Lynne Byrd

TISSUE ENZYME ACTIVITIES IN THE LOGGERHEAD SEA TURTLE (CARETTA CARETTA)

Abstract:  The loggerhead sea turtle, Caretta caretta, one of the seven species of threatened or endangered sea turtles worldwide, is one of the most commonly encountered marine turtles off the eastern coast of the United States and Gulf of Mexico. Although biochemical reference ranges have been evaluated for several species of sea turtles, tissue specificity of the commonly used plasma enzymes is lacking. This study evaluated the tissue specificity of eight enzymes, including amylase, lipase, creatine kinase (CK), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and alanine aminotransferase (ALT), in 30 tissues from five stranded loggerhead sea turtles with no evidence of infectious disease. Amylase and lipase showed the greatest tissue specificity, with activity found only in pancreatic samples. Creatine kinase had high levels present in skeletal and cardiac muscle, and moderate levels in central nervous system and gastrointestinal samples. Gamma-glutamyl transferase was found in kidney samples, but only in very low levels. Creatine kinase, ALP, AST, and LDH were found in all tissues evaluated and ALT was found in most, indicating low tissue specificity for these enzymes in the loggerhead.

PROLIFERATIVE DERMATITIS ASSOCIATED WITH A NOVEL ALPHAHERPESVIRUS IN AN ATLANTIC BOTTLENOSE DOLPHIN (TURSIOPS TRUNCATUS)

Abstract Herpesviruses and herpes-like viruses have been reported in only a small number of species of cetaceans, and, to date, clinical manifestations have been either as a life-threatening, disseminated infection or as a non-life-threatening dermatitis. A stranded juvenile Atlantic bottlenose dolphin, Tursiops truncatus, was admitted to the Dolphin and Whale Hospital for rehabilitation. On initial physical examination, the rostral skin had multifocal regions of hyperplasia, and the skin of the dorsum contained a large number of small papules. Histologically, epithelial hyperplasia was evident, and clusters of epithelial cells contained 5–15-μm intranuclear inclusion bodies. Transmission electron microscopic investigation revealed numerous 170–190-nm enveloped virions in both the intracellular spaces and the cytoplasm of epithelial cells, with numerous nucleocapsids noted in epithelial cell nuclei. Consensus primer polymerase chain reaction identified the presence of a novel herpesvirus associated with the lesions. Phylogenetic analysis of the deduced amino acid sequences of the herpesvirus DNA polymerase gene fragment showed it to align with alphaherpesvirus sequences from humans and domestic animals. Although clearly distinct, it was most closely related to two previously described alphaherpesviruses of dolphins. This case represents the first documentation of herpesvirus dermatitis in the Atlantic bottlenose dolphin.

Mating-induced ovulation in loggerhead sea turtles, Caretta caretta.

Mating-induced ovulation is common in mammals, but has been rarely described in other taxa. Observations of several mature female loggerhead sea turtles, Caretta caretta, held in captivity seemed to indicate that ovulation did not occur in the absence of a male. This study was designed to determine whether this was an effect of captivity or an effect of the absence of a male. Two mature female loggerheads were followed over six annual reproductive cycles. Ultrasound exams were performed approximately every 2 weeks to follow the development of follicles in the ovaries. During the first two seasons, no male was present, in the next two seasons, a mature male was present without mating, and in the final two seasons a mature male was present, mating with one or both females. When no male was present or when present without mating, ovarian follicles developed to full size, but ovulation did not occur and the follicles gradually began to decrease in diameter and undergo changes evident on ultrasound. In the fifth season, only one of the females mated, dropping two eggs after 7 days, and continued to oviposit throughout the following months (total 275 eggs). The unmated female did not ovulate, showing the same pattern as earlier seasons. In the final season, both females mated and ovulated, dropping eggs for the next four months (total 539 eggs). The following year, no males were present and neither female ovulated. This study provides clear evidence that ovulation in loggerhead sea turtles is induced by mating.

An Approach to the Rehabilitation of Kogia spp.

