Well worth a visit for a short stroll or an energetic spell of ball throwing. I would though stick to daylight hours. Watch for broken glass in some areas, particularly near the Belvedere.
Avenham Park didn't appeal to me as a place to take the dog as my previous visits tended to be on very busy days when bands were playing in the natural amphitheatre. Miller Park conjured up images of deserted pathways and broken glass.
I have to say though that more recently both of these parks have grown on me and the amphitheatre of Avenham Park in particular has proved very popular with myself and the dog as a venue for a good game of fetch. The game begins at the top of the amphitheatre with the ball thrown way down the hill across the huge grassy fields towards the river. It normally ends up with the dog becoming distracted and me searching in the grass to retrieve the said ball!
Access to the park is easy from Preston's main car parks. Why not take the dog for a quick run around the park whilst your better half is running around the shops. Alternatively, the parks are a natural extension to a trip down the Tram Road or a walk along the banks of the river Ribble.
There's a nice website from the Friends of Avenham and Miller Park.
Doggy rating 5/10