Anxiety related behavioural disorders and neurotransmitters in dogs

The aim of this research has been to verify possible correlations among some neurotransmitters and anxiety related behavioural disorders in the domestic dog. Twenty dogs affected by anxiety related behavioural disorders and 13 control dogs were studied. The dogs’ behaviour has been analysed through a detailed history case. Blood samples have been analysed by HPLC method to evaluate the plasma levels of dopamine (DA), norepinephrine (NE), serotonin (5-HT), 5- hydroxyindolacetic acid (5-HIAA), 3,4-diidroxyfenilacetic acid (DOPAC), L-DOPA and platelets levels of NE, DA and 5-HT in the two groups. Plasma levels of DA and 5-HT are significantly higher in the anxious dogs with respect to the control ones (DA: ng/mg prot. 0.074 ± 0.071 vs. 0.030 ± 0.001, [P < 0.01] and 5HT: ng/mg prot. 24.95 ± 36.64 vs. 5.94 ± 3.20, [P < 0.01]). The plasma levels of the other neurotransmitters are similar in the two groups. Platelet levels of NE (ng/mg prot. 0.133 ± 0.047 vs. 0.124 ± 0.061) and DA (ng/mg prot. 0.0552 ± 0.018 vs. 0.074 ± 0.039) are also similar in the two groups. A trend to higher 5-HT platelet levels (ng/mg prot. 509 ± 100 vs. 425 ± 117) in the control dogs compared to the anxious ones has been found.