Hi
Last year I read this in a paper and thought I would share it as it might be of some help.
Sorry I've not posted sooner, I've just found this site and its great :)

A pioneering vet from High Wycombe has developed a simple and cost effective way to diagnose heart disease in dogs.
Dr David Spratt of Crossroads Veterinary Centre has adopted a common blood test used for human heart attack patients and applied the principle to dogs.
Dr Spratt presented his paper to the European College of Vetinary Medicine at their annual conference in Barcelona last week and picked up 2 prestigious awards and an all expenses paid holiday to the USA for his trouble.
The test works by allowing vets to look for a protein in the blood called Troponin, which is normally stored inside the heart muscle.
If the heart is damaged, Troponin leaks out and the higher levels of Troponin, the more severe the heart disease is.
Until now vets had no accurate method for diagnosing heart disease and relied instead on a combination of guesswork and expensive X-rays and ultra sound tests.
Dr Spratt told Midweek "The beauty of this test is that any vet can take a blood sample and send it off for analysis and it is available now for clients across the UK. All they have to do is send their samples to Ross Dale and Partners in Newmarket for analysis. "
The test is especially useful for Dobermans and Newfoundland dogs that are naturally predisposed to heart disease and it may even be usable on cats.

Thanks for that, found it really interesting and out of curosity will ask my vets about it the next time I am in.

Margaret