Pharmacokinetics of enrofloxacin and ciprofloxacin in Atlantic horseshoe crabs (Limulus polyphemus) after single injection.

The pharmacokinetics of enrofloxacin and the metabolite ciprofloxacin were studied in horseshoe crabs after a single injection of 5 mg/kg. Twelve Atlantic horseshoe crabs (Limulus polyphemus) of undetermined age were injected with enrofloxacin into the dorsal cardiac sinus. Hemolymph samples were collected by syringe and needle at regular intervals for 120 hr. Samples were analyzed by high-pressure liquid chromatography and compartmental analysis performed on the results. Following injection, the elimination half-life (T½), peak concentration, area under the curve (AUC), and volume of distribution (VD) for enrofloxacin were 27.9 (29.13) hr, 8.98 (18.09) µg/ml, 367.38 (35.41) hr µg/ml, and 0.575 (20.48) L/kg, respectively (mean value, CV%). For ciprofloxacin, the elimination T½, peak concentration, and AUC were 61.36 (34.55) hr, 2.34 (24.11) µg/ml, and 304.46 (24.69) µg hr/ml. In these animals, the ciprofloxacin concentrations comprised an average of 45.8% of the total fluoroquinolone concentrations, which is substantial compared to other marine invertebrates. The total AUC produced (sum of enrofloxacin and ciprofloxacin) was 682.69 ± 180.61 µg hr/ml. Concentrations that were achieved after a single dose of 5 mg/kg horseshoe crabs were sufficient to treat bacteria susceptible to enrofloxacin and ciprofloxacin.

Population pharmacokinetics of ceftazidime after a single intramuscular injection in wild turtles.

Ceftazidime, a third-generation cephalosporin, is important for treating opportunistic bacterial infections in turtles. Antibacterial dosage regimens are not well established for wild turtles and are often extrapolated from other reptiles or mammals. This investigation used a population pharmacokinetic approach to study ceftazidime in wild turtles presented for rehabilitation. Ceftazidime was administered to 24 wild turtles presented to the Turtle Rescue Team at North Carolina State University. A sparse blood sampling protocol was used to collect samples from 0 to 120 hr with three samples per individual after injection. Plasma samples were analyzed by high-pressure liquid chromatography (HPLC). A nonlinear mixed-effects model (NLME) was fitted to the data to determine typical values for population parameters. We identified a long half-life (T½) of approximately 35 hr and volume of distribution (VSS ) of 0.26 L/kg. We concluded that this long T½ will allow for a dose of 20 mg/kg injected IM to maintain concentrations above the MIC of most wild-type bacteria for 5 days. Because of long intervals between injections, stability of stored formulations was measured and showed that 90% strength was maintained for 120 hr when stored in the refrigerator and for 25 days when stored in the freezer.

Phylogenetic analysis of spring virema of carp virus reveals distinct subgroups with common origins for recent isolates in North America and the UK.

Genetic relationships between 35 spring viremia of carp virus (SVCV) genogroup Ia isolates were determined based on the nucleotide sequences of the phosphoprotein (P) gene and glycoprotein (G) genes. Phylogenetic analysis based on P gene sequences revealed 2 distinct subgroups within SVCV genogroup Ia, designated SVCV Iai and Iaii, and suggests at least 2 independent introductions of the virus into the USA in 2002. Combined P- and G-sequence data support the emergence of SVCV in Illinois, USA, and in Lake Ontario, Canada, from the initial outbreak in Wisconsin, USA, and demonstrate a close genetic link to viruses isolated during routine import checks on fish brought into the UK from Asia. The data also showed a genetic link between SVCV isolations made in Missouri and Washington, USA, in 2004 and the earlier isolation made in North Carolina, USA, in 2002. However, based on the close relationship to a 2004 UK isolate, the data suggest than the Washington isolate represents a third introduction into the US from a common source, rather than a reemergence from the 2002 isolate. There was strong phylogenetic support for an Asian origin for 9 of 16 UK viruses isolated either from imported fish, or shown to have been in direct contact with fish imported from Asia. In one case, there was 100% nucleotide identity in the G-gene with a virus isolated in China.

Phacoemulsification of bilateral cataracts in a loggerhead sea turtle (Caretta caretta).

