Weight concern

[piggy blossom]

I have a 5 year old piggy whom I have been syringe feeding for sometime.
When we feed we always weigh beforehand and afterwards to make sure food is being recieved by the tummy.
This has gone well till a week ago where for some unexplained reason no matter how much we fed only a small amount of weight was gained.
During this week 100grams was lost, took piggy to the vet and was erxamined and decided teeth would be filed again which this was done but this has made no difference.
Am wondering if it could be cancer or maybe parasites or even a blockage?
Piggy is happily being syringe fed and can not understand where the food is going, it goes into the mouth but not all of it is reaching the tummy.
I have collected some poops which I will take to the vet and have tested for parasites. Hoping someone can help me. Thanks for reading.

 

[flintstones]

Has he been checked for Diabetes unexplained weightloss is a symptom, worth checking I guess.

Hope you get to the bottom of his problem soon.