Study Case — A
Mixed Breed Dog with Elevated Blood Glucose and PU/PD
James P. Stortz,
DVM; Kenneth S. Latimer, DVM, PhD; Bruce E. LeRoy, DVM, PhD
Class of 2005 (Stortz),
Department of Pathology (Latimer, LeRoy), College of Veterinary Medicine,
University of Georgia, Athens, GA 30602-7388
Signalment -
Canine, mixed breed, male, castrated, 10-year-old
Medical history – PU/PD,
elevated blood glucose, glucosuria
Laboratory
data -
Complete
blood cell count - |
| |
|
Units |
Reference Interval |
| Hct |
49.3 |
% |
35.0-57.0 |
| RBC |
7.06 |
x 106/µl |
4.95-7.87 |
| Hgb |
16.9 |
g/dl |
11.9-18.9 |
| MCV |
69.9 |
fl |
66-77 |
| MCH |
24.0 |
pg |
21.0-26.2 |
| MCHC |
34.3 |
g/dl |
32.0-36.3 |
| Platelets |
372 |
x 103/µl |
211-621 |
| MPV |
8.3 |
fl |
6.1-10.1 |
| RBC morphology |
slight
anisocytosis,
moderate poikilocytosis
|
|
|
| |
| WBC |
7.9 |
x 103/µl |
5.1-13.0 |
| Seg |
6.241 (79%) |
x 103/µl |
2.9-12.0 |
| Band |
0.158 (2%) |
x 103/µl |
0.0-0.45 |
| Lymph |
1.027 (13%) |
x 103/µl |
0.4-2.9 |
| Mono |
0.395 (5%) |
x 103/µl |
0.1-1.4 |
| Eos |
0.079 (1%) |
x 103/µl |
0.0-1.3 |
| Baso |
0.0 (0%) |
x 103/µl |
0.0-0.14 |
| WBC morphology |
occasional polychromatophils |
|
|
| Plasma Appearance |
1+ Lipemia |
|
|
| Biochemical
profile - |
| |
|
Units |
Reference Interval |
| BUN |
17 |
mg/dl |
10.0-30.0 |
| Creatinine |
0.9 |
mg/dl |
0.5-1.5 |
| Total protein |
7.6 |
g/dl |
5.2-7.3 |
| Albumin |
3.8 |
g/dl |
2.5-4.2 |
| Alkaline phosphatase |
871 |
U/L |
12-122 |
| Alkaline phosphatase
w/ levamisole resistance |
525 |
U/L |
0-94 |
| Levamisole resistance |
60 |
% |
|
| Alanine aminotransferase |
102 |
U/L |
12-108 |
| Glucose |
410 |
mg/dl |
77-120 |
| Sodium |
143 |
mmol/L |
146-154 |
| Potassium |
4.7 |
mmol/L |
3.9-5.0 |
| Chloride |
107 |
mmol/L |
107-125 |
| Bicarbonate |
14 |
mmol/L |
14-24 |
| Anion gap |
27 |
mmol/L |
11-28 |
| Calcium |
11.2 |
mg/dl |
9.3-11.4 |
| Phosphorus |
3.5 |
mg/dl |
3.2-5.4 |
| Magnesium |
2.4 |
mg/dl |
1.6-2.4 |
| Amylase |
687 |
U/L |
276-1007 |
| Lipase |
353 |
U/L |
117-578 |
| Cholesterol |
302 |
mg/dl |
129-264 |
| Triglycerides |
755 |
mg/dl |
26-138 |
| Total bilirubin |
0.1 |
mg/dl |
0.0-0.2 |
| Urinalysis
- |
| |
|
| Urine source |
cystocentesis |
| Color |
yellow |
| Turbidity |
clear |
| Specific gravity |
1.043 |
| pH |
6.0 |
| Protein |
2+ |
| Glucose |
3+ |
| Ketones |
trace |
| Bilirubin |
negative |
| Blood |
small amount |
| Sediment
- |
|
<10/hpf |
|
<5/hpf |
|
few transitional
epithelial |
|
few amorphous |
 |
Normal urine
dipstick (lower) and dipstick from a dog with diabetes mellitus
(upper) and a urinary tract infection.
