Learning the basics of parasite prevention is critical for maintaining your chickens in top health. Good flock keeping practices will help keep both internal and external parasites from becoming a problem for your birds.
Internal Parasites
The primary internal parasites affecting chicken flocks in the Pacific Northwest are worms and protozoa. Information on protozoan threats can be found in this article.
Most chickens naturally have worms and can manage a reasonable worm load. Your prevention strategy is to keep that load low and easily handled by the bird. Chickens get worms from something they eat, often insects that carry the worm eggs, or something on the ground that has been infected from the chicken's manure. Birds experiencing stress, whether environmental or social, can see their worm load increase as their immune system is depressed.
Roundworms are the most common type of poultry worm and live in the small intestine. If numbers are high, they can interfere with nutrient absorption. Capillary worms are tiny and not normally a problem. Cecal worms are very common and normally no problem to healthy birds. Gapeworm is uncommon in our area, but can be serious if a high infestation occurs. Tapeworms are difficult to treat, and require an intermediate host (worms, flies, slugs), so control of the vector is needed as well to prevent re-infection.
The primary symptom of a high load will be seeing worms in the bird's droppings or uncommonly in an egg. Additional signs are abnormal, foamy droppings, weight loss, listlessness and pale combs. If you see this type of evidence, a fecal test should be performed to verify type of worm before treatment can begin. We suggest working in consult with an avian veterinarian if you observe these signs, being careful not to use any wormers until the type of worm has been identified. Overuse and incorrect use of chemical wormers does lead to resistance, and a number of previously popular antihelmintics are no longer effective in the Pacific Northwest because of this.
However, worms at this level also indicate that your flock keeping practices need improvement. Proper prevention strategies should keep worm levels low and non-threatening to your birds. These strategies include:
External Parasites
The most common external parasites of chickens are lice and mites, small insects that may live on or off the bird's body and either bite them or suck their blood. Because of their small size, they may be difficult to detect. In the Pacific Northwest, the common species include the Northern Fowl Mite, the Red Mite, and Poultry Lice. Symptoms of an infestation include red, irritated skin--especially near and under the bird's vent--feather damage, low energy, increased appetite, and lowered egg production. Northern Fowl Mites live on the bird and can be seen as black dots moving on the skin, especially in the vent area. Their eggs are laid at the root of the feathers in large, grey clusters. They tend to be worse in damp weather and control is done on the bird. Red Mites are hard to see without magnification, and live off the bird in cracks in the coop. They come out at night to find the birds on the roost and feed on their blood. They can survive for a month off the bird, and control is of the coop and not on the bird. Poultry Lice live on the bird, and die quickly if they fall off. They eat the feathers, dry skin and other organic matter but don't suck blood. They lay clumps of white eggs at the base of feather shafts. Lice eat mites, so birds normally have one or the other, but not both. Lice can be found on various parts of the bird--head, wings, fluff--depending on their species. Like mites, they are worse in fall and winter. Photos of all three, and their egg cases, can easily be found on the internet to help you identify them.
Some of the same factors for preventing internal parasites are used for external ones. Good nutrition and a clean environment are the starting place. Additionally, dry dust bathing areas should be available for all birds at all times of the year. While most birds love a good dry dirt bath outdoors, during our wet winters it is necessary to provide a good dusting area as this is the time parasites are of particular concern. Building and maintaining an indoor dust bath for your birds is an excellent step to keeping them parasite free. Additional steps include discouraging wild birds from mingling with your poultry flocks as they may carry avian parasites that will happily move to your birds if given the chance, treating any new birds to your flock for external parasites while they are in their quarantine period, and disinfecting any used equipment you obtain. Dried garlic added to your bird's feed may help to repel external parasites as well.
While a variety of commercial pesticides are offered for treating external parasites, and may do so quite effectively, we prefer to use a more traditional method of using non-toxic sulfur powder. This can be dusted directly onto the birds (using a pillow case so the bird's head is excluded from the dust), added to dry dust baths, sprinkled in nest boxes and in litter, and hung in small cloth bags for the chickens to brush against as they pass through a doorway or into a nest box. Sulfur has been shown to be very effective in external parasite control with no toxic side effects, as well as to have a residual effect over time. For this reason, it works well as both a treatment and preventative for controlling external poultry parasites.
Internal Parasites
The primary internal parasites affecting chicken flocks in the Pacific Northwest are worms and protozoa. Information on protozoan threats can be found in this article.
Most chickens naturally have worms and can manage a reasonable worm load. Your prevention strategy is to keep that load low and easily handled by the bird. Chickens get worms from something they eat, often insects that carry the worm eggs, or something on the ground that has been infected from the chicken's manure. Birds experiencing stress, whether environmental or social, can see their worm load increase as their immune system is depressed.
