PHARMACOKINETICS OF SINGLE INTRAMUSCULAR ADMINISTRATION OF CEFTIOFUR CRYSTALLINE FREE ACID IN AMERICAN ALLIGATORS (ALLIGATOR MISSISSIPPIENSIS).

A pharmacokinetic study of ceftiofur crystalline free acid sterile oil suspension (CCFA) was performed in six apparently healthy juvenile American alligators (Alligator mississippiensis). A single intramuscular dose of 30 mg/kg was administered in the triceps muscle. Blood samples were collected prior to treatment and at 4, 12, 24, 48, 72, 120, 144, 192, 288, and 366 h post administration. Plasma samples were analyzed for ceftiofur equivalent concentrations using liquid chromatography-mass spectrometry. Pharmacokinetic parameters were determined by noncompartmental analysis. Mean peak plasma concentration was 23.2 µg/ml (range, 16.0-27.9), median time to maximum concentration was 72 h (range, 72-120), mean area under the curve from 0 to 366 h postdose was 4.24 h · mg/ml (range, 3.54-4.97), and mean terminal half-life was 143 h (range, 90.8-220). Plasma concentrations were maintained above the minimum inhibitory concentration for this study of 2.0 µg/ml, which was established from similar CCFA pharmacokinetic studies in other reptilian species, through the end of the data collection of 366 h. Because of prolonged plasma concentrations, a dosing interval could not be established in this study. Future studies should include extended collection time points and multidose studies to determine dosing regimens.

Successful Treatment of a Cervical Injury and Myopathy Using Integrative Medicine Techniques in an Eclectus Parrot (Eclectus roratus) Following Cervical Entrapment.

A 2-year-old female eclectus parrot (Eclectus roratus) was presented for suspected cervical myopathy due to trauma. Severe ventroflexion of the cervical spine and mental depression were identified during the physical examination. The bird was responsive to stimuli but otherwise quiet. Plasma biochemistry results were suggestive of a myopathy, based on marked elevations of both aspartate transaminase (25 652 U/L) and creatine kinase (253 240 U/L). Whole-body radiographic images were unremarkable. Treatment was initiated with supportive therapy for presumptive shock, dehydration, pain, myopathy, and possible spinal swelling. Allopathic therapy included subcutaneous fluids; vitamins A, D, and E; dexamethasone sodium phosphate; hydromorphone; and gavage feeding to treat the acute inflammatory process and provide nutritional support during healing. Supportive care through the Integrative Medicine Department (Louisiana State University, Baton Rouge, LA, USA) was also performed on the patient. Photobiomodulation, acupuncture, Tui-na massage, and rehabilitation exercises were instituted to provide adjunct treatment for relieving pain, promoting muscle healing, improving patient demeanor, and improving cervical mobility. Integrative therapies were well tolerated by the patient, with no sedation required. By day 3, mentation had subjectively improved by 50% despite the persistent cervical ventroflexion. By day 8, the elevated serum enzyme activities had decreased, the patient could eat and drink on its own, and it could readily step up and seek attention during handling. The bird was able to lift its head and could hold it at approximately 50% of normal posture. Integrative therapies were continued throughout hospitalization. The bird was released from the hospital 20 days after initial intake, with head carriage in approximately 80% of the expected normal position and no apparent cervical pain based on palpation. This case demonstrates the benefits of integrative therapies as an adjunct treatment for cervical pain and myopathy in a psittacine species.

An outbreak of systemic chlamydiosis in farmed American alligators (Alligator mississippiensis).

Chlamydia spp are reported to causes systemic disease in a variety of hosts worldwide including few reports in crocodilians. Disease presentations vary from asymptomatic to fulminant disease, some of which are zoonotic. The aim of this study was to describe the pathological, immunohistochemical, and molecular findings associated with the occurrence of a previously unreported Chlamydia sp infection causing a major mortality event in farmed American alligators (Alligator mississippiensis). The outbreak presented with sudden death in juvenile alligators mainly associated with necrotizing hepatitis and myocarditis, followed by the occurrence of conjunctivitis after the initial high mortality event. The widespread inflammatory lesions in multiple organs correlated with intralesional chlamydial organisms identified via immunohistochemistry and confirmed by 23S rRNA-specific real-time quantitative polymerase chain reaction (qPCR) for Chlamydiaceae bacteria. By sequencing and phylogenetic analysis of the OmpA gene, this uncultured Chlamydia sp grouped closely with Chlamydia poikilothermis recently described in snakes. This study highlights the significance of such outbreaks in farmed populations. Enhanced epidemiological monitoring is needed to gain further insight into the biology of Chlamydia sp in alligators, disease dynamics, risk factors, and role of carrier animals.

