Hematology, plasma biochemistry, and tissue enzyme activities of invasive red lionfish captured off North Carolina, USA.

The red lionfish Pterois volitans is important not only in the aquarium trade but also as an invasive species in the western Atlantic. Introduced to waters off the southeastern coast of the United States, red lionfish have rapidly spread along much of the East Coast and throughout Bermuda, the Bahamas, and much of the Caribbean. Hematology and plasma biochemistry were evaluated in red lionfish captured from the offshore waters of North Carolina to establish baseline parameters for individual and population health assessment. Blood smears were evaluated for total and differential white blood cell counts, and routine clinical biochemical profiles were performed on plasma samples. To improve the interpretive value of routine plasma biochemistry profiles, tissue enzyme activities (alkaline phosphatase [ALP], alanine aminotransferase [ALT], aspartate aminotransferase [AST], gamma-glutamyl transferase [GGT], lactate dehydrogenase [LD], and creatine kinase [CK]) were analyzed from liver, kidney, skeletal muscle, gastrointestinal tract, and heart tissues from five fish. The hematological and plasma biochemical values were similar to those of other marine teleosts except that the estimated white blood cell counts were much lower than those routinely found in many species. The tissue enzyme activity findings suggest that plasma LD, CK, and AST offer clinical relevance in the assessment of red lionfish.

Acute toxicity and tissue distributions of malathion in Ambystoma tigrinum.

The kinetics of the bioaccumulation of malathion (O,O-dimethyl phosphorodithioate of diethyl mercaptosuccinate) and the biological impact of exposure for tiger salamanders, Ambystoma tigrinum, were assessed through exposure to soil surface contaminated with 50 microg/cm(2) or 100 microg/cm(2 )malathion and ingestion of an earthworm exposed to soil contaminated with 200 microg/cm(2) malathion. Malathion and malaoxon burdens in salamanders sampled at different times after exposure(s) were measured by gas chromatography in four tissue/organ subgroups: liver, epaxial muscle, pooled viscera (except the liver and brain), and pooled avisceral carcass (muscle, skin, and bone). The total tiger salamander xenobiotic burdens were calculated from these data. The malathion/malaoxon burden 1 day after exposure was greatest in the avisceral carcass and 2 days after exposure was greatest in the viscera. Bioconcentration and bioaccumulation factors remained less than unity throughout the experiment and did not support the hypothesis of bioaccumulation of malathion in the tiger salamander. Biological impact was assessed with a colorimetric brain cholinesterase microassay. Brain cholinesterase activities in salamanders exposed to malathion-contaminated soil (50 microg/cm(2) or 100 microg/cm(2 )malathion) were suppressed approximately 50-65% and 90%, respectively, compared to unexposed controls. The exposed animals did not exhibit overt clinical signs of malathion toxicosis.

The identification of a genetically unique piroplasma in North American river otters (Lontra canadensis).

During a routine health check of a wild-caught North American river otter (Lontra canadensis) small piroplasms were noted within erythrocytes. Analyses of the 18S ribosomal ribonucleic acid (rRNA) gene sequences determined that this was a genetically unique organism most closely related to Babesia microti-like parasites found in other small carnivores. Subsequently 39 wild-trapped North American river otters from North Carolina were tested for the presence of piroplasma deoxyribonucleic acid (DNA) via polymerase chain reaction and piroplasma DNA was detected in 82% (32/39) of these samples. Sequencing of partial 18S rRNA genes from selected cases determined that they were identical to the sentinel case. This report documents the existence of a genetically unique piroplasma in North American river otters and indicates that the prevalence of piroplasma in North Carolina otters is quite high. The pathogenic potential of this organism for otters or other species remains unknown.

Observation and cogitation: how serendipity provides the building blocks of scientific discovery.

The identification of serendipitous findings in field-based animal research is challenging in part because investigators are reluctant to declare a discovery accidental. Investigators recognize that many factors must be considered. For example, the impact of using carefully ordered observational search patterns in ecologic, pathologic, and epidemiologic investigations could result in findings being categorized as "sought" versus "unsought." Team collaborations are common in these types of investigations and have advantages related to the application of multiple paradigms, paradigm mixing, and paradigm shifting. This approach reduces the perception of serendipity. Issues of search image refinement and the co-discovery of sought and unsought discoveries additionally cloud the identification of a truly serendipitous finding. Nevertheless, basic curiosity and observation are necessary precursors to scientific discovery. It should be recognized that serendipitous discoveries are of significant value in the advancement of science and often present the foundation for important intellectual leaps of understanding.

