Subclinical/Borderline Hypothyroidism and Aggression in Dogs

[ww3467]

Has anyone had any experience with subclinical/borderline hypothyroidism and aggression in dogs? I have had a couple thyroid panels run on my now 2-year-old Newfie due to some aggressive behavior. The first one (about a year ago) showed a slightly low Free T4 value and was considered ‘equivocal’ by OFA. The second one, done a few months ago, was better but slightly low in Free T3. My vet said it’s nothing to worry about. He is very high energy for a Newfie, so is definitely not lethargic. I have read some of the literature, particularly by Dr. Jean Dodds, on the correlation between borderline hypothyroidism and aggression, and it sounds like those dogs may not exhibit the typical lethargy, etc.

I sent his test results to Dr. Dodds, and she said he is definitely low for his age and breed and recommended a trial of Thyroxine. My vet isn’t in favor of medicating him, and neither is his breeder/co-owner (although she hasn’t seem him in a long time so has not experienced the issues personally). We are seeking additional training opportunities, and he has already done quite a bit of obedience and was heavily socialized. He just seems overly reactive to strange people, especially children, and to some other dogs. It’s gotten to the point where I don’t even want to take him anywhere, so I am trying to explore all possibilities. Just wondering if anyone had any first-hand experience with this.

[Marshfield]

Yes. Mac is a corgi from the first litter I produced with my mentor and co -owner. Co -owner kept him as a pet. Diane is a long time professional dog trainer. There are no holes in his upbringing. This spring he began to be nasty to his canine aunt who had helped raised him. His coat looked horrid. Hoping to find a medical cause, Diane had me run a thyroid panel. It was normal, but low normal. I prescribed low dose thyroid supplementation. Within three doses he was a different dog.

[ww3467]

Thanks for the reply! That’s very interesting feedback, especially coming from a vet. He has had a couple of skin infections also, but they have been at the same time of year both times, so that could be environmental.

[veetiepony]

I would love to hear more about this. I just looked up some articles online and now i’m considering testing my dog for low thyroid.

[Momto3]

Aggression is nothing to play around with. At 2 years old, your Newfie is just hitting social maturity, so the aggression is likely related to that. Hypothyroidism is Extremely rare in young dogs.

Please do yourself a favor, and ask your veterinarian for a referral to a behaviorist, not a trainer - before someone gets hurt!

[sketcher]

Listen to your instincts and try the meds. You will know relatively quickly if there is a change.

To the poster above, there are actually knowledgeable dog people out there. Not all dogs have training holes and this dog in question had questionable lab values.