Approach to the Bleeding Patient, Part 1
By Dr. Sasha Thomason
Belle, a 9-year-old female spayed Golden Retriever, presents to your clinic in sternal recumbency and had to be carried in by a very anxious owner. The owner reports she was fine one minute, but collapsed and was unable to rise on her own the next minute. She is an older pet but in otherwise great health. On physical exam, you notice a subtle increase in respiratory rate and effort. Her mucous membranes are very pale - almost white - in color. Additionally, it appears there might have some slight abdominal distention and on abdominal palpation there is confirmation of fluid.
With this common small animal emergency scenario, you have two physical exam findings that can help you get to the bottom of this situation quickly – the pale mucous membranes and the abdominal fluid. The only two rule outs for pale mucous membranes in a dog are anemia or hypoperfusion. Obtaining a peripheral blood sample and performing a quick PCV/TP (packed cell volume and total protein) can help you determine whether anemia is present or not. Obtaining a blood pressure reading can help rule out hypotension, a common perfusion issue. In this case, both anemia and hypoperfusion are likely involved. But when you perform the PCV/TP, you find that Belle has a PCV of 21% and TP of 4.8g/dL.
When both the PCV and the TP are low, anemia is likely due to blood loss. (You do have to be careful, though, because in the early stages of hemorrhage, the TP may be low but the PCV is normal because of splenic contraction. The spleen is a storage vat for red blood cells and can replenish that supply in the short term, but the protein portion of blood has no such compensation). With hemolysis or a bone marrow issue, only the PCV will be affected while the TP is normal.
If you have ultrasound capabilities in your clinic, you can easily check for abdominal fluid. If not, you can always complete an abdominocentesis to assess the fluid type. The easiest way to perform a blind centesis is to place the patient in right lateral recumbency. Clip and prep the area approximately two fingers below and two fingers caudal to the umbilicus. This is the centesis target area. Palpate the abdomen to make sure you do not feel a firm mass in that area first. Using a 6cc syringe attached to a 20 gauge/ 1 inch needle, insert the needle into the abdomen perpendicular to the body wall. You usually have to fully insert the needle into the abdomen to get a sample of fluid. For best results collect approximately 4mls of fluid.
For Belle, the fluid you obtained grossly appears to be straight blood. You perform a PCV/TP on this abdominal fluid and find this fluid has a PCV of 18% and a TP of 4.0g/dL, which is very similar to her peripheral blood composition.
It is best to always leave some space in the syringe if the gross appearance is blood. To make sure the sample was not directly from a blood vessel or organ is to see if the sample clots within the syringe within a few minutes. If the sample clots, the sample was probably not abdominal fluid.
The history, anemia and hemorrhage in the abdomen confirms a diagnosis of hemoabdomen. Because this patient is an older dog with an acute onset of clinical signs, the most likely underlying cause is a tumor rupture. For approximately 95% of similar cases I managed during my 17 years in practice as an ER veterinarian were splenic tumors. Other possible underlying causes include trauma and anticoagulant rodenticide.
Hemoabdomen is one of the most common after-hours canine emergencies in small animal practice, and rapid diagnosis is key to the successful management of this condition. The classic clinical presentation is an older, large breed dog with a recent history of collapse in addition to pale mucous membranes, a slight increase in respiratory rate and effort, and possibly a distended abdomen. When you hear/see this combination follow the appropriate diagnostic steps to confirm your suspicion.