E. Scott Weber

Disseminated phaeohyphomycosis in weedy seadragons (Phyllopteryx taeniolatus) and leafy seadragons (Phycodurus eques) caused by species of Exophiala, including a novel species

During the period from January 2002 to March 2007, infections by melanized fungi were identified with greater frequency in aquarium-maintained leafy seadragons (Phycodurus eques)and weedy seadragons (Phyllopteryx taeniolatus), pivotal species to the educational and environmental concerns of the aquarium industry and conservation groups. The objective of this study was to characterize the pathology and identify fungi associated with phaeohyphomycotic lesions in these species. Samples from 14 weedy and 6 leafy seadragons were received from 2 institutions and included fresh, frozen, and formalin-fixed tissues from necropsy and biopsy specimens. Fresh and frozen tissues were cultured for fungi on Sabouraud dextrose agar only or both Sabouraud dextrose agar and inhibitory mold agar with gentamicin and chloramphenicol at 30°C. Isolates were processed for morphologic identification and molecular sequence analysis of the internal transcribed spacer region and D1/D2 domains of the large subunit ribosomal RNA gene. Lesions were extensive and consisted of parenchymal and vascular necrosis with fungal invasion of gill (11/20), kidney (14/20), and other coelomic viscera with or without cutaneous ulceration (13/20). Exophiala sp. isolates were obtained from 4 weedy and 3 leafy seadragons and were identified to species level in 6 of 7 instances, namely Exophiala angulospora (1) and a novel species of Exophiala (5), based on nucleotide sequence comparisons and phylogenetic analyses. Disseminated phaeohyphomycosis represents an important pathologic condition of both weedy and leafy seadragons for which 2 species of Exophiala,1a novel species, have been isolated.

Hematologic and plasma biochemical findings in cold-stunned Kemp's ridley turtles: 176 cases (2001-2005).

OBJECTIVE To document hematologic and plasma biochemical values for a large number of cold-stunned Kemps ridley turtles at the beginning of rehabilitation, to investigate differences in hematologic and plasma biochemical values of turtles that ultimately survived versus those that died, and to compare values of survivors during convalescence with initial values obtained at the time of admission. DESIGN Retrospective case series. ANIMALS 176 stranded, cold-stunned Kemps ridley turtles hospitalized between 2001 and 2005. PROCEDURES Hematologic and plasma biochemical values obtained at the time of admission were compared retrospectively for turtles that died versus turtles that survived. Initial results for survivors were compared with convalescent results obtained later in rehabilitation. RESULTS Turtles that died had significantly greater plasma concentrations of sodium, chloride, potassium, calcium, phosphorus, and uric acid than did turtles that survived. For survivors, values obtained during convalescence for BUN concentration and plasma calcium concentration were significantly greater than initial values obtained at the time of admission, whereas values obtained during convalescence for glucose, sodium, and uric acid concentrations were significantly lower than initial values. CONCLUSIONS AND CLINICAL RELEVANCE Cold-stunned Kemps ridley turtles may be affected by electrolyte derangements, dehydration, and decreased renal function. Hematologic and plasma biochemical evaluation of such turtles provided useful clinical and prognostic information during the rehabilitation process.

Metabolic and respiratory status of cold-stunned Kemp’s ridley sea turtles (Lepidochelys kempii)

Abstract“Cold-stunning” of sea turtles has been reported as a naturally occurring stressor for many years; however, the physiologic status of cold-stunned turtles has only been partially described. This study investigated initial and convalescent venous blood gas, acid-base, and critical plasma biochemical data for 26 naturally cold-stunned Kemp’s ridley sea turtles (Lepidochelys kempii) from Cape Cod, MA, USA. Samples were analyzed for pH, pCO2, pO2, bicarbonate, plasma osmolality, sodium, potassium, chloride, ionized calcium, ionized magnesium, glucose, lactate, and blood urea nitrogen using a clinical point-of-care analyzer. Data were corrected for the patient’s body temperature using both species-specific and more general correction methods. In general, venous blood gas, acid-base, and plasma biochemical data obtained for surviving cold-stunned Kemp’s ridley sea turtles were consistent with previously documented data for sea turtles exposed to a wide range of temperatures and physiologic stressors. Data indicated that turtles were initially affected by metabolic and respiratory acidosis. Initial pH-corrected ionized calcium concentrations were lower than convalescent concentrations, and initial pH-corrected ionized magnesium concentrations were higher than convalescent concentrations.

