Introduction

Cetacean strandings are complicated events, involving interactions between many agencies and individuals. Because the attending veterinarian is a dominant figure in making decisions affecting the disposition of a stranded cetacean there is much pressure on that individual. All decisions and recommendations must be correct, defensible, and logical to lay as well as scientific communities. To make proper decisions the attending veterinarian needs as much information concerning previous strandings as possible. Such a data base allows for the correct interpretation of material collected from a stranded cetacean. This paper concerns live strandings of two Atlantic fin whales (Balaenoptera physalus) and the efforts to manage these cases. Hopefully, the data provided here will help in the decision making processes involving future fin whale strandings.

Case History

On 28 October, 1987 a 57 foot female fin whale stranded on Harbor Island, SC. The whale was trapped in shallow water with no hope of being freed, and was emaciated as evidenced by a prominent backbone and rib cage. With no way to keep the whale moist, she became sunburned and sloughed large areas of skin from her dorsal surfaces. Dr. McKee took blood samples from superficial vessels, and stored the blood in clot tubes and heparinized and EDTA vacutainer tubes. Samples were kept on ice and all tests were run within 12 hours of collection. An attempt was made to euthanize the individual by injection of 4.5 liters of euthanasia solution (T-61 Euthanasia Solution, Hoechst Corp., Somerville, NJ) through a 5.5 inch needle. The needle was too short to penetrate the peritoneal cavity and the solution was deposited in the abdominal musculature. As the solution was absorbed the whale gradually became sedated and her breathing slowed from 15 breaths per 5 minutes to 3-8 breaths per 5 minutes. On 29 October Dr. Mckee used a three foot needle/trocar (made by National Marine Fisheries Service (NMFS) personnel) to inject 4 Liters of T-61 into a large vessel or rete anterior to the pectoral flipper, and successfully euthanized the animal.

On 1 November, 1987 a 62 foot fin whale of unknown sex was found stranded in 3 feet of water in the James River, Newport News, VA. The whale was kept cool and moist with spray from a Coast Guard boat, and blood was drawn from a superficial vein in the dorsal fin. Because the animal was in moderately deep water, appeared to be in relatively good shape, and was highly visible to the news media and general public, NMFS personnel decided to try to free the whale. As the tide rose, a Coast Guard vessel herded the whale off the sandbar into the main channel, at which time the whale started actively swimming across the river. When last seen the whale was heading for open water, but contact was lost at dusk. For the next four days the whale rambled around the James, stranding on various sandbars at each low tide and drifting with the currents after the tide rose.

On 5 November the whale was relocated while stranded in 3 feet of water (54° Fahrenheit) on a rising tide. With the peritoneal cavity as well as all the larger vessels under water, Dr. George performed a cutdown on the dorso-lateral thorax caudal to the pectoral fin and attempted to insert a 36 french human chest drain (Sherwood Medical, St. Louis, MO) into the pleural space. Blood for a complete blood count was collected from the incision, but a sufficient quantity for serum chemistry determinations was unavailable. The chest drain penetrated the thoracic cavity, but air leaking from the lungs rushed out of the tube with such force that drugs could not be given through the tube. Three attempts to place the drain were met with similar results, and consequently the rescue team returned to their vessel to warm up.

Having exhausted all other routes Dr. George placed two IV administration tubes down the blowhole and rapidly infused a commercial pentabarbital euthanasia solution (Soccumb 6-Gr, Butler Go., Columbus, OH). Despite loss of some solution during exhalation the whale gradually became sedated and died after receiving 3.5 liters of euthanasia solution. The carcass was subsequently towed to sea by the Coast Guard.

Discussion

In 1986 Lambertson et al. published "Serum chemistry and evidence of renal failure in the north Atlantic fin whale population". The normal serum values used in this discussion are from Lambertson's work. Lambertson (1986) recorded values from 29 fin whales, one of which showed evidence of renal failure. Elevated creatinine, serum urea nitrogen, phosphate, and potassium levels supported a tentative diagnosis of renal insufficiency in that whale.