An immature free-living loggerhead sea turtle (Caretta caretta) of unknown sex was found moribund off the coast of Wise Point, Virginia. It was suffering from cachexia and had bilateral hypermature cataracts which were treated by phacoemulsification under general anaesthesia. The surgery restored the turtle's vision and it was returned to the wild.

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.

Orbital exenteration and placement of a prosthesis in fish.

OBJECTIVE: To develop a procedure for orbital exenteration and prosthesis placement in fish. DESIGN: Prospective study. ANIMALS: 5 cultured hybrid striped bass (Morone saxatilis x M chrysops) ranging from 30 to 50 cm in length. PROCEDURE: Exenteration was performed, using a dorsal approach in which blunt dissection was performed in the circumorbital sulcus. The orbit was then dried, and simple interrupted sutures were placed, leaving 2 suture loops within the orbit. The orbit was filled with polyvinylsiloxane, and a prosthetic glass eye was seated in the polyvinylsiloxane. RESULTS: All fish retained the prosthesis and had satisfactory cosmetic results at the end of the 8-week study period. CLINICAL IMPLICATIONS: The increase in popularity of pet fish and abundance of valuable aquarium and show fish have led to heightened awareness of piscine ocular disease. Aquarium fish are often euthanatized because of disfiguring ocular problems. The technique described here for surgical exenteration and cosmetic orbital prosthesis placement in fish may extend the captive life of public display fish.

Pneumocystectomy in a Midas cichlid.

A pet Midas cichlid with a 2-year history of a distended abdomen and inadequate buoyancy control was found, radiographically, to have an abnormally large swim bladder. A recirculating anesthesic machine was constructed, and the fish was anesthetized with tricaine methanesulfonate prior to removing a portion of the swim bladder. The entire procedure lasted 71 minutes. Buoyancy problems in pet fishes are common. Causes include subcutaneous air accumulation, infectious disease of the swim bladder inner ear disease, and gastroenteritis. Reduction of the volume of the swim bladder improved this fish's ability to maintain a normal posture in the aquarium.

Microsurgical excision of an abdominal mass in a gourami.

A female, sunset, thick-lipped gourami (Colisa labiosa) that weighed 8 g and was 5.4 cm from the snout to the end of the vertebral column was examined because of a 5-mm-diameter, midventrally located mass that had developed suddenly 1 month earlier. Cytologic examination of a sample obtained by use of fine-needle aspiration, survey radiography, positive-contrast radiography of the gastrointestinal tract, and Doppler ultrasonography were performed to evaluate the mass. These procedures were not able to provide a definitive diagnosis, but did facilitate surgical planning. The mass was excised, and the abdominal musculature was repaired, using microsurgical techniques. Redevelopment of the mass was not detected during the 5-month period after surgery. Histologic evaluation of the mass revealed an organized hematoma of undetermined cause. Successful management of this gourami illustrated that size should not be a deterrent to diagnostic evaluation and surgical intervention in diminutive fish.

Bronchoalveolar lavage in a dolphin.

Bronchoalveolar lavage (BAL) was performed twice to evaluate a stranded Atlantic bottle-nosed dolphin for pulmonary disease. A pediatric gastroscope with a working length of 1,090 mm and an outer diameter of 9.8 mm was of appropriate size for BAL in this dolphin. Fifty milliliters of sterile saline (0.9% NaCl) solution was used in each of 2 sites for the first lavage. Fluid recovery was 58 and 66% from the 2 sites; however, results of cytologic analyses were typical of a bronchial wash rather than BAL. Larger volumes of saline solution (85 to 100 ml/site) were used in the second lavage. Although fluid recovery was only 25 and 30% from the 2 sites, results of cytologic analyses were consistent with BAL. Mononuclear cells accounted for 72 and 90% of total WBC. Although the dolphin of this report did not appear to have pulmonary disease, experience obtained by performing BAL provided valuable information for the practical application of this technique in dolphins.

Surgical removal of an undifferentiated abdominal sarcoma from a koi carp (Cyprinus carpio).

An undifferentiated abdominal sarcoma was removed surgically from a koi carp. The diagnostic procedures, including radiography and computed tomography, and the procedures for general anaesthesia and the surgical approach for a celiotomy in a fish are described. The gross and microscopic appearance of the tumour is described and illustrated.

