Bad Breeder any advice

Post:

We just picked up a terrier puppy from a breeder who told us he was almost 2 months old and that it was okay to take him home. Everything seemed fine at pickup — they gave us pedigree puppy mash, paperwork, etc.

One thing that struck me as odd was their feeding advice. They told us to keep the puppy food wet and give him regular milk. From past experience with young puppies, I thought milk replacer is usually recommended, but I didn’t want to change his diet abruptly and risk stomach upset, so we followed their instructions at first.

Yesterday afternoon, we noticed he was having a hard time pooping, and I had to assist him. The stool was very hard and contained a chunk of the Pedigree mash we gave him the day before. Although that is the only time we had that issue otherwise he's pooping per usual.

This morning, the breeder called to ask how he was doing and told us that his sister became sick and later died, which they believe was due to dehydration. That obviously raised a lot of concern for us.

As for our puppy now: • He is eating • He is playful and alert • He urinates frequently • He is pooping, though the constipation concerned us that one time

The only things that seem odd: • He shakes/trembles from time to time (we assumed cold or scared because eventually he stops) • He sometimes has his tongue out even sleeping but then puts it back in.

as a sidenote, we've been feeding him with a syringe and a little bit of the Caesar mush and mixing them both in and syringe feeding him sometimes he takes it sometimes we give the bottle it just depends on him. Sometimes he likes it in the bowel. We also been feeding him 3 to 4 times a day.

Otherwise, he seems fairly normal, but given the littermate’s death and the feeding advice, we’re worried we may have been given incorrect information or that he might be younger than stated.

Has anyone experienced something similar or have insight into whether these signs could point to dehydration, low blood sugar, or being weaned too early? We’re planning to contact a vet, but I’d appreciate any advice or reassurance from people with experience