
The only company I know of (bearing in mind I've not looked for years) is Healthy Pets - they will cover up to 5 as I recall.
Good cover, but as with a lot of companies the premium jumped on my policy on yr 2 - it was Remy's premium that jumped (him being a dobe, the other dogs on there being crossbreeds) so I didn't carry on with it. It's one payment but they do split it on the system and assess the premium accordingly IME, hence Remy's jump.
If there is another company doing multiple dog cover and good cover I'd love to know about it too - fairly pointless right now as I have 4 dogs with existing lifelong conditions but the other 4 don't, and for future ref too.