Comparison of blind and endoscopic-guided orotracheal intubation on laryngeal and tracheal damage in domestic rabbits (Oryctolagus cuniculus).

OBJECTIVE: To compare blind and endoscopic-guided techniques for orotracheal intubation in rabbits and the number of intubation attempts with laryngeal/tracheal damage. STUDY DESIGN: Prospective, randomized experimental study. ANIMALS: A total of 24 healthy, intact female New Zealand White rabbits, weighing 2.2 ± 0.2 kg (mean ± standard deviation). METHODS: Rabbits were randomly assigned to blind (group B) or endoscopic-guided (group E) orotracheal intubation with a 2.0 mm internal diameter uncuffed tube. Intramuscular (IM) alfaxalone (7 mg kg-1), hydromorphone (0.1 mg kg-1) and dexmedetomidine (0.005 mg kg-1) were administered, and additional IM alfaxalone (3-5 mg kg-1) and dexmedetomidine (0.025 mg kg-1) were administered to rabbits with strong jaw tone. An intubation attempt was defined as the advancement of the endotracheal tube from the incisors to the laryngeal entrance. Tracheal intubation was confirmed via capnography and anesthesia was maintained with isoflurane for 2 hours. Following euthanasia, laryngeal and tracheal tissues were submitted for histopathology. Quality of anesthesia for orotracheal intubation, intubation procedure and tissue damage were numerically scored. Data were analyzed using Poisson regression, Spearman's correlation, t test, mixed anova, Mann-Whitney U test, Friedman and Chi square tests as appropriate. RESULTS: Median (range) intubation attempts were 2 (1-8) and 1 (1-3) for groups B and E, respectively. More rabbits in group E (91.6%) required additional alfaxalone and dexmedetomidine than in group B (16.7%). Median (range) cumulative histopathology scores were 6 (3-10) and 6 (2-9) for groups B and E, respectively. Scores were highest in the cranial trachea, but there was no difference between groups and no correlation between laryngeal/tracheal damage and the number of intubation attempts. CONCLUSIONS AND CLINICAL RELEVANCE: Both orotracheal intubation techniques were associated with laryngeal/tracheal damage. Although blind orotracheal intubation was associated with a higher number of attempts, the tissue damage was similar between groups.

EXTRAVASATION OF CONTRAST MEDIA AFTER SUBCARAPACIAL VESSEL INJECTION IN THREE CHELONIAN SPECIES.

The subcarapacial vessel is a popular site for venipuncture and intravenous medication administration in chelonians. Reports of adverse effects when using this site have increased, prompting evaluation of its safety. This study aimed to evaluate the anatomy of the subcarapacial vessel in 25 individual chelonians (2 box turtles, 3 red-eared sliders, and 20 red-footed tortoises) using computed tomography (CT). Individuals were sedated and administered contrast in the subcarapacial vessel. The vessel was visualized in 50% of the box turtles and red-footed tortoises, and 100% of the red-eared sliders. All species had contrast extravasation in the subarachnoid space, with red-footed tortoises having the largest percentage (70% compared to 50% and 33% of box turtles and red-eared sliders, respectively). Extravasation of contrast in the trachea or bronchi (70%) and lungs (80%) was seen in the red-footed tortoises only. Higher prevalence of contrast extravasation in the red-footed tortoises is likely because of anatomical differences, including a more cranially extending lung field and domed-shaped carapace compared to the other species. These findings highlight the risk associated with using the subcarapacial vessel for intravenous medication administration in certain species of chelonian.

COMPARISON OF SURFACE, ESOPHAGEAL, AND CLOACAL TEMPERATURES IN DIFFERENT REPTILE SPECIES.

