You're going to do your best to make your puppy's first visit to the vet a positive experience. The first visit is probably going to be to receive the first of a series of necessary dog vaccinations, so despite your best efforts, it might be a little bit traumatic for your fur baby. After all, your puppy is in a new place where a stranger (no matter how friendly the vet might be) is sticking a needle into them! But puppies are resilient, wee things, and ideally this resilience will be demonstrated by them having no reaction to the vaccination at all (aside from the mild surprise). Your vet will discuss the possibility of adverse reactions, along with the signs you need to look out for. And yet there is one possible reaction that can require quick action—even if that quick action is only some cleaning.
An Occasional Incident
Puppies (like any dog) can occasionally be affected by diarrhoea. It's not pleasant, either for the dog or for the person who has to clean it up (which is likely to be you), but it happens. Due to the common nature of the ailment, it's rare that it should be a cause for alarm. But what about when you suspect that the diarrhoea is a response to a recently administered vaccination?
Perhaps It's Just an Upset Stomach
Diarrhoea in the hours and days after a vaccination could conceivably be a reaction to the injection, but you should first attempt to rule out any other contributing factors. Has your puppy eaten anything that differs from their regular diet which could have upset their stomach? Ask everyone else who lives in your household, just to ensure that nobody has given the puppy a treat which has inadvertently caused problems.
Careful Monitoring
The situation requires monitoring, and the diarrhoea will hopefully disappear of its own accord, with your puppy's bowel movements returning to their usual frequency and consistency. If the diarrhoea seems to be increasing in occurrence and volume, contact your vet for advice. They might request that the dog is brought back for treatment if the situation worsens. In the interim, it's crucial to avoid the dehydrating effects of diarrhoea by ensuring that clean water is continuously available. When cleaning up the diarrhoea, it can be necessary to wash the fur around your puppy's anus using an appropriate puppy shampoo. It's not the happiest of tasks, but the liquid nature of the diarrhoea can mean that faecal matter has been deposited onto their fur.
So while an occasional bout of puppy diarrhoea isn't generally anything to be worried about, it can require additional consideration when it occurs after a vaccination.