I usually go to Qatar Veterinary Centre. They offer evrything fr checkups, to kennels and boarding, to food and pet accessories, and grooming. The range of pet accessories and toys are somewhat limited though, but so far , it's the best from the rest of other pet shops i've seen in Doha. They sell eukanuba and Royal canin pet food products. They are located opposite Villagio. For contact numbers and directions, visit their website:

http://www.qatarvet.name.qa/