Colchester Zoo in Essex have confirmed that they have carried out an investigation after five wolves escaped from an enclosure on Tuesday.
Three animals had to be shot dead after a decision was made that anaesthetic darts would not take effect in time to prevent a risk to the public.
"Following the escape and devastating loss of three of Colchester Zoo’s wolves on Tuesday 26th November a full investigation has been undertaken by Colchester Zoo’s senior management to assess the events that have taken place.
No evidence was found to prove foul play, however, senior managers are struggling to comprehend how in the time available to them, the wolves managed to break right through their purpose made, stainless steel, perimeter fence.
A clear system of regular, daily safety checks to all enclosures continues to remain in place and the senior management have complete faith in our competent and experienced staff to continue carrying out these duties as a daily procedure.
Under the Zoo Licensing Act, contingency measures are in place in the event of a dangerous animal escape and zoo staff are fully trained to carry this out including a twice yearly animal escape drill being carried out with a full debrief taking place.
– Colchester Zoo statement
Sue Thornton BSc, BVetMed, MRCVS, of the International Zoo Veterinary Group, consultant vets to Colchester Zoo, has confirmed that the decision to use lethal force rather than a tranquilliser in this situation was the correct one.
The zoo holds equipment and drugs available on site to deal with any of its animals should they escape within the boundaries of the zoo but the delay of the effects of the tranquilliser coupled with the danger to the public of a category 1 dangerous wild animal means that sadly lethal force is appropriate once the animal has breached the zoo perimeter."