75 per cent of rats 'resistant to poison'
An increasing number of rats in parts of West England are becoming more resistant to commonly sold poisons, scientists at Huddersfield University have found.
Researchers from the university have said that roughly 75 per cent of rats in Bristol, Gloucestershire and Wiltshire had built up a resistance, with the most serious mutations affecting rats in Bath and Wiltshire.
Experts have attributed this rise to the incorrect use of poisons where the dosages are too low, which mean the rats which are resistant to the poison are fattened up by the bait. They then survive and go onto mate with other resistant rats, thereby creating a generation of rats resistant to existing poisons.
Although mutations have been found in many areas of the UK, this study marks the first time the extent of the mutation has been measured in the west.
Veterinary practices are being urged to help owners safely dispose of any unused and expired pet medicines - not just antibiotics - during November's Animal Medicines Amnesty. 
