A dog is at large if –

(a) it is not under the effective control of a person in a public place or in or on premises without the consent of the occupier; or

(b) it is a dangerous dog in a public place and is –

(i) in the charge of a person under the age of 18 years; or

(ii) without a muzzle; or

(iii) not on a lead; or

(iv) without an approved collar.