Not so happy birthday?

On Friday, December 1, Britney Spears brought her pre-birthday celebration to a hult when she had to bring one of her dogs to the vet due to a “medical emergency.”

SOURCE: @BRITNEYSPEARS/INSTAGRAMBritney Spears often shows off her dogs on Instagram.

The pop sensation, who turned 42 today, apparently had to rush her pup to a 24-hour veterinarian clinic in L.A. at 2 a.m. The star appeared upset as she exited manager Cade Hudson’s house, where the party was being held. Spears’ brother, Bryan Spears, was also spotted at the event, as Britney entered her vehicle.

The blonde beauty wore a red and white flannel shirt, loose white pants and sneakers for the unfortunate late-night outing. It was unclear what happened to the pooch, however, reporters claim they saw the “Toxic” singer bring the dog into the clinic.

The singer was then spotted at the gas station and convenience store before returning to the vet. It was unclear whether the pet has been released or if it is healthy.

It was also unknown which of Britney’s five pooches had the medical issues.

SOURCE: @BRITNEYSPEARS/INSTAGRAMBritney Spears has five dogs.

As OK! previously reported, following her split from Sam Asghari, fans grew worried for her pets as she began displaying some erratic behavior.

On September 25, the 42-year-old uploaded a series of videos dancing around with allegedly “fake” knives, where the dogs were seen running in fear in the background.

After one user stated that the pooches “kind of looked scared,” many others began to express their concern.

“That was my thought when watching the video she could’ve tripped on the dog which she almost did she could’ve fell or dropped a knife on the dog,” a second person chimed in, while a third added, “She needs serious help.”

SOURCE: @BRITNEYSPEARS/INSTAGRAMBritney Spears recently got puppy Snow.

Despite the concern, Britney fought back against the haters, stating, “Don’t worry they are NOT real knives!!!”

Other users then defended Britney, claiming people’s concern for the dogs was overdramatic.

“She already said they weren’t real knives. Besides, the dogs have better lives than most of you, they’re fine,” a supporter wrote, though another user replied, “They’re clearly real. Real enough to fall on and kill one of those poor worried pups.”

“Omg the dogs weren’t anywhere near the knives! So what if she did a dance with two knives there’s loads of acts [using] blades, fire etc., it’s not the drama it’s been made to be,” someone else added.

SOURCE: @BRITNEYSPEARS/INSTAGRAMBritney Spears often dances with her pups in videos.

The celeb’s unusual use of knives came after her and Asghari broke up in August. Amid their separation the duo had a custody dispute over their pooches.

In the end, Britney obtained custody of four of the pets, including an Australian Shepherd named Sawyer, a Yorkie named Hannah and two other smaller dogs, while Asghari became the sole owner of a Doberman named Porsha.

Shortly after, Britney got yet another dog named Snow, which she debuted on Instagram. “The new edition to the family … it’s her world and we just live in it!!!” she captioned the August 23 post.

TMZ reported on Britney’s trip to the vet.