Heartworm Is Preventable And Prevention Is Simple. Prevention Is The Wiser And Safer Choice To Avoid Heartworm Disease In Your Dog, The Most Widely Used Drug To Prevent Heartworm In Australian Dogs For Over Ten Years.When Used As Directed, Valuheart Has A Wide Margin Of Safety For Dogs Of All Breeds, Including Stud Dogs, Breeding Bitches And Puppies 6 Weeks Of Age And Older.Valuheart Can Be Safely Combined With Flea And Tick Treatments. Yellow Label - Large 6S (21 - 40Kg)