Test description: Basal serum cortisol measurement, used in protocols for the diagnosis and monitoring of adrenal cortical disorders.
Comments: Important as a supplementary test, but a single isolated cortisol measurement is not indicated for the definitive diagnosis of hyper- or hypoadrenocorticism.

• Sample type: Serum
• Species: Canine and Feline
• Recommended volume: 0.7 mL
• Minimum volume: 0.5 mL
• Container: Tube with a red or yellow cap, without a gel separator
• Fasting: 8 a.m. to 12 p.m.
• Rejection Criteria: Incompatible sample or insufficient volume

SHIPPING
Follow the step-by-step instructions in our Pocket Guide.

Precautions:

• Cortisol is secreted in pulses, varying in response to circadian rhythms, stress, reproductive status, and the use of various medications (NSAIDs, antibiotics, glucocorticoids).
• Horses that have received intra-articular injections may have low or undetectable levels for weeks to months.
• The interpretation should always take into account clinical signs and confirmatory tests (ACTHst, LDDST).

Test Method
Chemiluminescent Immunoassay (CLIA).

Test description: Measurement of serum cortisol levels at baseline (T0) and after ACTH stimulation (T1).
Comments: Primary test for the diagnosis of hypoadrenocorticism (Addison’s disease) and assessment of adrenal reserve in cases of suspected hypercortisolism (Cushing’s syndrome).

• Sample type: Serum
• Species: Canine and Feline
• Optimal volume: 0.7 mL per cycle
• Minimum volume: 0.5 mL per cycle
• Container: Tube with a red or yellow cap, without a gel separator
• Fasting: 8 a.m. to 12 p.m.
• Rejection Criteria: Incompatible sample or missing time stamps (T0 and T1)

SHIPPING
Follow the step-by-step instructions in our Pocket Guide.
Clearly identify the basal (T0) and post-ACTH (T1) tubes.

• Adrenal insufficiency (Addison's disease): Low basal and post-ACTH cortisol levels confirm adrenal reserve insufficiency.

• Hypercortisolism (Cushing's syndrome): Normal dogs may have variable basal cortisol levels, but most dogs with Cushing's disease exhibit an increased post-ACTH response.

• Results should always be evaluated in conjunction with clinical signs, medical history, and additional tests.

Test Method
Chemiluminescent Immunoassay (CLIA).

Test description: Serum cortisol measurement performed 1 hour after administration of synthetic ACTH (T1).
Comments: An essential test for evaluating adrenal reserve, especially when hypoadrenocorticism (Addison’s disease) is suspected.

• Sample type: Serum
• Species: Canine and Feline
• Recommended volume: 0.7 mL
• Minimum volume: 0.5 mL
• Container: Tube with a red or yellow cap, without a gel separator
• Fasting: 8 a.m. to 12 p.m.
• Rejection Criteria: Incompatible sample or lack of clear time identification (T1)

SHIPPING
Follow the step-by-step instructions in our Pocket Guide.

• Low or undetectable post-ACTH cortisol levels confirm hypoadrenocorticism.

• It should always be interpreted in conjunction with baseline cortisol (T0) and in relation to the clinical presentation.

TEST METHOD
Chemiluminescent Immunoassay (CLIA).

Test description: Serum cortisol measurement performed 2 to 4 hours after administration of trilostane.
Comments: Used exclusively to monitor the therapeutic efficacy of Vetoryl® (trilostane) in dogs with hyperadrenocorticism (Cushing’s disease).

• Sample type: Serum
• Species: Canine and Feline
• Recommended volume: 0.7 mL
• Minimum volume: 0.5 mL
• Container: Tube with a red or yellow cap, without a gel separator
• Fasting: 8 a.m. to 12 p.m.
• Rejection Criteria: Incompatible sample; sample collected outside the recommended time window following trilostane administration

SHIPPING
Follow the step-by-step instructions in our Pocket Guide.

• Proper control: cortisol levels within the specific reference range for monitoring with trilostane.

• Low values: risk of iatrogenic hypoadrenocorticism (dose reduction required).

• High values: possible underdosing, malabsorption, or resistance to the medication.

• The interpretation should always take into account clinical signs, administered doses, and exact collection times.

TEST METHOD
Chemiluminescent Immunoassay (CLIA).

Test description: Measurement of serum cortisol levels at baseline (T0) and after ACTH stimulation (T1).
Comments: The test of choice for diagnosing hypoadrenocorticism and assessing adrenal response in cases of suspected hypercortisolism.

• Sample type: Serum
• Species: Canine and Feline
• Optimal volume: 0.7 mL per cycle
• Minimum volume: 0.5 mL per cycle
• Container: Tube with a red or yellow cap, without a gel separator
• Fasting: 8 a.m. to 12 p.m.
• Rejection Criteria: Incompatible sample or missing time stamps (T0 and T1)

SHIPPING
Follow the step-by-step instructions in our Pocket Guide.
Clearly identify the basal (T0) and post-ACTH (T1) tubes.

• Addison's disease: Low basal and post-ACTH levels confirm hypoadrenocorticism.
• Cushing's disease: an exaggerated response to ACTH suggests hypercortisolism; normal dogs show a variable response, so clinical correlation and additional tests are necessary.

TEST METHOD
Chemiluminescent Immunoassay (CLIA).

