674
edits
Changes
Investigation of canine thyroid function (view source)
Revision as of 15:53, 13 April 2022
, 15:53, 13 April 2022no edit summary
* Take 2ml of clotted or heparinised blood
* Take 2ml of clotted or heparinised blood
* Inject TRH slowly i/v over 1 minute using the dose rates below. Please note: TRH can cause mild side effects such as defecation, salivation, tachypnoea. If these cause a problem, atropine is an effective antidote. Thyrotropin Releasing Hormone is available on prescription as TRH Cambridge Laboratories*.
* Inject TRH slowly i/v over 1 minute using the dose rates below. Please note: TRH can cause mild side effects such as defecation, salivation, tachypnoea. If these cause a problem, atropine is an effective antidote. Thyrotropin Releasing Hormone is available on prescription as TRH Cambridge Laboratories*.
{| class="wikitable"
1-5kg 100μg TRH
|+
|1-5kg
5-30kg 200μg TRH
|100μg TRH
|-
>30kg 300μg TRH
|5-30kg
|200μg TRH
|-
|>30kg
|300μg TRH
|}
* Take a second 2ml of clotted or heparinised blood 4 hours after TRH injection
* Take a second 2ml of clotted or heparinised blood 4 hours after TRH injection
* If the pre-stimulation T4 is >25nmol/l, regardless of the post-stimulation concentration, the dog is normal
* If the pre-stimulation T4 is >25nmol/l, regardless of the post-stimulation concentration, the dog is normal
* With a pre-stimulation T4 <25nmol/l, the post-stimulation values can be interpreted as follows:
* With a pre-stimulation T4 <25nmol/l, the post-stimulation values can be interpreted as follows:
{| class="wikitable"
0-20nmol/l Hypothyroid or sick euthyroid
|+
|0-20nmol/l
20-30nmol/l Status equivocal
|Hypothyroid or sick euthyroid
|-
>30nmol/l Normal
|20-30nmol/l
|Status equivocal
|-
|>30nmol/l
|Normal
|}
* Dogs with equivocal values should be retested after 1 month
* Dogs with equivocal values should be retested after 1 month