Pathologic and parasitologic findings of cold-stunned Kemp's ridley sea turtles (Lepidochelys kempii) stranded on Cape Cod, Massachusetts, 2001-2006.

Necropsy reports for 28 stranded, cold-stunned Kemp’s ridley sea turtles (Lepidochelys kempii) that died between 2001 and 2006 were reviewed retrospectively. Gross and microscopic lesions were compiled to describe the pathologic and parasitologic findings in turtles that were found freshly dead on the beach or that died within 48 hr of stranding. Anatomic lesions of varying severity were identified in each of the examined turtles and were identified in tissues of the alimentary, respiratory, integumentary, nervous and sensory, and urogenital systems in order of decreasing frequency. Necrotizing enterocolitis and bacterial or fungal pneumonia were the most frequently encountered lesions that were considered clinically significant. Parasites and parasitic lesions were identified primarily in tissues of the alimentary system and included intestinal cestodiasis and parasitic granulomas containing larval cestodes or nematodes. Postlarval cestodes were also found in the coelom of two turtles. In many cases, the extent and severity of lesions were judged to be insufficient to have solely caused mortality, suggesting that additional factors such as metabolic, respiratory, and electrolyte derangements; hypothermia; and drowning may be important proximate causes of death in cold-stunned turtles. Results of this study provide insight into pathologic conditions that may be of clinical relevance to rehabilitation efforts for cold-stunned sea turtles.

Trace Metal and Organochlorine Pesticide Concentrations in Cold-Stunned Juvenile Kemp's Ridley Turtles (Lepidochelys kempii) from Cape Cod, Massachusetts

Abstract Whole blood and keratin mercury concentrations, complete blood cell counts, and plasma biochemical health profiles were evaluated in 31 juvenile cold-stunned Kemps ridley turtles (Lepidochelys kempii) from Cape Cod, Massachusetts. In addition, plasma copper, zinc, selenium, and cadmium concentrations were measured for 16 of these turtles. Liver mercury concentrations were measured for 6 turtles that were dead upon acquisition or died during rehabilitation. Concentrations of 18 organochlorine pesticides were measured in plasma of 18 live turtles, and liver, kidney, fat, and brain of 3 deceased turtles. Metal levels were generally similar to those previously published for sea turtles, with mean values (wet weight) of 24 ng/g for blood mercury, 67 ng/g for liver mercury, 389 ng/g for keratin mercury, 690 ng/g for plasma copper, 2290 ng/g for plasma zinc, and 490 ng/g for plasma selenium. Cadmium was not detected in any sample. Organochlorine levels were generally low in comparison to values published for cold-stunned juvenile Kemps ridley turtles in the 1980s. Several significant correlations between metal levels, hematology, and plasma biochemical health parameters were detected; however, the cause of these correlations could not be determined. This study demonstrates that Kemps ridley turtles may be exposed to contaminants at a young age. Further investigation of the sources and effects of contaminants in juvenile sea turtles is warranted.

Bacterial and parasitic diseases of pet fish.

Bacterial and parasitic diseases are very common problems in pet fish. Diagnostic testing for bacterial and parasitic diseases is simple to do; many tests can be done on ambulatory visits. When logical treatment strategies are initiated and supported by diagnostic testing, a successful outcome is possible. Identification of the correct pathogens also allows an educational opportunity for discussions on prevention and biosecurity practices with clients and although fish are poikilothermic, there are some bacterial and parasitic pathogens that are zoonotic.

Fish Analgesia: Pain, Stress, Fear Aversion, or Nociception?

The increasing use of fish resources and a greater understanding of aquatic animal medicine demands providing evidence-based veterinary care for these animals. Because fish are aquatic as well as being pokilothermic, there are several unique anatomic and physiologic considerations that must be understood when working with these animals. Veterinarians need to adapt methodologies for examining, performing diagnostics, and treating fish patients to decrease stress, decrease fear, and avoid and/or decrease nociception. This article briefly defines stress, reviews and compares fish neuroanatomic pathways associated with nociception, discusses behavioral observations, summarizes current use of analgesics for fish patients, and concludes with the ongoing controversy regarding pain on this topic.

