The most stressful cities for pet owners in the U.S., based on factors like vet costs, pet-friendly rentals, and environmental stressors, include:

1. **Boston, MA**: High pet ownership costs and limited pet-friendly rentals.
2. **Durham, NC**: Few pet-friendly apartments and high vet expenses.
3. **Milwaukee, WI**: Limited pet-friendly housing and fewer dog parks.
4. **Birmingham, AL**: Frequent thunderstorms and lax firework laws increase pet stress.
5. **Miami, FL**: High temperatures and costly pet care.

These cities pose challenges like high costs, limited pet-friendly spaces, and environmental stressors such as noise and heat, impacting pet well-being.[](https://www.mentalfloss.com/posts/most-and-least-pet-friendly-cities)