The objective of this study was to compare surface, esophageal, and cloacal temperatures in awake iguanas, chameleons, and snakes at two different ambient temperatures and in alligators at one ambient temperature. Surface, esophageal, and cloacal temperatures were measured in all animals twice, with exception of the alligators, where temperatures were taken once. The first set of temperature readings was done at lower environmental temperature. An analysis of variance (ANOVA) with a mixed-effect model was used to analyze the temperature difference between esophageal and cloacal temperature against each other, and against surface temperature. Significance was set at P < 0.05. In all animals, surface, esophageal, and cloacal temperatures increased significantly (P < 0.0001) with increased ambient temperature. Esophageal and cloacal temperature were not significantly different from each other in iguanas and chameleons at lower environmental temperature or in snakes and chameleons at high ambient temperature. In snakes, esophageal temperature 26.1 ± 1.6°C was significantly higher than cloacal temperature 25.2 ± 0.9°C (P = 0.0016) at lower ambient temperature. In alligators no difference between esophageal and cloacal temperature was observed at the given ambient temperature. Surface temperature was significantly lower than esophageal and cloacal temperature in all species investigated, except iguanas at lower ambient temperature. The results of this study suggest that in healthy awake iguanas and chameleons at any ambient temperature and in snakes at high ambient temperature, cloacal temperatures are reflective of esophageal temperature in the species evaluated. In alligators, rectal temperature reflected esophageal temperature at the given ambient temperature. Surface temperature in contrast was underestimating esophageal temperature in all species investigated.

Effects of Fluorescent Lighting Versus Sunlight Exposure on Calcium, Magnesium, Vitamin D, and Feather Destructive Behavior in Hispaniolan Amazon Parrots (Amazona ventralis).

Low exposure to ultraviolet light, and resulting vitamin D deficiency, has recently been linked to autism spectrum disorder in people. Captive psittacine birds that exhibit feather destructive behavior share similarities with people affected by autism spectrum disorder, such as repetitive (stereotypies) and self-harming behaviors. The metabolic and psychological effects of housing pet parrots indoors without ultraviolet B lighting are not typically considered in animal husbandry or veterinary care. Calcifediol (serum vitamin D), ionized calcium, and ionized magnesium levels were compared between 10 Hispaniolan Amazon parrots (Amazona ventralis) housed indoors and 10 Hispaniolan Amazon parrots historically housed outdoors. Although ionized calcium and magnesium levels were not significantly different, calcifediol levels were significantly greater in the colony of birds housed outdoors. Further, these 2 research colonies of individually housed birds were feather scored. Subjectively, the birds that were housed indoors had greater self-inflicted feather damage than did those housed outdoors; however, the difference was not statistically significant.

Pneumonia in a Captive Central Bearded Dragon With Concurrent Detection of Helodermatid Adenovirus 2 and a Novel Mycoplasma Species.

A 4-year-old captive male central bearded dragon ( Pogona vitticeps) was presented for recurrent episodic dyspnea and anorexia with occasional expulsion of oral mucoid discharge. Despite empirical antimicrobial therapy and supportive care, the animal died and was submitted for autopsy. Defining histologic features included heterophilic and lymphocytic interstitial pneumonia, with occasional amphophilic intranuclear inclusions and prominent type II pneumocyte hyperplasia. Transmission electron microscopy revealed intranuclear 80-nm, nonenveloped, hexagonal viral particles within pneumocytes. Helodermatid adenovirus 2 (HeAdV2) was determined as the etiologic agent through pan-adenoviral consensus polymerase (PCR) chain reaction and sequencing. Nucleic acid from a novel Mycoplasma sp. (provisionally called Mycoplasma pogonae) was identified by pan-generic PCR targeting the mycoplasma 16S ribosomal RNA gene with sequencing and phylogenetic analysis. As bacteria morphologically consistent with Mycoplasma sp. were not observed by special stains and transmission electron microscopy, the detection of M. pogonae nucleic acid is of indeterminate significance; however, M. pogonae and HeAdV2 coinfection may have exacerbated disease.

COMPARISON OF ALLIGATOR SNAPPING TURTLE ( MACROCHELYS TEMMINCKII) PLASMA BIOCHEMICAL PROFILES FROM TWO CLINICAL ANALYZERS.

