Trifexis for Dogs

Medical review by K9 Healthcare Council of America (K9HCA). Intended for educational purposes only. Always seek medical advice from your veterinarian.

Trifexis for Dogs – Is It Safe?

Dogs bring us immeasurable joy and companionship–making our lives richer in countless ways. However, alongside the love and companionship they offer, our canine friends can also face health challenges that require our attention and care.

Among these challenges are the often silent but significant threats posed by parasites such as heartworms, roundworms, hookworms, and fleas. These tiny invaders may seem inconsequential at first glance, but their presence can have devastating consequences for our beloved pets if left unchecked.

As responsible pet owners, it’s our duty to arm ourselves with knowledge and resources to protect our furry companions from these insidious parasites.

In this article, we delve into the world of parasites that afflict dogs and how to treat them using the #1 prescription for parasites in dogs, Trifexis.

What is Trifexis?

Trifexis is a prescription drug that’s given monthly and is intended to protect dogs from parasites like heartworms, roundworms, hookworms, and fleas.

Trifexis is prescribed for the following conditions:

  • Killing fleas
  • Preventing flea infestations
  • Preventing heartworm disease
  • Treating and controlling adult hookworm, roundworm, and whipworm infection in dogs (even though your dog may not even have worms).
Trifexis for dogs prescription
Trifexis for dogs. Conventional veterinarians prescribe this drug for its convenience, because it’s so easy to give one pill a month to prevent fleas, intestinal worms and heartworm disease. But do you really need to do that every month, year-round?

How Does Trifexis Work?

Trifexis is an anti-parasitic medication made from two active ingredients: Spinosad and Milbemycin oxide. Spinosad and milbemycin oxide are insecticides that work by affecting the insect motor system and altering the motor neurons.

Spinosad is a member of the spinosyn class of insecticides and is found in over 80 registered pesticide products. When insects eat or touch spinosad, their muscles begin to flex uncontrollably. Eventually, this leads to paralysis and death, usually within 1-2 days.

Trifexis’ other active ingredient, milbemycin oxide, works a bit differently but has the same basic effect. Milbemycin oxide works by binding to the chloride channels of parasites’ nerve and muscle cells. It forces these channels to stay open, which causes paralysis of the tissue, and eventually results in the death of the organism.

In Trifexis, spinosad is the active ingredient intended to kill fleas, while milbemycin oxide claims to kill hookworms, roundworms, and whipworms and prevent heartworm disease.

The fact that the drugs work by paralyzing the insects means that the active ingredients can cause some risky side effects in your dog.

Trifexis for Dogs Side Effects

The active ingredients in Trifexis have been linked to the following reported side effects. You’ll note that many of them involve neurological problems like convulsions or ataxia.

Milbemycin oxime

Ineffective against – heartworm larvae, ascarids, hookworms, whipworms.
Vomiting / Diarrhea (bloody)
Trembling / Convulsions / Ataxia


Ineffective against – fleas
Convulsions / Trembling / Ataxia
Unpalatable (dog won’t eat)

These side effects are especially troubling in an oral drug, because if your dog has a reaction, you can’t just stop it–sadly, the drug will remain in his system for at least 30 days. Many anecdotal reports from dog owners on social media blame Trifexis for seizures and other neurological problems in dogs.

Trifexis for Dogs Dosage

The recommended dosage for Trifexis depends on the size of the dog, so the manufacturer has organized their dosing recommendation by color. It starts with pink for small dogs 5-10 lbs, and goes all the way up to brown for large breeds of 60 -120 lbs.

Comfortis Plus Trifexis for dogs
In many climates, fleas and heartworms are only a seasonal risk, not year-round. And while preventing them is desirable, remember Trifexis also kills intestinal worms that your dog probably doesn’t have. There’s no reason to add unnecessary drugs to deworm your dog, unless he actually has worms.

Trifexis for Dogs by Weight

If you do decide to use the drug, make sure your vet prescribes the right one for your dog’s size, so you don’t give more than is needed.

