Deworming effect on puppy appetite?
We got our 8 week old bulldog/boxer mix this past Saturday from a rescue transport and he was having watery feces/diarrhea for the first couple of days. We figured this was stress due to the transport/new food & surroundings, and sure enough by Monday morning his feces looked healthier and more normal (soft, normal brown) and his energy level and playfulness were on the up and up.
On Tuesday we took him to a vet visit (per our rescue agreement) and he received a combo distemper/lyme vaccine (he already is neutered and had his first 2 sets of vaccines and 1 round of deworming meds before we received him) and a second dose of dewormer because the vet felt that his tummy was a little distended and that this was probably a sign of some parasites (we are still awaiting actual fecal results). He has continued to relieve himself normally and play happily since the vet visit, but for the past two days has now had less interest in food and is no longer voraciously scarfing down his meals (eats about half). We have had some success getting him to eat a little more by scattering it on the floor and making it a game, but the sudden change in interest is striking.
He's not vomiting but his belly swells largely after he eats (it isn't hard and is normal squishy, just distended). Could the extra deworming medicine have made his tummy hurt and made him lose interest in the food? Everything other than his appetite seems okay, we are just terrified of parvo, distemper or an intestinal problem because of his young age.
From what you are describing I wouldn't worry too much right now. Your little guy has had a lot of changes, plus two sets of vaccinations and deworming medications within a short space of time. It's not surprising that his tummy was a little upset, or that his appetite is reduced.
Also, during the first few days, or week or two, in a new home, many puppies are experiencing some anxiety and go through an adjustment period while they settle in. Loss of appetite, some lethargy (or a depressed or disinterested attitude), and minor digestive upsets are a common part of this.
Of course, you are totally right to be concerned about Canine Parvovirus and other communicable dog illnesses in such a young puppy. However, you're taking all the necessary precautions and as long as you continue to give him his puppy shots on schedule and don't allow him to come in contact with other unvaccinated dogs or areas where they may have been, then he's as safe as it's possible to make him.
Puppies are like little children and they go through phases and stages, appetite is often affected by these and may increase and peak right before a major developmental milestone or growth spurt, and then decrease again in between times.
As long as his bowel movements are firm and regular, he's not vomiting, or acting overly depressed or lethargic, then I wouldn't be too concerned. Of course, it can be tricky to tell the difference between a bout of 'homesickness' and real illness, especially at first, so if you are in doubt, always err on the side of caution and have your vet take a look at him.
Hope this helps, best of luck with your new puppy.