Lab mix can eat only soft food

Question
My 4 year old lab mix started vomiting exactly 2 weeks ago today. I took her to the vet two days after the symptoms started & they put her on Centrine & a canned, bland, easily digestible food. She is able to keep down the canned food fine (even without the Centrine, which she is no longer on) but as soon as I give her anything solid she regurgitates/vomits. Yesterday I gave her a single treat & she immediately threw it up along with some/all of the food I'd fed her two hours earlier. She is going to the bathroom fine & I've checked her stool & there is no blood or anything. She also acts like she feels fine & plays with our other dog like normal. Do you have any idea what could be causing this? I'm taking her back to the vet tomorrow but have been am worried about her now (& can't get in to see the vet) so I thought I'd see if I could get some input today.

Answer
Hi Aimee,

I understand your concern, but glad you've made an appointment for a return visit with your vet.

Of course, I'm not a vet, so I can only offer you guesses of what might be ailing your dog. A couple of things come to mind.

Irritable Bowel Syndrome, or IBS can manifest as chronic diarrhea, but it can also cause chronic vomiting/regurgitation. IBS is best treated by adjusting the dog's diet.
There are several dietary approaches that work to control different forms of inflammatory bowel disease. For dogs that are allergic or sensitive to certain food ingredients, all that is necessary is to avoid the food that causes problems. It can be difficult to identify the offending food, though. Besides the possibility of a food allergy to a food's main protein source, some dogs are allergic to things like preservatives, dyes, or the plant proteins such as wheat, corn or soybean. There are a couple of new diets on the market that are composed of hydrolyzed proteins, which produces a protein molecule
that is below the size that causes allergic responses, in theory making these diets ideal for dogs that
have a tendency to react to food. Hills makes z/d diet and Purina makes HA and LA diets in this manner.
From a medication standpoint, Metronidazole (Flagyl) works well, to get the dog's vomiting under control, and for the occasional flair up of symptoms.

There isn't a cure for IBS, but it certainly can be controlled. One of my dogs has it, and once he was finally diagnosed correctly, diet pretty much controls his vomiting/regurgitation, though he still throws up more than either of my two other dogs.

If your dog has IBS, you should stick to the prescription bland diet, in time you might be able to reintroduce some other foods, but your dog's system is irritated, and probably needs a rest. Of course it's possible that she may need to stay on the prescription diet for the rest of her life.

Another possibility is a condition known as Megaesophagus. With this condition, there is dilation of the esophagus has a loss of normal "peristaltic function". Peristalsis is the process by which waves of muscular contraction move along the contents (food in this case) of tubular organs. Animals with Megaesophagus regurgitate undigested food shortly after eating. Regurgitation of undigested food shortly after eating is the main sign with this disorder.

You can read about Megaesophagus here:
http://www.marvistavet.com/html/body_megaesophagus.html

In some dogs, esophageal problems such as hypomotility
associated with myasthenia gravis or other problems can lead to regurgitation that resembles vomiting but usually happens just after eating.

It is helpful to know the cholesterol and triglyceride
levels when chronic vomiting is a problem. Hyperlipidemia is a condition in which the amount of fats (lipids) in the blood are elevated. This includes both triglycerides and cholesterol being too high. Hyperlipidemia occurs normally for a short time after a meal, then returns to the correct level. However, some dogs have a metabolic problem which prevents the proper cleaning of the fat from the blood stream, resulting in the high lipids. This results in chronic pancreatitis or frequent attacks of acute pancreatitis, which can be a cause of the frequent vomiting. If the cholesterol and/or trigylceride levels are very high it might be helpful to switch to Hill's w/d diet, which can help reduce the lipid levels in the blood stream.

I hope I've been a help.
Best of luck,
Patti