HEALTH CARE
Cushings disease didn't show up in horse's blood test, but he has responded to treatment. Have you heard of this?
Yes it is possible. With any blood test it is possible to have a false negative result. A false negative result means that the horse actually has the disease, but the blood test did not identify it. When talking about Cushing's Disease, we are typically testing the blood for levels of ACTH (Adrenocorticotrophic Hormone)
ACTH levels vary with the different seasons throughout the year. For example during Autumn the results are typically much higher compared to non-Autumn months.
ACTH is also a very unstable hormone once it has been collected, therefore when it is transported long distances it needs to be frozen to improve its stability. If your horse has all the classic signs of Cushings Disease such as hairy coat, drinking large quantities of water, urinating frequently and laminitis, and has tested negative to Cushings Disease it may be worth while re-testing.