Diagnostics Flashcards
Why does the plasma protein concentration affect the total serum calcium concentration?
Serum calcium is bound to albumin, such that changes in serum total protein concentration can cause equivalent changes in serum total calcium (but not serum ionized calcium) concentration.
The ELISA heartworm test detects antigen from:
A) Microflora
B) Adult female worms
C) Adult male worms
B) Adult female worms
In dogs, the ultrasonographic appearance of a gallbladder mucocele resembles which cut fruit?
The kiwi fruit
What is the diagnostic test of choice for evaluating the magnitude of proteinuria in a dog or cat?
Urine protein to urine creatinine ratio (UP:UC or UPC ratio)
When measuring the following parameters in the same patient, which can be expected to be significantly different (e.g. more than 25%) in venous blood samples compared to arterial samples? PCO2, PO2, HCO3-, pH
Only PO2 is appreciably different - typically 50% lower in venous samples compared to arterial
Your heparinized blood gas sample shows marked hypernatremia that is inconsistent with the clinical picture. Which error likely occurred when obtaining the sample?
blood was drawn into sodium heparin rather than lithium heparin.
Grossly, hemorrhagic pericardial effusion can most reliably be differentiated from peripheral blood in which way?
It rarely clots (exceptions: cardiac rupture or severely hemorrhaging neoplasm)
Should brain tissue submitted for rabies testing be refrigerated or frozen?
Refrigerated
Heat precipitation or electrophoresis of urine is used for detecting which characteristic substance in cases of multiple myeloma?
Bence Jones proteins
What are the hallmark clinical pathologic findings of hemorrhagic gastroenteritis in dogs?
Increased hematocrit (50-80%) with normal to low total protein.
What is the diagnostic test of choice for salmonellosis (‘‘parathyroid’’) in chickens?
Direct bacterial culture, to allow identification of the Salmonella species
When drawing blood from a ferret for hematologic and biochemical panels, which two venipuncture sites are commonly used that provide the appropriate sample volume (about 1.5mL)?
The jugular vein and the cranial vena cava
How would you confirm a tentative diagnosis of myasthenia gravis?
Identify the presence of serum acetylcholine receptor antibodies; edrophonium (Tensilon) testing is considered obsolete.
What is the anticoagulant of choice in test tubes used for coagulation testing and blood typing?
Citrate (Blue top tube)
How can you explain that an animal with ketonuria has a negative ketones result on urine dipstick?
High level of beta-hydroxybutyrate. Urine dipstick ketone squares react to acetoacetate, but not beta-hydroxybutyrate.
Why is the blood glucose reading falsely low if left at room temperature for longer than 60 minutes?
Because of red blood cell glycolysis
In dogs, approximately which proportion of nephrons must be nonfunctional before abnormal concentrating ability of the kidneys is evident?
2/3 need to be non-functional (versus 3/4 for azotemia)
Which common characteristic of large animal urine can cause a false positive result for urinary protein?
Strongly alkaline urine
What is the organism most commonly isolated from cat bite abcesses?
Pasteurella multocida is the bacterium most often cultured from abscesses of cats caused by the bite of other cats.
If you make a radiographic diagnosis of hypertrophic osteopathy of a patient’s radius, what is your next diagnostic step?
Thoracic and abdominal radiographs, looking for a mass.
Knowing a patient’s serum electrolyte levels, how can you calculate the anion gap?
Anion gap = (Na+ + K+) - (Cl- + HCO3-)
How can you explain that hyperlactatemic calves have a normal blood lactate measurement?
They predominantly have high circulating d-lactate levels, whereas analyzers measure l-lactate.
If your patient’s pH is high and the pCO2 is decreased, which type of acid-base disturbance does the patient have?
Respiratory alkalosis
What is the diagnostic blood test of choice, and the expected abnormality, in a case of organophosphate intoxication?
Serum acetylcholinesterase levels
Low levels (Less than 50% normal) are consistent with intoxication.
Name the most common laboratory test abnormalities identified in acute canine Anaplasma phagocytophilum infection.
Thrombocytopenia, lymphopenia, elevated serum alkaline phosphatase and/or amylase activities.
In the pregnant female dog, mineralized fetal skeletons can be detected radiographically as early as how many days after the luteinizing hormone (LH) peak?
45 days
What is the Morgan line?
It is a radiographic finding that represents the formation of enthesiophytes on the caudal aspect of the femoral neck, medial to the trochanteric fossa. It occurs as a result of early degenerative joint disease of the coxofemoral joint.
What does serum protein electrophoresis do?
It quantifies the individual protein fractions that make up the total protein content of serum.
Gamma glutamyl transferase (GGT) is the liver enzyme most sensitive to cholestasis for all feline liver diseases except one. Which disease, and which enzyme is superior for it?
Hepatic lipidosis; alkaline phosphatase.
Which specific test is used for asserting the function of the intrinsic coagulation pathway?
Activated partial thromboplastin time
What are the 4 ECG characteristics of atrial fibrilation?
1) No P waves
2) Undulating baseline
3) Normal QRS complexes
4) Irregularly irregular rhythm
Mycobacteria all have which specific microscopic staining characteristic in common?
They are acid-fast staining
After what approximate period of time from the onset of anemia would you expect a maximum erythropoietic response from the marrow?
7 days
What is the fecal flotation medium of choice for demonstrating Giardia cysts?
Zinc sulfate
The prothrombin time evaluates which pathways of secondary hemostasis?
Extrinsic and common pathways
When testing serum bile acids in horses, only 1 sample is taken as compared to dogs and cats in which 2 samples are taken. Why only 1 in horses?
Because horses lack a gallbladder, there is no advantage in measuring a postprandial sample.
What is the mechanism of hypercalcemia leading to low urine specific gravity?
Hypercalcemia interferes with the action of antidiuretic hormone and renal concentrating ability.
What is the anticlinal space and where is it found in the cat and dog?
It is the narrowest thoracic intervertebral disk space. It is found between the 10th and 11th thoracic vertebrae (the 11th thoracic vertebra is the anticlinal vertebra).