How Deworming Dogs Works

Veterinarians commonly check for internal parasites when dogs come in for a health check.
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Your new family dog has just been diagnosed with parasitic worms, yuck! You probably wonder what kind treatment your dog will receive and how it will work. Several types of dewormers can be prescribed by your veterinarian for eliminating gastrointestinal worms, while only two specific drugs have approval as treatments for heartworms. Treatment will be specific to your dog's breed, health, age and type of worm.

How Intestinal Dewormers Work

Intestinal deworming products work in three ways. Some products cause the protective exterior of worms to dissolve, thus allowing natural digestion of the worms within the intestinal tract. Other products paralyze the worms, which causes them to be eliminated during bowel movements. Additional medications interfere with a worm's metabolism and cause worm death and elimination. Medications can be given orally, topically or by injection. More than one treatment is often prescribed and once a year deworming may be recommended.

How Heartworm Treatment Works

Treatment for heartworms is a bit more complicated. Adult heartworms must be killed in your dog's heart and circulating heartworm larvae must be killed in the blood. Two types of arsenic compounds have approval for use in killing adult heartworms. Due to drug toxicity, dogs must be hospitalized for injectable adult heartworm treatment and may experience complications during worm death. Three to six weeks after the adults are eliminated, a regular oral dewormer can be given to kill heartworm larvae.