Evaluation of the tissue reactions in the skin and body wall of koi (Cyprinus carpio) to five suture materials.

Five different suture materials (silk, monofilament nylon, polyglyconate, polyglactin 910, and chromic gut) were placed in the skin and body wall of 10 Doitsu (scaleless) koi (Cyprinus carpio). After seven days the sutures were retrieved from five of the fish in 5 mm and 6 mm punch biopsies, and after 14 days they were retrieved in the same way from the other five. The tissue reactions were evaluated by gross visual inspection and by histological examination. The total inflammatory reaction was graded on a scale from 0 (no inflammation) to 5 (severe inflammation). The synthetic suture materials generally induced a moderate inflammatory reaction that decreased after seven days. After 14 days the superficial reaction to monofilament nylon was substantial, and the tissue reactions to the organic suture materials were slightly greater than the reactions to the synthetics. The inflammatory response to silk was greater after 14 days than after seven, and chromic gut induced a moderately severe inflammatory response after seven days; the chromic gut sutures fell out before the biopsies were taken after 14 days. The organic materials induced intense inflammatory reactions which did not subside if the suture remained in the tissue.

Stabilisation of scoliosis in two koi (Cyprinus carpio).

Two koi (Cyprinus carpio) from the same pond developed similar lesions of scoliosis. Radiographic examinations showed that their spines had become malaligned as a result of vertebral compression fractures involving T14 to T16. The vertebrae in both fish were stabilised with screws, k-wire and polymethylmethacrylate. They both appeared to improve after surgery, but they began to decline and died within three months. A postmortem examination revealed multi-organ inflammation that was not associated with the surgical implants.

Emergency and critical care of fish.

The keeping of fish as pets is a hobby that has experienced increasing popularity over the past decade. The hobby has also become more sophisticated in recent years and a growing number of veterinarians are gaining clinical experience and knowledge in the area of pet fish medicine. The opportunity to apply this knowledge to a pet fish problem can be a rewarding experience. This article focuses on managing acute and critical problems of pet fish at times when veterinary intervention is required within an emergency time frame.

Pet fish formulary.

Aquarium fish are one of the most popular pets in the United States. Understanding the use of chemotherapeutics in these animals has increased markedly in recent years, and this information is now readily accessible to the private practitioner in this article. The authors introduce the veterinary clinician to the commonly used chemotherapeutics, routes of administration, species-specific precautions, and treatment tips where appropriate.

Surgery in fish.

Surgery in fish is feasible and practical for clinical and research applications. Certain adjustments in standard surgical procedures are necessary to accommodate piscine tissue handling, skin sensitivity, aqueous respiration, anatomic variations, and patient size. General considerations for fish surgery, including anesthesia, presurgical evaluation, equipment, suture selection, and surgical site preparation, have been presented here. Procedures described include celiotomy, enucleation, pseudobranchectomy, swim bladder surgery, gonadectomy, liver and kidney biopsy techniques, telemetry device implantation, and vascular catheterization.

Serum chemistry and hematology values for anesthetized American bullfrogs (Rana catesbeiana).

Samples taken from seven male and seven female adult American bullfrogs (Rana catesbeiana) were evaluated by complete blood count and serum chemistry to establish baseline data on commercially available frogs destined for laboratory use. Differences between sexes were analyzed and females had higher plasma protein, calcium, and sodium levels.

Pharmacokinetics of ceftazidime in loggerhead sea turtles (Caretta caretta) after single intravenous and intramuscular injections.

The pharmacokinetics of ceftazidime in yearling loggerhead sea turtles (Caretta caretta) following single i.m and i.v. injections were studied. Eight juvenile 1.25+/-0.18 kg turtles were divided into two groups. Four animals received 20 mg/kg of ceftazidime i.v. and four received the same dose i.m. Plasma ceftazidime concentrations were analyzed by reverse-phase high-performance liquid chromatography. The i.v. and i.m. administration half-lives were 20.59+/-3.24 hr and 19.08+/-0.77 hr, respectively. The volume of distribution was 0.42+/-0.07 L/kg, and the systemic clearance was 0.217+/-0.005 ml/min/kg. Ceftazidime was detected in all blood samples and its concentration exceeded the minimum inhibitory concentration for Pseudomonas for 60 hr after i.m. and i.v. injections.