Spoiler alert: Tail-wagging isn’t on the list.

Most dog owners would probably love to know what theirpetis thinking.

(And, no,tail-wagging does not necessarily meanthat your dog is full of glee.)

A person shaking hands with a golden retriever in a park setting

Its hard to be joyful if your basic needs arent met, and the same goes for dogs.

Kate Anderson, a veterinary behaviorist at Cornell Universitys Duffield Institute for Animal Behavior inNew York.

And that idea goes back quite a ways, to the 60s.

A person in denim gently pets a relaxed small dog resting on their lap while holding a phone

Nowadays, our understanding of dogs happiness goes beyond simple criteria like these, Anderson noted.

But having their basic needs met is a step in the right direction.

They have relaxed body language.

Smiling person cuddles a happy puppy, both with eyes closed, enjoying a joyful moment

Happy dogs should have very loose body language, Anderson said.

They shouldnt have any tension.

Their ears shouldnt be pulled back.

A fluffy dog lies on its back on grass, looking playful and happy

You shouldnt see the whites of their eyes.

They shouldnt be leaning back or standing with a paw up.

Thats, to me, a sign of a happy or content dog.

A woman smiles while holding a Golden Retriever. Both look happy outdoors

Anderson added that your dog is likely pretty happy if their movements are loose and they look like noodles.

They have relaxed facial expressions.

Think about it: When youre upset, your mouth probably droops and you may squint your eyes.

A woman in casual clothing sits on a park bench, smiling and petting a small white dog with a red collar

This is not the look of ahappy person(or dog).

Theres a set routine for your pet.

Just like toddlers and young children, dogs like things to be predictable, Anderson said.

An elderly person happily hugs a small white dog outside in a park

According to Anderson, the toughest times of the year for dogs are when human schedules change.

This can happen amid the holidays, a big trip or a return to the office.

They take part in enrichment, like exercise, training or using puzzle toys.

I categorize exercise under enrichment, and enrichment is a really broad topic, Anderson explained.

Its kind of the things in your life that are your self-care.

Beyond just exercise, this can include mental stimulation.

They have an owner who is willing to advocate for them.

Your dog may exhibit body language that shows how theyre feeling.

However, they cant flat-out tell someone to back off but you might.

All dogs have their own personality; some are social, while others are introverted, she said.

Just as humans are allowed to have preferences, dogs are too.