First I just want to make sure you know that claiming your pet as a wild hybrid comes with serious responsibilities and consequences. Some states ban owning a dog with any percentage of wolf or coyote, and all they need to legally seize a dog is for someone to claim it's a wolf or coyote mix. They won't go through genetic testing or anything to confirm, since that process is still expensive, time consuming, and not even entirely accurate. Some states allow hybrids but have very strict guidelines for keeping them (a sizable enclosure with double fencing at least eight feet high, for example), and again, if you claim your pet's a hybrid - even if you don't have proof - you can be found in violation of these laws if you don't comply.
Additionally, even if you live in a state where it's legal and are very confident you'll never have to move elsewhere, the rabies vaccine is ONLY tested and legally proven effective with 100% domestic dogs (and cats but focusing on canines here). Yes, it is very likely to be effective on most mammals as well, but because there aren't studies to back that up in wild species and hybrids, if a hybrid (or claimed hybrid) bites someone (or is accused of biting someone), they will be treated as if they're unvaccinated. Which, in the case of rabies, means they will need to be euthanized so their brain tissue can be tested for the disease.
For these reasons, I always urge people not to claim their dog is a wolf or coyote hybrid unless they're incredibly sure and know (and are willing to follow) their state's regulations. Even if you're just saying it online and it's not their listed breed on their vet records or registration. It's a big risk to take when you can't be sure of your pet's parentage.
As to what your dog looks like, I'd say coyote is very unlikely. Every confirmed coyote hybrid I've seen is impossible to mistake for a domestic dog - something about the coyote genes make for very wild looking hybrids. They also tend to be very shy, skittish, and even aggressive compared to dogs, and can be very difficult animals to live with - which sounds like the opposite of your boy!
I'd also say high or mid content wolfdog is very unlikely for essentially the same reasons. They're much more wolfy in looks and have unusual behavior - often including shyness and less social behavior with humans - that make living with them quite different from living with a domestic dog. Low content is possible, but I honestly don't see any features that couldn't also be explained by a mix of domestic dog breeds (I wouldn't be surprised if there's a lot of shepherd and some husky in there, which often produces features the read as wolfy). However, I'd lean towards assuming he's 100% domestic dog for the reasons I first mentioned, especially since he seems to have a really lovely, doggy temperament.
If you want to be extra sure, the only reliable DNA tests that include wild canine content that I'm aware of are Embark and the UC Davis Veterinary Genetics Laboratory. Many other dog DNA tests don't include it at all, or don't have as good a reputation for reliability.
