SAN DIEGO (Border Report) — In recent weeks, animal rights activists in Tijuana say they are seeing more and more vendors selling puppies to border commuters at the San Ysidro Port of Entry.

“It’s all out of control,” said Xochtil Zamora, an animal rights advocate and frequent border commuter. “The other day, a young man offered me a French bulldog for $3,500.”

Zamora told Border Report it’s not just one person doing it, but many.

Carmen Villarreal, an animal rights attorney in Tijuana, has also taken notice.

“We’ve seen a rise in the sale of dogs at the international border,” said Villarreal. “This is a network of systematic exploitation of the animals.”

And according to Villarreal, the puppies being sold are often sick and carry diseases, fleas, and ticks.

“They are ill and will likely infect other dogs north of the border,” she said.

Puppies that were for sale at San Ysidro Port of Entry. (Courtesy: City of Tijuana)

The practice is illegal, according to Tijuana Police, who have started cracking down on people selling small dogs.

But investigators say penalties for selling dogs without a license in Mexico don’t carry harsh penalties, and almost always, officers end up releasing the people they detain.

Border Report reached out to U.S. Customs and Border Protection to see if officers at the San Ysidro Port of Entry have seen a rise in the number of dogs coming through the border crossing and whether they are confiscating more of the animals.

But at the time of publication, CBP had not gotten back to us on those questions.

Rules and regulations related to dogs entering the U.S. are drawn by the Centers for Disease Control and Prevention and the U.S. Department of Agriculture.

Rules dictate a dog must be at least six months old to cross the border, and dog owners must have their animal’s updated vaccination documents, or the animal will not be allowed into the U.S.

“These are very young animals, separated from their mothers; they are often brought to the border in plastic bags; we have found some dogs barely alive,” said Villarreal.

Villarreal also told Border Report this problem is not isolated to the San Ysidro Port of Entry. She says they have seen it at the Otay Mesa border crossing.