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SMALL ANIMAL TESTING PROTOCOLS:
In all cases, a thorough clinical history and physical examination should
ultimately be used to suggest endocrine testing, and to eventually
diagnose any abnormalities. A hormonal evaluation alone will not
necessarily inform completely. The case history will suggest a specific
assay or assays that will assist in confirming the diagnosis.
ANOVULATORY BITCH
~ Initially test Total T4 and Progesterone.
~ If Progesterone is less than 4.0 ng/mL, a series of samples need
> to be drawn once a week, for three weeks.
~ Vaginal swabs should also be examined for presence of cornified
> cells.
~ If Progesterone is greater than 4.0 ng/mL, then she has in fact
> ovulated and may be a “hidden estrus” case.
~ If the Total T4 is less than 15 ng/mL, treatment for hypothyroidism
> may be beneficial.
OVARIAN REMNANT SYNDROME
1. Serial Estrogen and Progesterone
~ Test Total Estrogens and Progesterone in a series of samples
> over a three-week period.
~ Collect approximately three to five samples, two or more
> days apart.
~ Send all samples at the same time.
~ If Progesterone level is over 1.0 ng/mL, or Estrogen is greater
> than 40 pg/mL, it is suggestive of ovarian tissue present.
~ Vaginal cytology should also be monitored.
>>>>>>>>>>>>>>>>>>>>>>>OR
2. hCG Stimulation
~ Test Total Estrogens and Progesterone to detect the presence of an
> intact ovary, or an ovarian remnant.
~ Perform an hCG Stimulation Test
SAMPLES>>>>>>>>>>>>>>>>>>>>>>>>>>>HORMONES TO ASSAY
Baseline>>>>>>>>>>>>>>>>>>>>>>>>Progesterone,Total Estrogens
>>>>>>>>>>>>>>Administer 200 IU hCG, IM
90 Minutes Post Injection>>>>>>>>>>>>>>>> >>>> Total Estrogens
CRYPTORCHID
A single random sample assaying Testosterone has very little value
due to wide fluctuations. Therefore the recommended protocol to
analyze testicular production of Testosterone involves a stimulation
utilizing GnRH or hCG.
CANINE:
SAMPLE TIME>>>>>>>>>>>>>>>>>>> >>>>HORMONES TO ASSAY
Baseline>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Testosterone
>>>>>>>>>>>>>>Administer 1000 IU hCG, IM
>>>>>>>>>>>>>>>>>>>>>>>>or
>>>>>>>>>>>>>>>>>>>100ug GnRH, IM
2 Hours Post Injection>>>>>>>>>>>>>>>>>>>>>>>>> Testosterone
4 Hours Post Injection>>>>>>>>>>>>>>>>>>>>>>>>> Testosterone
FELINE:
SAMPLE TIME>>>>>>>>>>>>>>>>>>>>>> >HORMONES TO ASSAY
Baseline>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Testosterone
>>>>>>>>>>>>>>Administer 250 - 500 IU hCG, IM
>>>>>>>>>>>>>>>>>>>
1 Hours Post Injection>>>>>>>>>>>>>>>>>>>>>>>>>>Testosterone
2 Hours Post Injection>>>>>>>>>>>>>>>>>>>>>>> >> Testosterone
HYPOTHYROIDISM
Canine: Test Total T4, TSH, free T4 by Dialysis in a single sample.
FELINE: T3 SUPPRESION TEST:
SAMPLE TIME>>>>>>>>>>>>>>>>>>>>>>>>HORMONES TO ASSAY
Baseline>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Total T4
>>>>>>>>>>>>>>Day 1 - Administer T3 25 mg, TID
>>>>>>>>>>>>>>Day 2 - Administer T3 25 mg, TID
>>>>>>>>>>>>>>Day 3 - Administer T3 25 mg, TID
>>>>>>>>>>>>>>>>>>>
2 hours post 3rd injection>>>>>>>>>>>>>>>>>>>>>>>>>>>Total T4
4 hours post 3rd injection>>>>>>>>>>>>>>>>>>>>>>>>>>>Total T4
ALOPECIA
Initially test Total T4, Progesterone, Total Estrogen and Testosterone.
