When I use the dart gun, I use the medication in the dart when I am using Micatil for any animal or the Baytril for small animals. On cows, I have to use 2 darts because of the 10cc limit of medicine. I only tranquilize the animal if I have to. There is a risk any time you put one to sleep. I am told by my vet that if the temperature is over 80 degrees, there is a possible problem because when they are asleep, their body cooling process shuts down and they can have heat stroke and die. I probably tranquilize 5-10 cows each winter and probably 10-15 yearling calves each year. I do all this in the cool weather. If I need to tranquilize in the heat, I have used half-dose to partially tranquilize and then do the work with help of a rope and a tree. The reason for the yearling calves I have tranquilized is to castrate them in a field with no way to get them up into a corral. You put them to sleep, walk up and use the knife and they wake up and are just fine with almost no blood. For me, medicines like LA200 are too thick for the dart, especially in the cool weather, and you have to use too much medicine. In cold weather, you need to warm up the dart with the medicine in it enough to make the medicine inject into the animal. In the dart, there is a blasting cap that goes off on impact and shoots the medicine into the animal. Out of hundreds of shots, I have yet to find a dart that still had medicine left in it after the shot. I use 1/2 inch and 3/4 inche large gauge needles, with a gel barb on the needle that makes the needle stick until the gel warms and disolves, and I shoot the animals in the neck in the loose skin area. I believe this achieves the the result of subcutaneous injection. Reusable darts hold up to 15cc's but it takes alot of cleaning and you cant have them riding in the truck without alot of care and it takes alot of time and effort to put them together and retrieve them if you are shooting more than one dart. Disposable ones can be loaded in a few seconds and you can shoot as many as you need while you are waiting for darts to fall out. reusable darts cost 12-15 dollars plus the parts and disposable ones cost 2.50-3.50 depending on the size. They come in various sizes from 3-10 cc's