Topical treatments for skin ulcers and lesions
When topical treatments are used it is important to thoroughly
debride the affected area and remove all necrotic tissue and debris from
the lesion. This removes a source of continuing infection and helps the
healing process to start. Where there are large areas of ulceration,
topical treatments may assist osmotic stress by sealing the area against
water ingress, albeit for only a short time.
Thoroughly clean the lesion
The fish really needs to be sedated for this procedure (see anaesthetics pages). The lesion is
thoroughly cleaned using an antiseptic solution such as povodine-iodine
or similar using a cotton bud or small swab of cotton wool. If there are
any infected scales these should be removed, otherwise the scale pocket
will act as a continuing reservoir of infection. In the case of fin rot
it may be necessary to trim the infected area back to healthy tissue
using a pair of sharp, sterile scissors.
When the lesion is clean it should be dried with a tissue and covered
with waterproof cream or ointment. There are proprietary products
available. I tend to use Orabase from Boots the chemist. The secret with
this product is to only use a small amount but spread it thinly using a
wetted finger. The thinner it is spread, the longer it stays in place.
Avoid repeated debridement
Topical treatments can be successful on their own if the infection is
not too severe. They can also be used in conjunction with bath
treatments or antibiotics injections for enhanced effects. The procedure
may need to be repeated again a day or two later, but repeated
debridement of the lesion should be avoided as this may “wipe” away
new skin growth. Fish integument heals by a thin layer of skin cells
migrating across the lesion from the adjacent healthy tissue.
If, after the initial treatment it is felt that the fish would
benefit from further treatment to the affected area, the lesion should
be lightly swabbed with an antiseptic solution and the top dressing
applied very carefully
Assuming that the lesion was thoroughly cleaned initially one would
expect to see some signs of improvement by way of reduced inflammation
or signs of new skin growth within 5 –7 days. If after this time the
lesion shows no sign of healing a course of appropriate antibiotics may
well be needed.