There is the early case where James saves a bull suffering from sunstroke by running cold water from a hose to cool him down. James notes that it was very satisfying to see the bull thoroughly enjoying the soaking.
Siegfried's wedding present to James: Making him a partner in the practice.
James and Helen's homecoming to the practise, including a heartfelt discussion between James and Siegfried about the nature of being a country vet.
An elderly lady worries that she won't get to see her beloved dog again in heaven if animals don't have souls. James reassures her that if having a soul means being capable of love then many animals have better souls than people do.
Tristan jokingly mentioned to a customer he was thinking of setting up his own practise. When Siegfried hears about it he tears into Tristan, asking him why he doesn't have any loyalty and telling him to leave right away. Tris looks heartbroken. The next day Siegfried apologises unreservedly to Tris and explains he was terrified of actually losing him. The look of sheer relief on Tris' face...
A nasty customer is arguing with Tristan in the pub. Tristan is trying to explain about the illness in question but the customer cuts him down by pointing out he's not a qualified vet. Siegfried appears from nowhere with:
Siegfried: I am! And my brother is perfectly right!
Customer: Is that a fact?
Siegfried: Yes, it is a fact. And his knowledge of the subject is more profound that my own!
Siegfried and Tristan have a conversation while waiting to hear if war will be declared. Siegfried makes Tristan promise not to do 'any foolhardy empty heroics'. Tristan responds with 'nor you'.
Tristan has managed to drive a car through the back of the garage. Siegfried patches him up, snarking all the while.
Tristan's tetanus scare. Siegfried immediately drops what he's doing to take Tris to the doctor's. Tris comments the next day to James about how Siegfried always comes up well when things are really important.