Abstract Pygmy (Kogia breviceps) and dwarf (K. sima) sperm whales are rarely seen in the wild, but often seem to live-strand, particularly in cow-calf pairs. The rehabilitation of live-stranded individuals of both species has proven to be exceedingly diffi-cult. The few released animals might not have been completely healthy, an alternative chosen due to their poor survival in captivity. The rehabilitation challenges for Kogia are numerous because limited knowledge exists regarding even the basic biology of both species. This report provides information derived from the rehabilitation of 13 live-stranded K. breviceps and K. sima (including five calves) over the last decade at the Dolphin and Whale Hospital at Mote Marine Laboratory and Aquarium in Sarasota, Florida. One K. breviceps calf survived for almost 21 months in captivity and one K. sima survived for over 15 months, both apparent world-wide records. From these cases we learned that it is critical to provide supplemental fluids in addition to solid food to maintain continuous activity of the intestinal tract, especially if maintained in chlorine-treated water, and that digestibility of squid species typically fed to captive marine mammals was poor. Both species appear to be susceptible to adverse reactions to a number of the drugs commonly used during rehabilitation. In addition, an artificial calf formula was developed to provide adequate nutri-tion for young calves. Finally, gastric and intesti-nal stasis appears to lead to death in many of these whales in captivity.Key Words: Rehabilitation, pygmy sperm whale, dwarf sperm whale, calf formula, orphan calves, survival, captivity, Kogia breviceps, Kogia sima

PHARMACOKINETICS OF TICARCILLIN IN THE LOGGERHEAD SEA TURTLE (CARETTA CARETTA) AFTER SINGLE INTRAVENOUS AND INTRAMUSCULAR INJECTIONS

Abstract Three captive loggerhead sea turtles, Caretta caretta, were used in four trials, one i.v. and three i.m., to determine the pharmacokinetic properties of a single dose of ticarcillin. For the i.v. study, each turtle received a single 50 mg/kg dose and blood samples were collected at 0, 0.5, 1, 2, 4, 6, 8, and 12 hr and at 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, and 14 days after administration. For the i.m. study, each turtle received one of three dosages (25, 50, or 100 mg/kg) in a randomized complete block design and blood samples were collected at the same time intervals. Each trial was separated by a minimum of 28 days to allow for complete drug clearance. Drug concentration in plasma was determined by a validated liquid chromatography–mass spectrometry assay. For the i.v. study, the elimination half-life was 5.0 hr. The apparent volume of distribution and plasma clearance were 0.17 L/kg and 0.0218 L/hr/kg, respectively. For the i.m. study, mean time to maximum plasma concentrations ranged from 1.7 (±0.58) hr in the 50 mg/kg group to 3.7 (±2.5) hr in the 100 mg/kg group. Mean bioavailability ranged from 45% (±15%) in the 50 mg/kg group to 58% (±12%) in the 100 mg/kg group, and the mean residence time ranged from 7.5 (±2.6) hr in the 25 mg/kg group to 16 (±6.8) hr in the 100 mg/kg group. Two turtles had slight alanine aminotransferase elevations that were not clinically apparent at two different dosages, but otherwise, blood chemistries were unaffected. Possible i.m. dosage regimens for loggerhead sea turtles are 50 mg/kg q24 hr or 100 mg/kg q48 hr. Liver enzymes should be monitored during treatment.

DEHYDRATION AS AN EFFECTIVE TREATMENT FOR BREVETOXICOSIS IN LOGGERHEAD SEA TURTLES (CARETTA CARETTA)

Abstract:  Harmful algal blooms are known to cause morbidity and mortality to a large number of marine and estuarine organisms worldwide, including fish and marine mammals, birds, and turtles. The effects of these algal blooms on marine organisms are due to the various toxins produced by the different algal species. In southwest Florida, frequent blooms of the dinoflagellate Karenia brevis, which produces neurotoxins known as brevetoxins, cause widespread fish kills and affect many marine animals. In 2005–2007, numerous sea turtles of several species underwent treatment for brevetoxicosis at the Sea Turtle Rehabilitation Hospital. In green sea turtles, Chelonia mydas, and Kemps ridley sea turtles, Lepidochelys kempii, symptoms associated with brevetoxicosis were limited to neurologic signs, such as the inability to control the head (head bobbing) and nervous twitching. For these turtles, treatment involved removing the turtles from the environment containing the toxins and providing short-term supportive care. In loggerhead sea turtles, Caretta caretta, symptoms were more generalized; thus, a similar approach was unsuccessful, as was routine treatment for general toxicosis. Loggerhead sea turtles had more extreme neurologic symptoms including coma, and other symptoms that included generalized edema, conjunctival edema, and cloacal or penile prolapse. Treatment of brevetoxicosis in loggerhead sea turtles required a therapeutic regimen that initially included dehydration and systemic antihistamine treatment followed by supportive care.