Pharmacokinetics of sulfadimethoxine and ormetoprim in a 5:1 ratio following intraperitoneal and oral administration, in the hybrid striped bass (Morone chrysops x Morone saxitalis).

Selected pharmacokinetic parameters for sulfadimethoxine and ormetoprim, administered in a 5:1 ratio, via the oral and intraperitoneal (i.p.) routes were determined in the hybrid striped bass (Morone chrysops x Morone saxitalis). Plasma concentrations of both drugs were determined by high-performance liquid chromatography. A first-order one-compartment model adequately described plasma drug disposition. The elimination half-lives for sulfadimethoxine following i.p. and oral administration were 26 and 10.5 h, respectively. The half-lives for ormetoprim administered via i.p. and oral routes were 7.5 and 3.9 h, respectively. Cmax for sulfadimethoxine via the i.p. and oral routes were calculated to be 27.7 (+/-9.0) microg/mL at 3.6 h and 3.2 (+/-1.2) microg/mL at 1.2 h, respectively. Cmax for ormetoprim via the i.p. route was calculated to be 1.2 (+/-0.5) microg/mL at 9.1 h and 1.58 (+/-0.7) microg/mL at 5.7 h for the oral route. The oral availability of sulfadimethoxine relative to the i.p. route was 4.6%, while the oral availability of ormetoprim relative to the i.p. route was 78.5%. Due to the nonconstant ratio of these drugs in the plasma of the animal, the actual drug ratio to use for determining minimum inhibitory concentration (MIC) is unclear. Using the ratio of the total amount of each drug that is absorbed as a surrogate for the mean actual ratio may be the best alternative to current methods. Using this ratio as determined in these studies, (2.14:1 sulfadimethoxine:ormetoprim) to determine the MICs the single 50 mg/kg oral dose of the 5:1 combination of sulfadimethoxine and ormetoprim appears to provide plasma concentrations high enough to inhibit the growth of Yersinia ruckeri, Edwardsiella tarda, and Escherichia coli.

Comparative efficacy of tricaine methanesulfonate and clove oil for use as anesthetics in red pacu (Piaractus brachypomus).

OBJECTIVE: To compare the anesthetic efficacy and physiologic changes associated with exposure to tricaine methanesulfonate and clove oil (100% eugenol). ANIMALS: 15 adult cultured red pacu (Piaractus brachypomus). PROCEDURE: Fish were exposed to each of 6 anesthetic concentrations in a within-subjects complete crossover design. Stages of anesthesia and recovery were measured, and physiologic data were collected before and during anesthesia. RESULTS: Interval to induction was more rapid and recovery more prolonged in fish exposed to eugenol, compared with those exposed to tricaine methanesulfonate. The margin of safety for eugenol was narrow, because at the highest concentration, most fish required resuscitation. Mixed venous-arterial PO2 consistently decreased with anesthesia, while PCO2 consistently increased with anesthesia in all fish regardless of anesthetic agent. The increase in PCO2 was accompanied by a decrease in pH, presumably secondary to respiratory acidosis. Anesthesia was associated with increased blood glucose, potassium, and sodium concentrations as well as Hct and hemoglobin. Fish anesthetized with eugenol were more likely to react to a hypodermic needle puncture than fish anesthetized with tricaine methanesulfonate. CONCLUSIONS AND CLINICAL RELEVANCE: Anesthesia induced with tricaine methanesulfonate or eugenol contributes to hypoxemia, hypercapnia, respiratory acidosis, and hyperglycemia in red pacu. Similar to tricaine methanesulfonate, eugenol appears to be an effective immobilization compound, but eugenol is characterized by more rapid induction, prolonged recovery, and a narrow margin of safety. Care must be taken when using high concentrations of eugenol for induction, because ventilatory failure may occur rapidly. In addition, analgesic properties of eugenol are unknown.

Oxygen isotope variability in bones of wild caught and constant temperature reared sub-adult American alligators.

