HMRC accepts that guard dogs can be treated as ‘plant’ for capital allowance purposes, which gives relief for the full cost of purchase. … Where the working dog is an asset used in the business, the ongoing costs of feed and vets bills are allowable and any VAT costs can be recovered if the business is VAT registered
BUT when it comes to the following:
Vet bills
Food
Etc etc
Do we list this under Plant and Machinery [Asset] or as General Purchases or something else?
So this is an interesting one and I have to throw in a note of caution, if the dog guards your home (unless you can make a strong case like formal training) or was purchased before the company was incorporated then HMRC will reject it as a business expense. I have seen quite a few people claim a family pet as a guard dog.
Otherwise I would create a new nominal for these costs for example security and keep them all there.