Fast acting flea killer: Trifexis

The control of fleas is important for dogs to prevent infestations. One of the main ingredients of Trifexis is Spinosad, which protects your dog against fleas. It kills the fleas fast and is very effective, especially within 4 hours after administration. Trifexis not only protects your dog from fleas but also against the intestinal parasites and the heartworm disease. Some of the features of Trifexis include:

  • It lasts for a full month (30 days).
  • Kills fleas before they lay eggs.
  • Can’t be rubbed or washed off.
  • Used for dogs above 8 weeks old and weighing 5 pounds or more.
  • It is a chewable tablet.

Ingredients of Trifexis

Trifexis has two main active ingredients, which include spinosad and milbemycin oxime. The flavor of Trifexis is from artificial beef flavors. These are made from hydrolyzed soy and pork-based proteins.

How it Works

A study was conducted in a lab, and it indicated that when Trifexis is administered for three months consecutively, it is 100% effective against heartworm infections in dogs. It also indicated that a single dose of it is effective in clearing out roundworms, whipworms, or hookworms. The observation of this study was that spinosad demonstrated effectiveness in 4 hours and began killing the fleas around 30 minutes after it was administered.

Spinosad is likely to persist after a dose in cases where there is severe infestation because of the adult fleas which are already in the environment. Another study was conducted in the fields, in households with varying severity of existing infestations and it was noted that spinosad alone, during the three monthly treatments, reduced the fleas to percentages of about 98% to 99.8%.

Dogs with fleas showed improvements in erythema, papules, scaling, dermatitis/pyodermatitis, alopecia, and itching as a result of the effectiveness of Trifexis in eliminating fleas.

Benefits of Trifexis

  1. Trifexis rapidly kills fleas, it is quite effective in preventing, treatment, and control of heartworm disease as well as adult hookworm, roundworm, and whipworm infections in dogs or puppies.
  2. Approved by the Food and Drug Administration (FDA) to be safe and effective when correctly used.
  3. Kills fleas before they lay eggs.
  4. Artificial beef-flavored tablet.
  5. Begins to kill fleas on dogs within 30 minutes after administration.
  6. Continues to kill fleas for a whole month after treatment.
  7. Provides 3-in-1 parasite protection against heartworm, fleas, and intestinal parasites.
  8. Easy-to-administer because it is a chewable tablet.
  9. Side Effects

Sometimes side effects may occur, for example, dogs may vomit just after administering Trifexis. If your dog vomits within an hour of administration, then, consider administering it again with another full dose. Other mild effects that were observed include:

  • Itching
  • Decreased activity/depression
  • Diarrhea
  • Inflammation of the skin
  • Redness of the skin or ear
  • Decreased appetite
  • Trembling
  • Hypersalivation
  • Seizures

Food Interactions

Visit your veterinarian about the supplements your dog is already taking, before administering Trifexis because some serious adverse side effects may occur.


  • Spinosad, an ingredient in Trifexis may lead to severe reactions if not used properly.
  • Treatment with fewer doses than for three months after the last exposure to mosquitoes, may not be able to get full heartworm prevention.
  • Before administration of Trifexis, the dogs should be tested.
  • Use it with caution in breeding females.
  • Use it with caution in dogs with pre-existing epilepsy.
  • Note that puppies less than 14 weeks’ old are more prone to vomiting.
  • Use it with caution for pregnant or lactating dogs.
  • Visit your veterinarian to get recommendations about adult heartworms since Trifexis is not effective for adult heartworms.
  • Not for human use and therefore you should keep out of the reach of children.

Frequently Asked Questions

1. Is it safe for my dog?

  • Trifexis has been approved by the FDA for use in dogs, and it has shown to be safe in healthy dogs when used accordingly.
  • Spinosad is produced from natural sources.
  • Spinosad is toxic to the flea’s nervous system but non-toxic to mammals.

You should always talk to your veterinarian about the use of Trifexis, especially if your dog has a history of a certain condition/disease.

2. Will trifexis get rid of tapeworms on my dog?

No, this is because trifexis has been proved only for the prevention of heartworm disease, treatment of flea infestations and control of adult hookworm, roundworm and whipworm infections for dogs which are 8 weeks old or more and at least 5 pounds of body weight.

3. Does Trifexis protect against ticks?

No, Trifexis is not proved to treat or prevent ticks. There is no confusion or contradictions between Trifexis and treatments used for ticks.

4. Which heartworm lifecycle stage does Trifexis control?

Trifexis kills L3 and L4 larval stages before they head to the final stage since they act the same way as other preventives.

5. Should I give my breeding dogs Trifexis?

Visit your veterinarian and ask about the use of Trifexis in breeding females before administering it. The use of Trifexis in male dogs for breeding has not yet been evaluated to be safe or not.

6. Is Trifexis FDA approved?

Yes, it is approved by the Food and Drug Administration(FDA), and the prescription of this medicine should be given only by a licensed veterinarian with whom you have a proper veterinarian-client-patient relationship.


Dogs need to be provided with comfort and security. This can only be done through dog training using trainers or dog training collars, and dog care. Dog care involves preventing and treating the parasites infestations on the dog. Parasites can be found anywhere your dog goes, which includes your home. Be sure that your dog or puppy is protected from all infestations.

Trifexis has two active ingredients which effectively protect your dog from the parasites. It is easy to administer since you give orally and therefore no need to isolate your kids or other pets while administering it. One thing you should always remember is that Trifexis is only for dogs and you keep it far from children.

Available for Dogs of All Sizes

ORANGE Trifexis for 19-20 lb Dogs

GREEN Trifexis for 20-40 lb Dogs


BLUE Trifexis for 40-60 lb Dogs

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