re: Dog vomiting every 2-3 months

It's definitely food allergies. Put him on a limited ingredient dog food. Then rotate it every week. Ex. Lamb and brown rice one week. Turkey and sweet potato next week. Salmon and brown rice next week. Rotate protein and starch.

Dogs digestive systems are not designed to eat the same thing every single day for months on end. Yes, many dogs can...and if they can tolerate it fine. But, in the wild their food changes every day (just like humans). Some dogs will start getting sick/rejecting food if over exposed to it for weeks or months. Had this exact issue with our dog. We rotate his food and it's resolved the issue.