In the state's north police have tasered and attempted to shoot a mad dog which attacked a number of people.

Around midday the local council's rangers called for back up from police after a number of people were bitten near the Casino hospital.

Inspector Doug Conners from the Richmond Command said the dog was particularly nasty and rangers had trouble catching it.

"It was a very, very aggressive dog, it was foaming at the mouth and it was just highly agitated, it appeared to be very aggressive," Inspector Conners said.

Two police officers tried to assist rangers in catching the dog but were also attacked.

One officer struck the animal with a taser but that had little effect.

The dog continued and attacked the second officer who shot at the dog.

"We're uncertain if the round struck the dog but certainly the dog ran and it didn't stop the dog, it took off and hasn't been sighted since," he said.

Police are warning people to be on the look out for the grey Shar-Pei German cross.

The animal was last seen on the corner of Colches Street and Canterbury Street, Casino.