Cetacean Erysipelothrix rhusiopathiae infections usually present as either a dermal form or an acute septicemic form which is almost invariably fatal. A 19 year old male beluga whale (Delphinapterus leucas) presented with a 13 day history of progressive partial anorexia followed by 5 days of complete anorexia. The partial inappetence occurred during the breeding season and was similar to behavior exhibited in previous years. Following an unremarkable physical examination a blood sample was obtained from a vessel on the dorsal surface of the tail fluke and submitted for CBC, Chemistry, Erythrocyte Sedimentation Rate (ESR) and serum protein electrophoresis. A blood sample was also submitted for aerobic and anaerobic culture.

The results revealed a marked neutrophilia and a lowered hematocrit and red blood cell count. The blood urea nitrogen and creatinine were both elevated while all other biochemical tests appeared within normal limits (see Table 1). The ESR results were markedly elevated (see Table 1). Staphylococcus epidermidis was isolated from the aerobic blood culture while Propionibacterium spp. was isolated from the anaerobic blood culture, neither was believed to be significant. A diagnosis of infection and azotemia, either renal or prerenal, of unknown etiology was made. Supportive therapy was immediately begun which included oral fluid administration with 6 liters 5% dextrose orally BID, 1200 mg cimetidine orally BID and 6 gm ciprofloxacin orally BID. All medications were provided via stomach tube.

At 48 hours following initiation of therapy, the animal appeared more alert and accepted 3 lbs. of herring. Hematuria was observed with the animal in a full pool but no urine samples were retrieved in the empty pool due to the animal's size and resistance to catheterization attempts. No further episodes of hematuria were observed on subsequent days. At 96 hours after initiation of therapy, the animal was observed to be very responsive and was accepting medicated fish via free hand feedings. Therapy via stomach tube was decreased to once daily for an additional 48 hours and then discontinued as free feeding of fish increased dramatically along with a return to normal behavior. Ciprofloxacin was administered for a total of 21 days. Cimetidine was given for 30 days followed by a tapering dose for an additional 14 days.

Serum samples from prior to the episode as well as during and following the episode were tested for serologic evidence of a E. rhusiopathiae infection. Antibody titers were measured via a microtitration agglutination test (see Table 2). The seroconversion and elevated titers demonstrated presumptive evidence of an active E. rhusiopathiae infection.

Table 1. Selected CBC and Chemistry Results of a 19 year old male beluga whale Delphinapterus leucas) with Erysipelothrix rhusiopathiae infection

Table 2. Microtitration agglutination test from a 19 year old male beluga white (Delphinapterus leucas) with Erysipelothrix rhusiopathiae infection