Because the active ingredient in heartgard and the regular dewormers cover of different type of worms. So if you give only heartgard, not all common types of worms will be eliminated. Heartgard does contain pyrantel which kills some worms but the regular dewormers contain pyrantel *and* a couple other ingredients(which means the can eliminate more species of worms). Just google the active ingredients..and you should be able to find out which active ingredient covers which worms.
It also depends on the brand of deworming tabs you're giving...but most decent ones in the market have a few active ingredients. ,-._,-. \/)"(\/ (_o_)
depends wo... like my dog, stay indoor, take her for short walk in the evenings, walk on pavement n tar road, hardly on grass... so the vets in vet forum said deworm every 6 mths is ok, while taking heartgard mthly...
u know ar, 2 different vets at the same clinic told me different thing lo, 1 vet said deworm my dog every 3 mths, 1 vet said deworm every 6 mths... aiyo do they come from the same uni or wat har?
so now i deworm every 6 mths lo... hv u asked ur vet abt this?
everytime i ask whether they need to deworm or not, the vet will say no need...thats why now i change vet...haha...but i will deworm every 3 months...coz later on when i move to the new house, they will be outside...will build a dog house for them in the garden.
i think Drontal is the popular one.. Deworming shud be 3 months once if alwys go to garden and outdoors a lot.. If indoor dog 6 months once is fine.. But need to give 2 times for every deworming.. for example u feed today the 'booster' for deworming is 2 wks from now. So everytime u do deworming remember the 'booster'