Does an abnormal result on your dog’s lab work automatically mean there is a problem?
Not necessarily. That doesn’t mean you shouldn’t seek an explanation and retest.
Cookie’s elevated ALT
ALT is short for alanine aminotransferase, which is an enzyme found primarily in the liver but also in other tissues (kidneys, heart, muscles, and pancreas). When a cell is damaged, ALT spills into the bloodstream. ALT can be increased with a self-correcting, transitory liver insult, gastrointestinal irritation (vomiting/ diarrhea, etc), mild muscle injury.
Further information: Why Are My Dog’s ALT Levels High or Low?
Routine blood test we ran as part of Cookie’s regular wellness exam showed elevated ALT. Because she looks happy and healthy and the number was nothing crazy, we decided to wait and see whether it returns to normal in a few weeks.
Retesting
We ran the blood work again.
The ALT remained unchanged. It didn’t get higher, it didn’t get back down to normal. Cookie still looked happy and healthy. So now what?
Because of the prior elevation, they included a liver profile in addition to comprehensive blood work to check liver function.
What does it mean?
Other than the ALT everything else looked normal. The potential explanations include:
- these are normal level for Cookie
- there is a cause outside the liver, such as low grade duodenal or pancreatic inflammation (Cookie did have pancreatitis a bit over a year ago)
- it could be portal vein hypoplasia (PHV) which means that the blood vessels in the liver are reduced in number, resulting in reduced blood flow to the liver
- Cookie might have primary low-grade hepatitis, which is inflammation of the liver. If that was the case we’d have to figure out why.
What would be the next step?
Possible further diagnostic include:
- Liver ultrasound with biopsy to observe vasculature (PVH) and rule out primary hepatitis
- Treating empirically with 4 weeks metronidazole and retest
- GI function test (cobalamin, cPLI, folate)
- Monitoring and retesting annually (which is something we do anyway)
The vet noted that in conversation with an internal medicine specialist, many would consider this elevation to be an individual anomaly (normal for her) in light of the absence of clinical signs. PVH is possible, but not common in large breed dogs. If the owner is concerned however, non-invasive diagnostics (ultrasound only, etc) could be undertaken to rule out these other conditions.
Because the liver could be affected by something such as low-grade chronic pancreatitis, testing the GI function makes sense to me to either discover the culprit or rule it out.
Getting a second opinion
We also had Jasmine’s vet review the results.
He feels that unless there are any signs of illness that at this level of the ALT he would not explore further other than regular re-tests. He also feels that it is possible that this level is normal for Cookie. No other values point to an unhappy liver.
A side note:
The earlier blood work also showed elevated eosinophils, a type of white blood cells. Both Cookie and JD had the same elevation. The primary suspect were parasites, even though none showed in the stool. We treated with Panacur and Cookie’s eosinophils are back to normal.
There is a possibility that this is behind the ALT elevation and didn’t have time to resolve.
The decision process
I have to say that I don’t like it when the blood work shows an abnormality.
Though it is not all that unusual that on a full blood panel a test value might end up outside the normal range. It happened on Jasmine’s blood work a number of times that one value or another was off.
But that’s just it. In Jasmine’s case, it was a different value every time. This one popped up twice consistently.
I think that testing the GI function makes sense to me.
Ultrasound, while non-invasive, requires shaving of the belly. In the temperatures we’ve been having, running around with a bare belly doesn’t sound like a good plan. And putting a sweater on Cookie? The way she runs through the bush it would probably last five minutes if that long.
Putting Cookie through invasive diagnostics while she doesn’t seem to be sick at all doesn’t make much sense. Or does it?
Final decision
In the end, we decided to follow up with the ultimate diagnostics, ultrasound, and cytology to try and get to the bottom of things.
You can read here how that worked out: Cookie’s Elevated ALT: The Ultrasound and Cytology
Related articles:
Regular Wellness Exam: Cookie’s ALT Was Elevated
Further reading:
Understanding Your Dog’s Diagnostic Testing