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SAMPLE SUBMISSION
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| What should I do if I have a question about a sample submission or interpretation of a result?
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If the answer to your question is not in this FAQ section, please feel free to call the
Laboratory. We have a Board Certified small animal internist to answer your questions on test requests or interpretation of test results,
clinical
pathologists to answer your questions on cytology specimens and
interpretation of results, and anatomic pathologists, to answer your
questions about biopsies and necropsies. Two of our pathologists have
expertise in exotic animals, one pathologist has expertise in avian
disease, and our clinical pathologists are knowledgeable in interpretation
of large animal clinicopathologic test results. In addition, our office
staff can help you with general information questions including sample
submission and billing, and our laboratory manager and laboratory
technicians can answer questions about specific equipment or test
procedures. |
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| What should I do if I want to submit a
sample for a test that is not listedon the test request form? |
Please call PHOENIX LABORATORY.
Many additional or specialized tests are available at the LAB or on a send
out basis. |
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| What should I do if
I do not think I can obtain enough blood for all the tests I want to
request on a specific patient? |
Please CALL the LABORATORY. We may be able to help you prioritize the
testing or provide alternatives (microtainer collection tubes). |
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What is the MINIMUM VOLUME needed for a SMALL
MAMMAL PANEL WITHOUT ELECTROLYTES? |
100 ul is the minimum volume, without any
rechecks. |
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What is the MINIMUM VOLUME needed for a CBC?
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If you use
a standard 2 ml EDTA (lavender top tube), the tube should have a minimum
of 1.0 ml of blood to avoid artifacts of sample dilution.
If a microtainer tube is used, ideally,
we need 0.5 ml blood, but a CBC can be completed if we have at least 0.2
ml of blood in a microtainer tube. |
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What is the MINIMUM VOLUME of SERUM needed for
a CORTISOL assay
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At least 0.5 ml of serum is needed. |
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What is the MINIMUM VOLUME of SERUM needed for
a total T4 and a free T4?
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At least 0.6 ml of serum is needed. |
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What is the MINIMUM VOLUME needed for a
COAGULATION PROFILE |
For determination of the PT/PTT the ratio of blood
to anticoagulant (citrate) is critical (1 part citrate: 9 parts
blood). For the 2 ml light blue top citrate tubes we provide, each
tube requires 1.8 ml blood (the vacuum in the tube will fill the tube
to the proper level if there is no air in the sample and the tube is
not out of date). |
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Will the test results be altered if the CBC,
serum chemistry, or urine sample sits at room temperature overnight?
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Serum enzymes often are affected when the sample is stored at
room temperature, especially when the serum has not been
separated. Depending on the species and breed, potassium may be
artifactually increased, especially when hemolysis is present.
Cell morphology is compromised (CBC) when the sample sits. If a
well-made blood smear slide was made at the time of the sample
collection, the differential and assessment of the cell morphology and
adequacy can still be accurate.
Urine pH, crystals, and cell morphology changes with delayed
handling. Always, the most accurate information is acquired when the
urine is evaluated immediately after collection.
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What are platelet
clumps and how can I avoid them?
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Platelet
clumps are formed during phlebotomy, in storage in the EDTA tube, or
during preparation of the blood smear. They represent the normal adhesion
tendency of platelets and are "artifacts" in that they are not
circulating in the patient’s blood. The clumping becomes important in
interpretation of platelet numbers. When the platelets are not evenly
distributed in the sample, the platelet count may underestimate the
platelet number. At Phoenix Laboratory, certified laboratory technicians
evaluate a blood smear from every CBC to estimate platelet numbers and for
the presence of platelet clumps.
Platelet clumping can be minimized by getting a "clean
stick" during phlebotomy, immediately putting the blood into the EDTA
tube, and gently mixing the sample. Sometimes this is not enough to
prevent platelet clumping. When blood from a patient repeatedly has too
many platelet clumps to accurately assess platelet numbers, a blood sample
can be drawn into a heparin flushed syringe before putting the sample into
the EDTA (lavender top tube). |
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Which test should I use to diagnose an active
TOXOPLASMOSIS infection? |
A serum
IgM & IgG titer is the test of choice to diagnosis active disease.
Often, a convalescent titer is needed. |
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Will LIPEMIA affect the CORTISOL or THYROID
assay? |
There is no problem measuring cortisol or thyroid hormone
concentrations in lipemic samples. We ultracentrifuge lipemic samples
before performing the assay to obviate that problem, otherwise lipemia
will affect test results. |
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Does the blood sample
for [INSULIN] have to be centrifuged? |
YES. Proper handling of the sample is critical. The blood should
be centrifuged as soon as the clot has formed. The serum must be
decanted and kept cold. Hemolysis will alter the results. If the
sample is hemolyzed, a fresh sample should be collected. To help
diagnose an insulinoma, the [insulin] should be measured when the
blood glucose is < 60 mg/dl. Serum or plasma (gray top tube)
glucose concentration determination is included in the price for the
insulin assay. |
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What test should I use in a dog or cat that
PREVIOUSLY HAS BEEN SPAYED, but appears to have behavior similar to
ESTRUS? |
DOGS & CATS: LH test: Must be performed
when dog or cat is NOT exhibiting signs of heat. A single
low LH test (<1 ng/ml) confirms that the bitch or queen is
sexually intact. DOGS: There are 3 options depending on where the dog is in the estrous
cycle.
