The answer can be found in Chapter 25, which is when Katniss begins to suspect that there is something more about the mutts that pursue them so viciously than first meets the eye. It is only when she identifies one of the mutts as possessing some of the same attributes and objects as Glimmer did, the tribute that she killed early on in the games, that she identifies what the Capitol have done with the bodies of those who have died:
My head snaps from side to side as I examine the pack, taking in the various sizes and colours. The small one with the red coat and amber eyes... Foxface! And there, the ashen hair and hazel eyes of the boy from District 9 who died as we struggled for the backpack! And worst of all, the smallest mutt, with the dark glossy fur, hug brown eyes and a collar that reads 11 in woven straw. Teeth bared in hated. Rue...
As we learn later on in this trilogy, the Capitol has learnt the ability of genetic splicing, and here we can see that the identical eyes and colouring of the various dogs shows that the Capitol have spliced the genetic code of the various dead tributes with ferocious hounds to make a gripping finale between the three last tributes as they battle for survival.
Dogs are the most actively genetically manipulated animals from Ancient Babylon to the present. Katniss and Peeta sprint through the forest as two more of the dogs begin to pursue them. The Capitol had replenished the population and used them in.They look more like large, vicious, bulky dogs.Genetically engineered master dogs are mentioned in the Hunger Games. They are a number of genetic monsters being used by the evil and repressive govt. in the quite dystopian world of the Hunger Games trilogy . They suggest more Roman than Hellenic in the general meaning.This sort of use of specially bred animals in war and the like has been in use since the bronze age . Katniss and Ralph share many similarities as both characters are thrust into violent circumstances beyond their control; both characters find themselves isolated in a wilderness with other children. The dogs symbolize this wildness. The island inLord of the Flies and the arena in The Hunger Games leave the children exposed to harsh deadly elements, where they must fend for their own survival. Both Ralph and Katniss struggle with the elements of nature as much as they do the psychological trauma of the situation.Here the use of dogs become most significant
In Chapter 25 you will find descriptions of how the mutts physically resembled the tributes that are already dead.
Figuratively, the mutts represent the very worst parts of humans. Not just the tributes, but the people at home that are watching the Games for entertainment value. These monstorous creatures show (in a physical way) what the games have created (psychologically) within the viewers and competitors. Even while the tributes have been reduced to their most animalistic tendencies while the true monsters, those that view for FUN (and are not forced to watch by the Capitol) sit with painted faces at home.
The mutts that were chasing Katniss and Peeta had the eyes of each of the tributes that they resembled. They were also wearing tags with the number of the district the tribute was from.
I believe that Collins was trying to portray a worse side of the tributes, forcibly brought out by the Capitol.