Replied by 5 Pooches Home (U.s., U.s) on 05/02/2012
Usually you try BOTH black walnut and wormwood. You can also get them pre-mixed along with cloves. Just search it online.
For greatdane, you can give 30-40 drops twice a day. Also garlic is great for heart health and you can also give 'Healthy Heart Tonic' by Herb Pharm...I am not from the company. I have just used this for my dogs and it was great.
Good luck!