dojo loach dying from canned insect repellent spray

Question
We have two gold dojo loaches (they are my 7yr old sons). Two days ago my mother sprayed flying insect repellent in his bedroom and did not cover the tank. The tank has a lid,so I guess that's why it didn't occur to her to cover it. I went to feed them this morning, sadly one is definatly dead, the other is really bad off. I removed it from the tank into a bucket of water with some aquasafe water conditioner. The poor thing is not in good shape. He almost acts like he has swim bladder, his fins are streaked.Sometimes he looks dead, then he'll move again. I just want to know if there is anything I can do for him? Thankyou.

Answer
Hi Jessica,

Fish can be affected by air-borne toxins such as tobacco smoke, air freshener, insect repellent.

What you're describing sounds like fin-rot. Fin-rot is an extremely common disease that strikes fish that have been weakened by another cause. The bacteria that causes fin-rot is constantly present in Aquariums however they only strike when water quality deteriorates and the fish is gradually weakened.

The disease spreads quickly and fish usually die when the bacteria reaches the body. There are several ways you can treat your fish. Treatments based on phenoxyethanol, para-chloro-phenoxyethanl or nifurpirinol are usually effective. Bactericidal chemicals such as benzalkonium chloride can also be used. Also, it may be worth keeping an eye on water temperature. Cold water usually accelerates these kinds of attacks so make sure the water is maintained at, at least, 16C (61F).

Tom