The interpretation of plasma biochemical profiles can be confounded by the methodologies by which samples are analyzed. The goal of this study was to compare agreement between two biochemical analyzers for plasma samples from alligator snapping turtles ( Macrochelys temminckii). Blood was obtained from the dorsal coccygeal vein of captive-reared, juvenile turtles ( n = 34), stored in lithium heparin tubes, and centrifuged to separate plasma from whole blood. Plasma samples were stored at 5°C prior to and in between analyses on VetScan (VetScan2, Abaxis, Union City, CA 94587, USA) and Olympus (Olympus AU640, Beckman Coulter, Brea, CA 92821, USA) analyzers within 2 hr of each other. Agreement between the VetScan and Olympus analyzers was investigated using Passing-Bablok regression analysis for aspartate aminotransferase, creatine kinase, glucose, calcium, phosphorus, total protein, albumin, globulin, potassium, and sodium. Agreement between the two analyzers was outside of acceptance limits and outside of clinical allowable error limits for all analytes as established by the American Society for Veterinary Clinical Pathology. The results of biochemical analyses of alligator snapping turtle plasma cannot be compared between VetScan and Olympus analyzers in a clinical setting. Comparison of biochemical analyses within analyzer units, however, may still be clinically useful. Future studies are warranted to investigate the precision of each analyzer for alligator snapping turtle plasma.

EFFECT OF ROUTINE HANDLING AND TRANSPORTATION ON BLOOD LEUKOCYTE CONCENTRATIONS AND PLASMA CORTICOSTERONE IN CAPTIVE HISPANIOLAN AMAZON PARROTS ( AMAZONA VENTRALIS).

Increased glucocorticoids cause a characteristic stress leukogram in mammalian taxa. It is assumed that avians exhibit a similar response, but to date, there have been no controlled studies to correlate serial endogenous corticosterone levels to hematologic values. An established flock of 18 Hispaniolan Amazon parrots ( Amazona ventralis) was used as a model in a crossover study. The treatment group was subjected to the stress of transport, restraint, and common clinical procedures with serial blood samples collected at 20-min intervals for hematology and corticosterone levels; the control group was sampled at the same intervals. Longitudinal data analysis was performed with linear mixed modeling. For all hematologic analytes, the baseline value had a significant positive effect on subsequent values (all P < 0.001). The white blood cell, heterophil, and eosinophil counts and heterophil to lymphocyte ratio increased over time in the treatment group, whereas it remained stable in the control group ( P = 0.016, P < 0.001, P < 0.001, P = 0.02, respectively, for the time*treatment effect). Lymphocyte absolute counts decreased over time, although not significantly; the decrease was significant for the relative lymphocyte count in the treatment group. Monocytes and basophils were not significantly altered. The treatment group had a higher mean corticosterone level overall than the control group by approximately 60% ( P = 0.008). The mean corticosterone level also increased over time in both groups by three- to fourfold ( P < 0.001) by 20 min then plateaued. These results demonstrate that some significant hematologic changes may arise with routine handling and transportation of birds and should be accounted for in hematologic interpretation of cell counts.

Diabetes Mellitus With Concurrent Cerebellar Degeneration and Necrosis in a Domestic Goose ( Anser anser domesticus).

A 5-year-old sexually intact male Toulouse goose ( Anser anser domesticus) was presented for ataxia, polyuria, and polydipsia. The goose was cachectic and exhibited head tremors. Results of plasma biochemical analysis and point-of-care glucometry revealed persistent hyperglycemia. Despite supportive care and oral glipizide, the goose died within 48 hours of presentation. Necropsy revealed severe pancreatic atrophy and fibrosis with regionally extensive cerebellar encephalomalacia and generalized Purkinje cell degeneration and necrosis. On a wet basis, hepatic zinc concentration was determined to be twice the reference interval by atomic absorption spectroscopy. Based on these findings, the pancreatic insufficiency with secondary diabetes mellitus was attributed to chronic zinc toxicosis. Despite birds' relative resistance to high blood glucose concentrations, prolonged hyperglycemia is suspected to have caused selective Purkinje cell degeneration and necrosis by glial activation, mitochondrial dysfunction, and glutamate toxicity, which resulted in the clinically observed motor deficits. This is consistent with experimental diabetic rat models. This case highlights the need for further investigation of the complex pathophysiology of diabetes mellitus in birds.

