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My dog attacked our new puppy. Is the "taste of blood" myth true?

Updated On September 23rd, 2025

Pet's info: Dog | Mixed Breed | Female | spayed

Hello! My boyfriend recently got a puppy. We already have a 5 year old dog. This morning our dog attacked the puppy. My boyfriend’s family believes that once a dog has the taste of blood, that they will continually lust for blood, and as a result be aggressive and dangerous around small children and animals. I am not 100% percent sold on this theory. But my boyfriend is seriously considering surrendering our dog due to this belief. I did research online but didn’t get a definitive answer.

1 Answer

Most Helpful Answer

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Answered By Dr. Melanie, BVSc MS

Veterinarian

Published on January 14th, 2020

It's not good that Mona attacked the puppy, and while I don't agree with the theory that once a dog has the taste of blood it will attack again, I do know that dogs who attack a dog once can and will do it again. She may simply be aggressive to other dogs. You need to keep them completely separate and get Mona into professional training if you want to keep both of them.

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1Pet Parents found this answer helpful

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