All the secondary schools I have visited seem very clued up about SpLD and provide decent support but imo it is a bit late in the day to leave dx and support until high school.
My DS has only just been diagnosed (privately not through school) at end of yr 5 and speaking to other parents I have discovered we are not the only ones. I also know children from other primary schools who have only been diagnosed in yr5/6 after parents have pushed or gone private (usually the latter).
The teachers at my son's school admit they don't know much about it. I am surprised at this as I would have thought it would be part of teacher training-I'm sure upwards of 10% of the population are dyslexic so it's not as though it is rare.
If dyslexia is recognised and understood it's not difficult to make adjustments/use technology and learning programmes such as toe by toe. Instead it seems that a lot of kids are still left to flounder in bottom groups without the right support unless stubborn and pushy proactive parents like myself try and get to the bottom of what is going on.
Most dyslexic children show classic signs (difficulty with timestables, can't tell time, spelling problems, poor handwriting) which to me stand out a mile particularly when the child (and all the ones I know are) is verbally articulate.
I don't understand why, when a fair amount of emphasis is put on testing for and supporting SpLD at secondary, there seems so little at primary level. Most of the damage to self esteem, self belief has probably happened by the time they are ten. I remember the dyslexic kids who were failed when I was at primary and not a lot seems to have changed in 30yrs. 
I would be interested to hear POV of primary teachers as to whether this is normal across the country. Despite dyslexia being given a higher profile through celebs like Kara Tointon and this years Apprentice winner recognition still seems woeful.