If vaccinated for Cocci, can they still get it?

[kristipwith3]

I've lost 3 broiler chicks that are 2.5 weeks old. They were vaccinated for Cocci and Marek's disease and came from MurryMcMurry. All three have been fluffed up, standing still, eyes closed. I've not seen any bloody stool. I've given them appropriate food/water/space/light. They've also had Nurtri-drench. They are part of a 49 bird bird chick flock so I'm a bit freaking out that is going to continue.

Ideas on what it could be? The current one has a large crop right now.

 

[MeepBeep]

Yes they can still get it, the vaccine itself can give it to them, or they can get one of the other strains the vaccine does't inoculate against...

Do they have sufficient heat? Somewhere in the 90°F range?

I would start a treatment with amprolium just to be safe...