Signalment: Canine, St. Bernard, male, 3 years old
	History: 4-5 week duration of exercise intolerance and loss of stamina. Condition has gotten progressively worse but dog is mentally alert. Appetite is poor and dog has lost about 10 pounds. Owner reports that dog knuckles on front legs and seems ataxic and weak after exercise. Dog seems to improve after resting. No vomiting or diarrhea has been observed. Water consumption is normal.
	Physical Examination: T. 101.2 F; HR: 70; RR: panting; MM pale pink; CRT >3.0 seconds. Pulse is weak. Dog is thin with generalized loss of muscle mass. Bilateral otitis externa is present. Auscultation is negative. Abdominal palpation is negative. Neurological examination: alert, responsive. Reluctant to get up. With minimal exercise dog becomes very tired, stumbles on front feet, and develops fine muscle tremors. Cranial nerves, spinal reflexes, and postural reactions are normal.
	Diagnostic Plan:Using the POVMR format, identify the problems and formulate a diagnostic plan for this case.

No.	Problem
1.	Episodic weakness
2.	Weak femoral pulse
3.	Generalized muscle atrophy
4.	Anorexia
5.	Otitis externa
6.
7.
8.
9.
10.

B. Of the problems you have identified, which is (are) the most important to manage?

A. DX: List ruleouts for the problems you identified in Step 2.

Problem No.	Ruleout(s)
1.	Hypoglycemia; Myasthenia gravis; Cardiovascular disease; Adrenal insufficiency; Hypercalcemia; Myopathy
2.	Decreased cardiac output (heart failure, decreased blood volume, cardiac arrhythmia); severe hypotension
3.	Chronic anorexia; catabolic metabolic disease; myopathy
4.	Oral disease; primary neurological disorder; secondary to metabolic, infectious, neoplastic, or toxic disease.
5.	Bacterial infection; fungal-yeast infection; parasites; foreign bodies
6.
7.
8.
9.
10.

B. List those diagnostic procedures that will be most cost-effective.

1.  2.

3.  4.

5.  6.

7.  8.

9.  10.

Analyze the initial database results.

Hematology:

RBC Morphology:

Test	Value	Unit	Point your mouse here to view Hematology Norms	Test	Value
WBC	16700	x 103 /mm3		Normal
RBC	5.4	x 106 /mm3		Rouleaux	0
HGB	12.3	gr/dl		Polychrome	0
PCV	31.8	%		Aniso	0
MCV	69	fl		Poik	0
MCV	22	pg		Crenation	0
MCHC	34	g/dL		Target	0
PLT	261000	x 103 /mm3		Hypochrome	0
TP	5.4	g/dL		BasoStrip	0
FIB		mg/dL		Sphero	0
Retic	0	%		NRBC/100 WBC	0
PUNT
AGGR
SED RATE		x 103 /mm3

Differentials:

Assessment: What is your assessment of the hematology data?

Test	%	Absolute	Point your mouse here to view Hematology Norms	A mild non-regenerative anemia is present. Despite presence of stressful disease, normal lymphocyte and eosinophil counts are present. The findings are consistent with many chronic diseases but hypoadrenocorticism should be suspected and ruleout.
SEG		12191
Band		0
Lymph		2756
Eosin		501
Mono		1253
Baso		0
Other		0
PLTest
Toxic change

Biochemical profile:

Test	Value	Unit	Point your mouse here to view Chemistry Norms	Test	Value	Unit
Sodium	126	m mol/L		T. Bili	0.01	mg/dl
Potassium	7.7	m mol/L		ALKP	225	u/l
Chloride	99	m mol/L		ALT	75	u/l
TCO2	14	m mol/L		AST	28	u/l
Urea	125	mg/dl		LDH	275	u/l
Creatinine	2.5	mg/dl		CK	105	u/l
Calcium	13.9	mg/dl		GGT		u/l
Phosphorus	6.5	mg/dl		Magnesium		mg/dl
Glucose	65	mg/dl		Osmolality		mosm/L
T. Protein	6.5	g/dl		Anion Gap		mosm/L
Albumin	4.2	g/dl
Globulin	2.3	g/dl
A/G ratio

What is your assessment of the biochemical profile ?

Azotemia is present with urine specific gravity of 1.018. Hyperalbuminemia supports dehydration. Renal failure or hypoadrenocorticism could cause these findings. Hyponatremia, hyperkalemia, mild hypoglycemia, and mild hypercalcemia are present. Adrenal insufficiency is the major ruleout for these findings. Myopathy is not likely and acute myositis is ruled out. Elevated liver enzymes can be found in some cases of adrenal insufficiency (associated hepatopathy, possible immune mediated).

Urinalysis:

Microscopic Sediment Exam:

Test	Value	Unit		Test	Value	Unit
Volume	4	ml		WBC	0	ml
Color	pale yellow			RBC	0
Transparency	clear			Bacteria	0
Specific Gravity	1.018			Epitheliel	0
Phosphorus				Fat	0
Protein	0	mg/dl		Sperm	0
Ketones	0	mg/dl		CaOxalate	0
Bilirubin	0			CaCarbonate	0
Blood	0			TriplePhos	0
Urobili	0			Bilirubin	0	mg/dl
				Amorph	0	mg/dl
				Casts	0

What is your assessment of the urinalysis data?

In the face if dehydration and azotemia, dog is not concentrating urine. Suspect renal failure or adrenal insufficiency.

Identify the major ruleout(s) supported by this data.

Hypoadrenocorticism

Have you identified any new problems?	No Yes	If so, what are they?
Yes. A hepatopathy is present.

List the diagnostic tests or procedures that should be performed next.

ECG; ACTH Stimulation test

RX:

What immediate therapy would you prescribe for problems identified in Section 2?

Intravenous NaCl and soluble, rapid acting glucocorticoids are indicated. Should hyperkalemia worsen, intravenous glucose and insulin should given.

Learning Issues:

	Review/describe the causes of episodic weakness in dogs.
	Review the causes of bradycardia in dogs.
	Describe the ruleouts for hypoglycemia in dogs.
	Describe the etiology and pathophysiology of hypoadrenocorticism.
	Describe the diseases or conditions that might be found in association with hypoadrenocorticism.

Continue with Expanded Case Evaluation

Problems? Content: Dr. Michael D. Lorenz; Web page operation: Betty Handlin
Copyright^© 1999 Oklahoma State University College of Veterinary Medicine
This page was last updated 10/19/07 09:51:09 AM