At the moment they don't sell pet items, but I believe they're planning to. This is their website address: http://drfarisaltimimiclinic.com/
For flea/tick colars you could try the veterinary pharmacies near the racecourse, there's details here:
http://www.catsinqatar.com/CIQ/Cat_Care.html
I know they sell frontline and it's a lot cheaper than buying it at your regular vet