Hector is a dog, he's an important character in Cave Canem, the third book of Felidae series.
He's described as an ex-police dog of brownish colour (possibly a German sheperd) that despite not being young, is considered as a capable investigator by the dogs of the city.
Because of his experience, Hector is dispatched as partner for Francis, to investigate about the murderers of a number of animals. Hector display a friendly, loyal and polite behavior only to be received with diffidence by Francis.
Little by little, Hector earn the respect and the trust of Francis: despite being less smart than his partner, Hector is however intelligent and shows great reflexes and physical abilities saving Francis's life in two separate occasions.
The first time it's when Hector follows Francis after the cat declared his desire to kept on an individual job: while investigating into a ventilation tube of a large dog's pound, Francis is attacked by mysterious deformed dogs (that will later be revealed as former comrades of Hector). The dog manage to grab Francis and drag him away in safety.
When later Francis kept on his investigation into the General Horch's home (being unaware that it was the same residence of Hector), the cat falls into the Piranha aquarium of the General and again Hector manage to find and save Francis's life.
Hector past is shown step by step: he was actually an ex-military dog involved in peacekeeping operation after the Yugoslavian Wars, in that period he was shocked by the brutality of war but without being affected as many other of his comrades.
The dog manage to provide a valuable information for the investigation when he has the idea to search information from Andromeda: an old female dog that gives more clues.
He refuses to believe that his master, the General Horch, could have been responsible of the killings but when it's exposed the identity of the murderer (Mars, another ex-soldier), Hector follows Francis to the final confrontation.
Hector try to attack the man, only to be defeated and mortally wounded by him. In his last moments of life, Francis's feelings are exposed and the cat remain close to his friend.
Hector, as all the other victims, will be later avenged by Moses and the other cats of the Council after a wounded Francis will expose the truth.
The true reasons of the sick deformations and the abnormal and aggressive behavior of the ex-comrades of Hector are not clearly explained. However this can be explained by the use of depleted uranium bullets and other radioactive weapons by NATO forces in Yugoslavian Wars. Local inquiries among European NATO participants has exposed symptoms by radioactive pollution (including deaths due cancers) among human participants in peacekeeping operations. NATO and American officials rejected the allegations.