(1) The mean delta18O(BP) ( per thousandSMOW) for any given bone sampled from captive alligators maintained at high constant temperature was lower (indicative of higher temperatures of bone deposition) than that of the same bone from wild alligators caught in Northern Florida, but these differences were only greater than two standard deviations from the mean for the thoracic vertebrae and metatarsal bones. (2) Inter-bone variability of delta18O(BP) ( per thousandSMOW) was similar for captive alligators maintained at constant temperatures and the wild alligators, but intra-bone variability was much greater in wild alligators. (3) The order of mean delta18O(BP) ( per thousandSMOW) of bones (from highest to lowest) differed between treatment groups. However, intra-bone variability obscured the significance of those differences. Nevertheless, the thoracic vertebra had the highest mean delta18O(BP) ( per thousandSMOW), indicative of lower temperatures, and the lowest variability of bones in both groups of alligators. Conversely, the tibia was one of the warmest and more variable bones in both groups of alligators. (4) The pattern of delta18O(BP) ( per thousandSMOW) values across sites within long bones were identical between alligator treatment groups for the femur and humerus but differed between groups for the tibia and metatarsus, and differed between different long bones. The predicted intra-bone pattern for long bones of increasing delta18O(BP) ( per thousandSMOW) indicative of lower temperatures in more distal sampling sites was only obtained from the femurs. (5) Paired cortical and cancellous bone samples from the same site from all individuals in both treatment groups were available for proximal humeri and distal femurs. delta18O(BP) ( per thousandSMOW) values from cortical bone were more variable than those from cancellous bone for both bones. (6) Cortical bone had lower delta18O(BP) ( per thousandSMOW) values indicative of warmer temperatures than cancellous bone at sites sampled on the proximal humeri and distal femurs of all three animals from both treatment groups.

Amoxicillin pharmacokinetics in harbor seals (Phoca vitulina) and northern elephant seals (Mirounga angustirostris) following single dose intravenous administration: implications for interspecific dose scaling.

The pharmacokinetics of sodium amoxicillin after a single intravenous dose of 20 mg/kg were determined in ten harbor seals (Phoca vitulina) and ten northern elephant seals (Mirounga angustirostris). The seals ranged in age from 1 to 6 months and the mean weights were 11.7 kg (range, 9.5-18.5 kg) for harbor seals and 47.1 kg (range, 39.5-61.4 kg) for elephant seals. The median half-life of amoxicillin (quartiles) in harbor seals, 1.5 (1.0-3.1) h. was not statistically different from that of elephant seals, 2.0 (1.4-3.8) h, nor were the differences between the terminal elimination rate constants between the two species. The only statistically significant differences between species were for area-under-the-curve (AUC), and total systemic clearance. The lack of statistical significance for differences in the volume of distribution at steady-state (Vss) may have been due to minor differences in the time frame of data collection and dose administered between the two groups. A true physiologic difference in drug handling, possibly related to renal perfusion or tubal secretory efficiency could affect amoxicillin kinetics in these species, and longer administration intervals may be appropriate for elephant seals as compared to harbor seals when administering multiple dose amoxicillin therapy at 20 mg/kg.

Cardiorespiratory effects of four alpha2-adrenoceptor agonist-ketamine combinations in captive red wolves.

OBJECTIVE: To evaluate the cardiopulmonary effects of immobilizing doses of xylazine-ketamine (XK), medetomidine-ketamine (MK), medetomidine-ketamine-acepromazine (MKA), and medetomidine-butorphanol-ketamine (MBK) in captive red wolves. DESIGN: Prospective study. ANIMALS: 32 adult captive red wolves. PROCEDURE: Wolves were randomly assigned to 1 of 4 treatment groups: XK, MK, MKA, or MBK. Physiologic variables measured included heart rate, blood pressure, respiratory rate, tidal volume, oxygen-hemoglobin saturation (Spo2), end-tidal CO2, arterial blood gases, and rectal temperature. Induction time, muscle relaxation, and quality of recovery were assessed. RESULTS: Heart rates were lower in wolves in the MBK group than for the other groups. All 4 drug combinations induced considerable hypertension, with diastolic pressures exceeding 116 mm Hg. Blood pressure was lowest in wolves receiving the MBK combination. Respiratory rate was significantly higher in wolves receiving XK, MK, and MKA. Tidal volumes were similar for all groups. Wolves receiving XK, MK, and MKA were well-oxygenated throughout the procedure (SPo2 > 93%), whereas those receiving MBK were moderately hypoxemic (87% < Spo2 < 93%) during the first 20 minutes of the procedure. Hyperthermia was detected initially following induction in all groups. CONCLUSIONS AND CLINICAL RELEVANCE: The alpha2-adrenoceptor agonist-ketamine combinations provide rapid reversible anesthesia for red wolves but cause severe sustained hypertension. Such an adverse effect puts animals at risk for development of cerebral encephalopathy, retinal hemorrhage, pulmonary edema, and myocardial failure. Although the MBK combination offers some advantages over the others, it is advised that further protocol refinements be made to minimize risks associated with acute hypertension.

