Hi, Welcome to JustAnswer. I am a licensed veterinarian and I'm here to help you. I'm so sorry to hear that Gizmo seems to be in pain, has lost weight and has some nausea. The easiest cause would be that since your other Papillon is dominating Gizmo's food that Gizmo is not getting enough food. The solution for this would be for you to feed these two in separate rooms (doors closed) until they each have a chance to eat (about 10 minutes) and then pick up the food. You could offer food this way 2-3 times daily, and don't leave any food out. They will figure out very quickly that their food is only available these times.
Unfortunately, I am concerned that there is something more seriously affecting Gizmo, and he probably needs a diagnostic blood profile, a urinalysis, and xrays of his chest, spine and abdomen. Fortunately, he is a small breed, so more of him will fit on one xray film than a larger dog, and therefore x rays may be less expensive for you. Some of the possible diseases to consider are diabetes, kidney disease, spondylosis of his back bone, liver disease, chronic pancreatitis, etc.
Has Gizmo been drinking more water and/or urinating more lately?
He hasn't appeared more thirsty to us and hasn't been urinating more frequently. But i will keep a check on that. I will also separate the dogs at mealtimes and not leave food out and see if that makes a difference. I have a gut feeling unfortunately that something is not quite right and will need to take him to the vet very soon. Sometimes he will vomit a large amount of bright yellow stained phlegm . He also used to love certain treats and now he will sometimes take them and at other times he wont, but he always seems to be wary of the other dog sparkey even though sparkey does not like the treats gizmo does. Also Gizmo does not like being picked up in a sitting position now so it could be his back. We love him to bits he has given us so much joy.
Thanks for your response! Separating Gizmo and Sparkey for feedings should help some. . .I agree, but I too think that something else is going on that is causing Gizmo pain and nausea. Just the fact that he is less enthusiastic about food can be a sign of nausea.
I had asked about the water consumption and urination, because diabetes would cause an increase in both and can lead to a quick deterioration unless it is managed with insulin. Many dogs live for years with treatment.
When you do take Gizmo to the vet, you could either have all of the diagnostics done at once, or they can be staged. What that means is the first diagnostic is a thorough exam by your vet. The next tier or stage would be a complete blood profile and urinalysis. After these, the third tier or stage would be x rays and possibly an ultrasound.
All along the way of course, a diagnosis may come and further testing wouldn't be necessary.
I hope you can get him into your vet soon. Until then, you might try feeding him a gentle diet. . .gentle on his teeth and gums, and gentle on his GI tract. A food made by Hills that is well liked usually and is made for upset GI tracts is I/D. It comes in canned and dry, but sounds like canned food is the way to go with Gizmo for now.
You'd could also make a gentle diet at home with boiled white rice mixed 50/50 with cooked skinless chicken, cooked ground sirloin, or low-fat cottage cheese. This isn't a completely balanced diet, obviously, but is great to use temporarily.
I wish you and Gizmo the best, XXXXX XXXXX you have any further questions or concerns please just let me know.