Thank you for your patience. As you can imagine, there are a wide range of possible causes for Fig's vomiting and diarrhea. In an older cat we need to consider a range of internal organ issues and endocrine problems, as well as the more common causes for these symptoms (including infectious gastroenteritis, intestinal worms and food intolerance). Because this has been going on for a while now, and because it sounds like Fig has lost quite a lot of weight, you really are best getting Fig down to your local vet for a full check up and geriatric blood test. Further diagnostics here such as an abdominal ultrasound may also be necessary.
Old cats are very prone to hyperthyroidism and this causes symptoms very similar to what you are seeing here with Fig. The TT4 level isn't routinely checked in blood tests, and has to be specifically asked for or checked separately. Thankfully hyperthyroidism is easily treated with either tablets, iodine therapy or even diet these days. Ruling out hyperthyroidism would be an important step in Fig's work up, and this testing could be done in combination with the main geriatric blood test. You can read more about hyperthyroidism in cats online here: http://www.veterinarypartner.com/Content.plx?A=1197
If even hyperthyroidism is ruled out, then we have to start considering a primary bowel issue here. Possible options include IBD, a food allergy or even a tumor somewhere within your boy's bowels. The next best follow up step here is an abdominal ultrasound, and a dietary trial. Your vet will be able to put your cat on a hydrolysed diet like Hill's z/d ultra, or Royal Canin hypoallergenic. Fig would need to be on one of these diets for a full 6 - 8 weeks with no other food, and if he improved, we could confirm a dietary allergy. If the ultrasound reveals any major issues, then a trial of some medications for IBD could be the next step rather than invasive biopsies.
In the meantime until you can follow up with your vet, please consider trying a slow down bowl for your boy. If he is throwing up quite quickly after eating, this could in fact be regurgitation rather than vomiting. You can get slow down bowls at your local pet store, or online: http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=20531 . Also ensure he is up to date with his deworming treatments in the meantime, and be sure to use a reliable all wormer like Drontal, Milbemax or Panacur. Continue to feed him something he will eat for now, and also ensure he has plenty of fresh water available.
As above, the best next step here really will be to get Fig checked over by your local vet first thing tomorrow if possible. I hope all of the above makes sense? Please let me know if you have any other questions. My goal is to provide you with excellent service – if you feel you have gotten anything less, please reply back. I am happy to address follow-up questions. Thank you for your business and I hope to work with you again soon!
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