You can find segments of the UK dub, including promo materials and full episodes, archived on sites like Archive.org and through dedicated YouTube preservationists.
However, preservation efforts by fans have led to some successes: the wonder pets uk dub
Interestingly, the modern revival series, Wonder Pets: In the City , has moved away from this practice and does not currently have a separate British English dub. You can find segments of the UK dub,