View Full Version : Frontline side effects

Jun. 27, 2010, 10:56 AM

We've used advantage in the past on our dogs with no problems.

We switched to Frontline this year after finding some ticks on the big dog last summer. He had his second application yesterday, and something isn't right.

He's lethargic and mopey. He isn't interested in food. He seems unsteady on his feet, and yesterday he strained to pee frequently- very unusual. I did not put this all together until this AM, and he is actually a little better this morning than he was last night, but I have a call into the vet and I'm going to go scrub him down with dawn.

Has anyone experienced side effects from frontline? What were they, how long after application did they manifest, and what are you using now in it's stead?

Happy thoughts for my big galumpf of a pup as well please. I should have figured he'd react to frontline; he's a sensitive guy and if it's new to him, it's probably going to cause problems. :rolleyes: I'm feeling like a bad mommy right now.

Ride and Run
Jun. 27, 2010, 11:29 AM
I had one dog react to either Frontline or Advantage, I can't remember which (I use both). At the time, it was a new formula that had two active ingredients instead of one. I used it on several of my dogs, but one of them immediately started vomiting. I called the animal ER (it was on the weekend of course) who told me to wash her with Dawn and suggested I call the manufacturer.

The manufacturer explained that the two ingredients mixed together and if she didn't get a full dose, if there was any medication still in the container, she may have gotten more of one of the ingredients and reacted to it. I don't remember how long she was lethargic, maybe a day or two, and then she was back to her old self. I returned to my vet who replaced the one she reacted to with a version that only had one main ingredient that I had used on her in the past.

Jun. 27, 2010, 11:44 AM
We use it on cats and dogs (numerous ones) and never had a problem.

I'm thinking it's coincidental. Sounds more like a low grade kidney or urinary infection. While you're waiting for him to go to the vet give him plenty of water to drink.

Here's the contraindications though:


Jun. 27, 2010, 12:01 PM
I used it one time on a W-H Terrier. In the area it was applied he started to leak a serum sticky kind of fluid and continued to do that until he died at 15 years old. He had a permanent black gooey area between his shoulder blades.
Needless to say I have never used any of those products ever again, and found that merely removing carpets from my house keeps my animals flea free.

Jun. 27, 2010, 04:20 PM
If you google it, I think you'll find that a small % of animals had reactions to ANY of the brands of flea topicals. For example, I had big problems with Promeris on my older cats (making them sick). If you're concerned, you may just want to use a different type of flea treatment next time.

Jun. 27, 2010, 07:46 PM
RidenRun you need to be more clear as to which product you think may have caused a reaction. I don't think it is appropriate to post on a public forum that your dog had a reaction to frontline OR it could have been advantage (especially if you CAN"T remember)- two very very different products with different ingredients. How do you know that the product you used wasn't advantage but advantix (same company as advantage- bayer) which has 2 main ingredients in it for fleas/ ticks.

As for the OP, where did you purchase your Frontline? If you purchased it online or at least not from a veterinarian, you may have purchased counterfeit product. If you did purchase from a vet, call the vet that you purchased from, then also the manufacturer of Frontline which the number is written on the box to report the reaction.

Frontline is a pretty safe product, more safe than most of the flea/ tick products on the market, and it is rare to have a reaction to it- that being sad, if the product you purchased is Frontline from a vet. If you did buy it from your vet, the company guarantees the product. There is no guarantee if you did not buy it from a vet.

Last question, how and where did you apply Frontline to your dog?

It was purchased from a vet and was applied appropriately. The vet agrees that it seems to be a reaction the the FL; we won't be using it again. It doesn't surprise me in the slightest that he would have a reaction to it. He's "high maintenance", to put it mildly.

We had a cat who had mild reactions to advantage; I've also had plenty of creatures who have not had a reaction to either, but statistics in my house seem to suggest that reactions are not as rare as one might think. Ah well. Back to advantage and fine toothed combs!

Jun. 27, 2010, 08:12 PM
i'm sorry that this happened to you and I hope your dog is recovering well.

Jun. 27, 2010, 09:53 PM
Sometimes there are idiosyncratic reactions to Frontline or other topicals; if it was obtained from a vet and applied appropriately, your vet should be able to stand behind it and provide whatever care is necessary.

One of my cats, who had been getting Frontline for the entire 9 years of her life, suddenly developed hair loss/redness at the site this summer. Weird. Go figure. She won't be getting Frontline again; we'll just have to use something else for her.

Hope your dog is doing better and it was just temporary!

Jun. 27, 2010, 10:04 PM
I hope that your dog is feeling better. Just a heads up, straining to urinate frequently without actually voiding can be a sign of urinary stones. Urinary stones are life-threatening, and a dog that cannot pee must see the vet ASAP. If they cannot void for a day, they can become shocky.

Good luck.

As for Frontline, never had any problems.

Jun. 27, 2010, 10:44 PM
I hope that your dog is feeling better. Just a heads up, straining to urinate frequently without actually voiding can be a sign of urinary stones.

There has to be an observed effort to go, though, right? Like 'assuming the position' and then nothing happening?

Just checking because Pirate can occasionally be a championship Pee Holder and based on his behavior (sniffing, looking around, no movements to actually try to go) I've just been figuring that he's being picky. (This happens mainly on car trips or if we're away from home and there aren't any nice grassy patches or anything like that to go on - I think he doesn't like going on hard surfaces because it can splatter onto his legs.) But since I adopted him as an adult, I know nothing of his previous medical history and don't want to be missing a warning sign of a building health problem.

Jun. 27, 2010, 10:55 PM
There has to be an observed effort to go, though, right? Like 'assuming the position' and then nothing happening?

Yes. Our poor dog was trying and trying and nothing was happening. Fortunately, I was reading the Sunday New York Times, and there was a short article about a human having the same problem, and the article explained how life threatening the situation was, so we packed up the dog and went to the vet ER. If I hadn't read the article, Poor dog might have died.

Jun. 28, 2010, 10:09 AM
My cocker was fine with regular Frontline, but the Frontline Plus caused seizures.

Jun. 28, 2010, 10:14 AM
I'm sorry your admittedly high maintenance dog had issues. I've used FL for dogs and for cats for years w/zero incidents. Ours are all indoor/outdoor critters so flea and (esp) tick control are 100% necessary evils.

Jun. 28, 2010, 01:06 PM
My dogs are always a little droopy the day after frontline. (K9 Advantix is not an option; I have indoor cats in constant contact with the dogs.) Other than that,they're fine.