PHARMACOKINETIC EVALUATION OF MELOXICAM AFTER INTRAVENOUS AND INTRAMUSCULAR ADMINISTRATION IN NILE TILAPIA (OREOCHROMIS NILOTICUS)

Pharmacokinetic evaluation of meloxicam following intravenous and intramuscular administration in Crocodylus siamensis, a freshwater crocodile

The pharmacokinetics of meloxicam (MLX) remain largely unexplored in reptiles, particularly in Siamese crocodiles (Crocodylus siamensis). This study characterized the pharmacokinetic profiles of MLX following intravenous (IV) and intramuscular (IM) administration in Siamese crocodiles. Fifteen Siamese crocodiles were divided into three groups (n = 5) using a randomization procedure according to a parallel study design. MLX was administered IV at 0.2 mg/kg b.w. or IM at two different doses (0.2 mg/kg b.w. or 0.4 mg/kg b.w.). Plasma concentrations of MLX were measured using a validated high-performance liquid chromatography method with UV detection. The pharmacokinetic parameters were analyzed using a non-compartment model. The elimination half-life (t1/2λz) was long for all administration routes, with values of 132.34 hr (IV), 121.35 h (IM 0.2 mg/kg b.w.), and 181.44 hr (IM 0.4 mg/kg b.w.). The volumes of distribution (Vd) and clearance (Cl) after IV administration were 104.59 mL/kg and 0.55 mL/hr/kg, respectively. Based on these results, there was an extended t1/2λz of MLX in this species of freshwater crocodiles, highlighting significant differences in drug disposition compared to other reptilian and non-reptilian species. The findings contribute to an understanding of MLX pharmacokinetics in this animal species, and emphasize that the selection of the optimal dose of MLX should be considered based on disposition kinetics, efficacy, safety, and species-specific differences. Further investigation is required to identify the effective plasma concentration, which is critical for establishing the appropriate dose for the management of pain and inflammation.

Voriconazole Pharmacokinetics Administered at 4 mg/kg IM and IV in Nursehound Sharks (Scyliorhinus stellaris) Under Human Care

Fungal diseases, despite their low incidence in sharks and rays, are considered emerging diseases in this group of animals and can lead to high mortality rates despite treatment. The information available related to the treatment of fungal diseases in elasmobranchs is limited and is frequently based on the empirical knowledge provided by the professionals and clinicians working with these species. The use of azole antifungal drugs, especially voriconazole, has shown promise as a potential treatment option for fungal infections in elasmobranchs, with favorable outcomes in some registered cases. However, scientific knowledge regarding azole pharmacokinetics (PK) in fish remains limited, and despite the recent publication of a PK study with voriconazole in rays, there are still no published PK studies for azoles in sharks. In this study, voriconazole was administered at 4 mg/kg intravenously (IV) and intramuscularly (IM) to nursehound sharks (Scyliorhinus stellaris) (n = 6). Blood samples were collected before administration and at nine predetermined time intervals afterwards (0.25, 0.5, 1, 1.5, 2, 4,8,12, 24, and 36 h). Plasma concentrations were determined using a validated high-performance liquid chromatography (HPLC) method, and pharmacokinetic (PK) parameters were estimated using a non-compartmental model. The mean peak plasma concentrations (Cmax) ± SEM after IM administration was 3.00 ± 0.23 µg/mL. The volume of distribution (Vd) after IV and IM administration resulted in 1.39 ± 0.09 L/kg and 1.50 ± 0.18 L/kg, respectively, showing no statistically significant differences between the two routes. Clearance (Cl) values were 0.12 ± 0.01 mL/min after IV administration and 0.29 ± 0.05 mL/min after IM administration. No adverse effects were detected during the study or four weeks after administration. These results support the administration of IV and IM voriconazole in sharks; however, additional studies on toxicity and pharmacodynamics are necessary. Moreover, further research on the susceptibility of fungal pathogens affecting elasmobranchs is needed to establish an optimal dosing regimen for IM voriconazole in the treatment of mycosis in sharks.

