a joke

Feeling horrible, an alligator goes to the veterinarian. 'What seems to be the problem?' the vet asks. ' I just don't have the drive I used to,' the alligator says. 'Used to be, I could swim underwater for hours and catch any animal I wanted. Now all I can do is let them swim by.' Concerned, the vet gives him a thorough examination and hands him a few pills.
'What are these?' the alligator asks.
'It's a pill very similar to Viagra,' te vet answers.
'Hold on, I don't have that kind of problem,' the alligator protests.' What exactly is wrong with me?'
'Well,' the vet says,' you have a reptile dysfunction.'