Since ancient times, parasites have coexisted with animals and humans, and they are widespread among both domestic and wild species. In chickens, they can affect both the exterior and interior of the body, causing health problems, reduced productivity, and a clear decline in the birds’ well-being.

Parasitism is a relationship in which one organism benefits by living at the expense of another, thereby harming it. In poultry farming, this occurs when various parasites consume the hen’s blood, tissues, or nutrients, weakening it over time.

Birds can be divided into two main groups: external parasites or ectoparasitessuch as mites, lice, fleas, or ticks, and internal parasites or endoparasites, including protozoa and intestinal worms. Both can cause anemia, diarrhea, itching, weight loss, nervousness, a drop in egg production, and even death in severe infestations.

Some species have become particularly important in modern poultry farms, such as the red mite (Dermanyssus gallinae), which is very common in facilities, nests, and perches. Their presence may go unnoticed at first and later become a serious problem.

The best defense against parasites is prevention: regular hygiene, checking the birds, controlling humidity, cleaning perches and nesting boxes, proper handling, and isolating new or sick animals. If symptoms persist, it is always advisable to consult a veterinarian who specializes in birds.

In the following sections, you will find a brief explanation of the Most Common Parasites in Chickens. Click on each image to learn more about symptoms, prevention, and treatment.