Thyroid axis and adrenal activity in 28 day survivor and nonsurvivor dogs involved in recent road traffic accidents: A cohort study of 420 dogs

The objective of this retrospective cohort study was to determine the impact of a recent trauma on thyroid axis and adrenal activity in dogs and to assess the usefulness of urinary cortisol-to-creatinine ratio (UCCR), basal serum thyroid-stimulating hormone (TSH), total thyroxine (tT4), and free thyroxine (fT4) concentrations in predicting outcome in dogs traumatized by a road traffic accident (RTA). An RTA exposed group of 210 dogs was evaluated within 24  hours of the trauma. Their data were compared with data from a matched group of dogs with other diagnoses. UCCR was positively correlated with the trauma severity and was higher in the exposed group than in the nonexposed group (median 101.500 vs. 21.02;p <0.0001). tT4 values were statistically similar between the two groups, but were correlated with a trauma score, while TSH (median = 0.050 vs. 0.080 ng/mL;p <0.0001) and fT4 (median = 15.850 vs. 17.950 pmol/L;p = 0.0037) were significantly lower for the exposed group. Nonsurvivors in comparison to survivors presented and higher median UCCR (181.800 vs. 93.850 respectively;p = 0.020), and a lower serum fT4 (12.700 vs. 16.500 pmol/L, respectively;p = 0.0046). A similar pattern had been observed for tT4. TSH levels were not predictive of survival. This study provides insights into the endocrine characteristics of dogs suffering from acute trauma. UCCR was higher while fT4 and TSH were both lower in RTA-injured dogs than in dogs affected by other conditions. Furthermore low fT4 and tT4, and a high UCCR could be useful prognostic factors in dogs affected by RTA trauma.