Psychological fiction: 1980s, Man kills pet golden retrievers on wedding anniversary

I've been trying to remember the title or author of a book I borrowed from the library in the mid to late 1980s. It was a paperback, with a mainly white cover- possibly with a picture of a Rorschach inkblot on the front. The beginning of the book is very vivid in my mind because it was quite shocking. A man (the story is told in the first person from his own viewpoint) comes home from work on his wedding anniversary. On the back seat of the car is a large white box with a red ribbon, a present for his wife. There is a strange low level mist. He gets out of the car and goes into the house with the box. His pet golden retreivers rush to greet him and in the kitchen he kills first one then the other (possibly with an electric knife or saw) and puts their bodies into the box. The rest of the book is mainly about his relationship with his therapist and the reader is never quite sure whether the man is truly descending into paranoia and insanity or the victim of some sort of conspiracy. There is something about an alternative world/reality, a woman and a crystal which the man believes is in the therapist's chandelier. There is a scene in a restaurant (?) where he meets his wife on her birthday and gives her a bracelet. It is the first time they have met since he killed their dogs. She rushes away in tears and it is the therapist who asks him if he realised the box with the bracelet in is a tiny replica of the one in which he put the bodies of the dogs.
This book has stayed in my mind all these years, I would love to track it down as it was so unusual. Any clues would be most welcome!

~Saturngold

This is The Watcher by Charles Maclean. The same book came up in a recent query and LT user MyriadBooks pointed to another site where the query was solved.

OMG! I read this book while on holiday in Greece many years ago and like saturngold have never forgotten it. I posted an enquiry on this site many months ago, but had no luck. I have just ordered a used copy for the princely sum of £1.11 + P+P from abe books via the fantastic fiction site.
http://www.fantasticfiction.co.uk/m/charles-maclean/watcher.htm

Amazon.co.uk also have some copies too but they are pricey ... saturngold, I hope you manage to get a copy and thankyou Petroglyph for your help ...you are a star!