Keeping your backyard flock healthy requires understanding and managing internal parasites, one of the most common health issues in chickens. These parasites live inside a chicken’s body, consuming nutrients and potentially causing severe organ damage. Since chickens are constantly exposed to these parasites in their environment, it is essential to learn how to control and prevent infestations.
Common Internal Chicken Parasites
Internal parasites in chickens primarily include worms, which can be divided into two major categories: roundworms and flatworms.
Roundworms (Nematodes)
Roundworms are thin, tubular worms that invade different parts of a chicken’s body. Depending on the species, they may have a direct or indirect lifecycle. Indirect parasites require an intermediate host, such as insects, to complete their development.
Here are some common roundworms that infect chickens:
- Large roundworm
- Capillary worm
- Crop worm
- Cecal worm
- Stomach worm
- Eye worm
- Gapeworm
- Gizzard worm
Flatworms (Cestodes & Trematodes)
Flatworms have a ribbon-like or leaf-like shape and include two main types: tapeworms and flukes. Tapeworms, which infect the intestines, require an intermediate host. Flukes are more common in tropical climates.
Some common flatworms that infect chickens are:
- Short flatworm
- Microscopic flatworm
- Threadlike flatworm
- Large chicken flatworm
- Branching flatworm
- Sawtooth flatworm
- Nodular flatworm
How Chickens Get Internal Parasites
Chickens become infected when they consume worm eggs, larvae, or intermediate hosts (insects like cockroaches, earthworms, flies, beetles, and snails). Once inside the chicken, the parasites mature, reproduce, and multiply.
Parasites thrive in damp, swampy environments and are most active during spring and fall. Direct transmission also occurs when chickens ingest infected droppings from other birds or wildlife.
Effects of Internal Parasites on Chickens
Chickens with strong immune systems can naturally control small parasite populations. However, if their immunity is compromised or they ingest too many parasites, a worm overload can occur, leading to:
- Malnutrition and weight loss
- Reduced egg production
- Weakness and lethargy
- Organ damage, which can result in death
Even a minor infestation weakens the immune system, making chickens more prone to diseases like coccidiosis and respiratory infections.
Signs of Internal Parasites in Chickens
Physical Symptoms
- Pale or shriveled combs and wattles
- Weight loss
- Stunted growth
- Diarrhea (sometimes with visible worms)
- Dirty vent feathers due to diarrhea
- Worms in eggs or droppings
Behavioral Changes
- Ruffled feathers
- Isolation from the flock
- Lethargy and inactivity
- Weakness
Some parasites cause specific symptoms:
- Gapeworms: Gasping, coughing, yawning, head shaking
- Eye worms: Swollen eyes, blinking, eye irritation, blindness
How to Diagnose Internal Parasites
Fecal Examination
Since worms are internal, the best way to confirm an infestation is by checking droppings for worms, eggs, or segments. You can also perform a fecal float test, where a sample of fresh chicken poop is mixed with a liquid solution to make parasite eggs float for easy identification under a microscope.
Most veterinarians offer fecal tests, and home test kits are also available.
Treating Internal Parasites in Chickens
Drug Dewormers
These are the most effective for severe infestations but should be used cautiously to prevent resistance. The only FDA-approved dewormers for food-producing chickens are:
- Piperazine
- Hygromycin B
Drug dewormers are available as oral medications, injections, or water additives. However, they have a withdrawal period, meaning eggs and meat from treated chickens cannot be consumed for a specific time.
Natural Dewormers
Natural dewormers create a hostile environment for parasites in a chicken’s body. They work gradually and are best used for prevention rather than immediate treatment. Some effective natural dewormers include:
- Garlic: Contains allicin, which repels parasites
- Pumpkin seeds: Contain cucurbitacin, which paralyzes worms
- Brassica & Cucurbit Vegetables: Cabbage, broccoli, squash, and cucumbers have deworming properties
- Wormwood: Contains thujone, a compound that paralyzes worms (should be used sparingly)
Preventing Internal Parasites in Chickens
The best way to keep your flock parasite-free is through proper management and preventive care.
1. Healthy Diet & Supplements
- Protein: Strengthens the immune system, preventing infestations
- Vitamin A & B Complex: Helps repel worms (found in carrots, pumpkin, sardines, and leafy greens)
- Natural Dewormers: Include garlic, pumpkin seeds, and cucurbit vegetables in their diet
2. Clean Environment
- Keep Feed & Water Clean: Use raised feeders and water dispensers
- Prevent Stagnant Water: Parasites thrive in muddy, damp areas
- Control Intermediate Hosts: Reduce insect populations with fly traps and insect-repelling plants
- Regular Coop Cleaning: Remove droppings, change bedding frequently, and maintain dry conditions
3. Proper Space & Management
- Avoid Overcrowding: Stress weakens immunity and spreads parasites faster
- Health Checks: Regularly inspect chickens for symptoms
- Seasonal Prevention: Use natural dewormers in spring and fall when parasite activity is highest
Internal parasites can severely impact the health and productivity of your flock. Roundworms and tapeworms steal essential nutrients, leading to malnutrition, decreased egg production, and even death. Recognizing symptoms early and implementing effective treatment strategies—whether drug-based or natural—can help manage infestations.
The best defense is prevention. Maintaining a clean coop, providing a well-balanced diet, and using natural dewormers can help chickens build immunity against internal parasites. Regular health checks and fecal exams will ensure your flock remains strong and parasite-free, promoting long-term health and productivity.
FAQ’s
1. When should I deworm my chickens?
Seasonal deworming is most effective in spring and fall when parasite activity is highest. Regular fecal exams can help determine if additional treatments are needed.
2. Are there withdrawal periods for dewormers?
Yes, drug dewormers often require a withdrawal period during which eggs and meat from treated chickens cannot be consumed. Always follow the manufacturer’s guidelines or consult a vet.
3. Can internal parasites spread to humans?
Some chicken parasites are zoonotic, meaning they can infect humans (e.g., certain tapeworms). Proper hygiene, such as handwashing and wearing gloves when handling droppings, can minimize the risk.
4. Are there safe plants to help prevent parasites?
Yes, planting herbs like oregano, thyme, and mint around your chicken run can naturally repel pests and parasites while promoting health in your flock.