Pharmacokinetics of the analgesic and anti-inflammatory drug meloxicam after administration of multiple doses to nursehound sharks (Scyliorhinus stellaris)

OBJECTIVE

To determine the pharmacokinetics of meloxicam in the nursehound shark (Scyliorhinus stellaris) during multiple dose administration.

STUDY DESIGN

Prospective experimental trial.

ANIMALS

A total of eight clinically healthy adult nursehounds (four males, four females).

METHODS

Meloxicam was administered intramuscularly at a dose of 1.5 mg kg-1 once daily for 7 days. Blood samples were collected from the caudal vein for pharmacokinetic analysis at 2.5 hours and 24 hours after drug administration. After a 4 week washout period, meloxicam was administered orally at the same dose at 12 hour intervals for three repeated doses. Blood samples were collected at 1, 2, 4, 6, 8, 12, 24, 36 and 48 hours after the first administration. Sharks were visually monitored during each study and 4 weeks afterwards for side effects or signs of toxicity. Time required to achieve steady state was assessed by visual inspection and statistical comparison of peak and trough concentrations using a Friedman test; comparison between sexes was performed using a Mann-Whitney U test and p-value was set at 0.05.

RESULTS

No animal died or showed clinical signs of toxicity during the study. Meloxicam administered orally did not produce detectable concentrations in plasma. After intramuscular administration, steady state was achieved after five doses, and mean trough and peak plasma concentrations at steady state were 1.76 ± 0.21 μg mL-1 and 3.02 ± 0.23 μg mL-1, respectively. Mean peak concentration accumulation ratio was 2.50 ± 0.22.

CONCLUSIONS AND CLINICAL RELEVANCE

This study shows that intramuscular posology produces plasma concentrations considered therapeutic for other species. However, meloxicam was not detected in plasma after oral administration. These results suggest that meloxicam administered intramuscularly may be a useful non-steroid anti-inflammatory drug in nursehound sharks. Further pharmacodynamic studies are needed to fully evaluate its clinical use in this species.

PHARMACOKINETICS OF MELOXICAM AFTER SINGLE ORAL AND INTRAMUSCULAR ADMINISTRATION IN CHINA ROCKFISH (SEBASTES NEBULOSUS)

Fish species are important for various purposes including aquaculture stock and display animals, but there are significant gaps in the medical knowledge regarding pharmacological parameters and effective pain management. Meloxicam is a nonsteroidal anti-inflammatory drug (NSAID) that has been studied in few teleost species and with several administration routes. However, these species were typically freshwater or euryhaline fish, and evaluation in marine species is lacking. The pharmacokinetic properties of meloxicam were determined in nine adult China rockfish (Sebastes nebulosus), presumed healthy based on physical examination and benign medical histories. Based on a pilot study, China rockfish were given 1 mg/kg meloxicam via IM injection in the epaxial musculature, and, after a 48-h washout period, 1 mg/kg meloxicam was given by PO gavage. Blood samples were collected from the caudal vein at baseline and at nine time intervals over a 48-h time period following administration of meloxicam. Plasma meloxicam concentrations were determined by reverse phase high-performance liquid chromatography, and noncompartmental analysis was performed. The mean peak plasma concentration after IM injection was 4.9 µg/ml, and the mean terminal half-life was 5.0 h. The mean peak plasma concentration after PO administration was 0.07 µg/ml. Based on these findings, IM injected meloxicam reaches plasma levels consistent with therapeutic concentrations in select mammals, and peak levels were maintained for ≤12 h. Single-dose PO administration failed to achieve similar concentrations, and clinical practicality is unknown. Further studies evaluating NSAID multidose regimes and their pharmacodynamic effects may provide additional dosing information.

