Where Did All the “Lassies” Go? Why We See So Many Reactive Dogs Today

Do we really have more reactive dogs now?

At the park or online, it can feel like reactive dogs are everywhere. Barking, lunging, growling, freezing. Are there actually more “problem dogs” than 20–30 years ago, or did our world and our expectations change?

Science cannot give a simple yes or no. Long, comparable datasets are rare. But several big shifts explain why reactivity feels more visible and harder to live with in 2025: changes in environment, breeding, how dogs live with us, and what we expect of them.

1) The environment changed

Years ago, many dogs roamed the neighbourhood or stayed in the yard. Fewer nose-to-nose meetings on narrow sidewalks. Today, more dogs live in cities and suburbs, ride elevators, pass busy playgrounds, and meet strangers and dogs at close range. Urban living, low activity, and limited early exposure are linked with more fearfulness and noise sensitivity in dogs [1–2]. The “pandemic puppy” cohort also missed key early experiences, which raised later behaviour risks for many families [3–4].

What this means in practice: modern dogs face more unavoidable triggers. Even well-loved pets can reach a stress ceiling fast.

2) Genetics and the “wrong dog in the wrong place”

Line and purpose matter. A herding dog bred to notice movement may struggle in a condo full of skateboards and joggers. A protection-bred German Shepherd can overwhelm a low-structure home. When breeders prioritise looks over stable temperament, behaviour risks rise [5]. Dogs from high-volume commercial breeding also show higher fear and other behaviour problems later on [6–7]. Breed and line differences in traits like impulsivity and aggression thresholds are real, especially between working and show lines in some breeds [8–9].

Takeaway: match the dog’s genetic tendencies to the home, lifestyle, and local environment.

3) From the yard to the couch: more contact, more friction

Most companion dogs now live inside as full family members. That is good for welfare, but it raises the chance of clashes over food, rest, handling, or space. Surveys show notable rates of owner-directed aggression and dog-to-dog conflict within the same home, with training choices and management linked to risk [10–11]. Pain can also drive or magnify aggression and irritability, so veterinary checks are essential in behaviour cases [12].

Not new behaviour — just newly visible. We see and feel every moment now, because our dogs live where we live.

4) Human expectations and the Hollywood “superdog”

Popular culture has taught us that dogs should be intuitive, unflappable, and heroic. Think:

• Lassie, the endlessly helpful Collie everyone knows.

• Jerry Lee in K-9 (1989), the wise-cracking German Shepherd partner [13].

• Lulu in Dog (2022), the Belgian Malinois who heals and is healed by her human [14].

• Messi in Anatomy of a Fall (2023), a Border Collie whose acting won Cannes’ Palm Dog and global praise [15].

  
  

These stories are fun, but they prime people to expect instant understanding and perfect behaviour. In real homes, unrealistic expectations predict disappointment and even relinquishment [16].

5) The cost of waiting: delayed training in a tough economy

Money stress is real. Many owners still bring home a puppy, then delay support until small issues grow. Surveys in 2024–2025 show a large share of pet owners skipping or declining needed care because of cost [17–18]. Behaviour does not fade with age. Rehearsal makes responses stronger. By adolescence, change takes longer.

Better strategy: invest early in personalised, one-to-one coaching. Tailored plans fit the puppy, the family, and the home. Early management prevents problems and saves stress and money later.

So… are there more reactive dogs than before?

We cannot prove there are more. What we can say:

• Dogs are exposed to more triggers in modern life [1–2].

• Some breeding choices undercut stable temperament [5–7].

• Living indoors increases daily friction points [10–12].

• Media shapes unrealistic “superdog” expectations [13–16].

• Families often delay help until problems are bigger [17–18].

• We also keep more dogs in homes than in the 1970s, with far fewer euthanasias, so we live with and notice behaviour problems instead of losing those dogs from the data [19].

  
  

The “problem dogs” were always there. Today we see them, we care for them, and we can help them with humane training, medical support, and smart management.

Need help right now?

• Start Here

  
  

Start early, keep it kind, and tailor it to the dog and the family

References

1. Hakanen, E. et al. (2020). Active and social life is associated with lower non-social fearfulness in pet dogs. Scientific Reports. https://www.nature.com/articles/s41598-020-70722-7

2. Puurunen, J. et al. (2020). Inadequate socialisation, inactivity, and urban living are linked with social fearfulness in dogs. Scientific Reports. https://www.nature.com/articles/s41598-020-60546-w

3. Packer, R.M.A. et al. (2021). Pandemic Puppies: motivations and early experiences of UK owners. Animals. https://www.mdpi.com/2076-2615/11/9/2500

4. Brand, C.L. et al. (2022). Pandemic Puppies: early socialisation and habituation exposures. Animals. https://pmc.ncbi.nlm.nih.gov/articles/PMC8909199/

5. Morel, E. et al. (2024). Prioritising appearance over health and temperament harms welfare. Animals. https://www.mdpi.com/2076-2615/14/7/1003

6. McMillan, F.D. et al. (2011). Mental health of dogs formerly used as breeding stock in commercial breeding establishments. Applied Animal Behaviour Science. https://www.sciencedirect.com/science/article/abs/pii/S0168159111003005

7. Stella, J. et al. (2019). Improving canine welfare in commercial breeding: a review. Applied Animal Behaviour Science. https://www.sciencedirect.com/science/article/abs/pii/S0168159118306476

8. Fadel, F.R. et al. (2016). Trait impulsivity differs by breed and by working vs show lines. PLOS ONE. https://pmc.ncbi.nlm.nih.gov/articles/PMC4785826/

9. Duffy, D.L., Hsu, Y., Serpell, J.A. (2008). Breed differences in canine aggression. Applied Animal Behaviour Science. https://www.sciencedirect.com/science/article/abs/pii/S0168159108001147

10. Casey, R.A. et al. (2013). Inter-dog aggression within and outside the household: prevalence and risk factors. Veterinary Record. https://pubmed.ncbi.nlm.nih.gov/23193037/

11. Casey, R.A. et al. (2014). Human-directed aggression: contexts and risk factors. Applied Animal Behaviour Science. https://www.sciencedirect.com/science/article/abs/pii/S016815911300292X

12. Mills, D.S. et al. (2020). Pain and problem behaviour in dogs and cats. Animals. https://pmc.ncbi.nlm.nih.gov/articles/PMC7071134/

13. K-9 (1989 film). Plot and details. https://en.wikipedia.org/wiki/K-9_(film)

14. Dog (2022 film). Plot and details. https://en.wikipedia.org/wiki/Dog_(2022_film)

15. Pulver, A. (2024). Messi, the dog from Anatomy of a Fall. The Guardian. https://www.theguardian.com/film/2024/feb/17/messi-dog-anatomy-of-a-fall-interview

16. Powell, L. et al. (2018). Expectations for dog ownership and perceived problems. PLOS ONE. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0200276

17. Gallup (2025). 52% of U.S. pet owners skipped or declined veterinary care due to cost. https://news.gallup.com/poll/659057/pet-owners-skipped-declined-veterinary-care.aspx

18. AVMA (2025). Pet owners are more price sensitive; clinic visits down. https://www.avma.org/news/survey-results-highlight-pet-owner-price-sensitivity-veterinary-services

19. Rowan, A.N. & Kartal, T. (2018). Dog population and sheltering trends in the U.S. Animals. https://pmc.ncbi.nlm.nih.gov/articles/PMC5981279/