Vomiting and diarrhoea… two sides of the same coin and easily the most common reason families present to the veterinary emergency room with their dog or cat. Unfortunately for something so common, it is not as simple as many people think. There are textbooks the size of cinder blocks on gastrointestinal disease. But here’s what I often find myself saying in consult.
First off, we all need a certain amount of water each day. A patient with vomiting or diarrhoea will need more because of the extra fluids they are losing. Unfortunately, they often have no appetite or a reduced appetite and can’t keep up with their fluid losses. As a result, your pet can become dehydrated very quickly, which can be life-threatening. This is why many patients often need hospitalisation with fluid therapy or “a drip”. However, a drip in the hospital is usually just the starting point and doesn’t address the underlying cause.
In terms of causes for vomiting or diarrhoea, I often break up the causes into “the common things that are common” and the “weird and the wonderful”. Common things that are common, include:
- “I ate something (an object) and I’m BLOCKED!!!”
- “I’m a puppy and I have PARVOVIRUS!!!”
- “I ate something (usually gone off food) and I’ve got gastroenteritis”
- “I ate something (usually fatty foods) and I’ve got pancreatitis”
- “I ate something (an insect) and I’ve had an allergic reaction”
Now, if there is a blockage or parvovirus, they are game changers, as a blockage is a surgical emergency and parvovirus is highly infectious and takes a really long time to recover. So, my first line diagnostics is usually to try rule those out with some tests. Thankfully, the other common diseases will respond really well to fluid therapy, pain relief and some gut protectants and your pet will usually be back to themselves in no time. Unfortunately, no test is full proof. For example, radiographs or x-rays are often used to try to find a blockage. However, radiographs are a 2-dimensional image representing a complex 3-dimensional structure (the abdomen). So, it’s not like a photo of your dog’s stomach. So sometimes repeat images are needed or a follow up with ultrasound as a different type of imaging.
Usually, if my patient is not better within 12 hours, I look to do more tests because we have to open that “weird and wonderful” box at some stage. Some of the weird and wonderful causes include liver disease, kidney disease, some hormonal diseases as well as infectious diseases like certain parasites, viruses and bacterial infections. We can check for these with blood tests (some which can be done in the hospital and some are done in an external lab), faecal analysis and different types of imaging such as radiographs or ultrasound. Then once a diagnosis is made, I give specific treatment for that disease.
Now, this is all meant as very general information and I have changed my recommendations from this, depending on what has been going on at home and the physical exam. A puppy that is super bright and comfortable on physical exam, who had a few vomits but is still eating, I may discuss trying treatment at home first. A critically ill patient, I might recommend we do every test straight away because we don’t have time to see how they respond to supportive care. And another vet may have a different way of working up a vomiting or diarrhoea case. But if your pet develops vomiting or diarrhoea, do have a chat with your vet. Even if it is something benign going on, dehydration can still be life-threatening and I always recommend a visit to the vet.