When I've seen races in South America with no limit on whip use the horses go much faster and its much more exciting. On top of that its hypocritical as its common nowadays for horses to get a whipping in the stables before a race to wind them up for the race - i know I work in a stables. So why no leave it to the judgement of the jockey - some horses don't need much whipping but some need to be flogged pretty hard.
Animals are sentient creatures capable of pain and emotion. As such, wanton cruelty to animals is unjust – because consistent standards of moral consideration must apply. The government gives the severely mentally enfeebled rights, which means animals – which lack significant psychological differences to the mentally enfeebled – should also be given rights. Christine Korsgaard explains that humans feel empathy towards animals for a reason; we recognize that there are good reasons to change animal conditions from net negative mental states to positive ones. 
That’s fundamentally because moral decisions are based on desires and emotions. There’s no thing with intrinsic value except what we desire. What we find undesirable is inherently harmful. Animals feel pleasure and pain, so are worthy of the same moral consideration.
This brings us to the role of the government. The state’s role is to legislate based on what is reasonable and fair. I agree with St. Augustine that an unjust law is no law at all. Justice- being fair and reasonable- is critical to any understanding of the function of the state. Justice is, by definition, treatment without needless discrimination. Since any such discrimination is arbitrary and there are no morally relevant differences between humans and animals, it is unjust to deny animals basic rights.
 Korsgaard, Sources of Normativity, p. 153
b) Whipping horses causes pain
Horses are sensitive creatures and feel pain. In fact, a horse can feel a fly landing on it, which means whipping will cause intense pain. Whips cause bruising, inflammation and intense suffering.  Since I’ve already established- through the role of the government- that it is unjust to cause wanton suffering to animals, the government shouldn’t remove limits on whipping.
Pro says allowing whipping allows for more speed and excitement… this is completely irrelevant because the magnitude of intense suffering easily outweighs the magnitude of happiness from “excitement.” The same way the government doesn’t allow whipping of humans, whipping of sensitive horses is unjust and shouldn’t be permitted- or, at the very least, the limits that exist shouldn’t be removed.
Well your arguments work if you think causing pain is a bad thing and if you care about animals and I don't in both cases. like I think its good to whip your kids to discipline them which causes pain which is kinda that's the idea. So by whipping the horse or spurring it you cause pain so it goes faster. I don't see the problem with that.
Pro has two points: a) that pain isn’t necessarily a bad thing, and b) animals needn’t be cared about. I’ll respond to both.
First, it isn’t deniable that pain is undesirable. That’s the definition of pain. When things are “undesirable”, they’re bad unless they have a good consequence- I’m sure Pro agrees with me. If the pain has a good consequence, it is justified. But I’ve shown that the harm of the pain easily outweighs the “excitement” caused by whipping, and that’s the only good consequence Pro brings up.
Second, Pro drops all my arguments in favor of caring for animals. There are very little morally relevant differences between humans and animals- and when it comes to causing wanton suffering, there is an obligation to not cause it for both humans and animals. Applying inconsistent standards between humans and animals is being both unfair and unreasonable, so is unjust. An unjust law is no law at all.
Pro also seems to hold the despicable view that it is fine to ‘whip’ your kids to discipline them- but Pro fails to explain how that is morally permissible. It is immoral under almost every ethical system. Under utilitarianism, it causes more suffering and very little good consequences (whatever discipline is generated is easily outweighed by the pain if the whipping). Under deontology, it is committing an act of inflicting something deeply undesirable- which is immoral. Under egoism, it could potentially lead to psychological damage to the whipper as a result. Not that whipping children is relevant to the debate, but I just view it as a morally repugnant position. [Note: there are certain voters that will interpret my usage of words such as despicable and repugnant as conduct violations- those voters are wrong because I’m not insulting my opponent so much as criticizing their position, which is what debate is for.]