Use this code:
<?php
$birthDate = strtotime($rsPROFILE->getColumnVal("dogsdob"));
$ageInSeconds = time() - $birthDate;
$age = intval($ageInSeconds/(60*60*24*365));
$months = intval((($ageInSeconds/(60*60*24)) % 365)/12);
echo("Birthdate: " . $rsPROFILE->getColumnVal("dogsdob") . " age: " . strval($age) . " years " . $months . " months");
?>
What does it display?