been sick and loosing weight

Question
hi my 15 month old boxer boy is loosing weight, we feed him on pro plan puppy robust with added meat like steak, chicken, liver ect. we feed him 3cup fulls aday 3 times aday and he loves it.
but for some reason he is loosing weight.
i thought it might be worms despite his poo is ok and no signs of worms buti gave him a worming tablet just incase, 7hrs later he was sick and came out with lumps on his body, but he was still full of energy and happy. the bumps soon went.
the next day he was sick again, only water liquid type not actual food. his appetite is still good and his poo is good he is not weeing or drinking out of the ordinairy.

so what could be wrong with him?

any help you can give me would be appreciated.

Answer
First, worming medication is not a one-time pill.

You should be worming him once per year, with a yellow-banana smell liquid medication named "Strong" one time, and again two (2) weeks later. Approximately about 1-1 1/2 cc, depending on his weight.

Secondly, loosing weight is not a food allergy, although, skin rashes and bumps could be.

There is no absolute way of determining what is causing weight lost- and three (3) cups a day is definitely not enough food.

He should either be (1) self-fed where a bowl of food is always available to him, or (2) feed 6-8 cups per day..... Boxers do not follow a hunger schedule, they are "grazers" and tend to eat a full meal (full bowl) later at night before bedtime...therefore, I highly recommend the self-feeding method for a Boxer.

Get him to your vet about his weight loss; the vet will take a stool sample to test for worms and other parasites such as a tape worm causing weight loss, and do a heart worm test on him as well (if you live in an area with mosquitoes)... the vet should do a blood test for diabetes and thyroid disorders that can cause weight loss.

Get him to a vet. Any weight loss is serious and can be deadly.