Diseases: External Parasites

Introduction

• Live on or in skin and feathers of birds.
• Include lice, flies, fleas, mites, ticks

Clinical Signs

• Fleas may be found on the head of the bird where they suck blood.  Fleas cause irritation and blood loss, weakness  and reduced production. May cause mortalities especially in chicks.
• Ticks can be found on the head of the bird and regions with few feathers in adults.  Ticks also infest shelters (e.g. may be found under the bark of branches used to build shelters).  The ticks suck blood and cause weakness.
• Lice can be found all over the body.  The lice feed from feathers and some suck blood causing weakness.  A heavy infestation causes a weak or sick chicken that does not clean its feathers.
• Mites can be found all over the body or in chicken houses or nests.  The mites suck blood causing weakness, itching and restlessness.  This results in anaemia and decreased production.
• Flies and mosquitos can annoy or suck blood from birds.  Mosquitos may assist the transmission of Fowl pox.

Diagnosis

• Confirmed by demonstration of the parasite.

Samples

• Examine head, legs and vent for parasites.
• Examine roosts and walls of chicken house.

Transmission

• Spread from bird to bird.

Treatment

• Repeated application of kerosene on fleas.
• Smoke shelter and nests.
• Use suitable insecticides to spray shelter and empty nests when available.
• Ash should be spread on the floors and walls of poultry shelters.

Prevention and Control

• Management and good housing hygiene.
• Remove bark from timber used to construct shelters to reduce hiding sites for ticks and micks.
• Clean shelter and nests regularly.
• Place chicken manure on gardens and mix into soil to prevent flies from developing in the manure.
• Keep brooding hens free from fleas to prevent infestation of young chicks. Plants which repel fleas are used in some countries to line nests
• Allow chickens to bathe in sand or ash to clean their feathers.
• Apply insecticide to individual birds and housing.
• Other poultry, dogs, cats and rats should be screened since they may serve to maintain flea invasions.
• Sunlight, hot dry weather, excessive moisture and freezing hinder development of fleas.