When you see a dog out in public, it’s natural to want to greet or pet them. But before you approach, it’s important to pay attention to what the dog is wearing. Many dog owners and handlers use colored vests, leashes, or bandanas as a way to communicate important messages about their dog’s needs or behavior. One color you might notice is blue—and it carries a very specific meaning.

1. Blue Often Represents a Service or Therapy Dog
In many countries, dogs wearing a blue vest, leash, or harness are typically service dogs. These dogs are highly trained to assist people with disabilities, whether visible or invisible. Their tasks can include guiding the visually impaired, alerting a person with epilepsy before a seizure, providing mobility support, or calming someone with PTSD.

A dog in a blue vest isn’t a pet—it’s a working partner. That means they should not be distracted, petted, or spoken to while on duty. Even small distractions can break their focus and put their handler at risk.

2. Therapy Dogs May Also Wear Blue
Some therapy dogs wear blue bandanas or vests to indicate their role in providing comfort and emotional support. Unlike service dogs, therapy dogs are often taken into hospitals, schools, or nursing homes to spread calmness and joy.

While therapy dogs are friendly and approachable, it’s always best to ask the handler first before interacting.

3. Blue Can Signal Training in Progress
You might also see a puppy or young dog in a blue vest marked “In Training.” These dogs are preparing to become certified service animals. During this stage, they are learning to focus on commands, ignore distractions, and build the discipline needed for their future role.

Again, it’s important to give them space to work without interference.

4. Why the Color Matters
Different colors are often used in the dog world as a visual communication system:

Red – Do not approach (the dog may be reactive or aggressive).
Yellow – The dog needs space (anxious, nervous, or in training).
Green – Friendly and approachable.
Blue – Service dog, therapy dog, or training in progress (do not distract).
These colors are not universally standardized, but they are widely recognized and help the public understand how to interact with a dog.

Final Thoughts
If you see a dog wearing a blue vest, leash, or bandana, it most often means they are working—as a service dog, therapy dog, or trainee. The best way to show respect is to give them space, avoid distracting them, and always ask the handler before approaching.

By paying attention to these signals, you can help ensure both the dog and their handler stay safe and supported.