Treatment of Pain in Fish

This chapter provides an overview of our current understanding of clinical analgesic use in fish. Recently, the efficacy and pharmacokinetics of several analgesic drugs for use in fish have been investigated, and the most important data indicates that μ-opioid agonist drugs (e.g, morphine) are consistently effective as analgesics across fish species. In addition, bath application of some analgesic drugs may be useful, which affords multiple methods for delivering analgesics to fish. Although few published studies of non-steroidal anti-inflammatory drugs administered to fish show promise, we have much to learn about the analgesic efficacy of most drugs in this class.

PHARMACOKINETICS OF MELOXICAM AFTER A SINGLE 1.5 MG/KG INTRAMUSCULAR ADMINISTRATION TO NURSEHOUND SHARKS (SCYLIORHINUS STELLARIS) AND ITS EFFECTS ON HEMATOLOGY AND PLASMA BIOCHEMISTRY

A single-dose meloxicam pharmacokinetic (PK) study was performed with eight clinically healthy nursehound sharks (Scyliorhinus stellaris) maintained under human care. Meloxicam was administered IM at a dosage of 1.5 mg/kg to six animals; two animals were administered elasmobranch physiological saline solution (EPSS) IM as a negative control group. Blood samples were obtained prior to and at 12 predetermined times during the first 36 h after administration. Effects on hematology and plasma biochemistry were compared prior to and 24 h after administration. No animal died or showed clinical signs during the study. A significant increase in creatinine kinase and aspartate aminotransferase was found in both EPSS and meloxicam groups and could be considered a direct consequence of sampling and handling required for the PK study. Observed mean time to maximum plasma concentration ± SEM was 2.58 ± 0.47 h and observed mean maximum plasma concentration ± SEM was 806 ± 66 ng/ml; mean terminal half-life ± SEM was 15.97 ± 1.20 h; mean residency time ± SEM was 23.40 ± 2.25 h. Area under the plasma concentration-versus-time curve extrapolated to infinity ± SEM was 15.52 ± 1.70 h·µg/ml. This study suggests that meloxicam 1.5 mg/kg IM in nursehound sharks is likely to result in clinically relevant plasma levels for periods of 24 h without producing significant alterations in blood analytics, although further PK studies with meloxicam IV in sharks are needed. Future PK and pharmacodynamic studies with different drugs and doses are needed in elasmobranchs to establish safe and effective treatment protocols.

Pharmacokinetics of the Anti-Inflammatory Drug Meloxicam after Single 1.5 mg/kg Intramuscular Administration to Undulate Skates (Raja undulata)

The therapy database currently used in elasmobranchs is still mostly based on empirical data, and there are few efficacy and safety studies supporting clinical practice. In this study, meloxicam pharmacokinetics (PK) were evaluated after a single 1.5 mg/kg IM administration to a group of seven clinically healthy adult undulate skates (Raja undulata Lacepède, 1802). Blood samples were collected before administration and at 15, 30, 60 and 90 min and 2, 4, 8, 12, 24 and 48 h after the IM injection. The meloxicam concentrations in plasma were determined using high-performance liquid chromatography, and PK parameters were calculated using a non-compartmental model approach. The mean ± SEM values of the main PK values were 1.84 ± 0.31 μg/mL for peak plasma concentration, 1.5 ± 0.24 h for time to maximum plasma concentration, 11.43 ± 2.04 h·µg/mL for area under the plasma concentration vs. time curve, 3.55 ± 0.65 h for elimination half-life, and 5.37 ± 0.94 h for mean residency time. No adverse reactions were detected. The relatively high plasma concentration and short time to maximum plasma concentration suggest that meloxicam could turn into an efficient analgesic and anti-inflammatory candidate drug to be used in skates. Further efficacy, pharmacodynamic, and multiple-dose studies with meloxicam are needed in elasmobranchs.

