Side effects of Synulox in dogs?

[Bubaroo]

My 11 year old Collie cross was prescribed Synulox for a suspected chest infection, and since we started her on the tablets, she hasn't seemed her usual self at all, very lethargic and just wanting to sleep all the time. I haven't been able to find anything online, and I was wondering if anyone could tell me the side effects of these tablets?

Thanks guys!

[Unregistered]

our 14 year old collie has been taking synulox for 4 days now and has been very lethargic and sleepy ,infection seems to be clearing up so im keen to see what he's like once a.biotics are finished,back to vet tomorrow,he is a lovely ,very active dog despite his age.