Surgical insertion of transmitters and telemetry methods in fisheries research

Received June 25, 2013. Accepted November 11, 2013. From the Fish Ecology Division, Northwest Fisheries Science Center, National Oceanic and Atmospheric Administration, 2725 Montlake Blvd East, Seattle, WA 98112 (Rub, Moser); the Section for Freshwater Fisheries Ecology, Institute of Aquatic Resources, Danish Technical University, 8600 Silkeborg, Denmark (Jepsen); the Columbia River Research Laboratory, Western Fisheries Research Center, US Geological Survey, 5501A Cook-Underwood Rd, Cook, WA 98605 (Liedtke); and the Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616 (Weber). The authors thank Dr. Adrian Smith and JoAnne Butzerin for technical assistance. Address correspondence to Dr. Rub (michelle.rub@noaa.gov). U of electronic transmitter and monitoring systems to track movements of aquatic animals has increased continuously since the inception of these systems in the mid-1950s. The purpose of the present report is to provide information about veterinary principles and their incorporation into surgical implantation procedures for fish. We also intend to provide insight into the unique challenges of field-based aquatic surgical studies. Within this context, 4 aspects of the process for surgical implantation of transmitters in fish (ie, handling, aseptic technique, anesthesia, and implantation) will be described. Effects of surgical insertion of transmitters (ie, tagging) and aspects of the surgical implantation process where collaboration and professional exchanges among nonveterinarian researchers and veterinarians may be most fruitful will be discussed. Although this report focuses on surgical implantation, the principles and protocols described here (other than incision and suture placement) are also applicable to studies that involve injection of transmitters into fish.

Systemic iridovirus from threespine stickleback Gasterosteus aculeatus represents a new megalocytivirus species (family Iridoviridae).

Megalocytiviruses have been associated with epizootics resulting in significant economic losses in public aquaria and food-fish and ornamental fish industries, as well as threatening wild fish stocks. The present report describes characteristics of the first megalocytivirus from a wild temperate North American fish, the threespine stickleback Gasterosteus aculeatus. Moribund and dead fish sampled after transfer to quarantine for an aquarium exhibit had amphophilic to basophilic intracytoplasmic inclusions (histopathology) and icosahedral virions (transmission electron microscopy) consistent with an iridovirus infection. Phylogenetic analyses of the major capsid, ATPase, and DNA polymerase genes confirmed the virus as the first known member of the genus Megalocytivirus (family Iridoviridae) from a gasterosteid fish. The unique biologic and genetic properties of this virus are sufficient to establish a new Megalocytivirus species to be formally known as the threespine stickleback iridovirus (TSIV). The threespine stickleback is widely distributed throughout the northern hemisphere in both freshwater and estuarine environments. The presence of megalocytiviruses with broad host specificity and detrimental economic and ecologic impacts among such a widely dispersed fish species indicates the need for sampling of other stickleback populations as well as other North American sympatric marine and freshwater ichthyofauna.

Erysipelothrix septicemia in a little blue penguin (Eudyptula minor).

On June 25, 2002, aquarium veterinarians treated a 5-year-old, male little blue penguin (Eudyptula minor) that was acutely recumbent and dull, with inappetence of 24-hour duration. The penguin died within 10 minutes of presentation despite emergency resuscitation efforts. Gross pathologic findings consisted of pulmonary congestion and intestinal hemorrhage. Histopathologic findings included necrosis of tips of intestinal villi, increased numbers of mononuclear cells in pulmonary interstitium and hepatic sinusoids, and gram-positive bacteria in systemic microvasculature. Transmission electron microscopic examination revealed short gram-positive bacilli located in lumina of glomerular capillaries and in cytoplasm of mononuclear phagocytic cells in the lung and liver. Erysipelothrix rhusiopathiae was recovered from the lung, liver, and intestine by bacteriologic culture. Amplicons from polymerase chain reaction (PCR) tests using Erysipelothrix genus–specific primers and total genomic DNA extracted from formalin-fixed, paraffin-embedded tissue sections of lung and intestine demonstrated 99% nucleotide sequence identity with 16S small-subunit ribosomal DNA of E. rhusiopathiae and E. tonsillarum. The source of infection was speculated to be fish in the diet; however, repeated attempts to detect Erysipelothrix spp. from the mucous layer of food fish using bacteriologic culture and PCR were unsuccessful. This is the first report of erysipelas in a captive aquatic bird. Details of the isolation of E. rhusiopathiae and the application of molecular testing to identify Erysipelothrix DNA in formalin-fixed, paraffin-embedded tissue sections are given.