Pharmacokinetic Studies in Elasmobranchs: Meloxicam Administered at 0.5 mg/kg Using Intravenous, Intramuscular, and Oral Routes to Nusehound Sharks (Scyliorhinus stellaris)

Infectious and inflammatory diseases are the most frequently diagnosed pathologies in elasmobranchs maintained under human care. Non-steroidal anti-inflammatory drugs (NSAIDs) are frequently used in veterinary medicine for their anti-inflammatory, analgesic, and antipyretic properties. Meloxicam is a commonly prescribed NSAID in elasmobranchs, but there are still no published pharmacokinetic (PK) studies supporting its use in this group of animals. In this study, meloxicam was administered at a single dose of 0.5 mg/kg to eight healthy adult nursehound sharks (Scyliorhinus stellaris) intravenously (IV), intramuscularly (IM), and orally (PO), with a minimum 4-week washout period between administrations. Blood samples were obtained both beforehand and at predetermined times after each administration. Plasma concentrations were measured using a validated high performance liquid chromatography method, and PK data was obtained using a non-compartmental analysis. Meloxicam administered orally did not produce detectable concentrations in blood plasma, while mean peak plasma concentration was 0.38 ± 0.08 μg/ml after IM administration. The mean terminal half-life was 10.71 ± 2.77 h and 11.27 ± 3.96 h for IV and IM injections, respectively. The area under the curve extrapolated to infinity was 11.37 ± 2.29 h·μg/ml after IV injections and 5.98 ± 0.90 h·μg/ml after IM injections. Meloxicam administered IM had a mean absolute bioavailability of 56.22 ± 13.29%. These numbers support meloxicam as a promising drug to be used IM in nursehounds, questions the efficacy of its single PO use in elasmobranchs, elucidate the need for higher dosage regimes, and evidence the need for further PK studies in sharks and rays.

Fish Sedation and Anesthesia

Veterinarians often need to sedate or anesthetize fish to perform physical examinations or other diagnostic procedures. Sedation may also be required to transport fish. Painful procedures require complete anesthesia with appropriate antinociceptive agents. Regulations and withdrawal times apply to food animal species in many countries. Specific protocols are therefore warranted in commercial fish versus ornamentals. Tonic immobility of elasmobranchs and electric anesthesia should never be used to perform painful procedures. Anesthetic monitoring in fish remains challenging. This review summarizes ornamental fish anesthesia and discusses techniques used in the commercial fish industry and in field conditions.

Comparative Pharmacokinetics and Tissue Concentrations of Flunixin Meglumine and Meloxicam in Tilapia (Oreochromis spp.)

Evidence of pain perception in fish is well established, but analgesic use in aquaculture is limited. The objective was to investigate the comparative pharmacokinetics of flunixin administered intramuscularly (IM) and meloxicam administered IM or orally (PO) in tilapia. Two hundred and seventy fish were assigned to 1 of 3 treatment groups: flunixin meglumine IM (2.2 mg/kg); meloxicam IM (1 mg/kg); or meloxicam PO (1 mg/kg). Blood and tissue samples were collected from 6 fish per treatment at 14 time points for 10 days. Drug concentrations were determined using ultra-high-pressure liquid chromatography coupled with mass spectroscopy. Plasma concentration versus time data were analyzed with a non-compartmental approach using a commercially available software. Flunixin reached a mean maximum concentration (Cmax) of 4826.7 ng/mL at 0.5 h, had a terminal half-life (T1/2) of 7.34 h, and an area under the concentration–time curve extrapolated to infinity (AUCINF_obs) of 25,261.62 h·ng/mL. Meloxicam IM had a T1/2 of 9.4 h after reaching a Cmax of 11.3 ng/mL at 2 h, with an AUCINF_obs of 150.31 h·ng/mL. Meloxicam PO had a T1/2 of 1.9 h after reaching a Cmax of 72.2 ng/mL at 2 h, with an AUCINF_obs of 400.83 h·ng/mL. Tissue concentrations of both drugs were undetectable by 9 h. Flunixin reached a sufficient plasma concentration to potentially have an analgesic effect, while meloxicam, when administered at the given dosage, likely would not.

