There are some ultra sonic dog repellent devices.
Some are activated by infrared and riven by solar cells. Pretty cheap, won`t hurt the dog to much but keeps him away from your garden.

Start here:

Repellant Store

They even have Coyote urine in bottles (heaven knows how they collect that :mad: ). So you can skip the lion thing in the zoo grin

Yust ask google for a shop in your area.

Frank