The charity is ploughing �3m into animal welfare centres

In Edinburgh, the society is expanding its unit dealing with exotic species because so many reptiles are being abandoned across the country.

The modernisation project will take three years and create up to 15 jobs.

However, an animal welfare centre in Stirling has also closed as part of the charity's review of services.

This will have a major positive impact on improving standards of animal welfare Kay Driver Scottish SPCA chief executive

Kay Driver, Scottish SPCA chief executive, said part of the project would include doubling space for animals at the Lothian Animal Welfare Centre in Balerno.

She said: "We are very pleased to announce what will be the most substantial capital investment in animal welfare centres in the 167-year history of the society.

"We believe this will have a major positive impact on improving standards of animal welfare across Scotland."

'Dark side'

Scottish SPCA spokeswoman Doreen Graham said people were abandoning their pets at roadsides and in woodlands in the Lothians.

"There's been a rise in the popularity of exotic pets such as snakes and iguanas," she said.

"But we are also seeing the dark side of that, with more of these animals being abandoned.

"I think very often people grow bored of them or they cannot keep them. They like the concept of maybe having a reptile, but when it comes to feeding them dead rodents, they find it is unpleasant to watch.

"Other animals, such as iguanas, can grow to 5ft long and not a lot of people have room."

"We have had terrible injuries to snakes and they often come in with awful burns because they have been near a heat lamp that doesn't have a guard over it."

The charity is rescuing an increasing number of reptiles

Not all creatures who end up at the centre are abandoned. Snakes can escape captivity and some people simply hand in animals.

Centre manager Diane Stewart said the existing small room that provided respite for ill pets was to be overhauled, with new equipment.

She said: "We will be making much better use of the space by revamping the room and reorganising where things are kept, bringing in new equipment."

The revamp of the animal welfare centre will also see the number of kennels double to 66, providing more space for dogs and cats, and a larger reception, education centre and staff facilities.

The charity described the decision to close the Stirling centre as "regrettable".