Pharmacokinetics and bioavailability of meloxicam in rainbow trout (Oncorhynchus mykiss) broodstock following intravascular, intramuscular, and oral administrations

The pharmacokinetics and bioavailability of meloxicam were investigated after single intravascular (IV), intramuscular (IM), and oral dose of 1 mg/kg in rainbow trout broodstock at 11 ± 1.2°C. A total of 36 healthy rainbow trout (Oncorhynchus mykiss) broodstock weighing 1.40 ± 0.26 kg was used for the investigation. Plasma concentrations of meloxicam were measured with high-performance liquid chromatography-ultraviolet detection, and pharmacokinetic parameters were calculated by non-compartmental analysis. The elimination half-life for IV, IM, and oral routes was 3.63, 4.55, and 2.95 h, respectively. The IV route for meloxicam showed the total clearance of 0.05 L/h/kg and volume of distribution at a steady state of 0.20 L/kg. The peak plasma concentration was 2.97 μg/ml for the IM route and 0.84 μg/ml for the oral route. The bioavailability was 78.45% for the IM route and 21.48% for the oral route. Meloxicam following IM and oral administration displayed short t_1/2ʎz . The short t_1/2ʎz could be an advantage for the short-term use in acute conditions. The IM route with the good bioavailability can be preferred for the treatment of various conditions. However, developing new oral formulations with the good bioavailability for meloxicam is necessary to minimize stress and trauma through minimal handling in rainbow trout broodstock.

Pharmacokinetics and Bioavailability of Carprofen in Rainbow Trout (Oncorhynchus mykiss) Broodstock

The aim of this study was to determine the pharmacokinetics of carprofen following intravenous (IV), intramuscular (IM) and oral routes to rainbow trout (Oncorhynchus mykiss) broodstock at temperatures of 10 ± 1.5 °C. In this study, thirty-six healthy rainbow trout broodstock (body weight, 1.45 ± 0.30 kg) were used. The plasma concentrations of carprofen were determined using high-performance liquid chromatography and pharmacokinetic parameters were calculated using non-compartmental analysis. Carprofen was measured up to 192 h for IV route and 240 h for IM, and oral routes in plasma. The elimination half-life (t1/2λz) was 30.66, 46.11, and 41.08 h for IV, IM and oral routes, respectively. Carprofen for the IV route showed the total clearance of 0.02 L/h/kg and volume of distribution at steady state of 0.60 L/kg. For IM and oral routes, the peak plasma concentration (Cmax) was 3.96 and 2.52 μg/mL with the time to reach Cmax of 2 and 4 h, respectively. The bioavailability was 121.89% for IM route and 78.66% for oral route. The favorable pharmacokinetic properties such as the good bioavailability and long t1/2λz for IM and oral route of carprofen suggest the possibility of its effective use for the treatment of various conditions in broodstock.

PHARMACOKINETIC, PHARMACODYNAMIC, AND TOXICOLOGY STUDY OF ROBENACOXIB IN RAINBOW TROUT (ONCORHYNCHUS MYKISS)

