I have no idea about toxicity, but I grew up with dogs and always had:

• Ivy
• Myrtle
• Euonymus
• Pachysandra

I hadn't come across this in the past, but I just planted arctostaphylos (bearberry). I also planted some juniper.

All the above are evergreen in our zone. I planted some of the above at my current home and mixed with some ferns, flowering shrubs and flowering vines (honeysuckle, and clematis). These are randomly dispersed in a bed of river rocks.

I think there is also a few varieties of lilac that grow as ground covering, but I'm not certain if they'd be evergreen in zone 6 (not sure if that is important to you).

I have some Euonymus growing in my front garden (although I had no idea that's what it is called, hah!) That is a great ground cover! I might have to transplant some to the back. Thank you for your response, I will have to read more into the others!

Skip the ivy, euonymus and myrtle (vinca) - all are toxic to dogs that might chew on or nibble. Pachysandra prefers shade. And there is no groundcover form of lilac so not sure what that is in reference to.

Is the bed in shade or sun? That will make a difference :-)

It's facing south, so it gets both sun and shade. Thank you for saying those were toxic! I was just about to google Euonymus when you responded! I think I have some Creeping Jenny growing elsewhere in my yard, which I read is pet-safe. But I have hoping for a few more options. :)

I guess this is not related to actual lilac, but has the nickname "California Lilac" - ceanothus. Looking at it again, I don't think it would survive in zone 6... I thought there was a variety that would work in the zone, but maybe not.