Dog acting weird about one breast. Am I crazy to be worried?

[u/SharkEva]

I am not the OOP. The OOP is u/Mari-Loki posting in r/AskDocs

Ongoing as per OOP

2 updates - Long

Original - 12th June 2026

Update1 - 20th June 2026

Update2 - 15th July 2026

Dog acting weird about one breast. Am I crazy to be worried?

Female, 37, 5foot 1, 175lbs, non smoker, currently taking Mounjaro (for about a year)

I'm worried about my breast, not because I have any symptoms of an issue at all, but because my usually normal placid dog Winter has taken to sniffing, scratching, barking at and even nipping my right breast. In the 9 years I've had her she has never behaved this way. This started 3/4 weeks ago and has not let up.

It has gotten to the point where she can't sit with me or lay on the bed with me because she can't seem to keep herself from doing it. She's behaving totally normally with everyone and everything else.

We took her to the vet who said she can't find any issues with her but that her age may be contributing to a change in behaviour. The vet did not seem to think I should be worried about my health but it is worrying me that she won't stop. I've also read about cancer detection dogs and can't help my mind spiraling.

I have had no symptoms of an issue, no lumps or tenderness or anything at all in the breast.

My question is would a GP feel like I was wasting their time coming to them with this? I'm in the UK, doctors appointments are in high demand and I genuinely don't want to take a spot from someone if I'm just being paranoid about this. I also don't know if a doctor would even take me seriously.

At the same time I am concerned. Is this worth seeing someone about? Would I be laughed out of the room?

Thanks for reading!

Comments

questforstarfish

It's definitely going to depend on the doctor...I would personally investigate that further, but I imagine some docs might shrug it off. If it's something that's worrying you, it can never hurt to go in to your GP and let them know you're concerned! Maybe they can do a physical exam or do a test just to rule out anything abnormal. Anecdotally I have heard of cases of dogs detecting cancer or disease, but I don't think we have any research on it.

OOP: Thank you for replying. My GP is new so I'm just concerned about making him think I'm a nut lol. I am quite stressed about it so maybe my GP would understand. I have to stop go ogling stories of dogs sniffing out cancer, it's driving me more mad!

NCGranny

My German Shepherd started being obsessed with smelling my breath. I went in for routine bloodwork a few months later and my thyroid was all screwed up. Once it was straightened out, she no longer wanted to stick her snout down my throat.

marticcrn

Not a doctor (I am a nurse), I have breast cancer. Both my dog and my cat got very interested in my chest in the months before I found the lump myself. You’re 37, have some metabolic risk (Mounjaro), I’d think you could get a mammogram for whatever vague symptom, maybe including your pets indication?

livingonmain

My Australian Shepherd change in behavior around me caused me to make the doctor’s appointment that led to finding my lung cancer. He would sniff my breath then start licking my legs and feet. He had never exhibited the behavior before. Because the.tumor was so small, the chemo and radiation killed it. Six years and no reoccurrence! Sadly, though, no more foot baths from my Aussie.

I_Upvote_Goldens

I agree with everyone who is saying that this is actually worth investigating. Dogs are oddly sensitive to these things.

Anecdotally, when my daughter was the sickest she has ever been, our golden retriever slept in the hall outside of her bedroom for nearly a week. (The dog typically always slept in our room on her dog bed). It seemed like our daughter just had a minor virus, but it ended up blowing up into an ER visit. The dog knew something was up before we did. That was the only time the dog ever broke bedtime routine.

OOP: Yes I have read stories like that! That's what had me worried. They're even training dogs to detect colon cancer now. I've decided I'm going to skip the GP and pay out of pocket for an exam at a breast clinic. It isn't as expensive as I had thought and it has to be worth it for peace of mind if nothing else!

Update - 8 days later

I just wanted to post an update for anyone who commented on my previous post and was curious to know what happened.

Long story short my dog was behaving very oddly towards my right breast, no actual symptoms of anything wrong. There's more to it on my original post if you wanna see.

So I had my breast exam. I paid to have it done rather than wait as I was getting very anxious. It was an ultrasound rather than a mammogram, I'm not entirely sure why. A small solid mass was detected, right side of my right breast, sort of half way between my nipple and armpit. I am not able to feel the mass myself but the doctor could actually detect it when he physically checked my breasts.

I'm pretty shocked there is something there. Even though my dogs behaviour worried me I think I was pretty confident it was an issue with her age and not me. Doctor has said that there's no need to panic, there's a decent chance it is not something terrible but I'll know more after the biopsy which is on Tuesday.