Lungworm Infection in Three Loggerhead Sea Turtles, Caretta caretta

Abstract Although lungworms are known to infect many mammalian species and a few are known to infect snakes, lizards, and birds, previously none were known to infect chelonians. This study documents the first three known cases of lungworms in loggerhead sea turtles, Caretta caretta. It is unlikely that the lungworms were the primary cause of illness in any of the cases, and they may be only contributory or even incidental. Changes observed in the two cases that died included tracheal and bronchial epithelial hyperplasia and goblet cell hyperplasia. Lesions caused directly by the parasites seem to be restricted to the upper respiratory tree (trachea and main bronchi), but changes in the lungs themselves may be caused by the debris produced by the worms. Although neither case was successfully treated for the lungworms prior to death, it would appear that oxfendazole may be an effective treatment and has been used in the third case that is still undergoing rehabilitation.

SUBACUTE ATROPINE TOXICITY IN A PYGMY SPERM WHALE, KOGIA BREVICEPS

Abstract Atropine, an anticholinergic agent commonly used in human and veterinary medicine, is reported to cause toxicity associated with its antimuscarinic action. A juvenile pygmy sperm whale, Kogia breviceps, was treated with atropine in an attempt to relieve symptoms similar to pyloric stenosis, as has been used in humans. Two doses of 0.01 mg/kg were given i.m., 12 hr apart, followed by three doses of 0.005 mg/kg i.m. s.i.d. over the next 3 days. Symptoms associated with atropine toxicity developed gradually and included hyperexcitability, a generalized ascending paralysis of body musculature, shallow, rapid respiration, vomiting, aspiration of seawater, and pulmonary edema. Treatment with physostigmine salicylate (two doses of 2 mg i.m., 1 hr apart) was effective in counteracting the paralysis, as well as other symptoms, beginning in as little as 17 min after the first dose, and the whale was back to swimming on its own after 8 hr. All overt symptoms of atropine toxicity were gone in about 24 hr, but there were other possible sequella that lasted much longer.

Use of Human Granulocyte Colony-Stimulating Factor in a Green Sea Turtle, Chelonia mydas

ABSTRACT Trauma of undetermined cause resulted in the massive injury, infection, and subsequent stranding of a juvenile green sea turtle, Chelonia mydas. With an initial calculated total leukocyte count of zero cells/μl and no mature circulating heterophils on the differential, the turtle was treated with antibiotics and recombinant human granulocyte colony-stimulating factor, (hG-CSF, filgrastim), in an attempt to increase heterophil production and possibly activation. Three daily doses o f hG-CSF at 6.7 mcg/kg given subcutaneously resulted in a rapid increase in acidophilic progranulocytes, which subsequently declined over the next three days. A second regimen, consisting of a repeat of the first three-dose daily regimen followed by continued dosing every 48 hr for an additional nine days, maintained a white blood cell count of 11,600 – 24,700 cells/μl. Three weeks after initiating therapy, mature heterophils began to appear in the peripheral blood and the hG-CSF was discontinued. Finally, after the tur...

BLOOD CHEMISTRY AND HEMATOLOGY VALUES IN HEALTHY AND REHABILITATED ROUGH-TOOTHED DOLPHINS (STENO BREDANENSIS)

ABSTRACT Rehabilitation efforts for live stranded marine mammals are guided by diagnostic measures of blood chemistry and hematology parameters obtained from each individual undergoing treatment. Despite the widespread use of blood parameters, reference values are not available in the literature from healthy rough-toothed dolphins (Steno bredanensis) with which to infer the health status of an animal. We examined serum or plasma chemistry and hematology data from 17 rough-toothed dolphins either housed at Dolphin Quest French Polynesia or during their rehabilitation at the Dolphin and Whale Hospital in Sarasota, Florida, US between 1994 and 2005. Blood parameters were compared among healthy animals, rehabilitation animals that were eventually released, and rehabilitation animals that died. This study indicated significant differences in many blood parameters for the poorly known rough-toothed dolphin that are likely to vary between healthy and sick animals. These included aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, bicarbonate, and globulins, which were greater in sick dolphins, and alkaline phosphatase and total protein which were greater in healthy individuals. Total white blood cell counts were lower in healthy animals as were the absolute numbers of neutrophils, monocytes, and eosinophils. Analysis of first blood sample levels for glucose, sodium, and erythrocyte sedimentation rate may have value for triage and prognostic evaluation.