Participants are guided through a series of short exercises and demonstrations on structure and form before ending with a free draw at the sessions.
Organisers said the concept is as much about helping people relax as the art itself.
"It's just a wholesome activity to get involved in, to fuss some dogs and have a creative time," Barker said.
"I always say if it's a rubbish drawing we will blame the dog because they are moving, and they don't care what it looks like anyway.
"If the dog shuffles round that's fine, we start again or draw over the top."
There are between two and three dogs at each event at Blend at Sneinton Market.
Barker said a lot of students who miss their dogs while they are studying away from home come to join the sessions.
"A lot of people come back to see what flavours of dog we've got that week," she said.
"They go away saying how wholesome it is and how it's the best job in the world."