In May of 2002 my rat Rimsky suddenly became very ill with a respiratory infection. Previous to this, he had been on azithromicin for a couple of weeks to try and clear up some mild symptoms but then he suddenly went downhill. He was extremely lethargic, breathing heavily and refused to eat. He would only take a little water from a syringe. A trip to the emergency vet wasn’t very helpful (no proper antibiotics) but Rimsky did get some sub-cu fluids and oxygen. Rimsky had to wait until the morning to see a regular vet. In the morning, Rimksy looked near death, laying on his side heaving. We went in to see an exotics vet and they had some injectable doxy. Rimsky received an intramuscular injection of the doxy in two spots (one in each hind leg). Once I brought him home, I wondered if I had made the right decision because he looked to be in such awful shape. However, 12 hours later I could tell he was improving and 24 hours later he was back to his old self, jumping on the cage door and ready to come out and explore. I was amazed. This is known as the “booster effect”, a characteristic of injectable doxy. Noticeable improvement is observed in 12 hours or less. Oral doxy does not have this boostering effect, but rather causes a gradual improvement. (1a). This booster effect is very important for rats that are very ill and need immediate relief. Rimsky received another injection 7 days after the first. It is very important to give the second dose because the improvement caused by the booster effect is temporary. Seven days after the second injection Rimsky was put on oral doxycyline. For the most part he stayed on the oral doxy for seven months before he died suddenly of a stroke/heart attack. Extended use of antibioitcs is never a good plan, but the three times I took Rimksy off the oral doxy he had a flare up again within days where he would sound congested again.