Trifexis for Dogs 5 10 lbs (select pink box)
Trifexis for Dogs 10 20 lbs (select orange box)
Trifexis for Dogs 20 40 lbs (select green box)
Trifexis for Dogs 40 60 lbs (select blue box)
Trifexis for Dogs 60 120 lbs (selectbrown box)

Trifexis for dogs. Trifexis for Dogs 5 10 lbs. Trifexis for Dogs 10 20 lbs.
Trifexis for dogs dose by weight. Dosage of Trifexis for Dogs 5 10 lbs (PINK),Trifexis for Dogs 10 20 lbs (ORANGE), Trifexis for Dogs 20 40 lbs (GREEN), Trifexis for dogs 40 60 lbs (BLUE), Trifexis for dogs 60 120 lbs (BROWN). Trifexis for Dogs 40 60 lbs Trifexis for Dogs 60 120 lbs

What Are Symptoms of Hookworm, Roundworm & Whipworm Infections in Dogs?

Hookworm Infection:

    • Anemia: Hookworms feed on the blood of the host, leading to blood loss and subsequent anemia.
    • Weakness and Lethargy: Anemic dogs often exhibit signs of weakness, fatigue, and lethargy due to reduced oxygen-carrying capacity in the blood.
    • Pale Gums: Anemia can cause the gums and mucous membranes to appear pale or even white.
    • Bloody Stools: Hookworms can cause intestinal bleeding, leading to the passage of stools that may contain blood or have a dark, tarry appearance.
    • Weight Loss: Chronic hookworm infestations can lead to weight loss and failure to thrive, despite adequate food intake.
Trifexis for dogs signs of parasite infection
Trifexis for dogs. Be aware to spot signs of parasite infestation in your dog including diarrhea, bloody stool, lethargy and weight loss.

Roundworm Infection:

    • Potbellied Appearance: Roundworm infestations can cause the abdomen to become distended or bloated, giving the dog a potbellied appearance.
    • Vomiting: Dogs with roundworms may vomit, especially if the infestation is severe.
    • Diarrhea: Infected dogs may experience diarrhea, which can sometimes contain visible worms.
    • Coughing: In severe cases, roundworm larvae migrating through the respiratory tract can cause coughing and respiratory distress.
    • Poor Growth in Puppies: Roundworms can stunt the growth and development of puppies, leading to poor weight gain and overall health.

Whipworm Infection:

    • Diarrhea: Chronic diarrhea is a hallmark symptom of whipworm infection in dogs. The diarrhea may contain mucus or blood, depending on the severity of the infestation.
    • Weight Loss: The persistent diarrhea and damage to the intestinal lining caused by whipworms can lead to weight loss and malnutrition.
    • Dehydration: Prolonged diarrhea can result in dehydration, characterized by increased thirst, dry gums, and sunken eyes.
    • Lethargy: Dogs infected with whipworms may appear lethargic or depressed due to the discomfort and weakness associated with chronic diarrhea and malnutrition.
    • Anemia: Severe whipworm infestations can lead to anemia, although this is less common compared to hookworm infestations.

It’s important to note that some dogs infected with these parasites may not show any obvious signs or symptoms, especially in the early stages of infestation. Regular veterinary check-ups and fecal examinations are essential for early detection and treatment of intestinal parasites in dogs.

Does Your Dog Need Trifexis?

While protecting our dogs from parasites like heartworms, roundworms, hookworms, and fleas is crucial, our responsibility as pet owners extends beyond administering preventive medications. It involves a commitment to diligent monitoring and regular veterinary check-ups to ensure our furry companions remain in excellent health.

By staying attuned to subtle changes in behavior, appetite, and overall well-being, and by scheduling routine examinations with our trusted veterinarians, we can detect and address any potential health issues promptly.

Trifexis for dogs vet exam
Trifexis for dogs vet exam. An attentive veterinarian examines a dog for signs of intestinal parasites during a routine clinic visit. Remember, for accurate diagnosis and prevention of heartworms, regular check-ups with your vet are essential.

Natural Alternatives to Trifexis for Dogs

Natural alternatives to Trifexis for treating parasites in dogs involve various approaches aimed at prevention, reduction, and management of infestations. While these methods may not offer the same comprehensive protection as pharmaceutical treatments, they can still be valuable components of a parasite control regimen.

