Can I still use an old-style or UK-issued pet passport?
Yes, however an EU pet passport issued in the UK is no longer valid for travel to the EU. You will now need an EU pet passport issued in a current EU country, or a UK-issued EU Animal Health Certificate. UK-issued EU pet passports can be used to travel to Great Britain as long as it still shows compliance with pet travel requirements. You can find the latest guidance from DEFRA on taking your pet to the EU here.
You can still use an EU old-style pet passport as long as it was issued before 29 December 2014. All EU pet passports issued after 29 December 2014 must be the new-style pet passport.