EFFECTS OF PLANT PROTEIN DIETS ON THE HEALTH OF FARMED AMERICAN ALLIGATORS (ALLIGATOR MISSISSIPPIENSIS).

The objective of this prospective, blinded study was to compare plasma biochemical values and gross and histologic evaluation of kidney and liver from American alligators ( Alligator mississippiensis ) fed extruded diets with protein derived from animal or plant sources. Alligators in two treatment groups were fed an extruded diet with protein derived primarily from plant products for 7 (n = 20) or 10 (n = 20) mo prior to harvest. A control group (n = 20) was fed a commercial diet with protein derived from animal products for the duration of the study. Plasma biochemistry panels were obtained and gross and histologic examination of kidney and liver tissues was conducted for each animal. No differences were found between alligators fed diets with animal or plant protein in terms of either biochemistry profiles or gross or histologic examination of kidney and liver. Plant-based diets, fed for up to 10 mo, do not appear to have any ill effects on the kidney or liver of American alligators.

MYCOBACTERIOSIS IN CAPTIVE PSITTACINES: A BRIEF REVIEW AND CASE SERIES IN COMMON COMPANION SPECIES (ECLECTUS RORATUS, AMAZONA ORATRIX, AND PIONITES MELANOCEPHALA).

In 2015, three psittacines were presented within 30 days, each with differing clinical signs and patient histories. A 13-yr-old male eclectus parrot (Eclectus roratus) was presented for weakness, depression, and acute anorexia. On presentation it was determined to have a heart murmur, severely elevated white blood cell count (93.9 103/µl) with a left shift (2.8 103/µl bands), and anemia (30%). Severe hepatomegaly was noted on radiographs, ultrasonography, and computed tomography. A cytological sample of the liver obtained through a fine needle aspirate revealed intracellular acid-fast bacilli identified as Mycobacterium avium. A 20-yr-old female double yellow-headed Amazon parrot (Amazona oratrix) was presented for a 1-mo history of lethargy and weight loss despite a good appetite. The parrot's total white blood cell count was 16.8 103/µl and the PCV was 35%. Following its death, a necropsy revealed a generalized granulomatous condition that involved the small intestines, lungs, liver, spleen, and medullary cavities of the long bones, with intracellular acid-fast bacilli identified as Mycobacterium genavense. The third case, an 18-mo-old female black-headed caique (Pionites melanocephala), was presented with a 1-day history of lethargy and depression. On presentation, the caique had a heart murmur, distended coelom, palpable thickening of the coelomic organs, and increased lung sounds. Following the caique's death, a complete necropsy revealed mycobacteriosis of the liver, spleen, small intestines, pericardial fat, and bone marrow. The infection was identified as Mycobacterium genavense. The importance of advances in Mycobacterium spp. identification, continued presence of this organism in captive avian populations, difficulty in obtaining a definitive antemortem diagnosis, and conflicting recommendations regarding treatment are thought-provoking areas of focus in this case series.

A Novel Surgical Approach to Avian Femorotibiotarsal Luxation Repair.

A 3-month-old male umbrella cockatoo (Cacatua alba) was presented because of acute non-weight-bearing lameness of the right leg. Marked soft tissue swelling was present around the femorotibiotarsal (stifle) joint, and the radiographic diagnosis was right medial femorotibiotarsal subluxation. Surgical management was elected, and the stifle joint was approached via a lateral parapatellar incision. Joint exploration revealed damage to the lateral meniscus, tendon of origin of the cranial tibial muscle, and cranial cruciate ligament. After debriding the disrupted meniscus, the stifle joint was anatomically reduced. The femorotibiotarsal joint was stabilized by using a lateral extracapsular suture in a modified technique using a self-tapping cortical screw in the lateral femoral condyle and a hole through the proximal tibiotarsus. The bird regained function of the femorotibiotarsal joint for 3 months after surgery, allowing sufficient time for the bird to establish a physiologic perching angle so that ankylosis occurred to maintain functionality of the leg as a unit. This combination of orthopedic techniques adapted from techniques commonly used in small companion-animal species may be considered to provide young birds with femorotibiotarsal luxations and subluxation a good quality of life despite ankylosis of the joint.

Survey of ophthalmic anterior segment findings and intraocular pressure in 95 North American box turtles (Terrapene spp.).

