Possible singleton puppy?

Question
Hi, I just had my dog ultrasound yesterday at 29 days to confirm pregnancy.
We did indeed see a puppy but only one. The veterinarian did say that my
bitch was very gassy and her bladder was very full. You could see the serious
gas ripples on the ultrasound. Anyways, my question is, could my bitch
possibly carrying more puppies and we're not able to see them due to the gas
or is it too early for accurate reading?
The one puppy we did find was close to her ribcage but the veterinarian never
looked anywhere except the lower belly. I have so many questions regarding
this breeding. We did all the proper steps to do this successful such as
progesterone testing, we had the Veterinarian do the AI procedure (chilled
semen) and now the ultrasound plus I've invested $1800 on this breeding
alone. I'm very confused as to what to expect with this litter and if it is a
singleton, I worry that my bitch will get engorged and get mastitis and have to
have her teats removed. Also, how do you handle a singleton puppy?
She asked me to come back in for another ultrasound four days before her
due date but honestly if there is only one puppy, I'm tired of spending more
money. I wonder if my veterinarian even knows what she is doing half the
time? I look forward to your answers.  

Answer
Usually you want to do a palpitation, but only a qualified veterinarian should perform a palpitation. On day 29 they migrate lower into the horn into what is called the breach of the stem, but day 29 is the first day this happens. So usually day 30 or 31 are more accurate for counting the number of puppies you can expect. On day 32 they migrate back up to the top of the horn of the uterus, making puppy count impossible until day 50.  At that point it really is a waste of money to do another ultrasound unless there is a concern for the development of the pregnancy, and at that point it is more about the health of the bitch then the puppies.Because if a puppy is in front of a puppy, you will not be able to see the other heartbeat as far the ultra sound is concerned. It would be whether or not she is showing signs of distress. On day 55 or later you can do an x-ray for a definitive count with a qualified vet with 6 or less puppies. Most important information to have with any bitch in whelp, but it becomes especially important with 3 or less puppies is an appropriate therapeutic calcium level, do not start giving additional calcium until 8 or 9 days before day 63. What you will do at this time is get yogurt and add this to her food, she can eat up to 3 pounds a day not including food. You should also be switching her to a puppy food at this time as well. Usually if there is a singleton puppy they will get mastitis BEFORE the puppy is born, this can be avoided with a 10 day antibiotic treatment of Amoxi-clav that can be prescribed by your veterinarian. This will not affect the health of the puppies at all. It is important that if your bitch has not delivered by day 64 she see a veterinarian. If she still has not delivered by day 66 you seriously need to consider a c-section at this time. If you decide not to do this at that time it can have detrimental affects on your bitch and the puppies. This of course needs to be discussed with your veterinarian.

If this is a true singleton puppy, there is a high chance that you are going to need to do a c-section. I would say there is about a 70-74% chance for the c-section.

As always you need to be confirming and consulting a qualified veterinarian. If you for any reason feel that your veterinarian is not providing adequate care you need to find another veterinarian that will be able to answer all of your questions and concerns.

If you have any other questions feel free to email me again. I apologize for the delay, I wanted to give you the best possible response.