NEW YORK. Badly behaved pets may just be depressed, new research suggests.
Scientists who studied a number of aggressive animals, especially dogs, found they contained low levels of the “feel-good” hormone, serotonin. In humans, low levels of the hormone are known to be linked with depression.
The journal Applied Animal Behaviour Science reported a study of 80 dogs that had been sent to veterinary hospitals by their owners because they had behaved aggressively.
The dogs had substantially lower levels of serotonin than samples taken from normal-behaving dogs.