A 7-year-old terminally ill Wisconsin girl loves dogs and has been receiving photos of pups since her diagnosis earlier this year, but dozens of police departments thought she deserved something more. So, they surprised her — with their K-9 officers in tow.

Emma Mertens is battling a brain tumor called Diffuse Intrinsic Pontine Glioma (DIPG). The survival rates for DIPG are very low and there is no cure for the tumor, according to St. Jude Children's Research Hospital. The tumor begins in the brain stem, which controls breathing and heart rate, as well as other essential functions.

Emma was diagnosed with the tumor in January, according to a GoFundMe page set up in her name. "Last weekend she was having a normal weekend playing with friends, playing in the snow, and wrestling with her brothers," the GoFundMe page says. "Sunday though, she got a headache and started having flu like symptoms."

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She underwent radiation and surgery for the rare tumor, but is now living home after spending 10 days in the hospital, according to her Caring Bridge page. Emma, who loves dogs, was visited by a therapy dog in the hospital. "I haven't seen this little girl smile this much in a while," writes her father Geoff Mertens of the visit on her Caring Bridge page.

A friend of the family asked her friend to send Emma photos and letters from dogs — and the idea took off like wildfire on social media. "What was supposed to be 10-15 people quickly went viral as they all shared the request!" Geoff told CBS News. "I would guess that we have received 200,000 letters by mail, 250,000 emails and 50,000 Facebook messages."

There are no words....Pure Joy! Thank you to everyone who took the time to organize and participate in this. Emma is... Posted by Team Emma - Emmalovesdogs7 on Saturday, March 9, 2019

Emma received mail from people all over the world, but nothing could top her experience this weekend. Nearly 40 police departments from across Wisconsin stopped by the Mertens family house on Saturday — with over 35 K-9 dogs in tow. "They told us that 'a couple' police dogs would be stopping by to surprise Emma. We had no idea over 35 would show up! It was like a parade of squad cars and police dogs!" Geoff told CBS News. The surprise was organized by a friend whose husband is a police sergeant.

The dogs and officers approached Emma one at a time. "Each one gave her as much time as she wanted," said Geoff. "The officers were extremely generous with their time. We are forever grateful."

While Emma may be facing a tough road, her family is keeping positive. "All of this love for Emma is giving us ideas on how to pay it forward," posted Geoff on his daughter's Caring Bridge page after the K-9 visit. "God has picked us for a reason. I feel it is because we can handle it and WE CAN BEAT THIS!"