Effects of meloxicam on hematologic and plasma biochemical analysis variables and results of histologic examination of tissue specimens of Japanese quail (Coturnix japonica)

Determining the Pharmacokinetic Properties of Two Different Doses of Meloxicam in Barred Owls (Strix varia)

Anthropogenic activities have negatively affected many birds, including owls. The Wildlife Hospital of Louisiana (WHL) has seen a 3.2-fold increase in barred owl (Strix varia) cases over the past eight years (2023, 134; 2015, 42). Because most of these animals present with traumatic injuries, analgesics should be considered in their treatment plan. To date, no study has measured the pharmacokinetics of an analgesic in barred owls. The goals of this study were to determine the harmonic means, times to maximum concentration, and elimination half-lives for single 1 mg/kg and 2 mg/kg intramuscular doses of meloxicam. Twelve barred owls (1 mg/kg, n = 6; 2 mg/kg, n = 6) admitted to the WHL and determined to be clinically normal based on examination and blood work were recruited for this study. Meloxicam was administered intramuscularly, and blood samples were collected intermittently over 12 h to measure plasma concentrations using high-performance liquid chromatography. Both doses had rapid elimination half-lives (1 mg/kg, 0.99 ± 0.1 h; 2 mg/kg, 1.07 ± 0.43 h) and were below the limits of quantification (0.1 µg/mL) by 6-12 h. Based on these results, 1 and 2 mg/kg doses of meloxicam were found to produce plasma concentrations below therapeutic concentrations for less than four hours, making current twice-daily recommended dosing intervals unlikely to provide desired analgesia.

Drug prescription pattern in exotic pet and wildlife animal practice: a retrospective study in a Spanish veterinary teaching hospital from 2018 to 2022

Exotic companion animals have had an important role in our society since ancient times. Preserving animal health is necessary to do a responsible use of veterinary medicines. This study aimed to describe the prescription patterns of drugs in exotic pets and wildlife animals attending the Veterinary Teaching Hospital of the University of León (HVULE). A retrospective study was carried out between 2018 and 2022. Birds were the largest group of exotic animals attending the HVULE. Visits were related to emergency reasons and for musculoskeletal disorders. One-third of the animals were eventually euthanised. Regarding pharmacological treatments, the most frequently active ingredients used were pentobarbital, isoflurane, meloxicam, and within antibiotics, marbofloxacin (category B in the classification of European Medicines Agency).

Pharmacokinetics and bioavailability of meloxicam in Pekin ducks following intravenous, intramuscular and oral administration

OBJECTIVE

To determine the pharmacokinetics and bioavailability of meloxicam following intravenous (IV), intramuscular (IM), and oral administrations at a dose of 1.0 mg kg-1 in Pekin ducks.

STUDY DESIGN

Randomized experimental trial.

ANIMALS

A total of 18 clinically healthy male Pekin ducks.

METHODS

Pekin ducks were randomly assigned to three groups of six ducks: IV, IM and oral. Meloxicam (1.0 mg kg-1) was administered to each Pekin duck. A non-compartmental analysis was used to evaluate pharmacokinetic parameters.

RESULTS

No local or systemic adverse effects were observed in any bird. Meloxicam was detected in the plasma up to 120 hours following IV, IM or oral administration. The elimination half-life of the IV route was slightly shorter than that of the IM and oral routes (p < 0.05). Following IV administration, volume of distribution at steady state and total clearance were 133.17 mL kg-1 and 6.68 mL kg-1 hour-1, respectively. The mean absorption time was 2.29 hours for IM and 1.13 hours for oral route. There were significant differences between IM and oral administration for the peak plasma concentration (Cmax), time to reach Cmax and bioavailability (p < 0.05).

CONCLUSIONS AND CLINICAL RELEVANCE

Meloxicam showed long elimination half-life and high bioavailability following IM and oral administration. Meloxicam in Pekin ducks provided the effective therapeutic concentration indicated in other species for up to 48 hours. However, there is a need to determine the clinical efficacy of meloxicam in Pekin ducks.