Test description: Serum cortisol measurement performed 1 hour after administration of synthetic ACTH (T1).
Comments: Essential for assessing adrenal reserve, especially in diagnostic protocols for Addison’s and Cushing’s diseases.

• Sample type: Serum
• Species: Canine and Feline
• Recommended volume: 0.7 mL
• Minimum volume: 0.5 mL
• Container: Tube with a red or yellow cap, without a gel separator
• Fasting: 8 a.m. to 12 p.m.
• Rejection Criteria: Sample incompatible or not identified as post-ACTH time (T1).

SHIPPING
Follow the step-by-step instructions in our Pocket Guide.

• A very low post-ACTH cortisol level confirms Addison's disease.

• Elevated levels may suggest Cushing's syndrome, but should be interpreted in conjunction with baseline values and other confirmatory tests.

TEST METHOD
Chemiluminescent Immunoassay (CLIA).

Test description: Serum cortisol levels before (T0) and approximately 3 hours after administration of trilostane.
Comments: Specific protocol for monitoring the therapeutic efficacy of Vetoryl® (trilostane) in dogs with hyperadrenocorticism.

• Sample type: Serum
• Species: Canine and Feline
• Optimal volume: 0.7 mL per cycle
• Minimum volume: 0.5 mL per cycle
• Container: Tube with a red or yellow cap, without a gel separator
• Fasting: 8 a.m. to 12 p.m.
• Rejection Criteria: Incompatible sample, incorrect timing, or collection outside the recommended time window after medication administration.

SHIPPING
Follow the step-by-step instructions in our Pocket Guide.
Clearly identify the T0 (pre) and T3h (post-trilostane) tubes.

• Proper control: cortisol within the expected reference range for monitoring with trilostane.

• Low values: risk of iatrogenic hypoadrenocorticism.

• High values: This may indicate an insufficient dose, malabsorption, or resistance to the drug.

• Always consider clinical signs, dosage, and the exact time of trilostane administration.

Test Method
Chemiluminescent Immunoassay (CLIA).

Test description: Serum phenobarbital concentration measurement for therapeutic monitoring in dogs and cats receiving anticonvulsant treatment.
Comments: Serum levels should be maintained within the therapeutic range to ensure effective seizure control and treatment safety.

• Sample type: Serum
• Species: Canine, Feline
• Recommended volume: 0.7 mL
• Minimum volume: 0.5 mL
• Container: Tube with a red or yellow cap, without a gel separator
• Fasting: 8 a.m. to 12 p.m.
• Rejection Criteria: Hemolyzed sample, sample with a separating gel, or sample incompatible with the test.

SHIPPING
Follow the step-by-step instructions in our Pocket Guide.

• Within the therapeutic range: adequate seizure control.

• Below the banner: risk of insufficient efficacy.

• Above the range: risk of toxicity (excessive sedation, hepatotoxicity).
  Interpretation should take into account duration of use, dose administered, timing of sample collection relative to administration, and the patient’s clinical signs.

Test Method
Chemiluminescent Immunoassay (CLIA).

Test description: Dexamethasone suppression test using a two-sample protocol, used to diagnose hyperadrenocorticism (Cushing’s syndrome).

Comments: The protocol involves a baseline sample (T0h) and a follow-up sample 8 hours after dexamethasone administration (T8h). It assesses the suppressive capacity of the hypothalamic–pituitary–adrenal axis.

• Sample type: Serum
• Species: Canine
• Recommended volume: 0.7 mL
• Minimum volume: 0.5 mL
• Container: Tube with a red or yellow cap
• Rejection criteria: Incompatible sample, incorrect collection time, or insufficient volume

The absence of cortisol suppression following dexamethasone is consistent with hyperadrenocorticism.
Results should be interpreted in conjunction with clinical signs, imaging studies, and other hormonal tests.

Test Method
Chemiluminescent Immunoassay (CLIA) – Immulite 2000.

Test description: Dexamethasone suppression test using a 3-sample protocol, indicated for the investigation and differentiation of hyperadrenocorticism.

Comments: Includes baseline (T0h), 4-hour (T4h), and 8-hour (T8h) samples following dexamethasone administration, allowing for a more detailed assessment of the cortisol suppression pattern.

• Sample type: Serum
• Species: Canine
• Recommended volume: 0.7 mL
• Minimum volume: 0.5 mL
• Container: Tube with a red or yellow cap
• Rejection criteria: Incompatible sample or incorrect identification of collection times

Cortisol levels during the mid- and late phases help distinguish between pituitary-dependent and adrenal-dependent hyperadrenocorticism. Interpretation should always take into account the clinical context and additional tests.

Test Method
Chemiluminescent Immunoassay (CLIA) – Immulite 2000.

Test description: Single measurement of serum cortisol following administration of dexamethasone.

Notes: Select this test only for samples collected after dexamethasone administration, when there is no need to assess baseline levels in the same order.

• Sample type: Serum
• Species: Canine
• Recommended volume: 0.7 mL
• Minimum volume: 0.5 mL
• Container: Tube with a red or yellow cap
• Exclusion criteria: Incompatible sample or lack of information regarding prior use of dexamethasone

Post-dexamethasone cortisol levels should be interpreted in accordance with the clinical protocol used. It does not replace comprehensive screening or diagnostic tests when indicated.

Test Method
Chemiluminescent Immunoassay (CLIA) – Immulite 2000.