My Boxer is skinny but has a big stomach. Why is he so sick?

Fluid accumulation in the abdomen is often secondary to heart disease (valvular disease, heart worms, cardiomyopathy) ..or...some type of malignancy. Tumors in the abdominal cavity can sometimes be associated with fluid build up. It is important to do some additional diagnostic tests. Survey radiographs to start, then it may be advised to move on to an ultrasound....either of the heart or if the abdomen depending on radiograph findings. The ultrasound can be particularly helpful in cases like this where fluid accumulation reduces the ability to see vital structures on radiographs. This most likely had nothing to do with a case of overeating. There is likely some disease process that has been going on for some time. I hope you can get some answers soon. Thank you for using Petco Pet Education Center, formerly Petcoach.

He definitely looks very thin. The biggest concern with a dog that eats well, but doesn't gain weight is that he has a disease or heavy parasite burden. There are some inherited diseases like liver shunts that can cause them to be unthrifty like this and there are some acquired infections like Babesiosis that can also cause them to look like this. The only way to know is to have him evaluated by a veterinarian. I recommend taking him soon, because he doesn't look like he has much left to lose. It's also good to bring a stool sample to the vet, so they can check for worms. I hope that helps and Wekko gets better soon.

Zeus might be suffering from a medical condition causing him to lose weight, possibly intestinal worms, food intolerance or an intestinal disease. i would recommend taking him to your vet in order to try an investigate this issue.

I would have repeat blood work done on Thor just to check how his body is functioning. Things can change in a year or two, and it's always a good idea to do a recheck. If his blood work comes back clean, then I would discuss with your vet if they feel he needs to gain weight or not. He may just be a skinnier dog naturally. I had a Boxer who was the runt of his litter, and he was skinny his entire life no matter how much I fed him and he was perfectly healthy as well :-)

Tapeworms or other parasites are definitely a possibility if your pup eats a lot and doesn't gain weight. However, there are other causes that may also cause failure to gain weight such as metabolic illnesses or other underlying conditions. Signs of parasites may include issues such as diarrhea, visible worms in the stool (tapeworms will look like grains of rice, while roundworms will look like spaghetti), vomiting, etc in addition. If you're unsure if Mika has worms, it is best to bring in a sample of her stool to your local vet. They can check it for parasites, let you know if any/which type are there and provide medication to treat it with. If no parasites are found, a complete exam with your vet to rule out any other issues is also a good idea.

Jacko needs to see a vet. He is pretty skinny, and that combined with a distended abdomen means there may be something serious going on, such as heart disease or liver failure or heart worm disease. The vet will do an exam and may need to run x-rays or blood work to make a diagnosis so they can initiate proper treatment.

Thanks for using Petco Pet Education Center, formerly Petcoach! This may be due to parasites. Keep in mind that not improving with a dewormer does not mean is not parasites. It may mean you are using the wrong dewormer or the wrong amount or longevity. This can also be a number of other things like a foreign body obstruction, parvovirus, among other causes. I would recommend you consider having her evaluated by a veterinarian for further assessment and treatment. They would be able to check for these possibilities and start therapy accordingly. I am hoping for a speedy recovery!