Mikki, I got Shadow at 10 months, rehomed by the breeder. He was sold and returned in 2 weeks. Then sold again. He was boarded with the breeder for most of his next 7 months, only going to that home for a couple weeks here and there. I don't know much of his first 10 months except that he had never been left alone without having at least other dogs with him.
What I do know is that he came to me with several issues.
Motion sickness-he got sick on every car ride with the breeder. I have tried everything and nothing has helped really. 2 miles is when it starts. He is very happy to go for a ride and doesn't appear anxious.
So much to tell about Shadow. I do think he has food sensitivities. This bout of diarrhea is probably due to that. His stomach is sensitive. When I got him, he was pooping 7 times a day, every time he went outside, he would poop. He was eating puppy food. My vet said to switch to adult food. I selected a similar food with chicken/rice. Didn't help. Then it was Grainfree salmon & sweet potato. That seemed to fix his problem.
I do wonder if these issues were the reason he was returned twice. I have called the breeder. No response. I know that she was having health issues maybe 2 years ago that have probably gotten worse.
At almost 4 years, he is very sweet natured, stubborn like a little mule, loves everyone. The current diarrhea issue started 2 weeks ago. One day, he was fine til 3pm. Next day, better. Then the next day, it started. We went to the vet. This is not something that has been ongoing for an extended time.
Sounds to me like the diarrhea issue is a separate problem unrelated to his early start as a puppy since he's now 4-years old. At this time, it's hard to separate what's causing what problem. The medication is treating some type of infection or illness. He might have an intolerance to the medication if things have gotten worst with treatment - or maybe it takes more time for the medication to work.
Based on my understanding of what you've told me: If it were me, I would not experiment trying new foods because no matter what you feed Shadow he's going to have digestive issues if he's sick. After you fix that problem then you can work on trying different foods if you need to. I'd switch him back on the food recommended by your Vet or back to what he was eating before this issue developed since you know he tolerated his previous food.
Vets and other medical degreed people often have to work through symptoms, trying different treatments to figure out what's going on. You've only had one vet visit. Your vet has just gotten started. I assume your happy with your Vet. I doubt it's going to cost thousands of dollars to figure out a diagnosis. After that you can decide how far to go on medical treatments.
Personality Issues unrelated to this post...as a side note: My daughter has a Golden-doodle whose start in life is similar to Shadows. Lucy was returned to the breeder after several weeks. Our daughter, Nicole, purchased Lucy and wasn't able to pick her up for another month. I believe Lucy was five or six months old by the time Nicole got her. The breeder was seriously ill when Lucy's litter was born.
I believe Lucy was returned because she is innately an extremely Shy and Fearful dog and to make matters worse she lacked any socialization due to the breeders illness. During those important socialization periods she was left alone to hide under her blank in a crate.
After getting Lucy, frustrated and concerned Nicole talked to her Vet about returning her to the breeder for that same reason. Lucy would completely cover herself up and hide under the blanket in her crate. Had to be physically removed from the crate to go outside. Appeared to not want anything to do with people. She's never played tug of war or fetch or wanted to interacted with the kids. She was terrified to go outside during daylight hours. The Vet discouraged Nicole from doing that. So she kept Lucy and has dealt those issues. Nicole remove her from a crate and put Lucy in her bed and slept with her, which helped Lucy learn to bond with Nicole.
Lucy, also, had motion sickness in a car. We routinely travel long distances to a vacation home in the mountains and to visit a son which are 10 to 14 hour trips. Poor sick Lucy laid with her head under the sick on the floor of the back seat. She was given medication. Eventually, she over came car sickness. Because of her personality we could leave her in a kennel and didn't have anyone to stay with her. Besides a stranger would have made things worse.
Lucy still has to have her head hidden under a table 24/7. But, she has gotten better and vastly improved after we got Patti our Havanese three years ago. Lucy now will come to me for a pat on the head and and will take a treat from my hand. Lucy plays with Patti for short periods of time. Patti can be a pest. >
