Cavalier - Starting Horse

[Krky77]

Hi all!
Now, let's say a 1st level human Cavalier picks a horse for their mount. What do the rules say - does it have to be a light riding horse?
http://www.d20pfsrd.com/bestiary/monster-listings/animals/horse

Or can they start with a heavy horse?
http://www.d20pfsrd.com/bestiary/monster-listings/animals/horse/heavy-horse

Or even an advanced horse?
http://www.d20pfsrd.com/bestiary/monster-listings/animals/horse/horse-advan ced

I've seen several of these variants, but I don't know what's within the rules, and I'd really like to abide by them.

If these other variants are legal, do they also progress through the levels according to this table, so all the bonuses listed here apply to them as well?
http://www.d20pfsrd.com/classes/core-classes/druid/animal-companions

Also, can I raise my horse's intelligence to 3 by any means?
Even by raising an ability score once it reaches level 4?
Thanks in advance!
You'll help me a lot!

[theshoveller]

I'm fairly sure you're meant to use the animal companion horse in the Druid section of the CRB.

[Saldiven]

"A cavalier gains the service of a loyal and trusty steed to carry him into battle. This mount functions as a druid's animal companion, using the cavalier's level as his effective druid level. The creature must be one that he is capable of riding and is suitable as a mount. A Medium cavalier can select a camel or a horse."

It's the Druid animal companion Horse. Check the Druid section of the CRB for the stats.

[Nefreet]

*looks around for Flutter*

<.<

>.>

*shrugs*

Here, please take a union card.

[Krky77]

Thanks for the answers guys, and especially for this insanely useful link, Nefreet!

[Wolfsnap]

Don't be afraid to approach your GM about this question. In my group we usually go for the heavy horse just as a personal preference, but the druid horse is the default.

[Krky77]

Got it, much obliged!