OBJECTIVE: To describe the ophthalmic biomicroscopy findings and intraocular pressures (IOP) in a captive population of box turtles and to determine whether a relationship exists between body morphometrics or health status and IOP. PROCEDURES: Hundred and three box turtles (69 Gulf coast, 24 three-toed, one ornate, one eastern, and eight unidentified) were triaged into three different color-coded groups: green (healthy), yellow (abnormal physical examination with no need for immediate care), and red (immediate care required). Both eyes were evaluated by rebound tonometry and slit-lamp biomicroscopy. Body weight and morphometric data were recorded. RESULTS: Intraocular pressures measurements were available for 190 eyes, slit-lamp biomicroscopy was available for 170 eyes, and morphometric data were available for 81 turtles. IOP in Gulf coast turtles (138 eyes) was 6.7 ± 1.4 mmHg OU. IOP in three-toed turtles (48 eyes) was 8.3 ± 1.5 mmHg OU, which was significantly higher than in Gulf coast turtles (P < 0.0001). No significant IOP differences were noted between genders in both subspecies (P = 0.768). There was a correlation between IOP and health status in three-toed turtles only. There was a mild negative correlation between morphometrics and IOP in Gulf coast and three-toed turtles. Fifteen of 87 turtles had unilateral corneal or lenticular opacities; 3/87 had bilateral corneal or lenticular disease; and 3/87 had adnexal abnormalities. CONCLUSIONS: Different subspecies of box turtles have different normal intraocular pressures as measured by rebound tonometry, which was influenced by the animals' health status in one subspecies. Some morphometric parameters were found to be associated with IOP. Box turtles are often affected with ophthalmic abnormalities of unknown clinical significance.

Comparison of Calculated Radiation Delivery Versus Actual Radiation Delivery in Military Macaws (Ara militaris).

The skin and oral cavity are common sites of neoplasia in avian species. Radiation therapy has been described for the treatment of these tumors in birds; however, its observed effectiveness has been variable. One possible explanation for this variability when radiation is used to treat the head is the unique anatomy of the avian skull, which contains an elaborate set of sinuses not found in mammalian species. To compare a calculated dose of radiation intended to be administered and the actual amount of radiation delivered to the target area of the choana in 3 adult military macaws (Ara militaris), computed tomography scans were obtained and the monitor unit was calculated to deliver 100 cGy (1Gy) by using radiation planning software. The birds received 3-4 radiation treatments each from a megavoltage radiation therapy unit. A thermoluminescent dosimetry chip (TLD) placed in the choana of the birds was used to measure the amount of ionizing radiation delivered at each treatment. The TLDs were kept in place using Play-Doh as a tissue analog. The actual dose of radiation delivered was lower than the 100-cGy calculated dose, with the 95% confidence limits of predicted bias values between 2.35 and 5.39 (radiation dose from 94.61 to 97.65 cGy). A significant difference was identified between the actual amount of radiation delivered and the calculated radiation goal (P < .001). None of the TLDs received the intended dose of 100 cGy of radiation. The results revealed that the amount of radiation delivered did not reach intended levels. Because the combination of the significance of this discrepancy and the standard dose inhomogeneity could lead to greater than 10% dose inhomogeneity, future investigation is warranted for accurate dose calculation and efficacy of radiation therapy for neoplasia at the lumen of the choana in birds.

Cardiovascular tolerance of intravenous lidocaine in broiler chickens (Gallus gallus domesticus) anesthetized with isoflurane.

