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Why is my 4-month-old puppy suddenly scared and aggressive towards me?

Updated On September 23rd, 2025

Pet's info: Dog | Mixed Breed | Male | unneutered | 4 months and 6 days old | 18 lbs

My dog is adjusting to the kids just fine, but is scared and mildly aggressive towards me. My wife, he's sort of neutral with. Yes, I've had to tackle him once to catch him when my 2 year old son let him out. Only because he runs from me. What is happening?

1 Answer

Most Helpful Answer

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Answered By C. Rathjens, DVM

Veterinarian

Published on April 13th, 2019

It's not normal for a 4 month old to be scared or aggressive. I would recommend getting an appointment with a veterinary behaviorist (this person is a vet, not just a layperson) if at all possible -- your vet may have recommendations for someone nearby. It sounds like he could have been scared by the tackling incident, but it's still atypical for such a young dog to be aggressive. It would be like your 2 year old threatening to beat you up --- it's just not how their brains work at that age. The behaviorist can assess him and likely give you a pile of exercises to do at home and some medications. In the mean time, or if you can't take him to a behaviorist, avoid anything that makes him scared and hand feed him all his food as "treats" throughout the day as rewards for interacting with the family.

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