Hi Karin,
Because DHJST is a tonic, it can raise liver enzyme levels in animals that have latent tendencies to hepatic congestion. So it's not a side effect, but tells you something about the liver in that patient.
I guess I would check them out to see if they have a Shao Yang aspect to their case, such as a full 'wiry' mid-depth pulse and keynote symptoms like a tendency to hip dysplasia or CCL tears. In that case, I'd try Xiao Chai Hu Tang. If they develop Damp symptoms, then I'd look at Si Miao San.
If they are a disc dog, but have Shao Yang tendencies as described above, you can start them on 100g Xiao Chai Hu Tang with 12g Gui Zhi and 15g Bai Shao added. That should address both the disc and the liver
If none of that is making sense relative to what you're seeing in your patient, feel free to share more details
Steve