Symptoms of PTSD in humans include, but are not limited to, the following: dreams, flashbacks, paranoia, the inability to mantain relationships, the inability to recall key details from the stressful or traumatic event, avoiding places, things, and people that may trigger the memory of the traumatic or stressful event, insomnia, change in mood such as depression or rage, and hyperarousal. Several of the listed symptoms can be seen in dogs after a traumatic event, which contributes to the diagnosis of Canine PTSD in believed victims. Similarities include hyperarousal, insomnia, changes in mood/temperment, the inability to attach to its owners, and avoiding certain situations, places, or people that resemble the event. Hyperarousal is also known as the "fight or flight response".
Are Dogs Haunted by The Traumatic Event?
One area of difference between PTSD in humans and Canine PTSD is that it is impossible to know what dogs are thinking. They cannot verbally communicate if they are experiencing dreams, flashbacks, or recurring images from the event. Dr. Christopher Pachel, in an article run by Cesar's Way, stated that he is "...one of the hallmark signs of making a PTSD diagnosis is really some of those intrusive thoughts or replaying of events – flashback type episodes… We can observe some of that in dogs but it’s really difficult to know what exactly is going through their heads.” (He is board certified veterinary behaviorist based in Portland, Oregon.) This is one reason why he is "hesitant to use that term...on the human side", meaning he is hestitant to say PTSD in humans and Canine PTSD are the same and/or should be discussed in the same manner.
When Dogs Stop Performing a Certain Task
Another sign of Canine PTSD experts tend to see is when dogs stop doing something specific they were trained to do. This is extremely prevalent in military canines who develop Canine PTSD. For example, most military canines are used to sniff out explosives. If a military canine who used to sniff out explosives stops doing so, this can be a sign s/he is suffering from Canine PTSD. The tasks or jobs the dogs stop performing must be related to the traumatic or stressful event, however. It cannot be separate.