Abnormal findings
(from left to right): trace protein, pH 8.5, +++ blood, trace
ketone, + bilirubin, and marked glucosuria (= 2000 mg/dl).
Positive Acetest
tablet (purple, left) represents acetone which, unlike acetoacetate
and ß-hydroxybutyrate, does not react with dipstick test
pad for ketones. |
Problems
-
1. Lipemia. Hyperlipemia
often is present in the blood from the increased catabolism of lipids
seen with diabetes mellitus. In addition, lack of insulin results
in decreased lipoprotein lipase activity.
2. Hyperproteinemia.
Water loss (dehydration) results in increased concentration of plasma
proteins. This water loss is most likely a result of osmotic diuresis
caused by glucosuria. Since the slight hyperproteinemia is present
and the hematocrit is within the reference interval, the dehydration
is probably mild. If serum or plasma protein is measured with a refractometer,
the total protein value also may be increased because of the lipemia.
3. Markedly
increased alkaline phosphatase (ALP) activity with 60% levamisole
resistance. The increased ALP activity can mostly be attributed
to the production of the steroid isoenzyme as a result of exogenous
corticosteroid administration or endogenous cortisol production.
The remaining increase in ALP activity is most likely due to the
hepatic isoenzyme. This could be attributed to possible hepatic
lipidosis from the increased utilization of adipose tissue for
energy and a lack of insulin resulting in reduced lipoprotein lipase
activity.
4. Hyperglycemia.
Hyperglycemia is associated with a lack of insulin production in
diabetes mellitus. Blood glucose concentration increases because
of decreased glucose uptake by tissues. Glucose values also may be
falsely increased by lipemia in some endpoint assays.
5. Hyponatremia. Sodium
is decreased due to glucosuria-associated osmotic diuresis.
6. Hypercholesterolemia. Cholesterol
concentration is increased in the blood as a result of increased
lipolysis and decreased lipoprotein lipase activity.
7. Increased
triglyceride concentration. Triglycerides are increased
in the blood via increased lipolysis and decreased lipoprotein
lipase activity.
8. Proteinuria. Proteinuria
is most likely due to the glomerular disease that accompanies diabetes
mellitus in animals and people. This is due to widespread thickening
of the glomerular capillary basement membrane and diffuse glomerulosclerosis.
Lower urinary tract infection may commonly be present in cases of
diabetes mellitus and result in proteinuria. However, this is not
likely in this case because the sediment examination is not indicative
of urinary tract infection.
9. Glucosuria. The
increase in blood glucose eventually exceeds the resorptive ability
of the renal tubular cells and glucose is excreted in the urine.
This occurs when the blood glucose concentration exceeds 180 to 220
mg/dl in dogs.
10. Ketonuria. Increased
rates of lipolysis and ketogenesis for alternative sources of energy
result in ketone production (indicating a negative energy balance).
As ketones accumulate in the extracellular space, they eventually
surpass the renal tubular threshold for complete resorption and enter
into the urine. There is only a trace of ketones in this urinalysis,
indicating a low level of ketogenesis in the liver. In more severe
cases of diabetes mellitus, ketoacidosis and metabolic acidosis may
be present.
11. Small
amount of blood on urinalysis. Blood found on the urinalysis
is most likely a result of cystocentesis.
Diagnosis — Diabetes
mellitus
Case summary - The
diagnosis of diabetes mellitus can be made if there is an elevated
blood glucose concentration, glucosuria, and ketonuria at the same
time. The blood glucose concentration is best measured from a fasting
animal. Other tests, such as glycoslyated hemoglobin or fructosamine
determination can be used to confirm or exclude diabetes mellitus in
animals with unclear blood glucose test results. The other laboratory
abnormalities are only supportive of the diagnosis of diabetes mellitus.
References
Latimer KS, Mahaffey
EA, Prasse KW (eds): Duncan & Prasse’s Veterinary Laboratory
Medicine: Clinical Pathology, 4th ed. Ames, Iowa State Press, 2003
Ettinger SJ, Feldman
EC (eds). Textbook of Veterinary Internal Medicine. Diseases of the
Dog and Cat. W.B. Saunders Company, 2000.
"Doggie"
by
Patty Kempf is from the AbleArts website and is used with permission. |