Mycobacterium abscessus pneumonia in an Atlantic bottlenose dolphin (Tursiops truncatus).

Mycobacterium abscessus pneumonia was diagnosed antemortem in a 23-yr-old male Atlantic bottlenose dolphin (Tursiops truncatus). Clinical signs included lethargy, hyporexia, coughing, and bloody respiratory discharge. Diagnostic findings included neutrophilic leukocytosis, anemia, elevated erythrocyte sedimentation rate, and repeated forceful exhaled breath (sputum) cytology, with acute inflammatory cells and acid-fast positive beaded rods. The bacteria were initially identified free in the sputum sample and subsequently were seen within neutrophils. A culture was positive for a rapidly growing, white, colony-forming organism confirmed as M. abscessus by polymerase chain reaction and DNA sequencing. Clinical signs initially resolved with multidrug therapy. Concurrent Pseudomonas aeruginosa infection complicated clinical management and contributed to terminal decline. The dolphin was euthanized 5 mo after initial diagnosis. Necropsy results demonstrated acid-fast positive bacteria in lung tissue and supported the diagnosis of M. abscessus pneumonia. Acid-fast stains and mycobacteria cultures should be considered when evaluating ill dolphins.

Cross matching of blood in carcharhiniform, lamniform, and orectolobiform sharks.

The transfusion of whole blood in elasmobranchs could provide cardiovascular support following hemorrhage. Since donor and recipient compatibility is not known, a technique was established to allow cross matching of red blood cells and serum in sharks. Cross matching was carried out among 19 individuals from seven species: the nurse shark (Ginglymostoma cirratum), sandbar shark (Carcharhinus plumbeus), sandtiger shark (Carcharias taurus), white-spotted bamboo shark (Chiloscyllium plagiosum), brown-banded bamboo shark (Chiloscyllium punctatum), zebra shark (Stegostoma fasciatum), and spotted wobbegong (Orectolobus maculatus). Negative cross-matches showed no agglutination or hemolysis, suggesting that donor and recipient would be compatible. Cross-matches between conspecifics were all negative (sandbar, sandtiger, nurse, and white-spotted bamboo sharks). All cross-matches between sandbar and sandtiger sharks were also negative. Positive crossmatches consisted of agglutination or hemolysis of red blood cells, suggesting that the donor and recipient would be incompatible. Strong positive reactions occurred, for example, with red blood cells from sandtiger and sandbar sharks and serum from nurse sharks. Cross matching should be carried out in elasmobranchs prior to any blood transfusion.

Emergency and critical care of fish.

Most fish emergencies are the result of inappropriate environmental conditions and primary or secondary infectious disease or trauma. The immediate response should be to increase aeration, provide suitable water, and decrease stressors. A thorough history, evaluation of the fish and their environment, and some rapid diagnostic tests (particularly direct and stained cytology) often provide the information needed to make a diagnosis and render appropriate treatment. When cohorts are at risk and the patient is unlikely to recover, euthanasia and necropsy are recommended to reach a definitive diagnosis. Some common emergencies include ammonia and nitrite toxicity; low dissolved oxygen; copper and chlorine toxicity; gas supersaturation; and certain bacterial, protozoal, and viral diseases.

Characterization of ichthyocidal activity of Pfiesteria piscicida: dependence on the dinospore cell density.

The ichthyocidal activity of Pfiesteria piscicida dinospores was examined in an aquarium bioassay format by exposing fish to either Pfiesteria-containing environmental sediments or clonal P. piscicida. The presence of Pfiesteria spp. and the complexity of the microbial assemblage in the bioassay were assessed by molecular approaches. Cell-free water from bioassays that yielded significant fish mortality failed to show ichthyocidal activity. Histopathological examination of moribund and dead fish failed to reveal the skin lesions reported elsewhere. Fish larvae within "cages" of variable mesh sizes were killed in those where the pore size exceeded that of Pfiesteria dinospores. In vitro exposure of fish larvae to clonal P. piscicida indicated that fish mortality was directly proportional to the dinospore cell density. Dinospores clustered around the mouth, eyes, and operculi, suggesting that fish health may be affected by their direct interaction with skin, gill epithelia, or mucous surfaces. Molecular fingerprinting revealed the presence of a very diverse microbial community of bacteria, protists, and fungi within bioassay aquaria containing environmental sediments. Some components of the microbial community were identified as potential fish pathogens, preventing the rigorous identification of Pfiesteria spp. as the only cause of fish death. In summary, our results strongly suggest (i) that this aquarium bioassay format, which has been extensively reported in the literature, is unsuitable to accurately assess the ichthyocidal activity of Pfiesteria spp. and (ii) that the ichthyocidal activity of Pfiesteria spp. is mostly due to direct interactions of the zoospores with fish skin and gill epithelia rather than to soluble factors.

Effects of ozonation on the speciation of dissolved iodine in artificial seawater.

