Can flea treatment make my dog ill? Surprising Answer

How Veterinarians Diagnose Flea and Tick Medicine Poisoning in Dogs

After a complete physical examination, your veterinarian will make a presumptive diagnosis if there is a known or possible history of exposure to a product containing a pyrethrin or pyrethroid, or ingestion of flea/tick medicine. In a presumptive diagnosis, a veterinarian has a good reason to believe that something is causing the problem but cannot prove it with a specific diagnostic test.

What Is Flea and Tick Medicine Poisoning in Dogs?

While it is very important for your dog to be on flea and tick prevention to help minimize the risk of the many diseases these insects carry, there are strict guidelines to prevent toxicity when administering these medications.

Substances that are toxic to insects such as fleas and ticks can also be harmful when exposed to pets in large quantities. Some common flea and tick medications contain pyrethrins or pyrethroids. Pyrethrins are a class of drugs derived from the chrysanthemum flower/plant, and pyrethroids are synthetic derivatives of these pyrethrins.

Pyrethrins are rarely found in products used daily, but pyrethroids are commonly found in products used around the home for insect control, in addition to common preventative flea and tick medications. Dogs are often exposed to high doses in flea and tick preventives, and then to lower concentrations when these products are used inside or outside the home in the form of insect sprays, foggers, and granules.

A newer class of flea and tick prevention medications that have been linked to toxicity are isoxazolines. These medications were the first oral flea and tick products, and while they are highly effective, they can also cause toxicity if given incorrectly or an overdose occurs. These preventions are safe to use if the appropriate dose is administered. Isoxazoline-containing preventives include:

  • Bravecto (topical and oral)
  • Simparica
  • Simparica Trio
  • NexGard
  • Credelio
  • If your dog or cat is having a reaction to a flea and tick product, it may show some of the following symptoms:

    If you suspect that your pet has had an adverse reaction after using a flea and tick product, refer to the precautionary statement on the product label and consult your veterinarian immediately. In addition, bathe your pet with mild soap and rinse with large amounts of water. For flea and tick collars specifically, pet owners should remove the collar immediately if the pet is experiences any adverse reaction.

    Flea Treatment for dogs! Most are doing it wrong!?

    POLAND and LEWISTON, Maine (NEWS CENTER) – Two women from Maine and thousands across the country are blaming a popular flea and tick medication for making their dogs sick – and worse.

    Both the company that makes the drug, and some local vets say there is no scientific evidence that supports these claims.

    They have two different dog breeds, and theyve never even met – but their experiences are very similar.

    “Vomiting…the dehydration…lot of drinking, just excessive amount of drinking, the diarrhea started the next day, the fatigue, still very lethargic, the trembling all over,” Barbara Mandy of Lewiston and Ashley Jardine of Poland listed nearly identical symptoms.

    Its a story of two women and their dogs, from two Maine towns, two years apart – but with one very similar story.

    “The minute I saw [Callie], it was just instant love,” Barbara of Lewiston added. “She went everywhere with me. Just was my constant companion.”

    Both owners say the symptoms started within minutes of taking BRAVECTO, a prescribed, ingestible flea & tick medication.

    Ashley explained the moments after she gave the chew to her dog, Lizzie. “I got nervous, and my immediate thought was, Okay, shes experiencing some side effects from this medication I just gave her.”

    Ashley said she wished she “had done [her] homework before this product.” That homework included a quick internet search, and connecting with a Facebook group – 40,000 strong – “to talk about BRAVECTO and any potential impact it had on your dog.”

    But thousands of people claim the effects are much worse. In response to an open records request, NEWS CENTER learned that since BRAVECTOs release in 2014, more than 16,000 complaints (16,459) have been filed with the FDA about adverse effects in dogs who took the chew. Thats compared to 3 complaints for dogs who used the topical version of BRAVECTO. The reports for the chew cite seizures (508), vomiting (7,715), and even death (499).

    Ashley took 9-year-old Lizzie, who is diabetic, to see 4 vets—each one said BRAVECTO isnt the problem.

    Barbara says she went to the vet in 2015 when she needed a quick flea and tick medication for Callie before visitng her grandchildren. “They assured me that [BRAVECTO] was safe,” she explained. Her 8-month old Australian labradoodle, Callie, was prescribed BRAVECTO. “I remember asking three times, Are you sure its safe? Because there was just a little voice that said, ingestible pesticide,’” she said.

    Merck Animal Health denies that BRAVECTO caused these illnesses. A spokesperson, Noreen Verbrugge, said that in Lizzies case, “It would be premature and irresponsible – and potentially actionably false – to suggest or speculate otherwise.”

    No veterinarian has been able to definitively determine that BRAVECTO either was or was not the cause of illness for both Lizzie and Callie.

    “You want to trust these doctors,” Ashley said. “You want to trust in these pharmeceutical companies.”

    Why no scientific evidence? Vets we spoke with say many people dont get necropsies performed to determine their pets cause of death.

    This was true for Barbara. “Emotionally, I couldnt let them do [the necropsy],” she said. “I couldnt do it. And it was probably a mistake.”

    Both women have filed complaints of adverse effects with the FDA and to Merck Animal Health. Barbara also filed with the SPCA Poison Control Center and the European Medicines Agency.

    In an email to NEWS CENTER, a Merck representative wrote that the company takes “every report of a potential adverse event seriously and investigate[s] thoroughly.”

    Ashley says two weeks later, Lizzie still struggles with jaw paralysis and vomiting – but shes slowly making a recovery.

    Barbara documented every symptom Callie experienced, as her health declined over the course of seven weeks. She died seven weeks and two days after her dose of BRAVECTO.

    It took Barbara almost two years to have the courage to bring a new dog into the family – and even with Sunny Grace around, she cant get Callie off her mind.

    “I will always blame myself,” Barbara said. “That guilt will never go away, that I gave that [chew] to that poor sweet dog.”

    What both Ashley and Barbara want is more testing done, and a more descriptive warning label on BRAVECTO.

    But if theres no scientific evidence that BRAVECTO caused these symptoms, how – and why – would the company put a stronger warning on the box?

    Vets say not enough research has been done on dogs whose owners reported problems with the treatment. Its hard to determine a link between BRAVECTO and the symptoms their pets are experiencing. So, more necropolises would have to be done and tested before the company could consider changing the warning label.