Сравнение элементов в многомерном массиве

Скажем, у меня есть многомерный массив. Например:

 Array ( 
         [0] => Array ( 
             [animal_id] => 5494 
             [animal_name] => "Suzy"
             [animal_type] => "zebra" 
             [animal_location] => 0 
             [animal_awake] => 1
             [animal_age] => 3 ) 
         [1] => Array ( 
             [animal_id] => 5494 
             [animal_name] => "Joshua"
             [animal_type] => "panda"
             [animal_location] => 5
             [animal_awake] => 0
             [animal_age] => 8 )
        [2] => Array ( 
             [animal_id] => 5494 
             [animal_name] => "Debra"
             [animal_type] => "snake" 
             [animal_location] => 7 
             [animal_awake] => 1
             [animal_age] => 3 ) 
        [3] => Array ( 
             [animal_id] => 5495 
             [animal_name] => "Caleb"
             [animal_type] =>  "zebra"
             [animal_location] => 0
             [animal_awake] => 1
             [animal_age] => 3 ) 
        [4] => Array ( 
             [animal_id] => 5495 
             [animal_name] => "Joshua"
             [animal_type] =>  "panda"
             [animal_location] => 5 
             [animal_awake] => 0
             [animal_age] => 8 )    
        [5] => Array ( 
             [animal_id] => 5495 
             [animal_name] => "Debra"
             [animal_type] =>  "snake"
             [animal_location] => 7 
             [animal_awake] => 1
             [animal_age] => 3 ) 
        [6] => Array ( 
             [animal_id] => 5496 
             [animal_name] => "Emily"
             [animal_type] =>  "zebra"
             [animal_location] => 0
             [animal_awake] => 1
             [animal_age] => 3 ) 
        [7] => Array ( 
             [animal_id] => 5496 
             [animal_name] => "Joshua"
             [animal_type] =>  "panda"
             [animal_location] => 5 
             [animal_awake] => 0
             [animal_age] => 8 )    
        [8] => Array ( 
             [animal_id] => 5496 
             [animal_name] => "Debra"
             [animal_type] =>  "snake"
             [animal_location] => 7 
             [animal_awake] => 1
             [animal_age] => 3 )             
         )

И я хочу сравнить всех змей против змей и всех панд против панд и т. Д. (Но не змей против панды) и поместить уникальные элементы в массив (все уникальные элементы в один массив). Как я буду делать это. Поскольку они являются элементами в массиве, я немного озадачен. Кроме того, я заранее не знаю, сколько будет разных типов. Например, однажды мне можно было передать многомерный массив с Panda, Bear, Snake - В следующий раз мне можно было передать массив с Bird, Cat, Panda, Zebra.

Есть идеи?

FINAL OUTPUT

      Array ( 
     [0] => Array ( 
         [animal_id] => 5494 
         [animal_name] => "Suzy"
         [animal_type] => "zebra" 
         [animal_location] => 0 
         [animal_awake] => 1
         [animal_age] => 3 ) 
     [1] => Array ( 
         [animal_id] => 5494 
         [animal_name] => "Joshua"
         [animal_type] => "panda"
         [animal_location] => 5
         [animal_awake] => 0
         [animal_age] => 8 )
    [2] => Array ( 
         [animal_id] => 5495 
         [animal_name] => "Caleb"
         [animal_type] =>  "zebra"
         [animal_location] => 0
         [animal_awake] => 1
         [animal_age] => 3 )    
    [3] => Array ( 
         [animal_id] => 5495 
         [animal_name] => "Debra"
         [animal_type] =>  "snake"
         [animal_location] => 7 
         [animal_awake] => 1
         [animal_age] => 3 ) 
    [4] => Array ( 
         [animal_id] => 5496 
         [animal_name] => "Emily"
         [animal_type] =>  "zebra"
         [animal_location] => 0
         [animal_awake] => 1
         [animal_age] => 3 )    

     )

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