Introduction

A disease can spread rapidly among chickens because they are usually kept together in a cage or chicken house. They also share the same food and waterbowls, which can spread disease and infections from sick to healthy chickens. In an intensive system we place a great deal of pressure on the chickens to grow fast and to lay many eggs. This situation can cause disease to spread resulting in a lot of damage because of the stress the chickens experience.

Microorganisms Causing Disease

The organisms which bring about diseases in poultry are too small to be seen by the naked eye - a microscope needs to be used to see them. These microorganisms are: Bacteria, Viruses, Protozoa and Fungi. If the bird has a good immune system it can resist low grade invasions of these organisms.

Purpose of the Book

This book has been prepared to cater to the needs of students of the veterinary colleges, diagnosticians engaged in disease investigation and practicing veterinarians in different states of this country.