Urine Output Monitoring and Acute Kidney Injury in Non-mammalian Exotic Animal Critical Care

Acute kidney injury (AKI) is a sudden, severe decrease in kidney function which can occur in any species. There are various causes of AKI, some of which are seen in domestic species and some that are unique to birds, reptiles, and amphibians. These species present unique challenges with AKI management, such as differences in anatomy and physiology, intravenous and urinary catheterization, repeated blood sampling, and their tendency to present in advanced states of illness. This article will discuss AKI, diagnosis, treatment, and prognosis for non-mammalian exotic species.

Evaluation of histo-toxicity of nimesulide in Black Kites (Milvus migrans): a pharmacodynamic study

The present experimental work was conducted to elucidate the toxicity of nimesulide at three different doses in black kites (Milvus migrans). M. migrans is one of the most common raptors near human habitations. The goal of the current investigation was to determine whether nimesulide is similarly hazardous to raptors as was diclofenac sodium and to investigate the acute oral toxicity of nimesulide in these birds. For this study, eight adult male black kites (M. migrans) were randomly divided into four groups. M. migrans in the control group (n = 02) were not treated with nimesulide. The other three groups were given nimesulide doses. The birds in the first (n = 02) were declared the control group. The second (n = 02), third (n = 02), and fourth groups were administered nimesulide at a low, medium, and high dose of 2, 4, and 6 mg/kg live body weight of bird/day, respectively, for 10 days. Nimesulide-addled birds became listless and despondent, then anorexic. The birds were standing there with their eyes closed and showing no signs of life. There was an increase in saliva production, a slowing of breathing, and dilated pupils. No clinical signs were observed in the control group. No mortality was seen in the control or treated groups. The control group did not show lesions of gout, but black kites intoxicated with nimesulide at 2, 4, and 6 mg/kg live body weight of bird/day showed inflammation, apoptosis, hemorrhage, necrosis, and leukocytic infiltration tissues of the liver, kidney, and heart of black kites (M. migrans) treated with different concentrations of nimesulide. The treated groups also showed apoptosis of myofibrils and hyperplasia. The hypertrophy, atrophy, fibrosis, necrosis of skeletal muscles and hemorrhage were prominent in the muscles of black kites (M. migrans) intoxicated with nimesulide. All observed histological alterations got worse in a dose-related way. There was no significant difference in AST, ALT, ALP, serum uric acid, but a significant difference was observed in the values of serum urea (p = 0.001) and serum creatinine (p = 0.019).

Effects on hematology and blood biochemistry profile of intramuscular meloxicam injection in Brahminy kite and Barn owl

BACKGROUND

Meloxicam is used widely for exotic animal analgesia, but its toxicity in common raptor species in Thailand is unclear.

OBJECTIVES

This study evaluated the single-dose effect of intramuscular meloxicam in common raptor species in Thailand for short-term and long-term periods.

METHODS

Twenty-two raptors were administered a single 1 mg/kg dose of meloxicam individually via intramuscular injection. The following were evaluated: clinical appearance, body weight, body condition score, body temperature, fecal appearance, complete blood cell count, and biochemistry panel before (day 0) and after the injection (1, 7, and 30 days). The collected samples were categorized into three groups: Brahminy kite (Haliastur indus) (n = 10), adult Barn owl (Tyto javanica) (n = 4), and juvenile Barn owl (n = 8).

RESULTS

None of the raptors in the study groups showed any abnormalities. The hematological profiles were significantly different in the short-term period (day 1 and day 7). The creatinine, aspartate aminotransferase, and creatinine kinase increased in several groups. On the other hand, the packed cell volume decreased in the Brahminy kite and juvenile Barn owl groups. According to the findings, an intramuscular injection of 1 mg/kg meloxicam affected the blood biochemistry panel of the muscle, but the affected raptors recovered within one week.

CONCLUSIONS

An intramuscular injection of meloxicam at a single 1 mg/kg dose in Brahminy kites and Barn owls was not associated with the morbidity, hepatotoxicity, gastrointestinal toxicity, and nephrotoxicity in the short- and long-term periods.

Modulating disease phenotype in a songbird: A role for inflammation in disease tolerance?

