Alright, case number three. We have a one year old female spayed domestic shorthair cat and she is up to date on her vaccines and she is indoor only and she has a 24 hour history of severe vomiting 10 to 12 times and anorexia. All right, so here is her physical exam. All right. Her mucous membranes are pink. They're slightly tacky, but her CRT is less than 2 seconds. And on abdominal palpation, she feels tense in her cranial abdomen. 

Okay, so here is our serum chemistry panel. I'll give you a second to look at that. And then because today we are talking about blood gases, we will look at our venous blood gas as well. And here it is. So take a look at those values and just think for a second how you would describe this acid base abnormality. All right. And I've just included over here our electrolytes on this panel on the right so that we can look at our anion gap as well if we wanted to. All right. So let's start at the beginning. Is our pH normal? The answer is no. Our pH is higher than the reference range. And and remember, now we're talking about a cat, so our reference range is slightly different than a dog. So our pH is greater than 7.4, which is the upper end of our normal range, which indicates an alkalemia. So that means a loss of hydrogen or an accumulation of bicarbonate. Second question. Is our primary disturbance metabolic or respiratory? So remember, for a metabolic problem causing an alkalosis, our bicarb is going to increase and our base excess is going to increase. If it were respiratory, on the other hand, our PCO2 would decrease. So in this case, our bicarb is increased at 26 and a base excess is also more positive at plus eight. So that means that we can now classify our alkalemia as a metabolic bicarb alkalosis. So the next question is, is there compensation? So we're going to look at our PCO2 to try to figure that out. And if we look at our PCO2, we can say, what would we expect? Well we'd expect our PCO2 to increase, because CO2 is acidotic, and so we would expect our acid to increase to balance the alkalosis. And so remember, this happens very rapidly. So this can happen in a matter of minutes. And so we do see that there is some evidence of respiratory compensation. So we would say in this case that we have a metabolic alkalosis with respiratory compensation as well as a chloride loss. So we have hypochloremia. So then, of course, the question is why? And this kitty, remember, has a history of acute vomiting with a hypochloremic, loss of chloride, metabolic alkalosis. So this in this case indicates that we're losing gastric acid. Remember, gastric acid is hydrogen chloride. So we're losing chloride and we're losing hydrogen, which is making us alkalotic. This is fairly uncommon in small animals. We don't see it that much. But if you have a pyloric outflow tract or proximal duodenal obstruction, you may see this pattern. So it's an important pattern to recognize because it is sort of one of those classics. And in Juniper, we found that she had a pyloric outflow obstruction due to eating something silly. She's a one year old kitty. And sometimes one year old kitties like to do that and that is the cause of our hypochloremic metabolic alkalosis.