TECHNICAL ARTICLES Broilers/Layers/Breeders

Identification of Poultry Parasite Problem

There are a large variety of parasites that cause problems in the avian species. These problems can be corrected easier if a few facts are known about parasites life cycles, clinical signs, parasite identification and treatment. Poultry parasites ca be grouped in two broad categories: external and internal parasites. The external parasites are more readily observed and include various species of lice, mites, ticks, fleas and biting insects. Internal parasites include the various species of worms and protozoa and are usually more difficult to detect, and usually require microscopic examination of faeces to detect their eggs. One of the most common internal parasites is ascarids, usually referred to as roundworms.

Birds infested with roundworms may have weakness, diarrhoea, weight loss and poor conditioning. Occasionally an obstruction of the intestines can result causing sudden death. Heavily infested birds become more susceptible to other avian pathogens. Significant drops in egg production can be seen in breeders. The adult worms may be seen in droppings, but usually the condition is diagnosed by microscopic observation of eggs in faecal smear of floatation. Roundworms are easily controlled by regular use of drugs such as piperazine or fenbendazole. Good sanitation is also important to control roundworms since birds are infected by consuming materials which have been contaminated with roundworm egg laden faeces from infected birds. Available drugs remove only the adult parasite. It is important to administer drugs correctly, for example piprazine should be consumed in 5 – 6 hours, not over 24 hours and always ensure giving same dosage for different weights. Do not under dose. Disinfectants and other cleaning agents do not kill eggs. Eggs can survive in contaminated environment for 2 – 7 years.

Threadworm signs are similar to roundworm in that weight loss, poor condition and diarrhoea may be present in affected birds. May cause vomiting or swallowing difficulty. Treatment is similar to roundworm. Sanitation is important to prevent re-infection of birds via access to infected faeces.

Gapeworms cause difficulty in breathing. These worms live in the trachea and bronchi of birds respiratory system. Worm eggs are passed from an infected bird either ingested by a non-infected bird or eaten by an intermediate host (beetle, worm) which is in turn eaten by the bird. Sanitation is important and good insect control is necessary. Affected birds can be treated with compounds such as levamisole.

Tapeworms, in a severe infection can cause diarrhoea, weight loss, an even intestinal impaction. Tapeworms use intermediate hosts such as beetle. Effective treatment is by drugs such as niclosamide coupled with improved sanitation and insect control.

In controlling internal parasite, design a control programme that includes regular treatment, sanitation and litter management. Monitor status by using faecal samples and follow up on diagnosis.

Dr D. Clark, Extension Poultry Veterinarian, University of Arkansas

Date published: 2004-03-01

Dr D. Clark