Having just had my litter of pups vet checked one has been diagnosed with an irregular heart beat.Its a repeat mating from 18 months ago where all pups were just perfect.Vet gave me very little advice other than to keep an eye on it but pup is almost 8 weeks and going to his new home,i have no idea what to tell his owners,has anyone had a pup with this and what advice can i give his new owners? Thanks

Did the vet actually diagnose an irregular heartbeat as an Arrhythmia by listening using just a stethoscope or by electrocardiogram ?

Many puppies have
heart murmurs which can be diagnosed by stethoscope.

It was by listening with a stethoscope,she said it wasnt a heart murmur  but an irregular heartbeat,very worried x

I would want that investigated a little further before letting the pup go if it's not a mild puppy murmur. Can you get the pup in to see a cardiologist?

Dogs do have irregular heartbeats that are non threatening. I wouldn't accept a GP vet's diagnosis by stethoscope alone.

"An ECG (electrocardiogram) can show any abnormal premature contractions or accelerated/decelerated heart rate Atropine response test to find the true cause of the irregular heartbeat

Read more at: the website"

Unless your vet has studied cardiology as a speciality I would be asking for a referral to a cardiologist

Personally I'd not let this puppy go, for now.   He's very young yet and it's totally possible that whatever is going on at the moment will 'improve'.   If you want him out of there,  and his prospective new owners are prepared to take him on the understanding that he does have a 'possible problem' (and get it in writing so there's no misunderstanding) then so be it.   They should be having their own vet do a health check in any case so they should let him know what your vet has found, and take his advice - it would be like having a second opinion!  And it might be a good idea to let them know the name of your vet so their vet can speak with him, if needed.

Again, we'd only let our puppies go to their new homes at 8 weeks if I knew the people and they were experienced.   Often puppies do better when into a one-on-one situation.   Most of our puppies were 10 weeks when leaving us however.

I have a breed that would benefit not at all by leaving beyond 8 weeks. In fact, strictly they would probably benefit by going a week earlier. They just start to pack and in fight and they are strong and independent
and Mum has lost interest by about 6 weeks.
Anyway, that aside, just once, before I had vet checks, a pup did go to its new home at 8 weeks as normal. On going to new owners vet they said she had a heart murmur. I was in shock as never had this before. Luckily new owners did not go for it when vet said pay £500 for tests or you can wait a couple of weeks. AT 10 weeks, no heart murmur  was detected and she is now 5 and never had a problem.
I know a retired vet who I discussed this with and she said that when training as a young student they were told to ignore murmurs at that early stage but now they jump in too early with big guns.
If you are not happy with letting the puppy go, then hold on for a couple of weeks and fingers x'd you will have the same end as my puppy. The new owner might still want to take the pup, perhaps have it looked at by their own vet. In my case I said they could bring the pup back immediately, but they insisted she was staying come what may and that was only after a couple of days.
Now of course I do as you have done and have the checks done before they go.

The vet said if it was a low grade heart murmur it would be different because they do tend to disappear a couple of weeks later but she said an irregular heartbeat was different x

Is your vet a cardiologist ? Did they do an electrocardiogram to confirm what they heard ? I have a friend who is an experienced vet, they are now studying to specialise in cardiology. They tell me that without using an electrocardiogram they cannot confirm irregular heartbeat especially in puppies

No she isnt .Ive informed new owners and we are going to their vets with the pup tommorrow for a second opinion and that vets do have a cardiologist although we would have to wait for an appointment x

Good plan. Let's hope its nothing serious

Murmurs are usually investigated by way of an echo to check structure of the heart.  Murmurs aren't a heart rate they are usually related I believe to blood flow through the valves etc not the beat of the heart. 

A CT coronary angiogram would be a scan of the coronaries looking for calcification and narrowings.

Arrhythmias would mostly be diagnosed with an ECG as the others said - hopefully capturing it so it could be identified if it was not a permanent irregular beat always present - sometimes people can have extra beats called ectopic beats which are most often benign and other times people can have paroxysmal atrial fibrillation rather than permanent atrial fibrillation - an ECG would be the test for anything heart-rate related rather than blockages to the coronaries or structural/valve abnormalities related to murmurs,

Not all irregularities in a heartbeat are permanent or life altering - I hope any further tests rule out any sinister cause for your.  Let us know.

Just a quick update..pup was seen by firstly owners own vet(given all clear and declared perfect) and then by a cardiologist..again perfect but another pup in the litter who was diagnosed with a heart murmur also perfect.This was all within days of first vet visit so although im not happy at being told 2 pups had heart problems im relieved she got both wrong x

Brilliant news. I personally would always want a referral if a gp vet diagnosed a young pup with a heart problem. Glad you have no probs with the pups