My goldfish is flashing and has a white pimple thing on the side of his body?

[Rogue Wolf21]

As the title tells you my goldfish is flashing and has a white pimple on the side of his body, the place where my goldfish has developed the pimple is where he lost a scale a couple of days ago.

what is it and how should I cure it?

Here is a video of the pimple thing.
http://www.youtube.com/watch?v=b-QyXfFV0oE

Note:My water parameters are fine expect for my ammonia which is 0.25.

 

[Kaosu]

that looks like anchor worms,


not sue how to cure probably jungle lab's parasite cure.

or prazi pro.