Here are some natural alternatives:

  1. Dietary Supplements: Certain dietary supplements, such as garlic, apple cider vinegar, and diatomaceous earth, are believed to have natural anti-parasitic properties. However, their effectiveness varies, and it’s essential to consult with a veterinarian before introducing supplements into your dog’s diet.
  2. Herbal Remedies: Herbal treatments like neem oil, wormwood, and black walnut hulls are considered natural alternatives for controlling parasites. These herbs may help repel or eliminate certain parasites, but their efficacy and safety should be thoroughly researched and discussed with a veterinarian.
  3. Regular Grooming and Hygiene Practices: Maintaining proper grooming and hygiene practices for your dog can help minimize the risk of parasite infestations. Regular baths with mild, pet-safe shampoos and thorough grooming sessions can help remove fleas, ticks, and other external parasites.
  4. Environmental Management: Keeping your dog’s living environment clean and free of parasites is crucial for prevention. Regularly vacuuming carpets, washing bedding, and maintaining a tidy yard can help reduce the presence of fleas, ticks, and other parasites in your home.
  5. Natural Flea and Tick Prevention: There are various natural flea and tick prevention methods available, including herbal flea collars, essential oil sprays, and botanical-based topical treatments. However, it’s essential to use these products cautiously and according to instructions to avoid adverse reactions.
  6. Regular Vet Check-ups: While natural alternatives can complement parasite control efforts, they may not provide comprehensive protection against all parasites, especially heartworms.

Regular veterinary check-ups are essential for monitoring your dog’s health and ensuring early detection and treatment of parasites.

Trifexis for dogs natural alternatives
Trifexis for dogs natural alternatives include herbal remedies, dietary supplements, and carefully managing your dog’s home and play environment to reduce the risk of fleas, ticks and other parasites.

It’s important to note that while natural alternatives may offer some benefits, they may not be as effective or reliable as pharmaceutical treatments like Trifexis for certain parasites.

Always consult with your veterinarian before implementing any natural remedies or alternative treatments to ensure they are safe, appropriate, and effective for your dog’s specific needs.

Remember, our dogs rely on us not only for love and companionship but also for their healthcare needs. Through our unwavering dedication and proactive approach, we can provide them with the happy, healthy lives they deserve. Let’s continue to be their advocates, guardians, and champions of well-being…every step of the way!

FAQ’s About Trifexis for Dogs

Q: How does Trifexis work to protect my dog from parasites?

A: Trifexis is a comprehensive monthly oral medication that offers broad-spectrum protection against multiple parasites. It contains two active ingredients: spinosad and milbemycin oxime. Spinosad targets fleas by causing hyperexcitation and eventual paralysis, leading to the death of fleas. Milbemycin oxime, on the other hand, prevents heartworm disease by eliminating the tissue stage of heartworm larvae and controls intestinal parasites such as roundworms, hookworms, and whipworms by disrupting their nerve transmission.

Q: What are the potential side effects of Trifexis in dogs?

A: While Trifexis is generally safe and effective when used according to the label instructions, some dogs may experience side effects. The most commonly reported side effects include vomiting, diarrhea, lethargy, decreased appetite, and itching. In rare cases, more severe reactions such as seizures or allergic reactions may occur. It’s essential to consult your veterinarian if you notice any unusual symptoms after administering Trifexis to your dog.

Q: Are there potential alternatives to Trifexis for parasite protection in dogs?

A: Yes, there are several alternatives to Trifexis for parasite protection in dogs. Some alternatives including dietary supplements like garlic, herbal remedies like black walnut hulls and herbal flea collars are effective for controlling canine parasites.

Q: What is the proper dosing regimen for Trifexis in dogs?

A: Trifexis is available in multiple strengths based on your dog’s weight. It’s crucial to administer the correct dosage based on your dog’s weight as indicated on the product packaging indicated by color. Trifexis should be given orally once a month, preferably with food, to ensure maximum effectiveness. Additionally, it’s essential to follow the dosing schedule recommended by your veterinarian.

Q: Can Trifexis be used safely in dogs with certain health conditions or in combination with other medications?

A: Before administering Trifexis to your dog, it’s important to consult with your veterinarian, especially if your dog has underlying health conditions or is taking other medications. While Trifexis is generally safe for most dogs, there may be specific contraindications or interactions to consider based on your dog’s individual health status and medication regimen. Your veterinarian can provide personalized guidance and recommendations to ensure the safe and effective use of Trifexis in your dog.

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