Thursday, April 30, 2009

The $600 Allergy Test

Popeye has been scratching a lot for the past few months. A LOT. It started around the end of January but didn't escalate to a noticeably severe level until February. It seems that it started around the time the neck craning began (which in turn began around the time he got his cart), but that could just be a coincidence that I started noticing it around then.

For months now, he has been scratching and so far nothing has helped, other than the Prednisone he was on for 2 weeks. He rubs his chin and neck against the carpet. A LOT. It seems like during those moments when his neck craning is at its most extreme is when he plops down and starts rubbing his chin against the carpet. But again, just a coincidence I happen to notice it most during those times? Every morning he wakes up and starts scratching his chin like crazy.

He also chews between the pads of his front paws. A LOT. And scratches his face (or ears maybe?) with his paws. And to a lesser extent, chews on his forearms. He's got patches of hair missing there now.

Benedryl made not the slightest bit of difference. We're going back to acupuncture tomorrow for his 2nd session, but the chinese herbs he was given, along with the fist needle session, hasn't seemed to make any difference either.

Out of desperation, I had the vet draw some blood to submit for an allergen test. I had read that these tests are not necessarily accurate, but I had to try it. I didn't realize how expensive these tests were but even if I had, it probably would not have made a difference (that's what I keep telling myself anyway). I'm still desperate, by the way.

We got the results today. So what did the $600 allergy test determine? It determined that Popeye is not allergic to any of the things they tested him for. Well, maybe.

They ran 2 tests for Popeye--environmental allergens and food allergies. If a dog shows EA units of at least 150, then they are considered allergic to that particular item. Popeye's highest reading was at a mere 30. That was on the environmental test. Of course, only the most common allergens were tested.

There's a note on the results for environmental allergens that reads:

The reportable range of this ELISA is from 0 to 5000 EA units. EA units of 150 or higher may be considered significant provided they correspond with clinical signs; however, the magnitude of signal does not necessarily correlate with the severity of disease.

Based on some online reading (which I did after the fact of course), the gold standard for environmental allergens is a skin test rather than one based on a blood sample.

The vet said that had Popeye tested positive for environmental allergies, there is a desensitizing regimen he could have gone through whereby I think they would give him small shots of that allergen until he built an immunity to it. But no such procedure for food allergies. Which Popeye doesn't have anyway. Well, maybe.

His highest score on the food test was only 18, and that was for whole egg (which I don't remember ever feeding him, by the way). He had 16 and 15 scores for milk, cooked rice, and wheat grain.

You would think that his low scores would imply that he wasn't allergic to any of the foods they tested him for. But no, here's the note:

Not all patients with adverse reactions to food have significant scores on serum IgE tests. The gold standard for determination of food allergies remains the compliant food trial. Diet selection should include patient diet history and should supply a restricted number of one or two novel protein sources to which the patient has not had prior exposure. Diet trials should run a minimum of 10 to 12 weeks.

In other words, the test can yield inaccurate results, and the best way to determine food allergies is put the dog on an "elimination diet" of just 1-2 proteins which he's never had before. I may end up putting Popeye on an elimination diet (which I don't really want to do for any number of reasons I won't go into now), but I wish I had done more research about these blood sample-based allergy tests before doling out $600 for it.

At this point though, I'm not even convinced that the itching has anything to do with specific allergies. I sometimes wonder if it's just the manifestation of some other problem, possibly relating to his neck craning. For example, a nerve issue that manifests itself in tingling paws. If only Popeye could talk.


Wild Dingo said...

I have a wonderful fabulous vet who is a certified accupuncturist. I know you have one already, but if its too far, my gal is in san jose/campbell/LG area. she relieved pain in Maggie's inflamed liver that kept her from walking so much so, maggie could walk again. that's how good she is with the needles. Maggie could NOT walk at all and she walked until her last day. I like this vet so much because she did a very intense fellowship for 2 years in animal accupuncture and really believes that it's as much an art as a science. if you want, please email me and i'll send you her info.

I wonder too if it is a central nervous system tingling thing too... which accupuncture would be FABULOUS for.