That is correct. If you want the actual math for dosing it's body weight in lbs / 2.2 X 20mg /113.6 = dose.
So a 6 lb bird gets .48 ml, round to .5 for ease of dosing. Always round the fraction up, not down when rounding. You don't want to under dose. A little too much isn't going to hurt them, I've been using it for many years, never hurt a bird.
The bottle likely does have an expiration date, though valbazen is usually good for a couple of years at least. After the expiration date you may find it has reduced effectiveness at some point. I use mine a little past expiration, but not real long after. Depending on how often you worm and how many birds you have, you may use it all up before then. Some people who know others that have birds will split the bottle to reduce expense and waste.