Individual animals vary greatly in their responses to infection, either killing off the invading pathogen (resistance) or minimizing the per-pathogen costs of infection on host fitness (tolerance). Though we understand little about the physiological drivers of tolerance in wild animals, phenotypically, it manifests as milder clinical signs of disease. Here, we use a well-described disease system, finch mycoplasmosis, to evaluate the role of inflammation in disease tolerance. House finches (Haemorhous mexicanus) infected with the bacterial pathogen Mycoplasma gallisepticum (MG) develop conjunctival pathology that satisfies the cardinal signs of inflammation. We report on a captive trial performed in 2016 and replicated in 2018 that tested whether chemotherapeutics, specifically nonsteroidal anti-inflammatory drugs (NSAIDs), can reduce lesion severity, thus pushing individuals toward more tolerant phenotypes. Though birds treated with NSAIDs in the first trial developed milder pathology per unit pathogen load, we found no effect of treatment in the second trial, perhaps due to natural variation in baseline tolerance within the source population across years. Second-trial control birds developed markedly milder pathology than first-year controls, suggesting that the effect of trial swamped the effect of treatment in this study. Moving forward, using birds from a population in which the disease is absent or only recently emerged-and so tolerance has not yet been selected for-may better elucidate the role of pro-inflammatory mediators in disease tolerance.

Treatment of Pain in Birds

This article provides an overview of the current understanding of evidence-based clinical analgesic use in birds. The field of avian analgesia has dramatically expanded during the last 20 years, affording more options for alleviating both acute and chronic pain. These options include opioids, nonsteroidal anti-inflammatory drugs, local anesthetics, and/or other drugs like gabapentin, amantadine, and cannabinoids, acting at different points in the nociceptive system thereby helping to provide greater pain relief while reducing the risk of adverse effects when combined.

Pharmacokinetics of intravenous meloxicam, ketoprofen and tolfenamic acid in chukar partridge (Alectoris chukar)

1. The aim of this study was to determine the pharmacokinetics of meloxicam (MLX, 1 mg/kg body weight (BW)), ketoprofen (KETO, 2 mg/kg BW), and tolfenamic acid (TA, 2 mg/kg BW) in chukar partridge (Alectoris chukar) following intravenous (IV) administration.2. Twenty-four healthy chukar partridges were randomly divided into three equal groups (n = 8) as MLX, KETO and TA. Plasma concentrations of MLX, KETO and TA were measured using high-performance liquid chromatography-ultraviolet detection and analysed using non-compartmental analysis.3. No adverse effects were determined in chukar partridges after IV administration of MLX, KETO and TA. MLX, KETO and TA were detected in plasma up to 10, 12 and 12 h, respectively. The terminal elimination half-life of MLX, KETO and TA was 1.22, 1.77 and 1.95 h, respectively. MLX, KETO and TA exhibited volumes of distribution at a steady-state of 0.03, 0.23 and 0.41 l/kg BW, respectively. The total plasma clearance of MLX, KETO and TA was 0.02, 0.11 and 0.15 l/h/kg, respectively. The extraction ratios for MLX, KETO and TA were calculated as 0.002, 0.011 and 0.016, respectively.4. MLX, KETO and TA offer treatment in chukar partridges for various conditions with an absence of adverse reactions and properties such as short elimination half-life and low volume of distribution. However, there is a need to establish the safety and adverse effects of repeated administration, pharmacokinetics of other administration routes and pharmacological efficacy of MLX, KETO and TA in chukar partridges.

Pharmacokinetics of a Single Dose of Oral Meloxicam in Rehabilitated Wild Brown Pelicans (Pelecanus occidentalis)

Because of concerns regarding potential adverse effects of meloxicam in pelicans reported by several zoos and wildlife rehabilitation facilities, this study was undertaken to determine the pharmacokinetics of a single oral dose of meloxicam in brown pelicans (Pelecanus occidentalis). A pilot study was performed with 6 apparently healthy wild adult brown pelicans of unknown sex during rehabilitation, administered a single oral dose of meloxicam at 0.2 mg/kg. Plasma drug concentrations were monitored for 24 hours but failed to capture the elimination phase of the drug. Consequently, a principal study monitored plasma concentrations for 120 hours. Six additional adult wild brown pelicans, 3 males and 3 females, approaching releasable condition in rehabilitation were split into 3 groups and each orally administered 0.2 mg/kg meloxicam. Blood samples were collected at baseline and at 4 additional time points that differed between groups. Plasma concentrations were measured with liquid chromatography-mass spectrometry. The mean maximum plasma concentration was 1.22 µg/mL and was achieved at 24 hours after drug administration. The elimination half-life was 36.3 hours, the longest reported to date for any avian species. Further studies are needed to determine the pharmacokinetics of multiple doses of meloxicam and other routes of administration, as well as the pharmacodynamics and safety profile of meloxicam in brown pelicans. On the basis of the results of these investigations, caution is advised when dosing brown pelicans with meloxicam until more studies are completed. By extrapolation, close taxonomic relatives in the order Pelecaniformes may also warrant additional studies.

