I have sick chickens (respiratory) but my roo is sicker than the rest and I am going to give him tylan-50 injection and keep the others on the Duramycin-10 water. It seems to be helping them, but not the rooster. I'm afraid if I don't act quick, I may lose him. Is it ok for him to continue drinking the Duramycin water even though I'm giving him the Tylan-50 injections also? And just to double check, the dosage for Tylan-50 for a D'uccle is 1/4 to 1/2 cc under the skin of the neck?