Rescue dog health problems are considerably rarer than health problems of non-rescues at the same age. ❗ But a rescue German Shepherd and a non-rescue German Shepherd both are a German Shepherd. It's not that the healthier GSDs are given to shelters, and dog owners keep their sick GSDs. Right?
Right. Thus the only explanation we can think of is:
All shelter dogs get altered, while the majority of non-shelter dogs don't. Both the subsequent lack of roaming and subsequent lack of intimate contacts of altered dogs drastically reduce all types of sickness (disease, disorder, and defect): Less roaming means less scavenging and less stepping on contaminated soil, which helps to avoid all types of parasites and pathogens (bacterial, viral, fungal, and protozoan). Less roaming also means less accidents and concomitant ailments. And the lack of intimate contacts obviously avoids a myriad of consequential diseases and disorders, both acute and dormant.
Shelter staff overall don't subject their dogs to the foolish over-vaccination frenzy and blanket medicament "treatment" of symptoms only! They are better educated as regards dog health, and so they call in a veterinarian only when needed, not when the veterinarian is sending out those unethical if not criminal reminders "your dog's vaccination booster is due" in order to fund his next Porsche or whatever. 💡
Shelter dogs obviously have to deal with a lot more attacks on their health from the living conditions in the kennel than the average dog in a private home. This daily practice of all of the dog's body systems to tackle parasitic and pathogenic attacks makes rescue dogs more resilient, both physically and emotionally. The more a dog can routinely cope with, the less affected (s)he will be by sickness and stress and more sickness.
These three must be the reasons why when you get a rescue dog, you get a healthier dog. The mistake that many adopters then make: They think "We've got to catch up on a lot of vaccinations and treatment with better medicaments" - and their average ordinary allopathic vet obviously won't object - and promptly they bring down the rescued dog's health rather quickly. Instead of improving on it further.
The one area where you as rescue dog owner can further improve and perpetuate the dog's health is dog food. Understandably kennels have very little money and time to prepare quality homemade dog food, and not all shelters can arrange free food supplies from sponsors - in fact the problem is that sponsored foods often are the expired lots of the cheapest and worst lots!
So when you start your rescue dog on natural fresh homemade food (just like what you eat yourself, only leaving out certain "foods") then that's the best by far that you can do to solve current health problems and to prevent future health problems.
Now, if you are facing a specific health issue with your rescue GSD at the moment, note that we have addressed the 31 most common German Shepherd health issues in the MyGermanShepherd Health Manual here. We also address rescue dog health problems (and everything else) in the MYGERMANSHEPHERD PERIODICAL - which you may subscribe to for free here. And in case you are looking for some health remedy, you may find it on our dog health remedies page here.
Note that every key point raised above you can find more comprehensively explained in other places on this website. The menu is your friend. Here, links have been omitted only to keep this decision tree straightforward.
PLEASE NOTE: Posting a fragment of your overall dog problem in the comments below is not going to help. Provide complete details if you really seek the right solution. Of course we have a page for that as well: Dog Problem Consultation.