Sophie Aston’s black Labrador was left needing lifesaving surgery after she ended up with a five-inch wound on her neck.
The vet who treated her said the injury was consistent with her being slashed with a knife and that significant force must have been used to cause such a deep wound.
Sophie, from Crawley, West Sussex, was playing with her dog, Mia, in the park when she heard a loud yelp.
Sophie, who works at Crawley Hospital, took the injured dog to the vet where she was operated on straight away.
The faithful dog recovered quickly and his now back at her owner’s side.
Crawley Borough Council sent out officers to find out to see whether the injury could have been caused by wire or some other sharp object in the park.
A spokesman for the council said:
Sophie is warning other dog owners to be vigilant and if Mia’s injury was caused by a knife she is desperate for the attacker to be caught before they strike again.
A spokesman for Sussex Police confirmed they are investigating the incident and are keen to hear from any witnesses.