Britney Spears’ birthday celebrations reportedly came to a halt after one of her beloved dogs suffered an apparent medical emergency.

The Princess of Pop, who turns 42 Saturday, had to rush one of her pups to a 24-hour veterinarian clinic at around 2 a.m. local time in Los Angeles, according to TMZ.

Page Six reported that the outlet obtained photos of Spears appearing upset and concerned as she made her way into a vehicle outside of her manager Cade Hudson’s home, where they were reportedly having a “pre-birthday celebration.”

Her brother, Bryan Spears, is seen also exiting the residence and holding a can of Coke. The siblings recently reconciled their relationship amid her divorce from Sam Asghari.

The 46-year-old was dressed in a navy blue shirt, black jacket, newsboy cap and jeans, and pictured alongside an unidentified male friend.

Britney, for her part, was dressed casually in a red and white flannel shirt, loose white pants and sneakers for the late-night run.

It is unclear what exactly happened to the Grammy winner’s dog. The animal does not appear in any of the pics TMZ obtained, but photographers reportedly claim they witnessed it being brought to the clinic.

Page Six has reached out to Britney’s reps for comment but did not immediately hear back.

After the dog was reportedly dropped off, the “Oops! I Did It Again” singer was seen going into a gas station convenience store on the Sunset Strip with Hudson.

The longtime celebrity manager was photographed leaving the establishment with no shoes on and holding a plastic bag filled with items that appeared to have been bought at the store.

According to TMZ, Britney and her crew returned to the vet shortly after, but it is unclear what is the current status of her dog’s health and whether the pet has been released.

Britney was recently involved in a custody dispute with Asghari, 29, over their five dogs after their split.

However, the “Lucky” singer and former fitness trainer reached a deal in August, in which she got full-time custody of four of the pets, including an Australian Shepherd named Sawyer, a Yorkie named Hannah and two other smaller dogs, while he became the sole owner of a Doberman named Porsha.