Postoperative antinociception control in fish is currently suboptimal, as commonly used antiinflammatory drugs last for only a few hours at tested temperatures. Therefore, long-acting anti-inflammatory drugs, such as robenacoxib, could improve the welfare of fish. The pharmacokinetics, duration of antinociceptive action, and potential adverse effects of robenacoxib were evaluated through two prospective randomized blinded trials in rainbow trout (Oncorhynchus mykiss). Six healthy rainbow trout received a single IM administration of robenacoxib (2 mg/kg), and two control fish received the same volume of saline IM. Blood samples were collected at predetermined time points for 5 d. Plasma robenacoxib concentrations were measured using high-performance liquid chromatography-high-resolution hybrid orbitrap mass spectrometry and noncompartmental pharmacokinetic analysis. Ten additional rainbow trout received an intralabial injection of 0.05 ml of 2% acetic acid following a previously validated nociceptive model. The treated group (n = 6) received 2 mg/kg of robenacoxib IM and the control group (n = 4) received an equivalent volume of saline IM. The behavior, appetite, and opercular rate of the fish were evaluated every hour for 5 h, then once daily for 3 d. All 12 treated trout and 6 controls underwent histopathologic evaluation. Average maximum plasma concentration (C_max) was 329.9 ± 137.3 ng/ml observed at 2.1 ± 0.7 h (T_max) and terminal half-life was 12.6 ± 2.27 h. Plasma concentrations described as antinociceptive in domestic carnivores were measured for 3-4 d. This dose was associated with a significant decrease in rocking behavior (P = 0.017). No adverse effects were detected clinically nor on histopathology. Robenacoxib administered IM at 2 mg/kg appears to be safe and may provide an antinociceptive effect in rainbow trout. This study presents a new therapeutic option to provide long-lasting antinociception in rainbow trout.

Pharmacokinetics of danofloxacin following intramuscular administration of a single dose in koi (Cyprinus carpio)

OBJECTIVE

To determine the pharmacokinetics of danofloxacin following IM administration of a single dose (10 mg/kg) in koi (Cyprinus carpio).

ANIMALS

69 healthy adult koi housed in a 980-L flow-through-system tank.

PROCEDURES

3 fish were kept as untreated controls, and the remaining 66 fish were assigned to 11 treatment groups with 6 fish/group. Fish in the treatment groups were given a single dose of danofloxacin (10 mg/kg) IM in the left epaxial musculature. Fifteen, 30, and 45 minutes and 1, 4, 12, 24, 72, 96, 120, and 144 hours after administration of danofloxacin, fish in each treatment group were euthanized, and blood samples and samples of liver, spleen, gill, anterior kidney, posterior kidney, skin and muscle, and scales were collected. Plasma and tissue drug concentrations were determined by liquid chromatography-tandem mass spectrometry, and noncompartmental pharmacokinetic analyses were performed. Tissues from the untreated control fish and fish euthanized 144 hours after danofloxacin administration were examined histologically.

RESULTS

Maximum plasma concentration (mean, 8,315.7 ng/mL) was reached approximately 45 minutes after danofloxacin administration; plasma elimination half-life was 15 hours. Danofloxacin was detected in all examined tissues from all 6 fish euthanized 15 minutes after drug administration and was detected in some tissues from 3 of the 6 fish euthanized 144 hours after drug administration. For all tissues, results of histologic examination were unremarkable.

CONCLUSIONS AND CLINICAL RELEVANCE

IM administration of a single dose (10 mg/kg) of danofloxacin in koi resulted in rapid absorption, with maximum plasma concentration reached approximately 45 minutes after drug administration; the drug could still be detected in some tissues 144 hours after administration.

Pharmacokinetics of Ketoprofen in Nile Tilapia (Oreochromis niloticus) and Rainbow Trout (Oncorhynchus mykiss)

The objective of this study was to document the pharmacokinetics of ketoprofen following 3 mg/kg intramuscular (IM) and intravenous (IV) injections in rainbow trout (Oncorhynchus mykiss) and 8 mg/kg intramuscular (IM) injection in Nile tilapia (Oreochromis niloticus). Plasma was collected laterally from the tail vein for drug analysis at various time intervals up to 72 h following the injection of ketoprofen. In trout, area under the curve (AUC) levels were 115.24 μg hr/mL for IM and 135.69 μg hr/mL for IV groups with a half-life of 4.40 and 3.91 h, respectively. In both trout and tilapia, there were detectable ketoprofen concentrations in most fish for 24 h post-injection. In tilapia, there was a large difference between the R- and S-enantiomers, suggesting either chiral inversion from R- to S-enantiomer or more rapid clearance of the R-enantiomer. AUC values of the S- and R-enantiomers were 510 and 194 μg hr/Ml, respectively, corresponding to a faster clearance for the R-enantiomer. This study shows that there were very high plasma concentrations of ketoprofen in trout and tilapia with no adverse effects observed. Future studies on the efficacy, frequency of dosing, analgesia, adverse effects, and route of administration are warranted.