Vaginal cytology: The vaginal epithelium is a good biologic
assay for the presence of estrogen. If the dog is in late
proestrus or estrus, one should see > 80% to 90% superficial cells.
Serum Progesterone: If the dog had signs of estrus 2 weeks
to < 2 months ago, a single serum progesterone concentration
may be diagnostic (evidence of luteal structure).
HCG stimulation test: Estradiol is measured pre & post
HCG administration (250 IU HCG SQ, draw post sample 2 hours after
injection; refrigerate samples.) Note: Only choice if
exhibiting "heat" at time of sampling.
CATS: HCG Stimulation test: Serum progesterone is measured prior to, and 10 days after
injection of 250 IU HCG SQ Note: Only choice if
exhibiting "heat" at time of sampling. |
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What test should I
use in a dog or cat if the animal is supposed to be castrated but is
exhibiting male-like behavior?
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HCG stimulation test: Serum testosterone is measured prior
to and 2 hours after injection of 250 IU HCG SQ. |
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| What test should I use to determine if a
supposedly-castrated gelding has a remaining testicle?
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In a young
horse less than 3 years old, the test of choice is the hCG stimulation
test where serum testosterone is measured before ("PRE") and 2
hours after ("POST") IV administration of 10,000 IU of human
chorionic gonadotrophin (hCG). If there is testicular tissue present, the
post-hCG sample (possibly the baseline value too) will be elevated.
In a horse that is older than 3 years, the hCG stimulation test is one
option, but another is measuring resting serum estrone sulfate. This level
should be increased in male horses with testicular tissue. |
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What lab tests can I use to determine if a
mare is pregnant? |
After 60 days of gestation, serum estrone sulfate levels are significantly
increased in pregnant mares and can be measured to confirm (or rule out)
pregnancy.
Serum progesterone can aid in pregnancy diagnosis if it is high when it
should be low eg. out of the breeding season. A single random high value
is not confirmatory of pregnancy if taken during the breeding season and
the stage of the estrous cycle is not known (ie. it indicates only luteal
activity). However, if the level is still high 10 days later, then the
animal is most likely pregnant. A single low serum progesterone
concentration (<0.5 ng/ml) indicates the animal is not pregnant. |
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What lab test can I use to determine if a bitch
is pregnant? |
The plasma relaxin concentration rises after implantation of the canine fetus.
If the bitch was bred at the appropriate time in her estrous cycle,
pregnancy can be detected as early as 22-27 days after the last breeding
(26-31 days following the LH surge). If uncertain about timing of
breeding or fertile periods, it is recommended that a
negative test be confirmed by retesting 1 week later to
insure adequate time has been allowed for implantation. |
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When should the blood sample be collected for
THERAPEUTIC MONITORING of PHENOBARBITAL?
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There is no significant difference between serum phenobarbital
concentrations in samples obtained prior to dosing, or at 3 or 6 hours
postpill. Thus, when you are monitoring therapeutic serum phenobarbital concentrations in dogs, you can collect a sample at any
time of the day as long as: 1) the dose has been constant for at least
7 days; 2) the dog is not receiving any drugs that would alter the
P450 enzymes (cimetidine); and 3) the dog is receiving < 8 mg/kg/day of phenobarbital. |
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What is the
difference between a "CYTOLOGY" and a "FLUID
CYTOLOGY"?
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A "CYTOLOGY"
provides a microscopic evaluation of the slides (that were submitted by
the veterinarian or made in the Lab from the submitted fluid). A
"CYTOLOGY" should be requested for such lesions as subcutaneous
or internal masses, even if a liquid sample is collected. A
"CYTOLOGY" is slightly cheaper than a "FLUID
CYTOLOGY".
A "FLUID
CYTOLOGY" provides a cell
count and protein determination of the fluid in addition to the
microscopic evaluation. A request for a "FLUID CYTOLOGY" is used
for samples that have reference values for cell count and protein level.
Examples include peritoneal/ abdominal, pleural/ thoracic, pericardial and
joint fluids. There is no advantage to having cell counts and protein from
fluid aspirated from a subcutaneous or internal mass, urine, a tracheal,
nasal, or prostatic wash. A "FLUID CYTOLOGY" is slightly more
expensive than a regular "CYTOLOGY". |
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I want to know if there are neoplastic cells in a urine sample.
What test
do I request - urinalysis, regular cytology, or fluid cytology? |
Neoplastic
cells in the urine are best assessed with a "regular"
cytology evaluation. To maximize the
assessment of the urothelial cells, freshly made slides of urine sediment
(unstained) and a fresh urine specimen should be submitted. |
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How
should I submit a sample for
cytologic evaluation?
