Did the cocci build up immunity against Amprolium?

[PioneerChicks]

I have a large batch of chicks who have been raised on medicated feed. They're a month old right now.

A couple weeks ago I thought some seemed a little lethargic. I couldn't find any bloody droppings because they're on dirt. I started treating lightly with an old bottle of liquid Corid I had on hand.

Anyways, they haven't gotten super lethargic but it's definitely increased a bit. Most of my Welsummers seem mildly lethargic (though my hybrids seem fine). I found bloody droppings today from one.

I bought this bottle in 2020 or so and it has NOT been stored in a consistently cool environment. So maybe it's losing it's potency. I also think I dosed lower than I should have because I was running low and didn't want to buy more (bad idea, I see now).

I'm about to go buy more Corid, but now I'm worried. Did I help this cocci strain build up an immunity? Will Corid still work as a treatment for this batch of chicks?

 

[Wyorp Rock]

I started treating lightly with an old bottle of liquid Corid

Do you have photos of the poop?

I'd treat everyone with the fresh Corid, give the correct dosing and see if it helps. Corid will usually treat all strains of Coccidia, but if you find the Corid is not helping you can use Endocox (Toltrazuril).


Liquid Corid dose is 2tsp or Powdered Corid Dose is 1 1/2tsp per gallon of water given for 5-7 days as the only source of drinking water.
Do not add any extra vitamins/electrolytes that contain B1(Thiamine) to food or water during the course of treatment.