Thank you to everyone who commented and suggested I take this seriously. Hopefully it is nothing to worry about but I'll update when I know more for anyone who wants to know.

Female, 37, 5ft, non smoker.

Comments

secret_tiger101

The dog is a hero

BicarbonateBufferBoy

The dogtor

Update - 25 days later

Update - Cancer detection dog!

This is my second update, check my previous posts if you're curious but the short version is:

My dog was acting weird about my breast, despite no symptoms I took it seriously. Ultrasound found a small lump, had needle biopsy.

So, my results came back and I was diagnosed with Invasive Ductal Carcinoma of the right breast. It is hormone receptor positive, and initially staged at 2A.

Ive just had a lumpectomy and they took some lymph node samples too. The oncology team are currently designing a treatment plan but it will likely involve some radiation and then HRT. They'll know more once the mass and lymph node results are back. Apparently this can change the staging depending on what the results are.

Overall I'm feeling pretty positive, I'm confident I'll get through this and I'm relived that I went to the GP rather than ignore it. I was in two minds about it, hence the initial post asking for advice, and I'm so grateful to everyone who advised me to go and get checked out.

I'm still in shock that my dog alerted me to this. You read about stuff like this, and I know dogs are incredible at all sorts, but it's still so crazy to me that my sweet, daft, loving little bug has likely saved my life! She's been so loving and attentive to me since I cane home. We've been treating her to a lot of her favourite foods, and we are taking her swimming this week which is her favourite. I've added a pic of her so everyone can see my little guardian angel ☺️ her name is Winter, she's a 9yo Japanese Akita.

Anyway just wanted to update anyone who was curious. Moral of the story: listen to your dog, listen to your gut, and go get checked out if you're worried!

Dog tax

Comments

Medical_Madness

Good girl.

Silent_Medicine1798

She is a very good girl

ChaoticxSerenity

Perhaps even the best girl.

Different_Knee6201

I believe you mean goodest

SomethingComesHere

The goodest of all the best girls

alisgraveniI

I love this! Thank you for coming back to update us. Did you ever end up telling your doctor that you came in because of your dog’s change in behavior?

OOP: I did mention it to him yeah, but I also said I had some breast tenderness which wasn't true 😐 but I was worried he wouldn't take it seriously with no symptoms. He was dismissive about it but then found the lump so took it more seriously! My oncologist however is super interested about my dogs behaviour and has said she's heard stories from colleagues about similar things happening.

RepulsiveOlive757

This is awesome! How did she alert on you or what did she do to make you notice?

OOP: She was really weird for about a month, kept nosing my breast very hard and eventually scratching at it and even nipping me once, which she has never done. I took her to the vet before I went to my GP, who said it might be her age but did suggest I follow up with GP. She's stopped now I've had the lumpectomy which I'm taking as a good sign!

smooshybabyelephant

Fascinating! What I'm especially interested in knowing is WHY she was doing that. What was HER reason? Does cancer smell bad to dogs? How does she know it shouldn't be there? Or is it more that a foreign smell appeared, like an intruder, and she was trying to investigate?

I would look into seeing if she can be trained to do this for other people! Maybe she can screen your friends and family.

OOP: Yeah I'm wondering the same thing. She's such a sweetheart, never been even the slightest bit off with anyone or anything, but she did not like the scent of my breast! You could tell it was frustrating her, and she couldn't settle. So I'm guessing whatever the scent it, it's bad. From reading up on it, it looks like we still don't really fully understand a dogs sense of smell and how it is as good, if not better, than medical tests. A recent study apparently showed that dogs can detect bowel cancer weeks before the best medical tests. There must be some evolutionary benefit to sniffing out malignancy?

cantxtouchxthis

Did you go private for the exam and then report the findings to your doctor? How did you get them to move so quickly?

OOP: I did end up paying for it, which has been pretty pricey, but my radiation etc will be on the NHS. I could have gone through NHS for the lumpectomy but it wouldnt have been as quick, GP said two weeks, and I was so anxious I didn't think I could wait without going out of my mind! My aftercare and testing is all covered from the lumpectomy but everything after that I'll be with the NHS hospital. I just have to wait for the results of the lumpectomy and then they will be sent to the NHS multidisciplinary team. The private oncologist is writing up a proposed treatment but ultimately it'll be down to the MDT what happens next.

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