Thanks for your question. Before acquiring a pet chicken, be sure you check with your local code enforcement to see whether you are allowed to have farm animals where you live. They are prohibited in many areas.
Disease-free poultry are not really available other than in a laboratory setting. The addition of any pet carries some risk; however there are relatively few diseases that will be transmitted between chickens and budgies. The only vaccine that is routinely given to chickens would be Marek’s disease vaccine at 1 day of age.
The best advice is to purchase from a reputable breeder and have a health examination performed by an avian veterinarian immediately after purchase. Routine testing at that time would include fecal examination for parasites, testing for chlamydiosis, and possibly bloodwork. Assuming a clean bill of health, a quarantine period of at least 30 days is advised prior to any contact between the chicken and budgies.
Dr Peter Helmer is a Board-Certified Specialist in Avian Practice with lots of experience with pet chickens and he would be glad to meet you and your new pet. You can contact him at 813 885 4477.