I have a fetal doppler from when I was pregnant, I had a lot of problems with my own pregnancies so I bought one from Ebay. Would they work on a dog  ?

No a human doppler and canine have different heads.  They work at different lengths.
And because a canine foetus at 28 days is only the size of a pearl, some skill is needed to find them.  So the accurancy of the result is due to the experience of the operator.

I have a human one and it works fine on my girls when having pups.

A human doppler is 2MHz which the man who manufacturers the equipment says "this is will only detect big pups at the end of pregnancy.  It needs to be a 5MHz unit for puppies" 
Maybe you've had a lot of practice. :)

Is it worth me getting one, Sharon? Our breeds are similar size and I could hear heart beats with the stethoscope but wasn't very good at hearing them so thought a doppler would work better. Was it easy to hear them or did you have to hunt about?

I have a doplar and used it on my dogs as well as a friends when I went visiting, they were 5-6weeks gestation the first time.

One sex pup has a faster heart rate I think it is the girls,in a large litter it may be harder to pick up different pups.

i hired 1 but couldnt ear the heart beats ,it was 1 for dogs i could hear with a stephascope but not with doppler and it wasnt cheap!.

If I remember rightly, we proved by the serial number via the manufacturer that the rented machine was in fact a human doppler and not suitable for the purpose?  So not surprising that it didn't work on the dog.  :)

wow westcoast you have a great memory lol but i can remember now :) yes it was for human! :)

Maybe because I've been involved with the manufacturer for almost 20 years! :)

o yes thats right lol ;)

Perhaps my memory isn't quite that good!  I remember it was for another larger animal - not for a dogs, which is why it didn't work! :)
It really is crucial to use the right probe fr the right animal.

im not sure LOL :)! if it wasnt yesterday then i cant remember :(

Recently bought one off ebay. Tried it on my bitch who is 7 weeks with a largish litter.l couldnt hear anything like a heartbeat, only  a mix of random noises :-(