My rooster is sneezing, has a runny nose, and mites. What to do?

Hi, I’m sorry to hear about your rooster. Based on what you’ve described, an upper respiratory infection seems likely (mycoplasma, avian influenza, many other diseases could be at play). However, without examining him and maybe running some tests, I can’t say for sure. I would caution the use of antibiotics without he guidance of a veterinarian (in some cases depending on the medication this is even illegal in a food animal), as some can leave dangerous residues in meat or eggs, or if the wrong antibiotic is used, bacterial resistance can occur. Also, if the underlying cause isn’t bacterial, then the antibiotics won’t do anything while a more effective treatment has been missed. Therefore, I would recommend having a veterinarian examine him and they can prescribe the appropriate medications. Additionally, they can examine any other chickens you may have, since the respiratory issue and mites could possibly be spread to other birds and the environment. I am trained in traditional veterinary medicine, and therefore cannot recommend any home made remedy. I would worry that anything short of a prescription antibiotic and antiparasitic medication would not work. Best of luck to you!