My 9 month old labrador has suddenly gone off his food.  He used to wolf it down when it was placed in front of him, now he turns his nose up at it or will take forever to eat it.  I've tried changing the brand and giving him more meat etc but it just doesn't seem to help.  He seems really down too.  I don't know whether it's the warm weather as he cannot get comfortable and keeps going for the shade or somewhere cool.  Any advice or should I take him to the vet??

It could be the heat, my pups aren't eating at all during the day, they wait until late at night when it's cooled down. Could there be a bitch in season anywhere nearby? That could make him act like this too. If you're worried, see the vet though of course.

>It could be the heat, my pups aren't eating at all during the day<

Snap!  Mine havnt been eating till around 9 at night

It could be the heat,it could be a bad batch of food,what are you feeding? Could be a tummy bug. Is it just his normal food he is refusing? Will he eat something different if offered,or is he off ALL food?

I would take a fecal sample into the vet,just incase.It's always better to be safe than sorry.

Edited: Just noticed you've tried a different brand of food,but am still interested in what you're feeding :)

Try keeping him as cool as possible.Rub him down with wet towels,spray his belly and feet with cool water and plonk him infront of the fan, make sure he is kept inside in a cool room.Do not leave him outside during the heat of the day.

He has been on Beta puppy complete dry food from when he was born.  I bought the pedigree puppy pouches to add to the dry food and he liked this but now he's gone off it all together.  My friend gives her lab Tesco premium and he loved it so tried this but no luck - don't like it myself actually!  Just tried him purely on the pedigree meat and he wolfed it down so looks like I'm just going to have to give him meat for the time being.  I did want to incorporate a mixer with it but he turns his nose up at it.  We've just noticed that he is limping so going to take him to the vet to get checked over and will tell her about him being off his food too.

If you keep changing his food every time he turns his nose up at it, you are only training him to refuse his food for something tastier.

Instead, keep putting his food down every few hours and take it away after 10 mins if he hasn't eaten it.

I've yet to see a labrador starve!!!!

"Instead, keep putting his food down every few hours and take it away after 10 mins if he hasn't eaten it."

...and it works! Another piece of useful advice I read here a couple of months ago!
I spent a lot of time reading here and referring to manufacturers specifications, decided on JWB, and by using another piece of good advice (adding tiny amounts of tasy morsels to it) got ours to eat her meals when they were given. Didn't take long.

Also changing to better foods than pedigree bum and beta may help too ;)

Get a puppy, borrow a dog , and see then how much he's prepared to leave his food for .Put down ,pick up after 10 -15 min if not eaten, they soon learn that's the rule -Janet English