I generally find WordPress excerpts a little bit irritating. They ignore all formatting, including paragraphs, so you just end up with a block of text with no styling and sometimes little sense.
To make matters worse, if your content includes a URL you’ll end up with the whole thing displayed in the excerpt, no matter how long or nonsensical it looks. Luckily, this is easily remedied with a little code.
Drop the code below into your functions.php file and those URLs will be stripped out of the excerpt: