I've been avoiding the animal remedies for vegan reasons (I think that cruelty like the snakes being 'milked' for poison is criminal as much as crushing live ants and bees and starfish is evil even for homeopathic doses) as well as because I am still trying to work my way through plant and mineral remedies in the natural world.
But I still have a bunch of them that I've bought when dogs were dying and I was desperate in the past.
The surest cure for ears full of smelly fluid that I've seen in the past is Lachesis 200 and higher (brown dog in Broadway Police Qtrs). A couple of doses seems to be all it needs during the full moon cycle (3 days before full moon).
All the higher animal remedies work well during this period of the full moon cycle - Lachesis, Crotalus, Naja, Apis, Formica, etc. because the nerve poisons are similar to the nerve toxins our body is fighting and trying to throw out of the spine, brain and nerves.
I'm sure I'll find remedies in plants or minerals that do the same work more compassionately one of these days. But until then, I think that this is like a trace non-vegan element of homeopathy. (It shouldn't bother me as much as it does ... but it does! Like one ingredient in a package of mostly vegan foodstuff, it's annoyingly at the forefront of my mind. I might be drowning in non-vegan stuff in a restaurant, but that often doesn't bother me as much as a tiny hidden ingredient.:)