Tablets and chewables are the most common way of preventing heartworm and other intestinal parasites, but with the number of options on the market it is important to understand how these products compare.

Interceptor is a monthly flavored that prevents heartworm and controls hookworm and roundworms in dogs and cats, and whipworms in dogs.

Heartgard Plus is a flavored chewable for dogs only that prevents heartworm, roundworm and hookworm.

When choosing any parasitic treatment for your dog or cat, you must keep in mind the age and weight of your pet, and whether it is pregnant or nursing.

Interceptor can be administered to dogs and puppies as young and 4 weeks, with a body weight of 2lbs (0.9kg) minimum, and is safe for use on cats and kittens from 6 weeks, weighing at least 1.5lbs (0.7kg). Interceptor for Cats has not been evaluated for use on breeding, pregnant or lactating cats.

Heartgard Plus is suitable for dogs and puppies at least 6 weeks old, with no weight requirements, and is safe for use with pregnant and lactating dogs.

Top tip: Once pets develop heartworm it can be very hard to treat, so prevention is always better than cure. Compare the major brands of heartworm preventatives.