Corid Dosage for Chickens: Coccidiosis Treatment Chart

Quick answer: the most commonly used Corid dose for chickens is 2 teaspoons of Corid 9.6% liquid or 1.5 teaspoons of Corid 20% powder per gallon of water for about 5 days in a bad outbreak, or 1 teaspoon of liquid or 3/4 teaspoon of powder per gallon for a milder case. Make it the only water your birds can drink and mix a fresh batch every day.

This is not veterinary advice. Corid is labeled for calves, so please confirm doses with a vet, ideally after a fecal test.

The first time I saw bloody droppings in my brooder, I panicked and spent an hour trying to decode dosing charts that all said something slightly different. So here is what the actual product labels say, where the backyard numbers come from, and the places where sources disagree, so you can treat quickly and with confidence.

Corid dosage chart for chickens

These amounts are per 1 gallon of drinking water. They match the amprolium concentrations on the poultry-labeled product, Amprol 128 (0.012% standard, 0.024% for severe outbreaks, 0.006% follow-up), converted to teaspoons for the two Corid strengths.

Measure with proper measuring spoons, not the teaspoon from your cutlery drawer, and level the powder off. For the liquid, a cheap oral syringe marked in millilitres is the most accurate option.

Is Corid labeled for chickens?

No, and it is worth knowing this before you buy. The Corid 9.6% Oral Solution label and the Corid 20% Soluble Powder label from Huvepharma are both for calves only, against the cattle coccidia Eimeria bovis and E. zuernii. They do not mention poultry, and they only give dosing per 50 or 100 gallons or per 100 pounds of calf.

The amprolium product that is labeled for poultry is Amprol 128 20% Soluble Powder, also made by Huvepharma, for growing chickens, turkeys and laying hens. Its active ingredient and strength are the same as Corid 20% powder, which is why the teaspoon amounts match. Federal rules (21 CFR 520.100) set the poultry treatment at 0.012% amprolium in drinking water for 3 to 5 days, 0.024% in severe outbreaks, then 0.006% for another 1 to 2 weeks.

Using Corid in chickens is therefore extra-label use. Plenty of vets prescribe it and many keepers use it because it is easy to find at farm stores, but under US law extra-label use in food animals is supposed to be directed by a veterinarian. If you can get Amprol 128, it is the on-label choice for your flock.

What the Amprol 128 label says, in plain numbers

If you prefer to work from the poultry label itself, these are its mixing rates. Weighing powder on a kitchen scale is more accurate than teaspoons.

The label also says to give medicated water as the only drinking water, make it fresh daily, and that if birds have not improved within 3 days, you should reconfirm the diagnosis with your vet.

Where the sources disagree

You will see different Corid numbers online, so here is where they differ.

• Powder amount. The widely shared Backyard Chickens dosing chart uses 1.5 tsp of 20% powder per gallon for severe outbreaks and 3/4 tsp for moderate ones. The Chicken Chick gives 1/2 tsp per gallon for 5 days. The chart figures line up with the label concentrations; 1/2 tsp is a lighter dose. Teaspoons of powder also vary by how tightly you pack them, which is why grams are better.
• Liquid amount. The chart and The Chicken Chick agree here: about 9.5 mL (2 tsp) of 9.6% liquid per gallon for a severe case.
• Length of treatment. The poultry label says 3 to 5 days at the treatment level. Many keepers and some vets run 5 to 7 days, and The Chicken Chick’s vet added a second short round two weeks later. Follow your vet if they suggest something different.
• Eggs. See the egg section below; this is the biggest area of disagreement.

Can you eat eggs while treating with Corid?

Here is exactly what the sources say. The Amprol 128 label is indicated for laying hens and states that no withdrawal period is required when it is used as labeled; it makes no separate egg statement. The FDA has also set legal residue limits for amprolium in eggs (21 CFR 556.50). The Chicken Chick says there is no egg withdrawal for amprolium for that reason.

Corid is different. Because its label is for calves, it gives no egg withdrawal at all, and with extra-label use your vet is the one who should set a withdrawal time. Some keepers discard eggs during treatment and for about a week afterward to be safe. My honest take: if you used Amprol 128 as labeled, the label supports eating the eggs; if you used Corid, ask your vet and, if unsure, toss the eggs until a week after the last dose.

What are the signs of coccidiosis in chickens?

Coccidiosis is caused by tiny Eimeria parasites in the gut and is most common in chicks and young birds on damp, dirty bedding. Watch for:

• Bloody, red-brown or orange mucus in droppings (not to be confused with the normal orange-brown cecal poop)
• Hunched posture, puffed-up or ruffled feathers and eyes half-closed
• Lethargy, standing apart from the flock, sleeping more than usual
• Not eating or drinking, weight loss and pale combs or skin
• Chicks that stop growing, and sudden deaths in a brooder

Penn State Extension adds diarrhea, dehydration and paler skin, and notes that warm, wet bedding around waterers is a hot spot. For other symptoms that can look similar, see 13 signs your chickens are sick.

How long does it take for Corid to work?

Most keepers see improvement in 24 to 72 hours: chicks start eating, standing up straighter and the blood clears from droppings. If a bird is not improving after 3 days, the Amprol 128 label says to reconfirm the diagnosis with your vet. Something else may be going on, or the bird may be too weak to drink enough. A very sick chick that will not drink may need the medicated water dripped onto its beak; ask your vet how much to give.

What should I give my chickens after Corid?

Amprolium works by blocking thiamine (vitamin B1), which the parasites need more than your birds do. The Merck Veterinary Manual explains it this way. That is why I do not give B-vitamin supplements or vitamin packs containing thiamine during treatment, since they can work against the drug.

1. Finish the full course, then drop to the 0.006% follow-up level if your vet recommends it.
2. Once treatment ends, offer a poultry vitamin and electrolyte supplement in the water for several days to rebuild B1 and appetite.
3. Offer easy foods such as scrambled egg and moistened feed for birds that are thin.
4. Clean the brooder or coop completely and replace all bedding to cut down the oocysts that cause reinfection.

Medicated chick starter vs vaccinated chicks

Sources differ on timing here too. Many hatcheries and keepers use medicated starter from day one, while Penn State Extension advises against medicated feed for the first 14 days so chicks can develop their own immunity, and to treat only sick birds after that. Ask your hatchery whether your chicks were vaccinated before you choose. My guide to the types of chicken feed covers starter options in more detail.

Can you use Corid with medicated feed? The Amprol 128 label says to use it as the sole source of amprolium, so switch to non-medicated feed while you treat in the water.

When should I take my chicken to a vet?

• Birds are dying, or more than one or two are sick at once
• No improvement after 3 days of treatment
• Bloody droppings in adult birds, which can point to other diseases too
• You want a fecal float test to confirm coccidiosis (most vets and state diagnostic labs offer one)
• You are treating laying hens with Corid and need a withdrawal time

Coccidiosis can travel with worms, so your vet may also check for those. My guide to deworming chickens and how to control parasites in chickens cover the rest of the parasite picture.

Frequently Asked Questions