Hi! Yes they can! A great way of doing this , is to advertise for room mates and you can share the costs on a bigger villa.I know quite a few single guys doing this at the moment. Villa sharing in Doha is big.
Having a dog is great and I know, especially in education city, there are many people with dogs.
Not sure about a garden though.
These are very few and far between in DOha. The best you will get is a back yard.
Should be enough for your dog.
Also , there is a good boarding kennels in DOha called Pampered Pets , where you can leave your dog when you go on holiday.
It is British run.
Good hunting!