However, there are diseases that can cause serious problems and expense to your poultry enterprise because poultry diseases are numerous, and easily spread.

A disease by definition is a deviation from normal health. The effects of disease can range from reduced production, loss of energy, to death. Diseases can be infectious (contagious) or non infectious. Infectious diseases are caused by microscopic pathogens (germs). In backyard poultry there are four main classes of pathogens: viruses, bacteria, fungi and parasites. Parasites can be internal as with worms & protozoa (coccidian) or external as with mites and lice.