Could someone with experience of this please explain it to me?
I have an entire male and 3 entire females.  The male is unable to be neutered till growing plates close(after 18 mths) but one of my bitches have just came into season which means all 3 will soon come in too so I'm looking at 9 weeks of torture for my boy.  He 'finished' himself off in the living room last night, air-humping, right infront of the kids so this has to stop.  Will chemical castration affected his growing?  Will it be affective immediately?  How much does it cost?  How long will it last?
Thanks

I'd be interested to hear about this too.

My friend had her Giant chemically castrated [the implant] and it worked really well. His testicles shrunk, so she didn't show him for a while, but it calmed him down. I haven't asked her how long it took before it started working and she's in Ireland so prices would be different, but I'm sure somebody will know.
My older bitch has the implant to treat incontinence and it works wonders. It starts working pretty much instantly and lasts about 12 months [which I'd think would be the same with males].
She used to be a very bad leaker and needed both Propalin and Incurin, but stays completely dry with the implant.

it won't be any use to you now as it takes several weeks to work (suplelorin) and Tardak just reduces libido and would not be reliable to prevent mating.

The best method is to board the dog away from home, preferably with a reliable relative or friend, otherwise boarding kennels.

Alternatively the bitches can be boarded for the second two weeks of their seasons at kennels that accept bitches, and you can manage with seperation, the first week and week after they finish as he should e less affected then, but it won't stop him masturbating.

You could use the opportunity to explain reproductive biology and not make a big thing about it to the kids.  Mien were very matter of a fact having seen bitches mated etc, and could never understand their friends tittering about things at school.  My son once said I don't understand it at all, 'it's only sex'.

I found it useful to explain that the poor dogs were controlled by their drives at this time, that they too would be subject to such forces but should have the reasoning to understand it, control themselves to act responsibly. 

Seems to have worked reasonably well, both discussed birth control with me and sought my advice.  Daughter is 24, had a few short term boyfriends, and then two serious long term relationships.  The boy at 20 has not got any girl into trouble. 

I would imagine chemical castration is going to have the same effect on growth rate as surgical castration as you are depriving the body of the same hormones.

As has already been said Suprelorin takes 6 weeks to work -but also it is NOT recommended for immature males, so wouldn't be a good idea.