Dear Dr. Thompson: We have an 8-year-old female lab/chow mix. She has been vomiting for several weeks now, about every 10 to 12 hours, a yellow, foamy vomit. Ultrasound, X-rays, and blood work turned up nothing. She is having an endoscopy. We were told it might be cancer. Her appetite is good for certain foods but we have tried every kind of sensitive stomach foods, boiled rice with boiled chicken, hamburger, nothing helps. Does it sound like cancer?
ANSWER: Unfortunately, it sounds like you have a difficult problem that you and your veterinarian are working through. Chronic digestive problems can be very frustrating because any number of diseases can cause the symptoms you are describing. At her age cancer can cause chronic vomiting and may not be seen on X-rays or an ultrasound of the abdomen. Endoscopy is a noninvasive method of evaluating the upper part of the digestive tract, but it is of limited value if the problem is in the lower part of the small intestine because the endoscope will only reach so far.
There are many noncancerous conditions that can also be the source of the symptoms. Inflammation of the pancreas, or pancreatitis, will be difficult to detect on X-rays or ultrasound and screening blood tests can be normal. There is a very specific test for pancreatitis in dogs that can be run that may shed some light. Some hormonal diseases like an under-active adrenal gland can develop as dogs age and again a special test would be needed.
Inflammatory conditions of the upper GI tract will mimic cancer in some cases. This is a diagnosis that is made after other diseases, including cancer, have been eliminated. Some rare infections or inflammatory bowel disease often need a biopsy to establish a diagnosis. This can occasionally be accomplished with an endoscope, but you will frequently not be able to get the full-thickness biopsy which may be needed, and an exploratory surgery is usually required.
If it is cancer, some tumors can be treated with surgery. Certain solitary masses will respond great to surgical removal, and if there is no evidence of it having spread, occasionally it is curative. However, there is no way to know what type of cancer it may be without a surgical biopsy.
Your dog has a condition that is proving to be difficult to diagnose. I try to explain to people that it requires a step-by-step progression to get to the bottom of what is going on and without the luxury of running unlimited tests all at once, it occasionally will take a while. I hope that her endoscopy reveals what is wrong and there is a straightforward solution.
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