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The instructions for collection vary with the site and type of sample. For
optimal cellular preservation, all submissions should include slides
prepared at the clinic. Once the aspirated sample is in the syringe or
needle hub, eject this material onto slides and use either the wedge or
squash prep technique to spread out this material. Ideally, these will be
2-5 air-dried, unstained, unfixed, unoiled, and uncoverslipped smears.
Avoid any exposure to formalin vapors.
For liquid samples, also be sure to send along some of the fluid in tubes
- EDTA (lavender top) is preferred for cytology and a plain tube (red top)
is required for culture. Do not use serum separator tubes for cytologic
specimens. See question #1 above for the appropriate test request (routine
"CYTOLOGY"
vs "FLUID CYTOLOGY"). |
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When I
submit a biopsy specimen, should I request a "Mini Report" or
a "Full Report"?
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All biopsy specimens are evaluated similarly by the
pathologists. The only difference between a Mini
Report and a Full
Report is that FULL REPORTS
include a microscopic description of the lesion.
Which report you request depends on your interest in having a
copy of the microscopic description of the lesion and spending an
additional $6.00 to have the expanded report.
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How can I get the most
valuable INFORMATION from a SKIN BIOPSY?
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Providing
the pathologist with following information should greatly help in the
interpretation of biopsy:
- The distribution and duration of the lesion(s)
- A list of current and previous medications
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INTERPRETATION OF TEST RESULTS |
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How do I interpret a
LDDS in a dog?
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Before embarking on testing, and before one can interpret the LDDS
test, there are 4 important points to keep in mind:
- The first point to remember is stressful disease (sick, poorly
controlled diabetics, renal failure, etc) may cause false positive
test results. So the patient’s stressful disease must be
controlled before considering testing for hyperadrenocorticism.
Also, potentially stressful procedures should not be performed
during the 8 hour test (anesthesia, sedation, or procedures that
will need excessive restraint or cause excessive discomfort to the
patient. [If, for some reason, you have chosen to proceed with
testing, and the test result is in the reference range,
hyperadrenocorticism may be ruled-out, but if the test is suggestive
of hyperadrenocorticism, it may be a false positive].
- The second point to remember before you embark on testing, is
prednisolone and prednisone, and other corticosteroids (except
dexamethasone) cause interference with the assay. The animal should
not have received these drugs during the 24 hours prior to sample
collection.
- The third point to remember is that topical (skin, ears, eyes)
steroids may cause iatrogenic hyperadrenocorticism. These dogs may
have all the typical clinical signs and laboratory tests typical of
Cushing’s disease and the owners may forget to mention to you that
they are applying a skin cream on Scruffy’s neck. So do not forget
to ask the client if they are using ANY topical medication on
Scruffy before embarking on the diagnostic testing for
hyperadrenocorticism.
- The final point is no test is 100% specific and 100% sensitive.
At times, additional or repeated testing is needed to confirm your
clinical suspicion of hyperadrenocorticism.
The primary reason to perform a LDDS is to confirm a clinical
suspicion of hyperadrenocorticism. If the history, physical
examination results, and initial data base are not consistent with
hyperadrenocorticism, interpretation of the test result may not be
accurate.
To make that determination, you need to evaluate
the 8 hour sample.
If the dog does not suppress (to < 1.2 ug/dl), the dog has
hyperadrenocorticism (or another stressful disease).
Additionally, in some dogs, when the test is diagnostic for HAC, the
LDDS also can confirm the suspicion of pituitary dependent
hyperadrenocorticism.
Evaluate the 4 and 8 hour cortisol samples
- The 4 hr or 8 hr result is < 50% of the baseline, the dog has
pituitary dependent disease.
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What diagnostic tests can be used to
differentiate adrenal
versus pituitary
hyperadrenocorticism (if cannot make that determination from
the LDDS test result)? |
- Adrenal ultrasonographic evaluation
- High dose dexamethasone suppression test
- Plasma [ACTH]
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Why does the type
of urine crystal change from one sample to another in the same dog? |
Formation
of detectable crystalluria is dependent on the temperature, the pH, urine
concentration, diet, metabolic abnormalities, drugs, and specimen
handling. Some of these factors may be quite variable (ex. the postprandial
alkaline tide may result in altered urine pH compared to a
fasting sample, changing the diet and/or changing the pH in the sample may
alter the type of crystal seen). The best method of avoiding
artifactual alterations in the urine sediment is to evaluate the urine
specimen immediately after collection, with the sample still at body
temperature. |
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How can one explain
a fasting bile acids (BA) that is higher than the postprandial bile
acids?
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There are several possible explanations for this type of result.
- Food was not withheld for the 8- 12 hours.
- Only 30-50% of the newly formed BA are stored, so there is some
secretion of newly formed BA.
- There is delayed gastric emptying (highly stressed, or sedated
patient)
- Postprandial gall bladder contraction releases a variable
amount of bile (5 –65%), so that the postprandial sample is
"lower than expected".
- Bacterial overgrowth augments the unconjugated BA pool, which
enter the systemic circulation more readily.
- Mis-identification of samples
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