Trifexis for fleas, heartworm and intestinal worms in dogs

Trifexis is a newer flea, heartworm, intestinal worm product marketed for dogs. I do not recommend using it for dogs in the Pacific Northwest for these reasons:

1. Pacific Northwest doesn’t have a heartworm problem.
2. Trifexis hasn’t been on the market long enough for us to understand its long-term effects. I recommend waiting wait several years before trying new drugs or combinations of drugs unless the condition is life-threatening, Think of Thalidomide. Think of VIoxx. Think of Heartgard. When Heartgard was first introduced it killed hundreds of dogs over the first two years, then they got the dose right. Don’t be one of the early adaptors of any medication unless it is a life and death situation.
3. Fleas can usually be effectively controlled with supplements, essential oils, and bathing and without the use of chemicals.
4. Dewormers should only be used when the dog has a significant problem with worms. The more often dewormers are used the greater the likelihood of worm resistance, which is now quite high. Get a fecal test and deworm for the specific intestinal worms that are identified. If your dog has worms because it eats feces, deworm, then, start supplementing with enzymes & probiotics to reduce the likelihood it eats feces. Get behavioural training to reduce coprophagia. When Use a specific dewormer once or twice a year rather than monthly unless you have a dog that frequently eats feces. In that case,

What is in Trifexis?

Trifexis is a combination prescription medication for dogs that is given orally once a month. Trifexis is a combination of two other drugs, comfortis and milbemycin.

Comfortis (Spinosad)

Comfortis is an oral insecticide given orally as often as once a month to kill adult fleas in dogs (30 mg/kg). Humans use a similar spinosad chemical to kill head lice. Comfortis is given with a meal to improve absorption and help reduce the most common side effect, vomiting. Comfortis does not kill or prevent ticks and does not affect flea larvae, flea pupa, or flea eggs.

Any shampoo left well lathered on a dog for 10 min will kill all fleas on the dog, doing the same job as Comfortis. Vacuuming the home, dusting with nontoxic boric acid and washing bedding removes larva, pupa and flea eggs.

Comfortis, is used off-label for cats by some veterinarians.

Milbemycin (Interceptor)

Milbemycin at 0.5 mg/kg orally is used once a month to prevent heartworm disease (dirofilaria immitis). Milbemycin is not as effective as ivermectin in killing adult heartworms. Milbemycin (and ivermectin) help control hookworms, roundworms, and whipworms. Ivermectin products are often less expensive than milbemycin.

Alternatives to Trifexis

Identify the specific problems your pet has, then medicate for those problems. Here are some examples to consider that have been on the market for many years. Use them until Trifexis has been on the market for several years:

For fleas

• Capstar, an oral med given once, will kill fleas immediately.
• Frontline and Advantage (generics are available) are topicals given monthly for dogs with fleas, especially helpful for dogs inclined to vomit. Advantage can be applied every two weeks for dogs with serious flea allergy dermatitis.
• Frontline Plus is a topical medication that kills adult fleas, flea larva and eggs.

For fleas and ticks

• Frontline and Advantix are topical medications given monthly for dogs exposed to both fleas and ticks. Revolution isn’t helpful for ticks because it kills them so slowly that the ticks have time to release infections like Lymes disease into the dog’s blood before dying.

For heartworms

• Use ivermectin products, such as Heartgard (generics available) for heartworms.
• Use Advantage Multi for heartworms and fleas.
• Use Revolution for heartworm and fleas and intestinal worms, but not for dogs with ticks.

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