ABSENCE OF ACUTE TOXICITY OF A SINGLE INTRAMUSCULAR INJECTION OF MELOXICAM IN GOLDFISH ( CARASSIUS AURATUS AURATUS): A RANDOMIZED CONTROLLED TRIAL

Meloxicam is a nonsteroidal anti-inflammatory drug with preferential cyclooxygenase-2 inhibitory activity. It is frequently used in veterinary medicine, including in fish species. The efficacy and safety of meloxicam, however, has not yet been reported in adult fish. The purpose of this study was to evaluate the acute toxicity of a single intramuscular injection of meloxicam in goldfish ( Carassius auratus auratus). Following 3 wk of acclimation, 32 goldfish were randomly assigned to two groups of 16 individuals. Fish from the treatment group received a single intramuscular injection of 5 mg/kg meloxicam, while the fish from the control group received a single intramuscular injection of a 0.9% sodium chloride solution using a similar volume (1 ml/kg). No external lesions, mortality, or modifications in behavior or position in the water column were noted during the following 72 hr. Three days after the initial injection, all fish were euthanized by immersion in a solution of tricaine methanesulfonate. Complete postmortem and histologic evaluations were performed for each fish. Hemorrhage and muscular necrosis were observed at the site of injection in fish from both groups. Multiple granulomas of undetermined etiology were detected in numerous organs from fish of both groups. No statistically significant differences were detected in regard to the lesions observed in these two groups. This study demonstrates that a single intramuscular injection of meloxicam at a dosage of 5 mg/kg does not cause acute toxicity in goldfish.

Overview of Drug Delivery Methods in Exotics, Including Their Anatomic and Physiologic Considerations

Drug delivery to exotic animals may be extrapolated from domestic animals, but some physiologic and anatomic differences complicate treatment administration. Knowing these differences enables one to choose optimal routes for drug delivery. This review provides practitioners with a detailed review of the currently reported methods used for drug delivery of various medications in the most common exotic animal species. Exotic animal peculiarities that are relevant for drug administration are discussed in the text and outlined in tables and boxes to help the reader easily find targeted information.

The Educated Guess: Determining Drug Doses in Exotic Animals Using Evidence-Based Medicine

Lack of species-specific pharmacokinetic and pharmacodynamic data is a challenge for pharmaceutical and dose selection. If available, dose extrapolation can be accomplished via basic equations. If unavailable, several methods have been described. Linear scaling uses an established milligrams per kilograms dose based on weight. This does not allow for differences in species drug metabolism, sometimes resulting in toxicity. Allometric scaling correlates body weight and metabolic rate but fails for drugs with significant hepatic metabolism and cannot be extrapolated to avians or reptiles. Evidence-based veterinary medicine for dose design based on species similarity is discussed, considering physiologic differences between classes.

Evidence-Based Advances in Aquatic Animal Medicine

Fish and aquatic invertebrates deserve evidence-based medicine. Pharmacologic information is available; most pharmacokinetic studies are derived from the aquaculture industry and extrapolated to ornamental fish. Conversely, advanced diagnostics and information regarding diseases affecting only ornamental fish and invertebrates require more peer-reviewed experimental studies; the examples of carp edema virus, sea star wasting disease, seahorse nutrition, and gas bubble disease of fish under human care are discussed. Antinociception is also a controversial topic of growing interest in aquatic animal medicine. This article summarizes information regarding new topics of interest in companion fish and invertebrates and highlights some future avenues for research.