Strong smelling urine

My son is BF with introduction of some solids over the last week. Since then his urine has been smelling very strongly of ammonia, his nappies stink the room out they are so bad and seem to be getting worse. His urine continues to be pale and there is plenty of it so I don't think he is dehydrated and no sign of UTI either. He is still drinking plenty of breast milk, I can't quite figure out what may be causing it. I know that some foods can scent your urine but I can't imagine they would make it smell so strongly.

Any suggestions? Thanks.

It could be teething, have you had a look at his gums? When my kids have teeth coming through their nappies almost burn my eyes sometimes the ammonia is that strong!

That's a thought thanks. I think that there may be some coming through imminently, his top gums have flattened out but no sign of teeth quite yet.