Formula to compare if multiple cells no longer blank

Hi,

I need to check if any cells are no longer blank...

Basically I will be checking if corresponding cells in say columns ABC are no longer blank in columns DEF.

My intital way of going it was to do something along these lines...

=IF(AND(ISBLANK(A1)=TRUE,ISBLANK(D1)=FALSE),1,0)

and I was then going to surround this with another AND statement for cols Bs and Cs.

Unfortunately the way I'm implelmenting this will make the formula to long (I will be building the solution into an array formula to ultimately count all the rows where one column was blank and is no longer in it's corresponding column).

Apologies if I have over-complicated what I'm trying to do-I have put below a quick example.

Columns ABC headed Dog Cat Fish for 2009 and Columns DEF headed Dog Cat Fish for 2010.
Each row relates to if a person had one of the pets in each year and also what type Jack Russell etc.

In my overall forumula I want to count the number of people that now have a new pet category in 2010 that didn't in 2009. i.e. no Dog 2009 but now has one 2010. I'm not concerned if they had a dog in both years but the dog type changed...

If any of the columns was blank for 2009 but not for 2010 I want to count it as 1.

Ideally I want to do this without using any other formulas in other cells which I appreciate does complicate things...

Your thoughts/suggestions are really welcome.

Cheers

Is this something like this what you have in mind?