Not till at least March and then put netting over it. You might find its better to turf if dogs are such a problem?

I'd sow seed if there is an issue with dogs as due to experience they are capable of taking up the sods and throwing it around. Much less money wasted that way. Also the only way to dog-proof it is to temporarily fence it off until the lawn is established. All based on bitter experience :~(

Use bamboo canes with string wound between them to make a temporary fence to stop them getting in - you'll need "rows" of string to stop them jumping over or climbing inbetween, so get a large ball of string! Either that or sheets of polythene between the canes. And March is the earliest - if its still very cold that month, do it over Easter at the beginning of April.

In France you can buy quite cheaply ultrasonic devices which are set off by movement, and these are quite effective in keeping dogs away.
They may be available in the UK too unless they are thought to be cruel and unnatural punishment for the offending canine!
We have a large hound that hides under the bushes watching me when I sow carrots, and I am sure it is deliberate on his part when he proceeds to dance all over the newly sown carrot bed as soon as I have left the scene.