SANT VICENC DELS HORTS, Spain:Surrounded by parents and teachers, five children with disabilities in a Spanish special-needs school cannot hide their excitement when Soul the therapy dog walks in wagging her tail.

"What we have noticed a lot during the time of the pandemic is that they pay much more attention to the dog," special education teacher Meritxell Arias told Reuters as the children laughed and petted the golden retriever, who also appeared to be smiling.

She explained that because the teachers used face masks the children cannot see them smile. "But the dog does not wear a mask and that is giving us a response that we did not expect."

With the kids back at school in Sant Vicenc dels Horts near Barcelona after six months at home due to coronavirus restrictions, the therapy dog programme is a big help, said director Joan Frencesc Porras.

His students have become more responsive and collaborative, with faster reactions, "so we understood that (the dog) was a very important tool for us," he said.

For Hector Aguera, a 14-year-old with Asperger's syndrome from the nearby town of Terrassa, his first encounters with his own therapy dog Niko four years ago were somewhat scary.

"I was very afraid of him because I had never seen such a big dog," he said.

They are best buddies now: "Niko helps me when I am nervous or overwhelmed and I need help, he comes, I pet him, my nerves go away and I remain calm," said Hector.

His mother, Manoli Perez, agreed, saying it was Niko who brought Hector "the most calm".