FRISCO, Texas — Petland in Frisco is under the microscope. 

It started when The Humane Society of The United States planted an undercover investigator hired as a worker at Petland.

John Goodwin, senior director of The Humane Society of the United States' Stop Puppy Mills campaign, told WFAA that the investigator was at the Frisco location between July and August.

"We wanted to see what happens in the stores themselves, in the backrooms," Goodwin said.

For three weeks, the investigator took photos and video while working in the backroom. 

The Humane Society has done similar undercover operations before. 

Goodwin told WFAA that the Frisco Petland was the location for the seventh investigation done in a year's time because of "a disturbing pattern of bad treatment."

The Humane Society of the United States says the pets at Petland in Frisco are mistreated, sick and overcrowded.

In video posted by the HSUS, an employee is allegedly caught on camera telling the undercover investigator to not tell customers a pet has a cough. 

Warning: Video contains content some viewers find disturbing

Petland responded to the allegations in an email to WFAA, calling the undercover investigator "irresponsibly inaccurate and clearly uneducated."

"Every single day [the investigator] was there, there were multiple sick puppies," Goodwin fired back.

Goodwin said so many animals became sick during the investigation that they lost count. 

Petland contends the animals were routinely checked by a consulting veterinarian. Petland responded to pictures that appear to show overcrowding. 

A spokesman wrote that the animals were "housed temporarily during a quick cleaning procedure." 

Frisco police and the Animals Services division got involved. 

Both departments made several unannounced visits to the Frisco location. They identified several animals that needed immediate veterinary care. 

The Petland owner was cited for failing to comply with a city ordinance requiring Petland to provide proof of veterinary care upon request. 

The police department said while there was a violation of a city ordinance, they found nothing that met the Texas statute for cruelty to animals.

“Our Animal Services officers take such allegations very seriously,” said Frisco Interim Police Chief Greg Ward. “Petland Frisco has been cooperative with Animal Services during this investigation and has taken steps to become compliant. Our department continues to work with the Humane Society (of the U.S.) and Petland Frisco to make sure the animals are cared for appropriately within the law.”

Petland calls the allegations by the Humane Society libel. 

"The HSUS is a politically-oriented fundraising group that is out of touch with the animal world," a spokesman said in a written statement.

In a day-by-day diary, the investigator says many of the puppies had bloody diarrhea, vomiting, sneezing, coughing, or were visibly underweight. The HSUS told WFAA that there is even proof that a dead rabbit was stored in a freezer in the backroom.

"Truth is a defense against libel because we have the documentation to back up every single one of these claims," Goodwin said.

Protests outside the store are scheduled for the weekend.

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