In an appeal for more information, officers said the incident happened near St. Clement’s Parish Hall on Monday 23 August.
“The female owner was with another lady who was walking a small brown dog (shown in the picture),” they said in a post on Facebook.
“The owner briefly spoke to the boy who was injured and gave him a plaster before leaving the site.”
Anyone who recognises the dog and may be able to help identify its owner is being asked to call 612612.