Clostridium perfringens as the cause of death of a captive Atlantic bottlenosed dolphin (Tursiops truncatus).

A previously healthy captive female bottlenosed dolphin (Tursiops truncatus) died suddenly. At necropsy, Clostridium perfringens was isolated from dorsal muscle, blood, left heart ventricle, thoracic fluid, and abdominal fluid. An identical strain was recovered from pool water. A male dolphin in the same pool had inflicted several "rake" marks on the dorsal surface of the female. Water-borne bacteria probably entered these lesions which served as the focus for anaerobe penetration and spread.

Candidiasis in captive pinnipeds.

Diagnosis, treatment, and possible pathogenesis of candidiasis were studied in 5 species of pinnipeds in captivity: gray seal (Halichoerus grypus), harbor seal (Phoca vitulina), northern fur seal (Callorhinus ursinus), California sea lion (Zalophus californianus), and northern elephant seal (Mirounga angustirostris). The animals were kept outdoors in a freshwater exhibit. Candidiasis was characterized by purulent nasal discharge, inflammation of the lips at the mucocutaneous junction, periocular alopecia, vaginitis, and dermatitis. Administration of ketoconazole at dosages of 5 mg/kg BID and 10 mg/kg SID controlled the disease. Wild gulls were suspected as vectors of Candida albicans.

Bacteriology of the teeth from a great white shark: potential medical implications for shark bite victims.

Bacteria were cultured for the first time from the teeth of a great white shark (Carcharodon carcharias). Isolates included Vibrio alginolyticus, Vibrio fluvialis, Vibrio parahaemolyticus, and other genera. All are common in the marine environment and some may be associated with wound infections in humans. Shark bite lacerations may serve as a source of these potentially infectious bacteria, particularly Vibrio spp., and should be treated immediately. Antibiotic susceptibility patterns are shown for representatives of Vibrio isolates and indicate that a variety of new agents may be appropriate chemotherapy for shark bite victims.

Candidiasis in captive cetaceans.

Disseminated Candida albicans infections were found or suspected in 4 captive cetaceans. Ketoconazole at a dosage of 2.5 mg/kg, BID, administered orally for 18 days, followed by 8 biweekly oral doses of levamisole hydrochloride at the rate of 9 mg/kg, resulted in regression of clinical signs of candidiasis in an adult male Atlantic bottlenose dolphin (Tursiops truncatus). A higher dosage of ketoconazole (6 mg/kg, BID) was effective in eliminating the shedding of C albicans from an adult male belukha whale (Delphinapterus leucas). A juvenile female harbor porpoise (Phocoena phocoena) treated with nystatin died with disseminated candidiasis, as did a juvenile male longfinned pilot whale (Globicephala melaena) treated with nystatin and levamisole. Three other adult bottlenose dolphins, a juvenile female belukha whale, and a female Commerson's dolphin (Cephalorhynchus commersonii) kept in the same water system never had evidence of candidiasis. A 5th bottlenose dolphin (an adult female) was culture-positive on 1 occasion, but never had signs of the disease.

Removal of total organic carbon from marine mammal pool water by polymeric resins.

Chlorinated organic compounds comprise a portion of the total organic carbon (TOC) of marine mammal pool water. The long-term effects of these substances on the health of captive marine mammals are unknown, but good husbandry practices should include maintaining TOC at low concentrations. Two polymeric resins (trade names XAD-2 and XAD-4) were tested for their capacity to adsorb TOC from the water of a saline, closed-system marine mammal pool. At a concentration of 588 mg of XAD-2/L, TOC was reduced by approximately 9% after 96 hours; 630 mg of XAD-4/L reduced TOC concentrations by approximately after 77 hours. Equilibrium was not approached in any of the experiments. The 2 materials tested are ineffective in this particular application, but ion exchange resins may perform better.

The efficacy of UV irradiation in the microbial disinfection of marine mammal water.

A study was made on the efficacy of a commercial ultraviolet (UV) sterilizer in reducing the number of bacteria and yeasts ina saline, closed-system marine mammal complex. UV irradiation was effective in lowering bacterial counts in the effluent of the unit (greater than 75% reduction), but bacteria in more remote parts of the water system reached levels equal to or greater than pre-UV counts. Yeast reduction was considerably less, and a trend similar to that of the bacteria was observed in remote sections of the water system. It is concluded that UV irradiation is of limited value in the disinfection of marine mammal water. Factors contributing to the poor performance of the sterilizer were the long recycle time of the water and lack of a residual effect.

Effects of tertiary methods on total organic carbon removal in saline, closed-system marine mammal pools.

Organic matter accumulates in marine mammal pools that are not diluted continuously with clean influent water. Some of this material may be carcinogenic or mutagenic. Four tertiary methods were tested for effectiveness in lowering the total organic carbon (TOC) concentration in saline marine mammal pools. The TOC concentration at the start of each trial is shown in parentheses. Ozonation alone in duplicate trials had no effect on TOC during sequential contact periods of 25, 30, and 30 minutes (13.66 mg of TOC/L of sample water) and 30, 30, and 30 minutes (12.85 mg of TOC/L) when the dosage levels were 4.13, 4.03, and 4.52 mg of O3/L, respectively. Contacting marine mammal water with granular activated carbon in a single trial (12.91 mg of TOC/L) removed approximately 37% of the TOC in 10 minutes, but only an additional 11% was removed in 60 minutes. The amount removed in 10 minutes was equivalent to 20 days' accumulation at previously determined rates of increase. Brief ozonation of the water, followed by contact with granular activated carbon, was the most effective method tested. When results of the duplicate trials (12.95 and 12.65 mg of TOC/L) were averaged, the amounts of TOC removed were 60% (5 minutes), 70% (10 minutes), and 78% (30 minutes). Two experiments using superchlorination (114 mg of free available chlorine/L of water contacted for 4.5 hours) reduced the TOC concentration from 15.6 to 11.2 mg/L (28%) reduction), and from 15.6 to 10.2 mg/L (35% reduction).

Chronic cutaneous candidiasis in bottle-nosed dolphins.

In a 20-month period, generalized chronic cutaneous candidiasis developed in 3 performing bottle-nosed dolphins kept in an indoor pool. Extensive esophagogastric ulcerations were observed in 2 of the dolphins, each of which died, presumably because of these lesions. The 3rd dolphin died during a surgical procedure and did not have any esophagogastric ulcerations. Candida albicans was the only organism isolated from skin lesions but was not isolated from adjacent normal skin of dolphins. Treatment with antifungal drugs was unsuccessful. Subsequently, immunopotentiating treatment with levamisole phosphate resulted in formation of granulation tissue and healing of the skin lesions.