Pet Forum / Miscellaneous / Animal Health / February 2006

Considering that the blood results are all within norm - your vet is
right. Try another vet, but don't be the least bit surprised when you
get the same answer. Every one of the symptoms you describe can be
found in food adverse reactions. I don't know what your vet is
describing as "testing" for advrse reactions to foods. ELISA blood
testing is worthless for this purpose and the only reliable "test" is a
food elimination trial. Put the dog on a novel protein - follow the
instructions EXACTLY - NO treats, NO other foods of any kind whatsoever
for 6 weeks and see what happens.

Hey, there, Laura.

I'm sorry to say your pup's case isn't cut and dry.  I'll try to explain
what I mean:

-some of the clinical signs can be consistent with hypothyroidism.  On
the other hand, some of them show that you've been "over-researching"
and reaching for an answer.  I can assure you if your pup has "stunted
growth", it's not due to hypothyroidism.  Is he "hyperexcitable" or
"lethargic" with "mental dullness".  "Mood swings"- could be normal
chocolate lab:-)  I would doubt he truly has constipation AND diarrhea.
 Could he have intermittent diarrhea with straining (which looks like
constipation)?

-The skin signs you describe certainly CAN BE associated with
hypothyroidism, however also realize they may also be associated with
chronic allergic skin disease, chronic staph pyoderma and chronic yeast
overgrowth.  The rat tail, symmetrical hair loss, dull coat and dry skin
can be caused by hypothyroidism.  How about obesity?  You didn't mention
that, but clinically hypothyroid dogs are grossly overweight, almost
without exception.

-the thyroid profile is equivocal, for sure.  All veterinarians treat
these cases a little differently, so there's not a right or wrong way to
do it.  Personally, I'd try treating with thyroid supplements for 3-4
months, be sure the thyroid level is slightly above normal or in the
high normal range while on the medication and see how he does
clinically.  In the meantime, I'd be working on the likely secondary
problems, such as a staph infections and/or a yeast overgrowth.

-there's a chance he's not hypothyroid but is "euthyroid sick", meaning
his body is working on something else (chronic skin disease,
inflammation, infection, etc.) and that his thyroid level is low normal
secondary to that.  The fact that the Free T4 is within normal limits
makes this possibility a little more likely than true hypothyroidism.
On the other hand, there is a small percentage of hypothyroid dogs with
normal free T4 levels. So you know, the classic hypothyroid dog has a
low T4, a low fT4 and a high TSH level.

-allergies are certainly something to consider, Laura.  They're very
common, especially in Labs.  Are the problems seasonal at all?  If so,
then atopy (allergies to inhaled allergens) is likely.  Nonseasonal?  In
those cases, food allergy, house dust mite or mold allergies are more
likely.  There's a good chance both you and your veterinarian may be right!

-You mention the veterinarian won't increase the dosage.  Was his peak
thyroid level measured?  If not, I wouldn't increase the dose, either.
Thyroid supplements aren't benign.  If too much is given, there are
detrimental complications which can arise.

I hope this helps you.  These can be difficult cases to figure out, and
they often take months of testing/treatment to get a resolution, so
don't expect a miracle:-)  Please communicate well with your
veterinarian.  It doesn't sound to me like she's done anything wrong,
but I do think you two aren't communicating well.  If you're not
comfortable with her for whatever reason, then switching veterinarians
may be best, but sometimes we haven't explained our thought process well
enough, or the client is expecting too much, too soon.  There's a happy
medium in there that I hope you and your veterinarian can find.

Best of luck to you and your problem pup!

Sandy Christmus, DVM