I just got my rat colony started with about 15 rats of different ages. They are being kept on my screened in porch while the weather is nice.
We had a very unexpected cold snap one night where it got down into the 50's (I would have brought them in had I known) and the sneezing (myco flair up) started the next day. Previously, there was no sneezing.
I went to Tractor Supply Store and bought the Tylan 50 (50 is the small bottle, wish I would have gotten the larger one) needle and syringe and started oral treatment. 2 tsp (I will get back with you for the ml amount) per 1 gallon of water mixed with a little sugar to take the bitterness out and changed daily.
http://www.rmca.org/Articles/dchart.htm
It has been a little over a week since I started treating and most if not all the sneezing has gone away. I will continue treatment for the next 3 weeks as recommended.
I listened to their lungs and did not hear a rattle in their lungs and I also believe I caught it and started treatment soon enough. I do not believe someone will have the same luck with rats that are not treated quickly or are seriously ill, or it may take more time and a different medication to fix.
Just a little more information to what you can expect with the liquid Tylan.