate at 10-20 mg/Kg orally every 14 days for 2 treatments. The main use for this drug is for intestinal nematodes. It is poorly absorbed from the GI tract, so the safety margin is high
• Fenbendazole may be toxic to some species of raptors and it can cause feather abnormalities if given during the molt. The common name is Panacur
Serratospiculum:
• Remove all worms from the airsacs
• Ivermectin 0.4-1 mg/Kg orally, repeat in 7 days
• Nebulize with saline +/- antibiotic to help with the inflammation of the airsacs. Oral antibiotics and anti- inflammatories may also be required.
• No flying for 3-6 weeks post treatment. As the worms die and disintegrate, they have the ability to cause embolism with activity and exertion
Trematodes and Cestodes:
•Praziquantel at 30 mg/Kg orally and repeat in 7 days for cestodes
• Praziquantel at 10 mg/Kg orally once daily for 7-14 days for trematode infections
Coccidia: (2 medication choices)
•Ponazuril is a metabolite of toltrazuril, Use at 20 mg/Kg orally every 24 hours for 3 treatments
•Toltrazuril (Baycox) at 15-25mg/Kg orally every 24 hours for 2 days, or every 48 hours for 3 treatments
Protozoa: (3 medication choices)
• Carnidazole (Spartrix): 20 mg/Kg orally every 24 hours for 2 days
• Ronidazole (Ronivet): 6-10 mg/Kg orally daily for 6-10 days
• Metronidazole(Flagyl): 30-50 orally daily for 3-5 days
Suggested Reading
Parasites of Birds of Prey. Stephen A Smith.
Seminars in Avian and Exotic Pet Medicine. Volm 5 (2) April 1996
Parasitic Disease of Wild Birds. Carter Atkinson and Nancy Thomas
Parasitic Disease in Birds of Prey: Health and Disease. John Cooper
