By Jean Hofve, DVM In a seemingly diabolical plot, veterinarians and pharmaceutical companies have teamed up in a marketing campaign to frighten guardians into giving year-round heartworm preventatives to their cats. They say they're doing this to improve protection for individual pets, but the facts say they have other motives. With few exceptions, heartworms (Dirofilaria immitis) are a completely seasonal problem, so there is no reason to give heartworm medicine to ANY pet year-round--except to make money for those who make and sell it! Those financially-motivated folks say the number ...