S5·E14 Episode 298 (Tue 17th Feb 1976)

Sam visits Will and tells him that two sheep have been killed at Emmerdale Farm by a dog resembling Will's own Alsatian. He tells Will that if he's keen to arrest Fred maybe he should think about his own animal as well. Joe shoots the dog causing the fatalities and learns it is not Will's dog. Will decides not to continue with his prosecution of Fred.