I think the world of my vet, Dr Alexander Gerold at MyVets in Cham: http://www.myvets.ch
Dr Gerold is an internal medicine specialist, I first met him years ago at the clinic in Hünenberg when I came in panicking after Hooligan's first seizure. He has helped each of mine through some very serious illnesses.
Last summer Dr Gerold, along with Dr Yuri Béosier (surgery and orthapedics - he did Haifisch's amputation, and helped the Belltie avoid surgery), Dr Alexandra Lierau (general practice) and Dr Isabelle Zulauf (exotics) opened their own practice. Marco Mouwen also does physiotherapy at the practice one day a week. (He, along with Dr Béosier, are helping Heffalump learn how to walk correctly again.)
I know I am in good hands with Dr Gerold - and doG knows, my crew of 'medically interesting' mutts have proved his skill over and over again.
The practice is very personal, very customer-focused, the vets really do see the owner as a partner in our animal's care. Communication with the pet owner is excellent - I can drop Dr Gerold an email anytime should I have a concern.
The MyVets team still work closely with Hünenberg and the Tierspital when needed.
Very highly recommended.
And an FYI, the clinic at Hünenberg (Ennetsee) is the area's 24/7 emergency clinic in addition to being a general practice clinic. Also excellent, albeit as one would expect with a large institution more 'clinical' in approach. (The Belltie still sees Dr Laim there for his acupuncture sessions.) Whoever you choose as a primary vet, you should get acquainted with the clinic as a 'just in case'. http://www.ennetseeklinik.ch/site/index.cfm
The Animal Oncology and Imaging Center, led by Dr Kaser-Holz, is in the same building, should (doG forbid) you ever need their expertise. Outstanding care. http://www.aoicenter.ch
If you need a veterinary Opthalmologist, there is Dr Marianne Richter, who spends two days a week at Praxis Göbli in Zug itself http://eyevet.ch
You will be spoiled for choice in Zug.