It is advisable to have insurance for you dog as unexpected vets bills can be very costly, particularly if extended treatment is required. There are many providers of insurance and some policies my suit you better than others so it is worth shopping around.
Insurance can be a minefield and there are a number of things to look out for. For example what exactly does a life policy cover and are there any issues that suddenly aren’t covered. Look at the excess amount and what limit the policy covers up to.