OBJECTIVE: To determine the cardiovascular effects of lidocaine infused intravenously (IV) in broiler chickens. STUDY DESIGN: Two phase study: Phase 1, randomized up-and-down study to determine effective dose 50 (ED50) for lidocaine; Phase 2, prospective randomized study to determine the cardiovascular effects of lidocaine. ANIMALS: Seventeen Ross-708 broiler chickens (Gallus gallus domesticus) [11 chickens (Phase 1) and 6 chickens (Phase 2)], weighing 2.6-4.3 kg. METHODS: After induction of anesthesia with isoflurane and placement of monitoring equipment including invasive blood pressure, chickens were administered lidocaine IV. During Phase 1, using an up-and-down design, each animal received a variable dose selected based on the response of the previous animal. During Phase 2, each animal was administered 6 mg kg(-1) of lidocaine IV over 2 minutes. Clinically irrelevant cardiovascular effects were defined as a relative decrease of heart rate (HR) and mean blood pressure (MAP) <30% subsequent to IV lidocaine administration. The ED50 was defined as the dose rate that would cause clinically irrelevant cardiovascular depression in 50% of the population. RESULTS: During Phase 1, using an up-and-down study design (n = 11), the ED50 of lidocaine was determined to be 6.30 mg kg(-1) and 6.22 mg kg(-1) (95% confidence interval, 5.30-7.13 mg kg(-1)), when calculated by Dixon's up-and-down method, and logistic regression, respectively. During Phase 2, following infusion of lidocaine (6 mg kg(-1)), no clinically relevant effects on HR or MAP were detected in any animal. CONCLUSIONS AND CLINICAL RELEVANCE: Previous reports state that the dose of lidocaine used in birds should be ≤4 mg kg(-1). In this study, 6 mg kg(-1) of lidocaine injected IV was not associated with adverse cardiovascular effects. These results suggest that the dose of 4 mg kg(-1) can be exceeded, at least in chickens, and opens the possibility of other therapeutic uses for lidocaine in birds.

Plasma Drug Concentrations of Orally Administered Rosuvastatin in Hispaniolan Amazon Parrots (Amazona ventralis).

Atherosclerotic diseases are common in pet psittacine birds, in particular Amazon parrots. While hypercholesterolemia and dyslipidemia have not definitely been associated with increased susceptibility to atherosclerosis in parrots, these are important and well-known risk factors in humans. Therefore statin drugs such as rosuvastatin constitute the mainstay of human treatment of dyslipidemia and the prevention of atherosclerosis. No pharmacologic studies have been performed in psittacine birds despite the high prevalence of atherosclerosis in captivity. Thirteen Hispaniolan Amazon parrots were used to test a single oral dose of 10 mg/kg of rosuvastatin with blood sampling performed according to a balanced incomplete block design over 36 hours. Because low plasma concentrations were produced in the first study, a subsequent pilot study using a dose of 25 mg/kg in 2 Amazon parrots was performed. Most plasma samples for the 10 mg/kg dose and all samples for the 25 mg/kg dose had rosuvastatin concentration below the limits of quantitation. For the 10 mg/kg study, the median peak plasma concentration and time to peak plasma concentration were 0.032 µg/mL and 2 hours, respectively. Our results indicate that rosuvastatin does not appear suitable in Amazon parrots as compounded and used at the dose in this study. Pharmacodynamic studies investigating lipid-lowering effects of statins rather than pharmacokinetic studies may be more practical and cost effective in future studies to screen for a statin with more ideal properties for potential use in psittacine dyslipidemia and atherosclerotic diseases.

Evaluation of metomidate hydrochloride as an anesthetic in leopard frogs (Rana pipiens).

Metomidate hydrochloride is an imidazole-based, nonbarbiturate hypnotic drug primarily used as an immersion sedation and anesthetic agent in freshwater and marine finfish. To the authors' knowledge, there is no documentation in the literature of its use in amphibians. In this study, 7 male and 4 female leopard frogs (Rana pipiens) were induced with metomidate hydrochloride via immersion bath at a concentration of 30 mg/L for 60 min. The pH of the induction solution ranged from 7.63 to 7.75. Each frog was then removed from the induction solution, rinsed, and recovered in 26.6 degrees C amphibian Ringer's solution. After 210 min in the Ringer's solution, the frogs were transferred to moist paper towels for recovery. Heart rate, gular and abdominal respiration rates, righting reflex, superficial and deep pain withdrawal reflexes, corneal and palpebral reflexes, and escape response were monitored and recorded at defined intervals during both induction and recovery. The average time to loss of righting reflex and escape response was 17.36 min and 17.82 min, respectively. Metomidate produced clinical sedation in all frogs (n = 11). Surgical anesthesia was achieved in only 27% (3/11), with an anesthetic duration that ranged from 9 to 20 min. Recovery times were extremely prolonged and varied, with a range from 313 min to longer than 600 min. The findings of this study indicate that metomidate hydrochloride is unsuitable as a sole anesthetic agent in leopard frogs, and further research is needed to evaluate its suitability in other amphibians.