An excess helps to reduce the cost of your policy. It is the part of a claim you pay before your insurance starts paying.
For example, if you make a claim for £1,000 and you have a £110 excess, you will pay £110 and your insurance will cover the remaining £890.
This does mean that if your vet bill is £110 or less, then you won’t be able to make a claim, as the insurance will not be required to pay anything.
However, having an excess usually means a cheaper premium overall for the year.