I agree with Charlie H that a shotgun approach is cheaper and usually works. A great place to begin to be sure. He always has a realistic and practical approach. Specific cultures take time and add cost.
My comments began with the notion of recurrent and resistant infection that was not getting fixed. When the cheap and usually effective Baytril course isn't working, then being armed with better info really helps. In those tough cases, there is no substitute for good information such as cultures to make a better decision. My point was that a longer course of an ineffective strategy isn't a good strategy. I wish urinary imaging studies were available for gliders - we are spoiled taking care of people.
I also agree with his point that the body will attempt to rid itself of excess ingested acid, like that found in some fruit drinks. And as the body tries to maintain its normal blood pH in the face of extra acid in the diet
, it does so by putting more than the normal amount of acid in the urine. The helpful result is a more acidic urine pH and an environment not conducive to certain germs' growth.
The body also rids itself of other excesses. If extra calcium is eaten, a dramatic slowing of gut absorption occurs to leave much of it in stool unabsorbed. It is difficult in a normal critter to run their blood calcium level much above the normal range by diet
alone. The body also has many mechanisms to deal with a calcium level climbing a tiny bit above normal. If something happens that leads to a higher level that is desired, the body does selectively lose it in urine as well. I am not saying that calcium depositions don't happen throughout the body, (in people we see depositions of calcium in coronary artery plaque, breast masses, and other places), but those people rarely have elevated serum calcium levels and dietary excesses of calcium intake as the cause, and NEVER to the levels of 5 times normal.
When we run IV fluids into a patient, we can foul things up in a way that the elegance of the gut would never allow. If we error in calcium levels of IV feedings to an extreme that the gut would not allow, we won't see off the charts calcium levels. We'll lose that Code Blue way before we can get blood drawn. In patients with Parathyroid tumors and enormous PTH levels (a major hormone that regulates calcium balance between gut absorption, blood stream level, bone deposition/resorption and kidney excretion), the calcium levels only achieve 20-30% above normal, not 500%.
I may get in trouble with this one from our friend Charlie H, but I strongly believe it to be true - I personally believe the only credible explanation for a blood calcium level 5 times normal is lab error / collection error. It is terribly difficult to draw from a tiny vessels. Vacuum tubes can draw extracellular fluid into the sample that is no longer blood only. Calcium EDTA and other products are used in some tubes to keep blood from clotting. But that level is very suspicious for lab error. The heart won't beat at those levels, and muscles would rigor tremendously. Just another observation.