Personally, I think "quelques chevaux" is perfectly alright to say, whereas  "un couple de chevaux" might be a little closer to "a pair of horses"?

But certainly, "quelques chevaux" is not wrong?  Maybe using "couple" here is English creeping into the language? or even French Canadian? 

Also "clôture" could be used instead of "barrière".  I hear people saying "J'ai hâte de (faire ceci et cela)" all the time, in the sense "I am excited" (to do something),  but  I think one has be to be really careful and really sure of oneself before attempting "je suis excitée". And sure, maybe you could say a child or a dog is "surexcité" but would you say the L'homme est surexcité? Haha, not so sure about that!