Iodine in the form of iodide is required for synthesis of tri-iodothyronine and thyroxine in fish. Iodine chemical speciation in aliquots of raw artificial seawater mix was measured before, during, and after exposure for fixed time periods to air only and to concentrations of ozone required to achieve oxidation-reduction potentials typical of a protein skimmer (400 mV) and an ozone contact chamber (800 mV). Chemical species of iodine were also measured in tank water from a large, recirculating, ozonated aquarium system that has a low-grade incidence of thyroid lesions (e.g., thyroiditis, hyperplasia, adenoma, and adenocarcinoma) in its fish. With increasing exposure to ozone, concentrations of iodide and dissolved organic iodine (DOI) decreased, whereas iodate levels increased. As a result of exposure to 400 mV, iodide concentration dropped to less than half the amount found in raw artificial seawater mix. After exposure to 800 mV, initial iodide levels decreased by 67%, and DOI became undetectable, whereas iodate concentration increased by 155%, with no remarkable change in total iodine concentration. These results indicate ozone-induced conversions from iodide to iodate, and DOI to iodide or iodate (or both). Iodide and DOI were not detectable in the aquarium system's water samples. Ozonation of artificial seawater may alter the relative concentrations of iodine species in a closed tank system, so that iodide supplementation of the diet or tank water of captive teleosts and elasmobranchs living in ozonated seawater is advisable.

Comparison of functional aspects of the coagulation cascade in human and sea turtle plasmas.

Functional hemostatic pathways are critical for the survival of all vertebrates and have been evolving for more than 400 million years. The overwhelming majority of studies of hemostasis in vertebrates have focused on mammals with very sparse attention paid to reptiles. There have been virtually no studies of the coagulation pathway in sea turtles whose ancestors date back to the Jurassic period. Sea turtles are often exposed to rapidly altered environmental conditions during diving periods. This may reduce their blood pH during prolonged hypoxic dives. This report demonstrates that five species of turtles possess only one branch of the mammalian coagulation pathway, the extrinsic pathway. Mixing studies of turtle plasmas with human factor-deficient plasmas indicate that the intrinsic pathway factors VIII and IX are present in turtle plasma. These two factors may play a significant role in supporting the extrinsic pathway by feedback loops. The intrinsic factors, XI and XII are not detected which would account for the inability of reagents to induce coagulation via the intrinsic pathway in vitro. The analysis of two turtle factors, factor II (prothrombin) and factor X, demonstrates that they are antigenically/functionally similar to the corresponding human factors. The turtle coagulation pathway responds differentially to both pH and temperature relative to each turtle species and relative to human samples. The coagulation time (prothrombin time) increases as the temperature decreases between 37 and 15 degrees C. The increased time follows a linear relationship, with similar slopes for loggerhead, Kemps ridley and hawksbill turtles as well as for human samples. Leatherback turtle samples show a dramatic nonlinear increased time below 23 degrees C, and green turtle sample responses were similar but less dramatic. All samples also showed increased prothrombin times as the pH decreased from 7.8 to 6.4, except for three turtle species. The prothrombin times decreased, to varying extents, in a linear fashion relative to reduced pH with the rate of change greatest in leatherbacks>green>>loggerhead turtles. All studies were conducted with reagents developed for human samples which would impact on the quantitative results with the turtle samples, but are not likely to alter the qualitative results. These comparative studies of the coagulation pathway in sea turtles and humans could enhance our knowledge of structure/function relationships and evolution of coagulation factors.

Mycobacterium chelonae osteoarthritis in a Kemp's ridley sea turtle (Lepidochelys kempii).

A stranded Kemp's ridley sea turtle (Lepidochelys kempii) was rescued and treated at the National Aquarium in Baltimore (Maryland, USA) for inappetence and epidermal appendicular and plastral lesions. After 4 mo of care, the turtle developed a swollen left elbow joint. Within 1 mo of initial swelling, osteolytic lesions developed in the proximal radius and ulna. The elbow joint was surgically debrided, flushed, and cultured. The incision dehisced 10 days after surgery. Mycobacterium chelonae was cultured from the left elbow joint and from a skin nodule of the dorsum of the right front flipper. The turtle was euthanized due to apparent systemic infection with M. chelonae. Mycobacterium chelonae was isolated from cultures taken at necropsy of the lung, liver, spleen, kidney, and pericardium. Osteoarthritic infections with M. chelonae have not been reported in reptiles. Additionally, primary osteoarthritic diseases of synovial joints are uncommon in reptilian species. Due to the paucity of reports of mycobacterial diseases in sea turtles, the continued documentation of these cases will increase knowledge and understanding in caring for these endangered animals.

Modern CT applications in veterinary medicine.

Although computed tomography (CT) is used primarily for diagnosis in humans, it can also be used to diagnose disease in veterinary patients. CT and associated three-dimensional reconstruction have a role in diagnosis of a range of illnesses in a variety of animals. In a sea turtle with failure to thrive, CT showed a nodal mass in the chest, granulomas in the lungs, and a ball in the stomach. CT of a sea dragon with balance and movement problems showed absence of the swim bladder. In a sloth with failure to thrive, CT allowed diagnosis of a coin in the intestine. CT of a puffin with failure to thrive showed a mass in the chest, which was found to be a hematoma. In a smooth-sided toad whose head was tilted to one side and who was circling in that direction, CT showed partial destruction of the temporal bone. CT of a domestic cat with listlessness showed a mass with focal calcification, which proved to be a leiomyosarcoma. CT of a sea otter showed pectus excavatum, which is caused by the animal smashing oysters against its chest. In a Japanese koi with abdominal swelling, CT allowed diagnosis of a hepatoma.