Roundworms are the most common type of poultry worm and live in the small intestine. If numbers are high, they can interfere with nutrient absorption. Capillary worms are tiny and not normally a problem. Cecal worms are very common and normally no problem to healthy birds. Gapeworm is uncommon in our area, but can be serious if a high infestation occurs. Tapeworms are difficult to treat, and require an intermediate host (worms, flies, slugs), so control of the vector is needed as well to prevent re-infection.
The primary symptom of a high load will be seeing worms in the bird's droppings or uncommonly in an egg. Additional signs are abnormal, foamy droppings, weight loss, listlessness and pale combs. If you see this type of evidence, a fecal test should be performed to verify type of worm before treatment can begin. We suggest working in consult with an avian veterinarian if you observe these signs, being careful not to use any wormers until the type of worm has been identified. Overuse and incorrect use of chemical wormers does lead to resistance, and a number of previously popular antihelmintics are no longer effective in the Pacific Northwest because of this.
However, worms at this level also indicate that your flock keeping practices need improvement. Proper prevention strategies should keep worm levels low and non-threatening to your birds. These strategies include:
- Provide high quality, age appropriate nutrition for all of your birds.
- Do not feed your birds on the ground, where they may ingest worm eggs from fecal matter.
- Do not overcrowd your flock space. Crowded birds are stressed birds, and high parasite loads can be one of the results.
- Keep all feeders clean of droppings, bedding and spoiled food.
- Provide clean, fresh water. Consider using nipple waters to keep water from being contaminated by droppings.
- Have a good manure management system, using droppings boards or a sand/PDZ flooring under roosts to catch night droppings. Coops should be cleaned as often as necessary to keep manure loads low. Deep litter systems should be thoroughly cleaned at least once a year.
- Remember that sun and heat helps disinfect, while rain and wet conditions encourage parasites. In the Pacific Northwest, our wet winters are a prime time for parasite loads to increase.
- Use a rotational pasture or pen system to allow birds to run on fresh ground, while breaking the parasite cycle on soiled ground by letting it rest.
- Provide preventative feeds to discourage worm loads. The most effective is including 3%-5% dense fiber in the diet, such as sunflower seeds with shells or pumpkin seeds. Additionally, free feed granite grit at all times in the bird's life cycle, no matter their diet or whether they free range or not. These feed additives work by making the bird's internal environment inhospitable to the worms, but they do not control any existing worm loads
External Parasites
The most common external parasites of chickens are lice and mites, small insects that may live on or off the bird's body and either bite them or suck their blood. Because of their small size, they may be difficult to detect. In the Pacific Northwest, the common species include the Northern Fowl Mite, the Red Mite, and Poultry Lice. Symptoms of an infestation include red, irritated skin--especially near and under the bird's vent--feather damage, low energy, increased appetite, and lowered egg production. Northern Fowl Mites live on the bird and can be seen as black dots moving on the skin, especially in the vent area. Their eggs are laid at the root of the feathers in large, grey clusters. They tend to be worse in damp weather and control is done on the bird. Red Mites are hard to see without magnification, and live off the bird in cracks in the coop. They come out at night to find the birds on the roost and feed on their blood. They can survive for a month off the bird, and control is of the coop and not on the bird. Poultry Lice live on the bird, and die quickly if they fall off. They eat the feathers, dry skin and other organic matter but don't suck blood. They lay clumps of white eggs at the base of feather shafts. Lice eat mites, so birds normally have one or the other, but not both. Lice can be found on various parts of the bird--head, wings, fluff--depending on their species. Like mites, they are worse in fall and winter. Photos of all three, and their egg cases, can easily be found on the internet to help you identify them.
Some of the same factors for preventing internal parasites are used for external ones. Good nutrition and a clean environment are the starting place. Additionally, dry dust bathing areas should be available for all birds at all times of the year. While most birds love a good dry dirt bath outdoors, during our wet winters it is necessary to provide a good dusting area as this is the time parasites are of particular concern. Building and maintaining an indoor dust bath for your birds is an excellent step to keeping them parasite free. Additional steps include discouraging wild birds from mingling with your poultry flocks as they may carry avian parasites that will happily move to your birds if given the chance, treating any new birds to your flock for external parasites while they are in their quarantine period, and disinfecting any used equipment you obtain. Dried garlic added to your bird's feed may help to repel external parasites as well.
While a variety of commercial pesticides are offered for treating external parasites, and may do so quite effectively, we prefer to use a more traditional method of using non-toxic sulfur powder. This can be dusted directly onto the birds (using a pillow case so the bird's head is excluded from the dust), added to dry dust baths, sprinkled in nest boxes and in litter, and hung in small cloth bags for the chickens to brush against as they pass through a doorway or into a nest box. Sulfur has been shown to be very effective in external parasite control with no toxic side effects, as well as to have a residual effect over time. For this reason, it works well as both a treatment and preventative for controlling external poultry parasites.