[Clinical symptoms of and diagnostic possibilities for hypophyseal adenoma in horses].

The research paper discusses clinical indications and diagnostic possibilities for pituitary gland tumors in horses, findings show that hirsutism was most common among symptoms, while hyperglycemia and glucosuria were key lab results, and a positive dexamethasone suppression test confirmed the condition.

Symptoms of Hypophyseal Adenoma

• Hirsutism, or abnormal hair growth, was found in all 13 examined horses indicating it as the most common symptom of a pituitary tumor.
• Moreover, muscle atrophy was noticed in 10 horses, hyperhidrosis which is excess sweating in 8 horses, polyuria/polydipsia (excessive urination or thirst) in 5, presence of supraorbital fat or bulging in 3, polyphagia (excessive hunger) in 2, apathy (lack of interest) in 2 and seizures in 2.
• Laminitis which is an inflammation of the soft tissue structures that attach the coffin or pedal bone of the foot to the hoof wall was a commonly occurring concurrent disease in 8 horses.

Lab Results and Diagnostic Tests

• With regards to laboratory results, hyperglycemia (high blood sugar levels) was observed in 13 horses with a mean of 9.9 +/- 3.71 mmol/l, and glucosuria (excessive glucose in urine) found in 7 horses with a median of 55 [range, 2-55] mmol/l, which were the most significant lab findings. These results indicate problems with the body’s ability to control sugar, which can be related to issues in the pituitary gland.
• The dexamethasone suppression test was positive for all tested horses (n = 9) 20 hours after the administration of dexamethasone, which suggests the possibility of a pituitary gland tumor. This test is performed by administering dexamethasone and measuring the body’s ability to suppress cortisol production, if it does not suppress cortisol, it can indicate a pituitary problem.
• The use of computed tomography (CT) scans showed the presence of the pituitary gland tumor in all 7 horses that underwent the procedure, thus demonstrating the diagnostic utility of this imaging technique.

Conclusions

• From the analysis of the observed symptoms, coupled with the laboratory results and diagnostic tests, the study concluded that a pituitary gland tumor could be suspected with the presence of the typical symptoms.
• Furthermore, the presence of hyperglycemia and glucosuria can support a preliminary diagnosis. In addition to other symptoms, a positive outcome on the dexamethasone suppression test can allow for a definitive diagnosis of a pituitary gland tumor in horses.