Abstract

Within a group of captive Tursiops truncatus held in a closed system, chlorine-treated oceanarium, approximately one-third of the animals have been afflicted with cutaneous candidiasis. Pharmacologic therapy has not proved successful in managing this problem which has been present over the past four years. As an alternate management regimen, fecal coliform concentrations have been monitored and controlled. Early results reveal than when exposed to fecal coliform bacteria, Candida lesions cease spreading or even begin healing. There is a marked decrease in Candida isolates from lesions as compared to those in animals maintained in sterile or near sterile water conditions. Problems have been encountered in maintaining consistent fecal coliform levels in the existing system.

Notes

Treatment

Thiofluorasidozine at 50-100 mg/kg is the only effective treatment for systemic Candidiasis in dolphins. This treatment is expensive.

Histopathology

There was ballooning degeneration in the outer epithelial layers of the epidermis.

Relation to Fecal Coliform Count: When the fecal coliform count was high, the Candida lesions got a membranous covering, there were fewer canidia grown on culture and it took longer to grow Candida than when the fecal coliform count was low. Greater than 1,000 coliform colonies per 100 ml water gave the best Candida suppression. It would be valuable to find the level of pool chlorine treatment which suppresses bacteria enough to prevent bacterial disease yet allows enough coliforms to be present to suppress Candidiasis.

• Florida marineland - use copper treated

• Seaquarium – water

• Other systems use fluorine

Pool Management Suggestions:  Injecting air into water after it passes through the filter will decrease the need for chlorine.

The use of free iodine (used presently on an experimental basis in human pools) can cut chlorine levels down by 2/3. A mixture of an acid (6% I) and a base (also 6% I) at pH of 7.1 is used. This clears up the algae and once the desired level of I is attained and the pool is stable, one simply adds free iodine.

Theories

1. Levels of chloramines are more important than just Cl^- levels. The former can damage skin directly, allowing Candida in as an opportunist.

2. Chlorine may be immunosuppressive.

3. Chlorine may change the pH, allowing Candida to take hold (as with human vaginitis and cystitis).

Factors predisposing to Candida infection:

1. Antibiotics/steroids: indiscriminant use

2. Sterile skin environment. This occurs with chlorine treated water.