Serum oxytetracycline concentrations in African elephant (Loxodonta africana) calves after long-acting formulation injection.

Serum oxytetracycline pharmacokinetics were studied in 18 African elephant (Loxodonta africana) calves. Each elephant received separate injections of oxytetracycline at approximately 18 mg/kg i.m. and 8 mg/kg i.v. in a cross-over study. Blood samples were drawn at 0, 24, 48, 72, and 96 hr postinjection. An additional sample was drawn 110 hr before the animals were reinjected in the cross-over study and a final blood sample was drawn 48 hr after the second dose. No lameness or stiffness was observed following i.m. injections. Serum oxytetracycline concentrations >0.5 microg/ml were present 48 hr after initial dosing for all elephants (i.m., i.v., high or low dosage). Only elephants given the high i.m. dosage (18 mg/kg) maintained levels >0.5 microg/ml 72 hr postinjection. No significant difference in serum oxytetracycline concentration with time was observed between the groups given different i.v. dosages. These studies demonstrated that quantifiable serum oxytetracycline concentrations can be maintained in young African elephants with a low-dosage multidose i.m. regimen.

M6P/IGF2R imprinting evolution in mammals.

Imprinted gene identification in animals has been limited to eutherian mammals, suggesting a significant role for intrauterine fetal development in the evolution of imprinting. We report herein that M6P/IGF2R is not imprinted in monotremes and does not encode for a receptor that binds IGF2. In contrast, M6P/IGF2R is imprinted in a didelphid marsupial, the opossum, but it strikingly lacks the differentially methylated CpG island in intron 2 postulated to be involved in imprint control. Thus, invasive placentation and gestational fetal growth are not required for imprinted genes to evolve. Unless there was convergent evolution of M6P/ IGF2R imprinting and receptor IGF2 binding in marsupials and eutherians, our results also demonstrate that these two functions evolved in a mammalian clade exclusive of monotremes.

Cardiovascular evidence for an intermediate or higher metabolic rate in an ornithischian dinosaur.

Computerized tomography scans of a ferruginous concretion within the chest region of an ornithischian dinosaur reveal structures that are suggestive of a four-chambered heart and a single systemic aorta. The apparently derived condition of the cardiovascular system in turn suggests the existence of intermediate-to-high metabolic rates among dinosaurs.

Hematology and serum biochemistry parameters of North American river otters (Lontra canadensis).

Blood samples were obtained from 155 North American river otters (Lontra canadensis; 94 adult males, 38 adult females, 10 juvenile males, and 13 juvenile females) to establish baseline hematology and from 50 adult river otters (40 males and 10 females) for baseline serum biochemistry parameters for the species. The otters were livetrapped from eastern North Carolina (USA) during a 4-yr period. Data for 14 routine hematologic parameters and 22 serum chemistry assays showed significant differences in total leukocyte count and absolute neutrophil and monocyte numbers for adults versus juveniles, red blood cell counts and hemoglobin between adult and juvenile males, and calcium and alkaline phosphatase values for adult males between years of the study and an increase in leukocyte counts and absolute neutrophils with increased degree of trap injury sustained.

Evaluation of epidural morphine for postoperative analgesia in ferrets (Mustela putorius furo).

We evaluated the analgesic efficacy of epidural morphine for relieving postoperative pain in domestic ferrets by evaluating behavior and fecal cortisol concentrations. The 12 laboratory-reared, intact, female, domestic ferrets were anesthetized then underwent ovariohysterectomy and bilateral anal sacculectomy. Using a double-blind procedure, we provided epidural morphine (0.1 mg/kg) to six ferrets and epidural saline (0.1 mL/ferret) to the remaining animals prior to surgery. Compared to the animals that received saline, the morphine-treated ferrets were more likely to have attenuated pain responses, and they returned more rapidly to preoperative behavior. Although fecal cortisol concentrations during the first 24 h after surgery increased in all animals, the increase was statistically significant only in the ferrets that received saline epidurals. These data suggest that morphine epidurals administered to ferrets prior to surgery may attenuate both the physiologic and behavioral manifestations of surgically induced pain.