Platy disease

Hello,
I've always had platies in my aquarium ever since I began my aquarium hobby a few years ago. Every once in a while, a platy (or two) gets really skinny and sickly looking. Their heads all of a sudden get slanted downward like the one pictured in the post and then a week or two later they die. What's causing this? Has anyone else had these problems? My water parameters are normal, and I do regular water changes. Why does this keep happening and how can I stop it?

 

Look at the anus of your fish. Do you see anything red sticking out? I had this same issue and it tuner out to be camellanus worms. If so, your tank is already infected and needs to be treated with Levamisole HCI. If you don't see red worms sticking out of any of your fish though, it's probably something else.

 

I don't really see anything like that but now that you mention it a couple of weeks ago I saw this tiny white worm floating around my tank and I couldn't identify what it was. Could that be the cause? How could I treat it?

 

That worm was probaby either a nematode or planaria worm. Planaria are much flatter looking than nematodes, and are completely harmless. Most nematodes are harmless as well, but if you spotted it near the anus of your fish it may be parasitic. To get rid of planaria or nematodes (I quite like having both in there, I find them cute) Just feed your fish less and siphon the gravel more.
As for what disease your fish has, does it eat and still loose weight? Is it's colour fading? Are the fish significantly older than the rest? Are they from a different source? Sorry about all the questions, but it's important. Also, what size is your tank and what other fish do you have in there? Stocking details would be great.

 

They do seem to still eat but not as much as they used to. Their color is fading some. These fish are a little bit older than some of my newer fish but only by 6 months or so. They're all from the same pet store. I have an assortment of barbs, tetras, and platies

 

Have any other fish besides the platys shown these symptoms? Do the fish slowly lose weight then just before death look like they've got dropsy and balloon up with pinecone like scales? The best I can come up with is camellanus worms. They're parasitic and deadly, my tank had them and I lost two fish
Go onto SubAquaria, they sell Levamisole HCI, which is amazing at getting rid of most parasitic worms, camellanus included. The best part about Levamisole is it won't kill a cycle, hurt plants, or kill fish as long as you dose right.
The dosage is .06 grams per 10 gallons. I dosed .04 and the treatment was jus as effective. Treat once for 36 hours, then three weeks later treat again for 36 hours. Do water changes, as large as you can, after each treatment. Turn off your tank lights and move everything out of the gravel so you can vacuum all of it.
Levamisole paralyzes parasites so the fish can pass them, they then fall in the gravel to be taken out by you. The second treatment will kill of any eggs that survived the first treatment. As long you don't overdose, your fish will be fine. And also, feed your fish a bit extra during treatment, to help them pass the worms better.