Borax Toxic Poison Pets. How much borax is poisonous to dogs? 02 ounces of boric acid per pound of bodyweight.

Although it is not acutely toxic, if your pet ingests a large amount of this product, it may be toxic especially to smaller animals including your dogs, cats or hamsters as compared to human beings. It can also cause skin and eye irritation. Borate, or sodium borate, is used in laundry detergent, cleaning products, and pesticides.