Pharmacokinetics of meloxicam, carprofen, and tolfenamic acid after intramuscular and oral administration in Japanese quails (Coturnix coturnix japonica)

The aim of this study was to determine the pharmacokinetics of meloxicam (MLX), carprofen (CRP), and tolfenamic acid (TA) in Japanese quails (Coturnix coturnix japonica) following intramuscular (IM) and oral administration at doses of 1, 10, and 2 mg/kg, respectively. A total of 72 quails were randomly divided into 3 equal groups as MLX, CRP, and TA. Each group was separated into two sub-groups that received IM and oral administration of each drug. Plasma concentrations of MLX, CRP, and TA were determined using HPLC-UV and analyzed by non-compartmental method. The t_1/2ʎz and MRT of MLX, CRP, and TA after oral administration were similar to those after IM administration. The V_darea /F of MLX, CRP, and TA after IM administration was 0.28, 2.05, and 0.20 L/kg. The Cl/F of MLX, CRP, and TA after IM administration was 0.12, 0.19, and 0.09 L/h/kg. MLX, CRP, and TA after oral administration showed significantly lower C_max and longer T_max compared with IM administration. The relative bioavailability of MLX, CRP, and TA following oral administration in quails was 76.13%, 61.46%, and 57.32%, respectively. The IM and oral route of MLX, CRP, and TA can be used for the treatment of various conditions in quails. However, further research is necessary to determine the pharmacodynamics and safety of MLX, CRP, and TA before use in quails.

Diseases of the Avian Urinary System

Diseases of the renal system can be caused by infectious and noninfectious processes. Creating a relevant differential diagnosis for kidney disease in the live or dead bird requires a structured approach where the list of differentials is narrowed based on the signalment of the bird; its history, including its diet and management; physical findings; and other diagnostic findings. This article aims to provide the reader not only a list of the diseases that occur in birds but also the guidelines on when a disease should be considered in a differential.

Pharmacokinetics and Safety of Intramuscular Meloxicam in Zebra Finches (Taeniopygia guttata)

Meloxicam is the most frequently used NSAID in birds; however, its elimination t_1/2 is highly variable among species. Because zebra finches that require analgesia could benefit from receiving meloxicam, we performed a pharmacokinetic study involving a single intramuscular dose of 1 or 2 mg/kg. Data analysis showed that C_max, t_1/2, and elimination rate constants were not significantly different between the 2 doses. In contrast, C_max for 1- and 2-mg/kg doses of meloxicam approached a significant difference, and those for AUC_0-∞ were significantly different. Importantly, a plasma concentration of 3500 ng/mL, considered a target level for meloxicam in other avian species, was maintained for approximately 9.5 h in finches that received 2 mg/kg, which was 4 h longer than in birds given 1 mg/kg. Both doses reached low plasma concentrations by 12 h after administration. Subsequently, 8 total doses of 1 or 2 mg/kg were administered to birds at 12-h intervals; these regimens caused no significant changes in select biochemical analytes or the Hct of meloxicam-treated birds. In addition, histopathologic changes for injection sites, kidney, liver, proventriculus, and ventriculus were minimal and similar between control and experimental groups after the multiple doses. These results suggest a 12-h or more frequent dosing interval is likely needed in zebra finches and that meloxicam at 1 or 2 mg/kg IM twice daily for 4 d is safe. The higher dose might provide longer analgesia compared with the lower dose, but a pharmacodynamics evaluation of meloxicam in zebra finches is needed to confirm analgesic efficacy.

