So hard to tell... I know of a human that had similar symptoms and there were dozens of things the Dr said could be causing it, so I thought maybe the same thing for a dog... but I remembered something I'd read on it (I have dozens of bookmarks!) and it was ask a vet or something:
Question: Dr. Mike,
Wilma, my 7yr. female Dalmatian has gained 10 pounds in two months,
drinks a large amount of water and pants. Her vet ran the ACTH test for
Cushings. Negative. Urinary infection and diabetes also negative. What are
your recommendations?
Bob
Answer: Bob-
There are more than 20 disorders that can lead to increased drinking
and urinating. It can be frustrating to sort through them all but the only
thing that you can do is to start somewhere, as you have done, and
eliminate the disorders until you find the one that is causing the
problem.
The list of disorders I can think of that cause increased drinking
include:
1) kidney failure (chronic, acute, infectious (leptospirosis, esp.))
2) hyperadrenocorticism (Cushing's disease)
3) diabetes mellitus
4) liver failure
5) hypoadrenocorticism (Addison's disease)
6) pyometra (uterine infection, applies to females only, obviously)
7) intestinal obstruction (occurs after toxins begin to be absorbed
from the damaged intestine)
pyelonephritis (infection of the kidney)
9) hypercalcemia (most commonly from cancer)
10) diabetes insipidus -- can be central (brain related) or
nephrogenic (kidney related)
11) behavioral or psychogenic water drinking
12) acromegaly
13) polycythemia
14) hypokalemia
15) renal glycosuria (Fanconi's syndrome)
16) partial obstruction of the urinary tract
17) neurologic damage leading to urine retention or difficulty voiding
18) medications (diuretics, corticosteroids)
19) pheochromocytoma (a form of cancer)
20) pericardial effusion
21) hypothyroidism (dogs) or hyperthyroidism (cats) -- not too common
with these
22) paraneoplastic syndromes (usually this is hypercalcemia but
sometimes other substances linked to tumors cause increased drinking)
Most of the time a number of these conditions can be eliminated based
on the physical examination and initial blood chemistry panel, urinalysis
and complete blood cell count. That usually leaves the hormonal disorders
and psychogenic causes, plus some of the rare conditions like
pheochromocytomas.
The hormonal illnesses can be tested for individually. Determining the
right order to test for them is difficult and is often a judgement
call. We usually start with Cushing's disease if we have no idea which illness
seems most likely based on our initial findings and tests. We do this just
because it is a common cause of increased drinking and urinating (and
weight gain). Acromegaly is normally associated with diabetes so we may
skip testing for this one in the absence of diabetes unless we don't
find anything else. Hypoadrenocorticism is less common than Cushing's
disease so we usually test for it second and often only if the cortisol levels
were low on the samples taken for the Cushing's disease testing. Diabetes
insipidus is most easily tested for clinically by judging response to
treatment using desmopressin (DDAVP Rx).
It can take some time to sort through these possibilities but with
persistence it is usually possible to find a cause for the increased
drinking and urinating. It is sometimes necessary to test for
Cushing's disease several times in dogs with strong clinical signs but normal
test results -- there are false negative test results between 5% and 25% of
the time (percentage varies depending on which studies you read and which
tests are run).
Mike Richards, DVM
8/20/2001
Anyways... I always hate to see people worrying before the final diagnosis... and as the doctor eventually told my relative after a bunch of tests (for diabetes, etc) that ALL came back with nothing... perhaps its just the summertime and with the dog days lately, maybe he is just drinking a lot more and his tiny bladder cant handle all of the fluids it isnt used to, so he is having accidents. I am happy that you caught on to it and are doing some tests, and keep us updated.
AcmeChats.Com
Author
