Four years ago I did some pet-sitting for a Flat-Coated Retriever. The dog had a yeast infection in it's ears, so I gave the owners a bottle of Epi-Otic I had leftover to dry the dogs ears and told them to get it to a Vet to have a culture taken.
Jump ahead to last week. Family goes on a trip and I agree to look after the Flat-Coat.I notice he is sleeping an awful lot and rubbing his head all over my furniture.I lift up his ears, only to see that not only had they "cauliflowered"...but the ear canals were almost completely shut.
So....I take the dog to MY Vet....who is shocked....and prescribes 21 days of Surolan, plus more Epi-Otic.
I leave the family the $160.00 Vet Bill.
Turns out....they never got that ORIGINAL ear infection cleared up.(four years!

)
On one hand I didn't want to interfere...but on the other hand...they left the dog IN MY CARE...and to me, that means EVERYTHING.If I notice the dog is ill, or in pain you can bet I'll take him to the Vet.
Of course when the family got home they were embarrassed...the wife said she noticed the dog couldn't hear very well and they only cleaned his ears out sporadically.
These people live in a million dollar home....spend hundreds on a pet-sitter....but can't get their "in-pain-nearly-deaf" dog to a VET?????
Even if they didn't agree with me taking the dog in, and I lose a client out of this...I still believe I did the right thing.