Greetings from Texas, welcome to the forum, and thanks for considering a "repurposed" Doberman!
Looking for a Companion/Guard dog...I currently live in a townhouse with one other person...
I advise you check with your landlord to see if Dobes are allowed. Some property owners do not allow Dobes (and GSDs, Rotts, APBTs, Chows, etc.) because their insurance company deems them a "dangerous breed". If you own your home, check with your homeowner's insurance company to see if they'll drop you for having a Doberman.
...my wife likes to jog and I want her to have something intimidating by her side.
Adopting an adult Dobe is a good choice for folks who want a jogging partner now. The dog's growth plates in its long bones have already closed and it can tolerate "forced" exercise.
...That means the doberman would be by himself for around 7 to 9 hours (monday through friday) depending on the day. Is that too long for a doberman to be alone?...
Look for a pet-sitter that can come to your home and give your dog a mid-day potty break.
Do rescue organizations check [their dogs] for health issues or would I be taking a big risk and hope nothing is wrong when I take it to the vet for tests?
It depends on the rescue group's finances. Some simply don't have the funds to do more than a basic HW test. Others will test for vWD, thyroid functioning, hip dysplasia, arthritis, tick-borne diseases, intestinal parasites, the DCM mutation, etc.
Then it depends on the level of care the dog received from its previous owner. Some dogs come in to rescue from unknown backgrounds and in poor physical condition. It's rare, but some dogs come in to rescue with complete vet records, from a responsible owner who can no longer care for the dog (for example, the owner died).
I recommend you learn about the most common health problems that affect Dobermans as a breed, the most common health problems affecting dogs as they age, and the most common health problems seen in abandoned/neglected dogs. Then you can draw up a list of "deal-breakers" and let the rescue know you don't want to adopt a dog that has or may develop any of those health conditions*. (But please be realistic. Some conditions, such as arthritis and many cancers, can't be avoided, only treated.)
Also, bear in mind that dogs that test in the low range of normal thyroid functioning before their spay/neuter can be hypothyroid six months later. De-sexing
does not cause hypothyroidism. It's just that the sex hormones can compensate for low-thyroid functioning. Once the gonads are removed and the dog no longer produces sex hormones, the underlying pre-existing low thyroid functioning can become apparent.
There is another source to consider: some ethical breeders have non-baby Dobes of their breeding available. Some of these dogs are older pups they kept from a litter to see how they'd mature. The pup did not mature in the way the breeder hoped and the breeder wants to place it in a companion home. Also, some ethical breeders have adult Dobes that were returned to them because the owners couldn't take care of them anymore (death, illness, loss of income) and would like to place them with active owners.
Best wishes for a successful DoberSearch!:wavey:
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*For example, I foster dogs who have almost any condition, but my premises are simply not set up to safely house a blind dog. So, I can foster a dog with sarcoptic mange, but not a blind one.