If all are within the normal range, then perform a Cushing's screen
(see protocol).
BETA CELL TUMOR
~ Most dogs with beta cell tumors are persistently hypoglycemic
> (glucose is less than 60 mg/dL).
~ Fast animal until glucose falls below 60 to 70 mg/dL, as
> determined by glucose reagent strips.
~ Obtain serum sample for Insulin analysis. In 68% of dogs with
> beta cell tumors Insulin levels were greater than 20 µI.U./mL.
~ 24% had levels between 10 - 20 µIU/mL, and 8% had levels
> between 5 - 10 µIU/mL.
CANINE HYPERADRENOCORTICISM (Cushings Syndrome)
1. ACTH STIMULATION
SAMPLE TIME>>>>>>>>>>>>>>>>>>>>>>>>HORMONES TO ASSAY
Baseline>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>Cortisol
>>>>>>>>>>>>>>Administer Cortisol - 40
>>>>>>(porcine aqueous gelatin ACTH) 2.2 IU/kg, IM
>>>>>>>>>>>>>>>>>>>
2 Hours Post Injection>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>.Cortisol
>>>>>>>>>>>>>>>>>>>>>>>>OR
1. ACTH STIMULATION
SAMPLE TIME>>>>>>>>>>>>>>>>>>>>>>>>HORMONES TO ASSAY
Baseline>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>> Cortisol
>>>>>>>>>>>>>>Administer Cortrosyn - 40
>>>>>>>>>>>> (synthetic ACTH) 0.25 mg, IM
>>>>>>>>>>>>>>>>>>>
1 Hour Post Injection>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>. .Cortisol
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~ Normal baseline Cortisol
> level:>>>>>>>>>>>5 – 60 ng/mL
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~ Normal Cortisol level post
> ACTH:>>>>>>>>> 60-170 ng/mL
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~ Borderline cortisol level
> post ACTH:>>>>>170-220 ng/mL
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~ Consistent with Cushing’s
> disease diagnosis:> > 220 ng/mL |
2. DEXAMETHASONE SUPPRESSION
(Low dose Dexamethasone suppression)
SAMPLE TIME>>>>>>>>>>>>>>>>>>>>>>>>HORMONES TO ASSAY
Baseline>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>Cortisol
>>>>>>>>>>>>>>>Administer dex. Sodium phosphate; 0.01 mg/kg, IV
>>>>>>>>>>>>>>>>>>>
4 Hours Post Injection>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>.Cortisol
8 Hours Post Injection>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>.Cortisol
>>>>>>>>>>>>>>>>>>>>>>> OR
(High dose Dexamethasone suppression)
SAMPLE TIME>>>>>>>>>>>>>>>>>>>>>>>>HORMONES TO ASSAY
Baseline>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>Cortisol
>>>>>>>>>>>>Administer dex. In polyethylene glycol; 0.1 mg/kg, IV
>>>>>>>>>>>>>>>>>>>
4 Hours Post Injection>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>.Cortisol
8 Hours Post Injection>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>.Cortisol
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~ Normal baseline Cortisol
> level:>>>>>>>5 – 60 ng/mL
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~ Normal Cortisol level post
> ACTH:>>>>>> >< 10 ng/mL
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~ Borderline cortisol level
> post ACTH: >10 -14 ng/mL
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~ Consistent with Cushing’s
> disease diagnosis:
>>>>>>>>>>>> >>>14 ng/mL |
3. ENDOGENOUS ACTH LEVELS
~ Sample PLASMA between 8-9 AM after overnight hospitalization.
~ Collect PLASMA in a CHILLED, silicone-coated EDTA tube,
> CENTRIFUGE, transfer to a PLASTIC VIAL, and then FREEZE.
~ Send sample OVERNIGHT, FROZEN on dry ice.
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~ Normal Endogenous ACTH
> level:>>>>>> 10 - 45 pg/mL
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~ Pituitary dependent
> hyperadrenocorticism:
>>>>>>>>>>>>>>< 45 pg/mL
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~ Adrenocortical tumor
> hyperadrenocorticism:
>>>>>>>>>>>>>>< 10 pg/mL |
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