Table 1 compares the serum chemistries of the two stranded fin whales with the chemistries of normal animals from Lambertson (1986). Also included are serum values from the animal diagnosed as having renal dysfunction (Lambertson, 1986). The creatinine levels of both stranded fin whales are not only higher than values established as normal, but at 5.2 and 5.9 mg%, were markedly higher the "sick" whale's values. Paradoxically none of the other parameters one would expect to be altered in an animal suffering from renal disease (such as SUN, potassium, and phosphorous) were significantly changed.

The serum glucose of the whale stranded in South Carolina was much higher than expected. The elevated glucose level of 244 mg% may have been in response to a high endogenous cortisol and/or catecholamine level in a severely stressed individual.

Hemograms from both strandings fit the expected pattern for animals in a severe stress situation. The South Carolina whale had been stressed from desiccation and sun exposure by the time it was bled, and the whale's blood values reflected that stress. When compared to normal values reported by Del Monte (1979) and Lambertson (1986) there was a mild leukopenia. An examination of the absolute values showed the leukopenia due to a severe lymphopenia and eosinopenia. High cortisol levels can cause the number of these cells in circulation to decrease.

In contrast to the South Carolina whale, the first sample from the Virginia whale was obtained while the animal was relatively unstressed. It was in enough water to help support its immense weight, was well cooled, and appeared alert and responsive. Analysis of the blood showed a leukocytosis due to a neutrophilia and eosinophilia. The second blood sample was taken from a more depressed and stressed animal. The whale was moribund, its body condition had deteriorated, and it was being battered by waves. The second blood counts showed a decrease in all cellular components. A rising hematocrit indicated the possible onset of dehydration which may have masked an even further drop in the white blood count. The second blood sample also showed trends of neutropenia, lymphopenia, and eosinopenia probably associated with stress. The most interesting part of the Virginia whale's blood was the number of eosinophils in the peripheral blood. The presence of high levels of circulating eosinophils is generally associated with conditions involving parasitism or allergic reactions.

Lambertson (1986) showed that up to 95% of all fin whales in certain Atlantic populations may be infected with the giant kidney worm, Crassicauda boopis. Adult Crassicauda inhabit the interrenuncular spaces and displace the interrenuncular venous system. The worms head burrows into the primary renal vein where it is encapsulated by fibrocellular reactive tissue that arises from the tunica intima and the tunica media. Multiworm lesions of up to 5 kg have been reported in fin whale kidneys. These lesions may obstruct the vessel lumen and disrupt the blood flow through the kidney. Although the evidence is not conclusive, it appears that the two stranded fin whales may have suffered from renal insufficiency secondary to Grassicauda infections. Both whales were emaciated, indicating an insidious disease process such as chronic kidney failure and both had elevated serum creatinine values. The Virginia whale's eosinophilia pointed toward a parasitic etiology. Since necropsy data were unavailable for these two cases, confirmation of a diagnosis of renal failure secondary to Crassicauda was not possible. Dunn (1977: unpublished data) recorded a fin whale stranded in New England where similar laboratory values were obtained.

Since a number of fin whale strandings have occurred that follow a pattern similar to the two stranded whales discussed here, the veterinarian attending such a cetacean stranding should consider renal disease as a possible reason for the stranding. This information may make it easier for the veterinarian to make decisions necessary for the successful handling of the case.

Table 1. Fin whale serum chemistries. Normal and abnormal values from Lambertson (1986). Standard deviations in parenthesis

Table 2. Fin whale hemograms. Normal values from Del Monte (1979) and Lambertson (1986). Standard deviations in parenthesis

Acknowledgments

We would like to thank all persons involved in helping with the strandings, especially the Virginia Institute of Marine Science and NMFS personnel. Partially funded by the Virginia Commission of Game and Inland Fisheries, Nongame Division.

References

1.  Del Monte, T. and G. Pillery. 1979. Cetacean hematology two: The blood cells. Investigations in Cetacea. Vol 10. Bern Switzerland Brain Anatomic Institute.

2.  Lambertson, R.H. 1986. Disease of the common fin whale: Crassicaudiosis of the urinary. system. J. Mammal. 67: 353-366.

3.  Lambertson, R.H., B. Birnir, and J.E. Baur. 1986. Serum chemistry and evidence of renal failure in the north Atlantic fin whale. J. Wildl. D 22: 389-396.