I have 20 years experience treating patients (humans) in the hospital with respiratory infections as a respiratory therapist. I don't have nearly the experience with ball pythons, but I do have a couple hundred in my personal collection and I have treated several with respiratory infections. The following are my observations and experience.
1. Prevention is the best cure. Keep temps where they should be, and remember that the lower racks will be considerably cooler than the upper racks (especially on a concrete floor in the basement).
2. Time is of the essence. If you catch RI's early, most will resolve by increasing the temps to approx 92 degrees. The snakes immune system works MUCH better at warmer temps. Catching it early means catching it before the animal is blowing bubbles. One of the first signs is continual stargazing. The other thing here is that I prefer to heat the entire cage to around 90 degrees because many snakes still try to seek the cool end if you only raise the hot spot.
3. If the infection has progressed beyond the "early" stages and is blowing bubbles, breathing with it's mouth open, coughing, mucous at the corners of it's mouth etc. you should begin appropriate antibiotic treatment immediately. A delay of a day can mean the difference between life or death for your snake. NEVER delay treatment of a snake with an advanced RI.
4. Culturing - Culturing can never hurt as long as treatment is not delayed waiting to get one. A culture must normally be obtained prior to beginning antibiotic therapy to be useful. If one can be obtained immediately and appropriate treatment begun then a culture can identify specific causitive organisms and the most effective antibiotic. My personal bias would be to never delay treatment more than a few hours in order to get a culture.
5. Antibiotics - there are several antibiotics which are used to treat RI in reptiles (Baytil, Amikin, Fortaz, Tylan, Cipro, etc). They all work, but have individual differences in specificity and side effects. I am not going to discuss individual drugs, doses and specific side effects for particular drugs as I will leave that to your vet. In my experience in the vast majority of cases, early and administration of the CORRECT dose is more important than the specific drug. A large number of animals die due to delay of treatment, and/or to incorrect dose and resulting side effects. These drugs are ALL toxic to varying degrees. They are especially hard on the kidneys and high and/or prolonged doses can permanently damage the kidneys and cause them to shut down which will ultimately result in the death of your snake.
6. Hydration & Humidity - Finally, I am convinced that the convential wisdom of reducing humidity is exactly the WRONG thing to do. Additionally, I think maintaining proper hydration is critical to successfully treating RI's and preventing kidney damage from the medication. I have seen many in this forum recommend decreasing humidity to "dry out the secretions". This is not the thing to do. In the hospital, people with advanced respiratory infections are given fluids and breath air that has been humidified with ultrasonic humidifiers. This added humidity and hydration helps to maintain the viscosity of the mucous and secretions so that the patient is better able to clear them from their lungs and airways. The medications used to treat RI's in snakes tend to have a dehydrating effect on the animal over time and many snakes with RI's do not drink as they normally would. This results in the mucous and secretions in the snakes lungs becoming much thicker and more tenacious and much harder to clear. Also, when a snake is dehydrated, the medications are much harder on the animals kidneys. For this reason, I now administer fluids (3-5cc fluid for each 100 grams of body weight given with a syringe with a long bulbed needle) once a week to all snakes that I am treating for RI's and I have noticed a profound improvement in outcomes. The difference the fluid therapy makes has been nothing short of remarkable in my experience.
Hope others find this useful.
Grant Whitmer