Here are a few harsh facts that you are not going to like hearing, sorry in advance. If you can not catch the bird for a diagnosis you are not likely to find out what the problems are. Sick birds are easy to catch. The bird would need to be caged during the treatment period. Not all information you find on the net is good, it is fair to question mine as well. If he has a gurgle and shows no other outward signs of being ill then he likely has MG or microplasma. There is no getting rid of that but he can live a long and healthy life although he is apt to pass it on to other birds and you should not bring healthy birds on your property as long as he is there, IF he has it. The best treatment for MG is Tylan 200 injections given SQ on day one, three, and five. The recommended dose is 2.0ml for a mature cock, which is higher than the official dosages given in medical books. You cn try the Tylan powder in the water but he would still have to be contained with no other water source. The rate is normally one teaspoon per gallon made fresh daily and be sure to NOT put your hand in the solution or you will get severe skin burn.