questions
More than once I wondered if breaking the ritual is what led to the writer's block. In the daytime, I could dismiss this as supernatural twaddle but at night that was harder to do. At night your thoughts have an unpleasant way of slipping their collars and running free. And if you've spent most of your adult life making fictions, I'm sure those collars are even looser and the dogs less eager to wear them. Was it Shaw or Oscar Wilde who said a writer was a man who had taught his mind to misbehave?

Question 1: breaking the ritual --- in this case, what does ‘ritual’ refer to? ( I mean, what kind of ritual? )

Question 2: In this case, what does ‘the dogs’ refer to?

Question

questions
More than once I wondered if breaking the ritual is what led to the writer's block. In the daytime, I could dismiss this as supernatural twaddle but at night that was harder to do. At night your thoughts have an unpleasant way of slipping their collars and running free. And if you've spent most of your adult life making fictions, I'm sure those collars are even looser and the dogs less eager to wear them. Was it Shaw or Oscar Wilde who said a writer was a man who had taught his mind to misbehave?

Question 1: breaking the ritual --- in this case, what does ‘ritual’ refer to? ( I mean, what kind of ritual? )

Question 2: In this case, what does ‘the dogs’ refer to?

Answer

'ritual' refers to something the writer has probably described just before this passage, and it could be anything habitual. He/she uses the same pen, or wears the same shirt, or has the same kind of tea. They've done something differently, and they're blaming that fact for their writer's block.
'Dogs' is an extension of the metaphor in the previous sentence, where thoughts are described as wearing collars, like dogs do. The author is saying that for writers, their thoughts are more likely to wander into imaginative terrain, like dogs that wear loose collars and like to slip out of them and run free.