Count Unique Text Cells Ending In X - Function Only

I have some data in a column, starting at row 6 that I'd like to find the number of unique text values for. For this I have been using this formula

Code:
{=SUM(IF(FREQUENCY(IF(LEN(A6:A10000)>0,MATCH(A6:A10000,A6:A10000,0),""), IF(LEN(A6:A10000)>0,MATCH(A6:A10000,A6:A10000,0),""))>0,1))}

The data is dynamic so I picked an arbitrarily large number (10000) and the above formula successfully ignores blank fields.

However, I'd like to now find the count of unique text values that end in X. For example, let's say the data are as follows

Dog_Cat
Mouse_Dog
Mouse_Cat
Mouse_Cat
Mouse_Cat
Mouse_Mouse
Elephant_Elephant

How would I go about (in one function) finding the unique values that end in "_Cat", in this case 2 ("Mouse_Cat" and "Dog_Cat")?