Treatment for Norwich canary chicks that are going light?

Q: What is the best treatment for chicks that are going light? I have Norwich canary chicks that are getting to 20+ days and then going light.

“A question – by going light do you simply mean the birds are losing weight? Or is it a general issue of listlessness, losing weight and weakness? Are the birds puffed up as well (their feathers are puffed out)? If it is the second case, then it is likely coccidiosis. So I suggest use of Nuovo Apacox (at first 2 mL/liter of drinking water) for 7-10 days, suspend 10 days and then repeat at 1mL/liter of drinking water. This should then be repeated preventatively one week per month. Has the breeder done any anti-coccidiosis treament on these chicks? With these symptoms it seems unlikely that coccidiosis prevention has been done and 20 days is the incubation period/growth cycle for this protozoa. If it is simply weight loss please advise and I’ll get back to you. It seems unlikely that there is a drastic weight loss at 20 days without some infective/parasitic cause.”