NAVLE PRACTICE SET QUESTIONS AND ANSWERS
SET A+
✔✔Hyperadrenocorticism is suspected in a 9-year old female spayed dog with a two-
month history of increased appetite, thirst and urinary accidents. Which of the following
diagnostic test is most reliable when results are positive?
Urine Cortisol Creatinine Ratio (UCCR). Sensitivity=90% , Specificity =25%
ACTH Stimulation. Sensitivity=80% , Specificity =85%
Low Dose Dexamethasone Suppression. Sensitivity=95% , Specificity =50%
A - Low Dose Dexamethasone Suppression (LDDS)
B - ACTH Stimulation
C - Urine Cortisol Creatinine Ratio
D - Cannot say without knowing the positive predictive value
E - Cannot say without knowing the negative predictive value - ✔✔B
ACTH Stimulation. The two diagnostic screening tests used most commonly for
diagnosis of hyperadrenocorticism are the ACTH stimulation test and the LDDS.
Remember your Ps and Ns.
ACTH Stim is the most sPecific (fewer false Pos, so trust a POS test more). LDDS is
more seNsitive (fewer false Negs, so trust NEG test more).
Either way, these 2 tests are useful to screen for Cushing's, but a confirmatory test is
usually required if you get a positive, to differentiate between a pituitary HAC or an
adrenal HAC case [high-dose dexamethasone suppression test (HDDST) or ACTH
concentration].
The Urine Cortisol Creatinine Ratio (UCCR) has a low specificity (~25%), which means
high false positives. 75% of dogs with non-adrenal illness will have a UCCR result
consistent with HAC.
, So, a positive UCCR is not useful to identify HAC, however, a negative is very useful to
rule-out HAC as dogs with a normal UCCR cannot have HAC.
✔✔You are visiting a small "back-yard" flock of chickens and examining the animals.
You find several small gray-red mites (approx 0.7 mm) on several of the chickens which
you recognize as Dermanyssus gallinae and Ornithonyssus sylviarum. How are these
mites best controlled?
A - Ornithonyssus sylviarum is controlled primarily by thorough insecticidal treatment of
the environment and Dermanyssus gallinae must be controlled by application of
approved pesticides to affected birds
B - Dermanyssus gallinae is controlled primarily by thorough insecticidal treatment of
the environment and Ornithonyssus sylviarum must be controlled by application of
approved pesticides to affected birds
C - Control of both Ornithonyssus sylviarum and Dermanyssus gallinae relies on
application of approved pesticides to affected birds
D - Control of both Dermanyssus gallinae and Ornithonyssus sylviarum relies on
thorough insecticidal treatment - ✔✔B
Dermanyssus gallinae (the common red mite) maintains the majority of the population in
the environment so it is important to monitor and treat the environment including the
cracks and crevices where mites tend to reside. Ornithonyssus sylviarum mites
(northern fowl mites) spend their entire life cycle on the bird. This allows them to
multiply more rapidly and makes it essential to treat the birds themselves to control the
problem.
✔✔Which one of the following choices is the mechanism of action of omeprazole?
A - Cyclooxygenase blocker
B - Beta-adrenergic receptor agonist
C - Synthetic prostaglandin E1 analog
D - H2-receptor antagonist
E - Proton pump inhibitor - ✔✔E
Omeprazole is a proton pump inhibitor that decreases gastric acid secretion.
Omeprazole inhibits the sodium/potassium proton pump at the luminal surface of
parietal cells. Parietal cells normally secrete hydrogen ions into the stomach, a key
component of acidic HCL.
Other drugs that decrease gastric acid secretion include the H2-receptor antagonists
cimetidine, ranitidine, and famotidine and a synthetic prostaglandin E1 analog called
Misoprostol.
Carprofen, Etodolac, Deracoxib, Meloxicam and Firocoxib are all nonsteroidal anti-
inflammatory drugs (NSAIDS) that may CAUSE gastric acid secretion.
