WARNING: THIS VIDEO CONTAINS STRONG LANGUAGE AND SCENES SOME VIEWERS MAY FIND DISTURBING

A dog groomer has been fired after a customer secretly filmed her hitting and yanking a tiny puppy.

Distressing footage shows the PetSmart worker handling the dog roughly as she clips and combs its coat.

Horrified owner Brooke Vowers said she felt “betrayed” when she saw how her one-year-old Shih Tzu Luna was treated and said the pup has been scared ever since.

Irvine Times:

The 22-year-old had dropped Luna - nicknamed Boo - off at her local branch of PetSmart in Katy, Texas, US, on Thursday afternoon for pampering.

She said the “very friendly and nice” groomer told her Luna had been “a sweetie” when she returned to collect her and pay for the $45 session later that day.

But as Brooke left the store, fellow customer Terah Leder, 22, stopped her and said she had seen her pet being handled roughly.

Brooke spoke with the groomer, who she claims told her she had needed to use a little extra force because Luna had been “biting her”.

But when Terah showed her video of the incident she says she "felt betrayed" and realized the groomer had been lying.

The clip has since been viewed more than 360,000 times on Facebook.

PetSmart, America’s leading pet retailer, confirmed on Friday morning that the groomer, who signed off Luna's grooming report using the name 'Charlotte', has been fired.

Brooke, a space planner of Katy, Texas, said: “I was in shock when I saw the video. I never would have guessed the lady would do such a thing - she was very personable.

Irvine Times:

“I felt very betrayed that I trusted her with my dog and paid for a service “I think she should never be allowed to work with pets again and no one else should go through this.

“Luna is OK she’s just scared. She has been acting timid ever since and she hid under the bed today, which she never does."

Brooke said she used Petsmart regularly in Sidney, Nebraska, where she lived before moving to Texas. It was her first time visiting the Katy store.

She said: “The groomer was very friendly and nice when I dropped Luna off. I came and got her about four hours later and asked her how it went.

"She said, ‘Good, she was a sweetie but likes to move around a lot.' I paid and thanked her and walked out the door.

“That’s when Terah walked up to me asking if that was my dog. She said she had been waiting for me because she had witnessed the groomer mistreating my dog terribly.

“I was in shock and thanked her for the info. I got in my car and called the groomer asking about this.

“She said Luna was ‘biting her’ and needed extra force and she thought the girl misunderstood how dog grooming was.

"She explained how she loved dogs and had been doing this for ten years and apologized.

“I told her thank you and that it must have been a misunderstanding but I just wanted to make sure everything was okay.

“Then Terah sent me the video and I found out very quickly she was lying.

“PetSmart should install cameras in the grooming rooms and pick more quality workers.”

Terah, an entrepreneur from Houston, Texas, was at the store with her rescue dog Leah, when she saw the groomer being "aggressive" with another pooch.

She said: "She had an ugly face on and seemed miserable.

"The way she was brushing the dog's hair - if there were any tangles they would have been ripped out instead of combed through.

"I decided to stick around and start filming. It was hard to watch.

"If I sat down at a hair salon and someone was pulling my hair like that we would have had a fist fight. It was ridiculous.

"I waited about 30 minutes to tell the dog's owner that I had seen the grooming lady being aggressive.

"Honestly I'm happy she has been fired because it probably saved a lot of dogs from being hurt like that.

"That dog didn't deserve that and I would be worried to leave any other dogs with her."

PetSmart confirmed that the employee has been fired.

A spokeswoman said: “This treatment is completely unacceptable and will not be tolerated. The associate is no longer with PetSmart.”