the more I research, the more scared I get

[R-Teddy]

Originally Posted by pstinard

Hi,

I looked at the scholarly literature and found that Revolution is 100% effective against heartworms. I think that a problem with topicals not being effective is that people don't always use them properly. The drops are supposed to be put at the base of the hair in direct contact with skin so that the active ingredient can be absorbed properly into the blood. Sometimes if the dog is squirming, the drops get on the hair only, and not the skin. Here is a link to an article on Revolution (selamectin). It's behind a pay wall, but I believe that everyone can read the abstract. Just in case, I copied the abstract below:

Prevention of experimentally induced heartworm (Dirofilaria immitis) infections in dogs and cats with a single topical application of selamectin

Prevention of experimentally induced heartworm (Dirofilaria immitis) infections in dogs and cats with a single topical application of selamectin. McTiera et al. 2000. Veterinary Parasitology. Volume 91, Issues 3–4, 23 July 2000, Pages 259–268.

Abstract

In a series of six controlled studies (four in dogs, two in cats), heartworm-free dogs and cats were inoculated with Dirofilaria immitis larvae (L3) prior to topical treatment with the novel avermectin selamectin or a negative control containing inert formulation ingredients (vehicle). Selamectin and negative-control treatments were administered topically to the skin at the base of the neck in front of the scapulae. In dogs, selamectin was applied topically at dosages of 3 or 6 mg kg−1 at 30 days post-inoculation (PI), or of 3 or 6 mg kg−1 at 45 days PI, or of 6 mg kg−1 at 60 days PI. Cats were treated topically with unit doses providing a minimum dosage of 6 mg kg−1 selamectin at 30 days PI. Of the animals that were treated 30 days PI, some dogs were bathed with water or shampoo between 2 and 96 h after treatment, and some cats were bathed with shampoo at 24 h after treatment. Between 140 and 199 days PI, the animals were euthanized and examined for adult D. immitis. Adult heartworms developed in all control dogs (geometric mean count, 18.7 worms) and in 88% of control cats (geometric mean count, 2.1 worms). Selamectin was 100% effective in preventing heartworm development in dogs when administered as a single topical dose of 3 or 6 mg kg–1 at 30 days after infection, 3 or 6 mg kg−1 at 45 days after infection, or 6 mg kg−1 at 60 days after infection. Selamectin was 100% effective against heartworm infections in cats when administered as a single topical unit dose of 6 mg kg−1. Bathing with water or shampoo between 2 and 96 h after treatment did not reduce the efficacy of selamectin as a heartworm prophylactic in dogs. Likewise, bathing with shampoo at 24 h after treatment did not reduce the efficacy of selamectin in cats. These studies demonstrated that, at the recommended dosage and treatment interval, a single topical administration of selamectin was 100% effective in preventing the development of D. immitis in dogs and cats.

That makes sense. I can certainly see where the owners not putting it on properly could be a problem.

[R-Teddy]

Originally Posted by P-Nut Mom

We use Advantage Multi for both pups - no problems. I was using Trifexis for P-Nut for about 6 months. He was having significant GI issues that whole time, but I never associated it with the Trifexis. He was at the vet's at least once a month for vomiting and diarrhea. Then I read about suspected issues with it here on YT. There seemed to be a lot of anecdotal evidence but not much actual proof that Trifexis was the problem in numerous cases I read about, but I stopped using it anyway. We've been gastroenteritis free ever since! I checked to see if P-Nut getting sick could be correlated to the day I gave Trifexis and it was usually about 4 days after he got his monthly dose that he became ill.

Like the OP, my research into flea, etc meds just made me afraid to give anything, but the Advantage has been fine.

I have used advantage before on my bigger dogs in the past.

[Hrossen11]

Both my boys use revolution puppies since it comes in 5lbs and my boys weigh about 4lbs, have not had any issues