Common health issues in gerbils include respiratory infections, dental problems, diarrhea, and obesity. To prevent these health issues, ensure your gerbil has a clean and well-ventilated living environment, a balanced diet with fresh vegetables and limited sugary treats, regular exercise opportunities, and access to chew toys to keep their teeth healthy. Additionally, monitoring your gerbil's behavior and appearance for any signs of illness can help catch health issues early. Regular veterinary check-ups are also recommended to ensure your gerbil's overall health and well-being.