SET A+
✔✔Hyperadrenocorticism is suspected in a 9-year old female spayed dog with a two-
month history of increased appetite, thirst and urinary accidents. Which of the following
diagnostic test is most reliable when results are positive?
Urine Cortisol Creatinine Ratio (UCCR). Sensitivity=90% , Specificity =25%
ACTH Stimulation. Sensitivity=80% , Specificity =85%
Low Dose Dexamethasone Suppression. Sensitivity=95% , Specificity =50%
A - Low Dose Dexamethasone Suppression (LDDS)
B - ACTH Stimulation
C - Urine Cortisol Creatinine Ratio
D - Cannot say without knowing the positive predictive value
E - Cannot say without knowing the negative predictive value - ✔✔B
ACTH Stimulation. The two diagnostic screening tests used most commonly for
diagnosis of hyperadrenocorticism are the ACTH stimulation test and the LDDS.
Remember your Ps and Ns.
ACTH Stim is the most sPecific (fewer false Pos, so trust a POS test more). LDDS is
more seNsitive (fewer false Negs, so trust NEG test more).
Either way, these 2 tests are useful to screen for Cushing's, but a confirmatory test is
usually required if you get a positive, to differentiate between a pituitary HAC or an
adrenal HAC case [high-dose dexamethasone suppression test (HDDST) or ACTH
concentration].
The Urine Cortisol Creatinine Ratio (UCCR) has a low specificity (~25%), which means
high false positives. 75% of dogs with non-adrenal illness will have a UCCR result
consistent with HAC.
, So, a positive UCCR is not useful to identify HAC, however, a negative is very useful to
rule-out HAC as dogs with a normal UCCR cannot have HAC.
✔✔You are visiting a small "back-yard" flock of chickens and examining the animals.
You find several small gray-red mites (approx 0.7 mm) on several of the chickens which
you recognize as Dermanyssus gallinae and Ornithonyssus sylviarum. How are these
mites best controlled?
A - Ornithonyssus sylviarum is controlled primarily by thorough insecticidal treatment of
the environment and Dermanyssus gallinae must be controlled by application of
approved pesticides to affected birds
B - Dermanyssus gallinae is controlled primarily by thorough insecticidal treatment of
the environment and Ornithonyssus sylviarum must be controlled by application of
approved pesticides to affected birds
C - Control of both Ornithonyssus sylviarum and Dermanyssus gallinae relies on
application of approved pesticides to affected birds
D - Control of both Dermanyssus gallinae and Ornithonyssus sylviarum relies on
thorough insecticidal treatment - ✔✔B
Dermanyssus gallinae (the common red mite) maintains the majority of the population in
the environment so it is important to monitor and treat the environment including the
cracks and crevices where mites tend to reside. Ornithonyssus sylviarum mites
(northern fowl mites) spend their entire life cycle on the bird. This allows them to
multiply more rapidly and makes it essential to treat the birds themselves to control the
problem.
✔✔Which one of the following choices is the mechanism of action of omeprazole?
A - Cyclooxygenase blocker
B - Beta-adrenergic receptor agonist
C - Synthetic prostaglandin E1 analog
D - H2-receptor antagonist
E - Proton pump inhibitor - ✔✔E
Omeprazole is a proton pump inhibitor that decreases gastric acid secretion.
Omeprazole inhibits the sodium/potassium proton pump at the luminal surface of
parietal cells. Parietal cells normally secrete hydrogen ions into the stomach, a key
component of acidic HCL.
Other drugs that decrease gastric acid secretion include the H2-receptor antagonists
cimetidine, ranitidine, and famotidine and a synthetic prostaglandin E1 analog called
Misoprostol.
Carprofen, Etodolac, Deracoxib, Meloxicam and Firocoxib are all nonsteroidal anti-
inflammatory drugs (NSAIDS) that may CAUSE gastric acid secretion.
