Now let’s consider pulses in more detail. What is the CV response to exercise, stress or pain? Tachycardia and increased force of contraction. This generates a taller than normal pulse that is narrower because of the faster rate. The response to early hypovolaemia is exactly the same but the pulse will be narrower because of the reduced intravascular volume. The ONLY way you will tell the difference is by being able to appreciate that the dog with early hypovolaemia has a narrower pulse. As hypovolaemia worsens the pulses become gradually shorter and narrower. And the height and width will always match the other CV parameters if it is plain old hypovolaemia such as haemorrhage.The other great thing is that as you give IV fluids and volume replace an animal, the CV parameters will go back through the same stages in reverse so you can assess whether your response to treatment is appropriate or insufficient. It is vitally important that you learn the stages of simple, uncomplicated hypovolaemia so that you can recognise when the CV parameters do not fit together. That is how you will be able to recognise the other perfusion abnormalities.