Worming Your Flock: Why, How, When & With What
When it comes to taking care of your chickens, it’s fairly easy to find plenty of solid research on proper feed requirements, housing needs and general care of your backyard flock. But when it comes to worming and deworming medications for backyard chickens, there simply isn’t a lot of clear advice for chicken owners or products labeled for chickens.

The reason for this gap is a simple one. Commercial egg-laying hens are raised for the entire duration of their lives in a strictly controlled environment. They simply do not have a way of coming in contact with most internal parasites, therefore the companies that develop the vast majority of deworming medicines have not done the expensive research and testing needed to label a product for use in chickens. It’s hard to believe, but the backyard chicken population isn’t large enough in numbers to make the drug companies spend their money on the research and development needed for chicken usage labeling.
So what’s a backyard chicken owner to do? I’ve done some research for you on worming chickens and here are my best practices for my flock of 150 laying hens.
First, a disclaimer. None of the information or recommendations here should be construed as medical advice. Please consult a veterinarian if you are dealing with a persistent illness or losses within your flock. Chickens are odd birds, they often show very few if any symptoms before they are seriously ill. It is worth your time to establish a client relationship with a veterinarian who can treat poultry before you have an emergency.

Why Worm Your Flock
Chickens that are allowed to roam freely on the ground will no doubt be exposed to many different parasites. In chickens, roundworms, gapeworms and tapeworms are the most common. In reality, most backyard chickens are probably walking around every day with a small parasite load. Truth be told, most of us probably are unaware of what’s really lurking inside our hens. Is that a problem? Maybe, maybe not.
Chickens that live their lives in stationary housing on the same ground year-round will likely have a higher chance of developing parasite infestations than chickens who are in a rotational-grazing system, or moved onto clean ground several times a year. Moving onto fresh ground breaks a parasite’s life cycle. My flock is in stationary housing, so worming is of higher importance.
There are a few main types of internal worms that can affect chickens; roundworms, gapeworms, threadworms and tapeworms being the most common. A heavy load of worms can interfere with a hen’s ability to absorb nutrients and therefore affect her health and egg production. But most hens can probably handle a light parasite load and not really have their health or production put at risk. For sure, there is a bit of a gross feeling for me knowing that my hens may have worms. And rarely, I’ve heard of some folks actually finding a roundworm inside of an egg. Yuck!

When To Worm
For those reasons, I worm my entire flock twice a year in fall during their molt and again in the spring. Prior to the fall worming, I take a fecal sample to my veterinarian. They can help me determine what types of worms I may be dealing with and how heavily loaded the flock may be.
How to Worm
Since I have quite a large laying flock of usually around 150 hens. I find it easiest to use dewormers that I can put in their drinking water. With a large number of hens, making sure that each one gets an individual dosage is nearly impossible. With a dozen or so hens, giving an individual dosage to each hen isn’t difficult, so paste-type dewormers are a possibility.
Worm Them With What?
There are two main approaches to deworming chickens: all natural home-remedy type methods and products and the medicine-type products. Your veterinarian (you did find one, right?) will help you decide what’s best for your flock given your location, number of birds and other local factors that may play into your decision.
Chemical Dewormers
I worm my flock twice a year with three different products on a rotating basis. I use a fenbendazole product (Panacur or Safeguard) at a rate of 3 cc per gallon of drinking water and offered to the flock for 24 hours. I also use ivermectin 5mg/mL topical solution at a rate of 5 drops per hen applied to the skin at the nape of the neck. I also use albendazole (Valbazen) at a rate of ½ cc orally per bird. There are no stated egg withdrawal periods established for the use of any of these medications for chickens intended to be used for egg and/or meat production. I do a 2-week egg withdrawal period on my personal flock, but that is mainly because of my personal aversion to possibly finding a worm in an egg! Be aware that fenbendazole and albendazole are in the same “family” of drugs, so if possible, don’t use them back to back to help limit the possibility of any parasites developing drug resistance to the “zoles”, as I call them.
Natural Dewormers
You’ve no doubt heard about all the greatness of diatomaceous earth as a poultry parasite buster. Diatomaceous earth can help with external parasites, but since diatomaceous earth loses its effectiveness when wet, using it as a dewormer for internal parasites is anecdotal at best. If you feel better giving it internally to your flock, go for it. But be careful since it can irritate the eyes and lungs of both birds and humans.
Feeding your flock pumpkin and squash seeds and flesh is another popular deworming option that has many faithful followers. Because there have not been any scientific studies done on the effectiveness of pumpkin seeds, diatomaceous earth, wormwood or other natural home remedies, I personally do not rely on these to control worms in my flock. The pumpkins and squashes make great treats and help prevent my flock from getting bored in the winter and developing bad behavior, but I use scientifically proven products for treating my flock for worms when needed.

