Use of parvovirus test paper

My dog is very small. He was discharged from the hospital today. It is very expensive to have an examination at your place. We checked the canine distemper once *** 1 10. If the test paper is second-hand, we sell 30 yuan and canine distemper 50 yuan here. I saw the doctor stick a cotton swab into the dog's ass, and it will get feces on it, that is, take feces from the intestine and poke it twice in a liquid (I think it should be water, but the Internet only says it is a buffer, I really don't know what it is, I think you can use mineral water or cold boiled water). It should be to let the feces blend in and let the test paper absorb. If it's feces on a cotton swab, the test paper won't absorb it. Drop it on the test paper and observe the reaction of the test paper. Check for canine distemper with blood and drop it on the test paper. Two columns are infection, and only one column is health. I think you can ask the boss if you go to the pet store to buy one, but I think you can buy one more, because you are not a professional after all, and it is not good to check it wrong. Welcome to ask questions. I'm going to the hospital to pick up the dog this afternoon. By the way, I'll ask for you ~

Hello, I asked the doctor that the mineral water was not good, but a special solvent was used. He said that buying a special test board (that is, test paper) would send a solvent.