PHP MySQL Count Query Result is String, Not Integer

I have the following MySQL query, and PHP code to format the Count result in a single array:

$equalDimensions_query = 
"SELECT 'allEqual' AS COL1,COUNT(*) AS imgCount FROM (
    SELECT imgHeight, imgWidth, imgId AS primaryId FROM primary_images
    UNION ALL 
    SELECT imgHeight, imgWidth, primaryId FROM secondary_images
) AS union_table
WHERE primaryId = $imgId AND imgWidth = $maxImageWidth AND imgHeight = $maxImageHeight
UNION ALL
SELECT 'widthEqual' AS COL1,COUNT(*) AS imgCount FROM (
    SELECT imgHeight, imgWidth, imgId AS primaryId FROM primary_images
    UNION ALL 
    SELECT imgHeight, imgWidth, primaryId FROM secondary_images
) AS union_table
WHERE primaryId = $imgId AND imgWidth = $maxImageWidth AND imgHeight != $maxImageHeight
UNION ALL
SELECT 'heightEqual' AS COL1,COUNT(*) AS imgCount FROM (
    SELECT imgHeight, imgWidth, imgId AS primaryId FROM primary_images  
    UNION ALL 
    SELECT imgHeight, imgWidth, primaryId FROM secondary_images
) AS union_table
WHERE primaryId = $imgId AND imgWidth != $maxImageWidth AND imgHeight = $maxImageHeight";

$equalDimensions_data = mysql_query($equalDimensions_query) or die('MySql Error' . mysql_error());

while ($row = mysql_fetch_assoc($equalDimensions_data)) { 
    $cnt[$row['COL1']] = $row['imgCount']; 
}

var_dump($cnt);

(Notice I included var_dump($cnt) as the last line)

The var_dump returned the following array:

array
(
  'allEqual' => string '2' (length=1)
  'widthEqual' => string '0' (length=1)
  'heightEqual' => string '0' (length=1)
)

I'm curious why the count is being returned as a string, and not as an integer?

Should it be returned as an integer? Or is it the norm when dealing with count queries, for the result to be returned as a string?

Thanks.