Lifetime cover is good, but there is a catch - they can put up the premiums at the end of each year; as many have said, these rocket with some companies even when you haven't made a claim. So, it's not worth much having lifetime cover if you can't then afford the premiums!

That's a risk you take though - if your dog gets a chronic problem and you've got lifetime cover it is then covered, but if you've only gone for 12 months cover in case the premiums go up then you can be royally stuffed - Saffi's arthritis is currently costing £200 a month in meds and hydrotherapy, versus £32 for her insurance.  And Soli - she came to me with just incontinence, about £17 a month in meds and £16 on insurance; by her last renewal she'd jumped to £37 with £120 excess and 20%, but she had several ongoing conditions which cost just shy of the £4k cover in her last year.  Even with the increasing premium, it was considerably cheaper to keep the insurance going!

Of course, if the dog doesn't develop something chronic you can still shop around at renewal - but then there's a risk of the new company not covering something in the dog's history.