Donald E. Cooperrider, DVM, MSc
One of the first confirmed bacterial diseases of "porpoises" (bottlenose dolphins) was erysipelas due to the invasion of Erysipelothrix insidiosa (rhusiopathiae).
This was isolated by Seibold and Neal at the School of Veterinary Medicine, Auburn University, in 1956, and by Simpson and Wood at the University of Florida in 1958.
Both dolphins originated from a marine-life attraction in Florida.
It is not the purpose of this paper to describe anything other than the skin lesions seen on two dolphins received at the Animal Disease Diagnostic Laboratory from two widely separated marine-life attractions. Several dolphins have been received at the laboratory and the first thought is of the lesions or signs of erysipelas. More isolations of E. insidiosa have been made than the two pictured here, but the disparity of the lesions is of interest.
In addition, since several marine-life attractions have other types of aquatic or amphibious life on display, there are included several slides of E. insidiosa infection in a crocodile. This also represents an infection of "skin" though scales are the proper designation.
In all these instances, including the crocodile, the main source of food is fish and it would be of interest to conduct some research on the possibility of E. insidiosa infection in fish. More especially since this organism has occasionally been recovered from fishmeal. .
The skin lesions noted have varied from "diamond-shaped", 1" X 2" scattered lesions, to round, ± 2" scattered, deep, to extensive shapeless, contiguous and continuous, diffusely scattered pustular-appearing lesions.
The lesions seen in the first slides are those of the second of the isolates from Tursiops truncatus. These are not the typical "diamond-shaped" lesions which we noted on the first isolate. We have no slides of the first isolate. The second group of slides shows how extensive this condition can be before producing death. This dolphin was under treatment which obviously was unsuccessful. Other organisms including Streptococcus sp., Staphylococcus sp., and Pseudomas were recovered from the deep skin lesions. These three organisms were found to be resistant to all antibiotics except Nolvasan and Polymixin B.
The third group of slides pictures the "skin" lesions of E. insidiosa on a crocodile and this is being reported in the literature presently. This animal is still alive and, in addition to the erysipelas organism, a fungus was also recovered. Which of the infections are primary is open to speculation, but could probably never be settled. The main point in showing these is to demonstrate that sources of bacterial contamination of the environment can originate or be maintained by members of the aquatic species other than warm-blooded forms.
Color slides illustrating the skin lesions on two dolphins and a crocodile are presented and described.
Seibold, H. R., and James E. Neal: Erysipelothrix Septicemia in the Porpoise. JAVM, 128, No. 11, June 1, 1956, p. 537-539.
Simpson, Charles F., F. G. Wood, F. Young: Cutaneous Lesions on a Porpoise with Erysipelas.JAVMA 133, No. 11, December 1, 1958, p. 558-560.