加拿大警犬專家 Bob Eden 擁有 37 年軍犬和警犬訓練經驗，曾經為加拿大及美國警方成立警犬隊，並任職首警犬訓練師達 16 年之久，更創辦國際警犬交流會議。著有多本犬隻訓練專書及手冊，並經常在國際期刊及雜誌專欄發表心得。
Bob Eden 早前收到許多關於警犬及催淚煙的查詢，及後去信香港愛護動物協會(SPCA)，要求協會為針對香港警方的不實指控作出澄清，「不要以虛假訊息為事件火上加油」：
Bob Eden, a police veteran and expert in law enforcement and military dog training with 37 years of experience, urged the SPCA to “set the record straight rather than fuel the situation with mis-information” against Hong Kong Police:
“I just sent the following to the SPCA because they too are spreading information and it reduces the credibility for all involved: I have been contacted by numerous people regarding the use of police dogs by the Hong Kong police in a tear gas environment. The information being spread by those who believe the gas is harmful to the dogs is incorrect and is mis-information.
I have trained thousands of dogs around the world and have put well over a thousand dogs through CS and OC environments during training I have conducted with police and military forces. The dogs suffer no ill effects from working in the gas and in fact are fully functional and able to use their olfactory capabilities to actively search and locate hidden suspects who are hiding in a tear gas environment.
Dogs have a very advanced lacrimal system which allows them to flush their eyes at a much greater rate than a human being. In fact their eyes naturally have the ability to flush a rates up to 10 times greater than that of a human being. If they eye does become over saturated with gas at a rate that the eyes cannot flush efficiently, the nictitating membrane draws across the eye to protect it and the dog is still fully capable of working. Dogs do not apocrine sweat glands over their bodies like humans do and only produce sweat on areas not covered with fur such as the nose and paw pads which limits their exposure to the gas to extremely limited areas of their body. In most cases, they would not feel any effects on the bottoms of their feet. Finally, the canine body PH is slightly alkalis, which provides a natural neutralization of the some of the acidic value of the gas they are exposed to.
In short, while heavy doses of gas directly into the face of a dog could have a negative affect on the dog, normal deployment of dogs in a tear gas environment has little to no affect on the dog, particularly dogs that have been trained and acclimated to the environment during training. To suggest otherwise is spreading information that is incorrect and simply not true.
I understand the people of Hong Kong are in a very volatile political situation at the current time, and they are using whatever means possible to discredit law enforcement, however to use false information and for the SPCA or any other organization to spread information that leads people to believe that the use of OC or CS gas around these dogs is causing the dogs harm in any way only reduces the credibility of those who choose to spread this type of information and does not serve to benefit anyone involved.”
愛護動物協會其後在無任何解釋下刪除 Bob Eden 的留言。
SPCA later deleted Bob Eden’s post without any explanation.