How to Prevent and Treat Common Chicken Parasites

Inside: Learn how to prevent and treat common chicken parasites to keep your backyard flock healthy, thriving, and free from serious health issues.

Parasites are a main concern for every backyard chicken keeper. Whether it’s internal worms or external mites and lice, infestations can affect egg production, weight gain, and overall bird health. Left unchecked, they can lead to serious problems, including secondary infections or even death in young birds or older birds with weaker immune systems.

chicken looking a little rough with How to Prevent and Treat Common Chicken Parasites text overlay

This post may contain affiliate links, see my disclosure policy for more information.

Table of Contents

How to Prevent and Treat Common Chicken Parasites

Understanding the type of parasite and how it spreads is the best way to protect your flock and ensure long-term health.

Get updates & freebies delivered to your inbox!

Know the Types of Common Chicken Parasites

Chicken parasites fall into two main categories:

Internal parasites (worms and protozoa): These affect the intestinal tract and digestive system, feeding on nutrients meant for the bird. Common internal worms include:
- Large roundworms (Ascaridia galli): visible to the naked eye, living in the small intestine
- Cecal worms (Heterakis gallinarum): live in the ceca, may host protozoan parasites that cause blackhead disease
- Small roundworms: may not be visible but still cause weight loss and poor condition
External parasites (mites and lice)These live on or under the chicken’s body, sucking blood or irritating skin.
- Red chicken mite and northern fowl mite: feed on blood meal at night or constantly, causing skin irritation and anemia
- Scaly leg mites: burrow under leg scales, deforming feet and legs
- Species of lice: lice eggs cling to feathers, lice feed on skin debris and feathers

Recognize the Symptoms of Parasite Infestations

Early detection is critical. Watch for clinical signs including:

Pale combs and wattles
Diarrhea or pasty vent
Drop in egg yolk quality or output
Scratching, feather loss, and scabbing
Visible worms in droppings or eggs
Weight loss or slow decline in condition

A fecal exam from your local veterinarian can confirm worm eggs or parasitic infections.

Prevent Parasites with a Clean Coop and Good Practices

Prevention is always easier than treatment. Focus on good practice with these steps:

Keep the hen coop and nest boxes dry and clean
Change bedding frequently, especially during summer months
Offer dust baths with sand and diatomaceous earth to help control external parasites
Add apple cider vinegar (1 tbsp/gal) to drinking water as a gentle gut support
Rotate free-range areas to reduce exposure to parasite egg buildup in the environment

Treating Internal Parasites the Right Way

For worm infestations, use a veterinary-recommended dewormer and follow all label directions. Products that treat large numbers of worms or multiple worm species can be most effective. You can use natural dewormers to prevent worms!

Tip: Treat all birds at once and retreat in 10-14 days to catch any that have reached the adult stage.

Some common medications target adult worms only, missing immature stages
Always check egg withdrawal periods before consuming eggs after treatment

Handling External Parasites and Their Hiding Places

Mites and lice often live in coop cracks, perches, or crevices in the chicken house. They can multiply rapidly in large numbers if not treated.

Use powder form insecticides like permethrin on birds and coop crevices
Treat again 5–7 days later to break the entire life cycle
Clean and sanitize nest boxes, roosts, and walls
Avoid bringing new birds in without quarantining

Severe infestations of red mites can cause heavy infestation stress and even death from blood loss.

Interrupt the Parasite Life Cycle

Many intestinal parasites have an indirect life cycle, needing an intermediate host like earthworms or insects to complete development. Wild birds, game birds, and rodents may carry parasitic worms or mites into your flock.

Block wild animal access to feeders
Store feed securely
Keep feeders clean and dry to discourage contamination

Keep a Routine Parasite Control Schedule

A regular treatment schedule and observation routine is the best way to keep parasites in check. Rotate products occasionally to avoid resistance and note any trends in health problems among your birds.

Set a quarterly health check that includes:

Visual body checks
Coop inspection for pests
Optional fecal float tests

Parasites are part of life with chickens, but they don’t have to cause severe cases or ongoing health problems. With consistent care, early detection, and smart prevention, you can protect your backyard chickens and their egg production for future generations of your flock.

By recognizing the signs of infestation, following good biosecurity and parasite prevention habits, you’re playing an active role in your birds’ health.

Frequently Asked Questions About Chicken Parasites

How do chickens act when they have parasites? Eventually, they will become lethargic, tail down and not interested in eating. Their combs and wattles will also become pale and miserable looking.

How often should you deworm chickens? Some poultry keepers worm at least every 3-6 months, between 2 to 4 times a year.

Is it safe to eat eggs from chickens with parasites? There is no risk to humans who eat eggs or the meat of infested chickens.