Retrospective evaluation of circulating thyroid hormones in critically ill dogs with systemic inflammatory response syndrome

Abstract

Critical illness can be associated with transient alterations in circulating thyroid hormone concentrations, indicating the presence of non-thyroidal illness (NTI). NTI is well described in humans, but there are few reports on its occurrence and prognostic significance in dogs. This retrospective study assessed the occurrence of NTI in a population of dogs with systemic inflammatory response syndrome (SIRS) and investigated its association with disease severity (APPLEfast scores). A total of 41 SIRS dogs were included and were divided by SIRS origin (non-septic SIRS, n = 10; septic SIRS, n = 41) and final outcome (survivors, n = 37; non-survivors, n = 4). Healthy, age-matched dogs (n = 15) were included as controls. Serum thyroid hormone levels including total T3, free T3, total T4, and reverse T3 were measured upon admission. Compared to controls, there were significant changes in serum thyroid hormone concentrations in SIRS dogs, suggesting the presence of NTI. Septic SIRS dogs had higher APPLEfast scores and lower serum thyroid hormones concentrations than those in non-septic SIRS and control dogs. In conclusion, NTI was frequent in dogs with SIRS and may be associated with the presence of sepsis or high illness severity.

Investigation of adrenal and thyroid gland dysfunction in dogs with ultrasonographic diagnosis of gallbladder mucocele formation

“…However, in dogs with gallbladder mucocele formation, a much larger percentage of dogs had an abnormal total T3 at all degrees of illness severity (mild, moderate, severe; 86, 62, and 78% respectively) compared to reports of euthyroid dogs with NTI that were similarly stratified (3, 18, 27%, respectively)[44]. Moreover, the median total T3 in dogs with gallbladder mucocele formation was at or below the reference range in all categories of illness severity, while in other studies this was only observed in the most critically ill dogs[74, 75] or not at all[44]. In this study, 15% of dogs had serum total T4, total T3 or both below the limit of detection of the assay (i.e.…”

“…Finally, 20% of dogs with gallbladder mucocele formation had a FT 3 below reference range. Few reports exist on interpretation of FT 3 values in dogs, however one study demonstrated no significant effect of systemic inflammatory response syndrome on FT 3 measurements[75]. In contrast, prior studies report a significant association between illness severity and percentage of dogs with low FT 4 (mild, moderate, severe; 7.6, 16.8, and 43.5% respectively)[44].…”

Prognostic value of systemic inflammatory response syndrome and serum concentrations of acute phase proteins, cholesterol, and total thyroxine in cats with panleukopenia

“…Critical illness is a cause of NTI in both dogs and cats. In dogs, many studies have evaluated the prognostic implication of thyroid hormones in sick patients . It has been determined that serum tT4 concentrations in cats with NTI progressively decrease with the worsening of the disease .…”

“…In dogs, many studies have evaluated the prognostic implication of thyroid hormones in sick patients. 8,19,[26][27][28][29] It has been determined that serum tT4 concentrations in cats with NTI progressively decrease with the worsening of the disease. 30 Another study in cats with various diseases not associated with the thyroid gland showed that serum tT4 concentrations are inversely correlated with mortality.…”

Use of 2‐dimensional speckle‐tracking echocardiography to assess left ventricular systolic function in dogs with systemic inflammatory response syndrome

“…Sepsis is a systemic inflammatory response to infection . In canine medicine, SIRS has been reported in many infectious diseases and also in several noninfectious inflammatory disorders such as pancreatitis, trauma, neoplasia, and immune‐mediated diseases . When SIRS occurs, an excessive release of cytokines results in progressive endothelial dysfunction, increased microvascular permeability and activation of the coagulation system, which can potentially lead to secondary multiple organ dysfunction syndrome and death .…”