It’s a crowdfunding campaign seeking to pull on heartstrings and save a puppy in bad shape, but this request by the Guggenheim in Bilbao is on a different scale. The museum is asking for €100,000 in donations to restore the American artist Jeff Koons’ 12.4-metre-tall Puppy.

The flower-covered sculpture of a west highland terrier stands at the entrance to the museum. Its vibrant 38,000 plants, which include petunias, impatiens, marigolds and begonias, are replaced twice a year.

“The exterior is fantastic and hasn’t deteriorated at all,” said Ainhoa Sanz, the head of restoration at the museum. However, after 24 years in the open air, parts of the irrigation system are leaking and need to be replaced, as does some of the stainless steel structure. “We want it to be in good shape for the next 25 years,” Sanz said.

Begoña Martínez Goyenaga, the museum’s communications head, said this appeal for money was the first time they had used crowdfunding. “We decided to crowdfund because it’s a work that’s so iconic and loved and photographed and so representative of the city and we want to give all the people who love the Puppy the chance to participate in restoring what is both a work of art and a vertical garden.”

Puppy was first exhibited in Germany in 1992. It was later re-erected in Sydney harbour in 1995. The Solomon R Guggenheim foundation bought it in 1997 for its new museum in Bilbao designed by Frank Gehry.

Koons said he chose the sentimental imagery of a puppy and flowers to convey optimism and instil “confidence and security”.

In an interview with the Guggenheim this year, Koons said: “Puppy was inspired by my visits to Europe’s baroque cathedrals and the way they achieve this balance between the symmetrical and the asymmetrical and between the eternal and the ephemeral.”

In 1997, just before the museum opened, three members of the Basque terror group Eta disguised as gardeners planted flower pots filled with grenades which they planned to throw at King Juan Carlos as he attended the inauguration ceremony.

The attack was foiled by Jose María Aguirre, a local policeman, who was shot dead as the three made their escape. The square was later named in Aguirre’s memory.

Two-thirds of the museum’s income comes from ticket sales, shop sales or from sponsorship, and the remainder comes from the Basque government.

The crowdfunding campaign has so far raised about a tenth of the €100,000 target. Work on the restoration is expected to begin in late September and be completed by mid-November.