Respiratory issue in my flock

[Chickie Baby]

Question regarding 5 hens that I have in a separate 'hospital' due to the treatment. I have a flock of 30 and I've pulled out 5 of them because they were the worst with wheezing/coughing and sneezing. I've been treating these for 3 days with Tylan 50 injections. Because my others in the big run is also sneezing like crazy, but I don't see them slowing down, I decided to treat their water with Oxytetracycline. We've had a good bit of rain each day and I think the dosage may be a little low.

My issue is this, can I integrate the ones completing Tylan with the others on the Oxy? Or do I just keep them separate until the Oxy treatment is completed at day 7? Would it hurt the ones completing Tylan to begin drinking the Oxy water?

In addition, I've been giving 5 tsp. per gallon of Oxytetracycline in the water daily. Due to the rain, should I just add an additional teaspoon? I don't see the improvement in the sneezing with the Oxy group like I have with the Tylan.

BTW, I've had no new birds or changes to my flock to warrant this outbreak. I keep a closed flock due to Mereks. I'm not sure where this came from unless I have a carrier from way back. 2 years ago, I had to treat for runny nose and sneezing, this could have been the source.

 

[Eggcessive]

If you are using Durvet brand of oxytetracycline, you can give 1 1/2 to 2 1/2 tablespoonsful per gallon of water. Sick chickens don't always drink a normal amount of water, which can affect how much medicine they are getting. Tylan also comes in a powder for the water, but is pricey. You might want to get some testing done, or if one should die, get a necropsy done by the state vet or local poultry lab. If possible, I would keep the two groups separate while getting their separate medicines.