What kind of weed killer can I use that won't harm my dog?
Are you talking about something for spot treatment or whole yard application ?
There are particular weed killers which are natural. You can use them and they are safe.
My dad used to use boiling water, or spray vinegar on them. Can't remember if this worked but he did it for years so it must have. It depends on how big an area you're talking about I suppose.
Yes, there are weed killers that won't do harm to pets. You simply need to be specific when making a purchase. Look for products that are natural. I remember my parents making use of boiling water as well to kill weeds sprouting on some parts of the laws.