Many dog owners noticed their pets acting strangely before a life-changing moment – and experts say there's a clear explanation behind the sudden change in behaviour11:49, 06 Aug 2026Many women eagerly wait for the day they can announce they're expecting - but for some, their dog seems to know long before anyone else does. While your four-legged friend can't understand pregnancy in the same way humans do, experts say they are incredibly sensitive to changes in scent, behaviour and body language. As a result, some pups become extra affectionate or protective, while others simply carry on as though nothing has changed.‌According to the American Kennel Club, it's impossible to know exactly when a dog first detects a pregnancy. However, thanks to their remarkable sense of smell, they can pick up on hormonal changes long before a baby bump appears. Experts believe dogs don't understand why their owner smells different, but do recognise that something has changed.‌Behaviourist Russell Hartstein said: "Dogs are highly sensitive and intimate in studying behaviour and subtle movements." But how they react varies from dog to dog...‌Some dogs become protectiveMany owners notice their pets becoming clingier or more protective throughout pregnancy.Veterinarian Dr Rachel Barrack said: "Many pregnant people report that their dogs are more affectionate or protective during their pregnancy. It's likely due to the scent and your hormones, as well as possible changes in your mood."‌One woman shared how her family's Vizsla completely changed its behaviour after she became pregnant.She said on Reddit: "Within just a few weeks of my pregnancy, the dog's demeanour changed. If we were playing sports with my siblings, and he sensed things were getting too intense, he'd bark and run over to check on me."Another owner said her normally well-behaved dogs suddenly became hyper-vigilant whenever she walked them while pregnant, but behaved perfectly when someone else held the lead.‌Others don't react at allBut not every dog becomes a little bodyguard, as other owners claim their pets barely acknowledged the pregnancy.One Reddit user said: "Absolutely nothing at all. Thought she was going to react to my belly but nothing. It's kind of annoying considering that there are so many cute reactions from dogs."‌Another joked: "I am 25 weeks and my Shiba Inu can't care less. Super aloof breed I think?"Some become your shadowFor others, the biggest giveaway is how clingy their dog suddenly becomes.One owner wrote: "My dog has gotten so clingy recently. He's always needed a lot of attention but recently he's just constantly all over me.‌"The other day I was in the bathroom and instead of going and sitting with my husband on the sofa he leaned against the door and cried until I came out."I really didn't think he had noticed anything for the longest time... but I feel like he knows something is up and he's worried about it."Another summed up her experience in just three words: "Sentient Velcro."Article continues belowShe added: "They're both obsessed with me, the bump, etc. And have been since before I got my positive test."