UPDATE 1-Golf-Pacesetting Castano would swap title for lost dog

* 'Gonzo' hits front with 64 at Scottish Open

* Goosen and Kaymer one stroke off the pace

* Lost dog more important than title for Spaniard

(updates at end of round)

By Tony Jimenez

LOCH LOMOND, Scotland, July 11 (Reuters) - Spain's Gonzalo Fernandez-Castano snatched the Scottish Open lead with a dynamic seven-under-par 64 on Saturday but said he would swap potential victory for the chance of finding his lost dog Petra.

The 28-year-old moved one shot ahead of German Martin Kaymer (66) and South African Retief Goosen (69) on 14-under 199 at the end of the third round.

Sharing fourth place on 202 were Briton Jamie Donaldson, who registered two birdie hat-tricks in his 65, and Dane Soren Kjeldsen (67).