Tell Us What You Use?
I hope you find my reasoning and best practices for deworming my flock helpful to you as you manage your flock. If you have any questions or advice for other readers that you’ve found helpful in deworming your flock, leave us a message and let us know about it.
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Hi…this is great information, thanks so much for posting it! So this may be obvious from what you wrote, but just to clarify, you use one of these medications a time, twice per year, and rotate each. So for example, you might treat them with Safeguard in the spring, Ivermectin in the fall, and then Valbazen the following spring?
That’s correct, Steve. Always rotate worming meds to help avoid any parasite from developing resistance to the limited worming meds we do have for poultry!
Hi! I am in the process of deworming with Safeguard. I did it through the feed route….I only have 18 chickens ans I am on day 2 of them eating the treated feed. It was a ratio of 1oz to 15lbs of feed…so it’s going to take them another couple days to get through this feed. Should I pull any unfinished? Or let them eat until it’s gone?
Also, do I need to repeat in 10days?
Hi Kendall. Thanks for reading our blog and for your question. The instructions for Safeguard does say to repeat in 10 days for another 3-day treatment. I would remove any uneaten feed with the Safeguard in it after they are done with their 3-day treatment.
Is it possible to administer the albendazole in the drinking water, as you suggest for the Safeguard? I ask because I have a good sized flock and it will be pretty hard to get 1/2 cc into each one individually..some of them are kind of ornery! :=)
Hi Ron. Thank you for reading our blog and asking your question. The product label for your albendazole will have information as to how it should be administered. Generally, albendazole is poorly soluble in water so it’s probably difficult to find a product that will work for mixing into drinking water.
Thank you so much for this post and for sending it out by email what great timing. One of my chickens is losing weight but otherwise has no symptoms so I wanted to try worming. I even have the fenbendazole already but you are absolutely right it’s really hard to find chicken dosage information on the Internet. I really appreciate this post thank you!!
Hi Tracy! Glad that you found this blog post helpful!
After using the drops of ivermectin on chickens’ backs/under wings, o you repeat this process in a certain number of days or is this a once and done?
Hi Debbie. Thanks for your question. I do not repeat the ivermectin drops as a matter of routine. But I take a fecal sample to my poultry veterinarian about three times a year to check the effectiveness of my de-worming program.
Great post. Has your vet ever found any worms in the fecal sample and if so, did he/she recommended any different treatment other then you’re already doing? Also, about how much is it to get a fecal sample tested from your specific vet?
Hi Alicia. Thank you for reading, and I’m glad you found this post helpful. My poultry vet charges $18 for a fecal float test and has on occasion, found roundworm eggs, which the ivermectin and fenbendazole both treat for. So no further recommendation from my specific vet to change course of action. As a side note to all: I strongly suggest to everyone that they develop a client-patient relationship with a vet who will see chickens BEFORE a medical emergency arises.
Hi! So just to be clear, you only deworm once (not multi days in a row as safeguard says)?
Hi Chicken Gal. You’ll want to follow the label directions for any deworming product you intend to use. Or follow the directions of your poultry veterinarian. I personally use Safe-Guard Aquasol, and it’s a 5-day treatment.