Don't get this boy wrong; Kiba probably has one of the strongest bonds in the series — the only argument that can counter this is the fact that, that bond, was only for one creature, and he's Akamaru.
At first glance at Kiba, you see him as another ruthless loudmouth, very much similar to Uzumaki Naruto himself. However, the key value that separates Kiba from Naruto is that — without a doubt — the dogboy is beyond arrogant. Further more, he knows who is stronger than him and who's not. Kiba also likes to play the leader of his group as well; call it a slight alpha complex.
That isn't what's unique about him, though; Kiba's constant surrounding by animal turn him almost half-man half-beast, but is still evidently human. Not only that, he aquires very canine-like characteristics, including his personality. When we first meet Kiba, he was aggressive and very rough to the unknown party.
An example: how he treats Naruto when they had first fought in the Chuunin Exams. He'd thought Naruto was an easy win because of a little piece of memory of his skills during the Ninja Academy times — and that really excited Kiba. This contributes yet another part of his character as well, but we will get back to that in moment. Now, here Kiba constantly puts Naruto down as he does not give up after he and Akamaru had pulled some hard punches on the demon-boy.
Speaking skillfully (and totally disregarding Kyuubi), Inuzuka Kiba could have definitely won Naruto; the only reason that had gotten him in a corner during the battle was the fact that, in doing Shikyaku no Jutsu, his senses is boosted up to a thousand times. So, when Naruto had farted right into Kiba's nose, it not only blinds all of his senses, but it borderline-paralyzes him for a good couple seconds — that's all Naruto needs to finish off his opponent (since one of Kiba's strong point is speed; he had to keep Naruto from performing his jutsu).
After being beat in their heated battle, Kiba comes to an understanding that Naruto cannot be underestimated, and becomes (almost) bipolarly friendly to Naruto. This trait is common with pets — more specifically, dogs; they may growl, bark, and snarl at you upon first meet, but once they get to know you, they'll show their upmost respect for you. That is Kiba's loyalty.
Now, let's rewind a little — to the part where Kiba was ecstatic about getting Naruto (of all people) as an opponent. Thinking that he would be an easy win, Kiba cheered for himself and was thoroughly excited. While the Inuzuka is the type whose headstrong and would enjoy a very thrilling battle, he is also one to take the easy road out of a challenge — without appearing like a sore loser. Ultimately, he has this part of mind without knowing so. To make it short: winning is all it's about with Kiba during the Chuunin Exams. This, however, is just a speculation coming from a small piece of detail; no further proof has been set to actually confirm.
To make a long strong short: Kiba is just another loudmouthed energizer of Team 8 with a deeper, more caring side to him than the eye meets.