Why do some flocks get coccidiosis and others don't if it's everywhere

[TwoCrows]

Clearly a feed medicated with amprolium does not block all thiamine or pathology labs across the US would see thousands of chicks with thiamine deficiencies.

I am not sure just how much Corid blocks Thiamine, however it contains a synthetic Thiamine which fool the cocci into believing its real. The cocci consume it and quickly die from Thiamine deficiency.

 

[Kiki]

I copied and pasted from this Vet Drug book...it doesn't copy just right:
http://www.armchairpatriot.com/Home-Vet/Plumb's Veterinary Drug Handbook [Desk Ed.] 6th ed. - D. Plumb (Blackwell, 2008) WW.pdf

SCROLL TO PAGE 62 to read it.
Pharmacology/Actions
By mimicking its structure, amprolium competitively inhibits thia- mine utilization by the parasite. Prolonged high dosages can cause thiamine de ciency in the host; excessive thiamine in the diet can reduce or reverse the anticoccidial activity of the drug.

Amprolium is thought to act primarily upon the rst generation schizont in the cells of the intestinal wall, preventing differentiation of the metrozoites. It may suppress the sexual stages and sporulation of the oocysts.


Drug Interactions
The following drug interactions have either been reported or are theoretical in animals receiving amprolium and may be of signi - cance in veterinary patients:
! THIAmINE: Exogenously administered thiamine in high doses may

reverse or reduce the ef cacy of amprolium

 

[TwoCrows]

Here is the link from the Corid page itself:

http://www.corid.com/CoridProducts.html

 

[Scotty from BI]

So I now have a pretty good handle on whether or not to feed medicated, but since we are now talking about Corid, I am wondering, what is the up or down side of treating an outbreak of coccidiosis should it occur? Assuming the chicks are not medicated and need to be treated for 5 days with a full dose of Corid, will they then be immune or do you start from scratch. Meaning, treat and cure and start to feed medicated or will it become a never ending cycle of treating waiting, treating, etc? Sheesh,

 

[TwoCrows]

Outbreaks do happen. Using Corid won't effect their ability to become immune, it will only knock down the infestation. As long as birds are healthy, their systems will again begin to re-establish a healthy immunity.

Keep in mind that wet summers can increase a flocks chances of becoming overwhelmed, as do older and young birds with weaker immune systems.

 

[Scotty from BI]

Thanks again TwoCrows, I think I am ready on this aspect of chicken tending.

 

[TwoCrows]

Also...parasites of all kinds are everywhere. You can't avoid them when keeping livestock. If you see a trend each year of worms or cocci at certain times of year, you may need to start a prevention program of deworming and occasional Corid doses before these become outbreaks.

 

[TwoCrows]

And remember, you may never have a problem with this issue. But this stuff is good to know.