PHARMACOKINETICS OF A SUSTAINED-RELEASE FORMULATION OF MELOXICAM AFTER SUBCUTANEOUS ADMINISTRATION TO AMERICAN FLAMINGOS ( PHOENICOPTERUS RUBER)

Meloxicam is commonly used in avian medicine to relieve pain and inflammation, but the recommended dosing frequency can be multiple times per day, which can contribute to stress during convalescence. In this study, the pharmacokinetics of a sustained-release formulation of meloxicam were determined after subcutaneous administration of a single 3-mg/kg dose to eight healthy adult American flamingos ( Phoenicopterus ruber). Blood samples were collected before (time 0) and at 0.5, 1, 4, 8, 12, 24, 48, 96, and 120 hr after drug administration. Analysis of meloxicam in plasma samples was conducted with the use of reversed-phase high-performance liquid chromatography, and pharmacokinetic parameters were calculated by noncompartmental analysis. Plasma concentrations reached a mean maximum (±standard deviation) of 7.65 (±2.39) μg/ml at 0.56 (±0.18) hr with a terminal half-life of 1.76 (±1.41) hr. Based on these findings, this sustained-release formulation of meloxicam does not extend the interval between treatments as compared to the regular formulation, so it is not recommended in American flamingos at this time.

Pharmacokinetics of a Sustained-release Formulation of Meloxicam After Subcutaneous Administration to Hispaniolan Amazon Parrots (Amazona ventralis)

Meloxicam has been shown to have a safe and favorable pharmacodynamic profile with individual variability in Hispaniolan Amazon parrots (Amazona ventralis). In the current study, we determined the pharmacokinetics of a sustained-release formulation of meloxicam after subcutaneous administration to Hispaniolan Amazon parrots. Twelve healthy adult parrots, 6 males and 6 females, were used in the study. Blood samples were collected before (time 0) and at 0.5, 1, 2, 6, 12, 24, 48, 72, 96, and 120 hours after a single dose of the sustained-release meloxicam formulation (3 mg/kg SC). Plasma meloxicam concentrations were measured by high-pressure liquid chromatography. Pharmacokinetic parameters were determined by noncompartmental analysis. Plasma concentrations reached a mean C_max of 23.4 μg/mL (range, 14.7-46.0 μg/mL) at 1.8 hours (range, 0.5-6 hours), with a terminal half-life of 7.4 hours (range, 1.4-40.9 hours). Individual variation was noticeable, such that some parrots (4 of 12 birds) had very low plasma meloxicam concentrations, similar to the high variability reported in a previous pharmacokinetic study of the standard meloxicam formulation in the same group of birds. Two birds developed small self-resolving scabs at the injection site. On the basis of these results, the sustained-release meloxicam formulation could be administered every 12 to 96 hours in Hispaniolan Amazon parrots to manage pain. Because of these highly variable results, the use of this formulation in this species cannot be recommended until further pharmacokinetic, safety, and pharmacogenomic evaluations are performed to establish accurate dosing recommendations and to understand the high pharmacokinetic variability.

Pharmacokinetics of meloxicam during multiple oral or intramuscular dose administration to African grey parrots (Psittacus erithacus)

OBJECTIVE To determine the pharmacokinetics of meloxicam in African grey parrots (Psittacus erithacus) during administration of multiple doses. ANIMALS 6 healthy African grey parrots. PROCEDURES Meloxicam was administered at each of 3 dosages (1 mg/kg, IM, q 24 h, for 7 days; 1 mg/kg, PO, q 24 h, for 12 days; and 1.6 mg/kg, PO, q 24 h, for 7 days) with an 8-week washout period between treatments. Blood samples were collected 12 and 24 hours after each drug administration (times of presumptive peak and trough drug concentrations) for pharmacokinetic analysis. Birds were visually assessed during all experiments and monitored for changes in selected plasma and urine biochemical variables after administration of the drug at 1.6 mg/kg. RESULTS Mean trough plasma concentrations at steady state were 10.7 and 9.16 μg/mL after meloxicam administration at 1 mg/kg, IM, and 1 mg/kg, PO, respectively. Plasma drug accumulation was evident (accumulation ratios of 2.04 ± 0.30 [IM treatment] and 2.45 ± 0.26 [PO treatment]). Plasma and urine N-acetyl-β-d-glucosaminidase activities were significantly increased at the end of meloxicam treatment at 1.6 mg/kg. CONCLUSIONS AND CLINICAL RELEVANCE Plasma concentrations of meloxicam were maintained at values greater than effective analgesic concentrations described for other avian species. Although administration of meloxicam at a dosage of 1 mg/kg IM and PO daily for 1 week and 12 days, respectively, was not associated with adverse clinical effects in this population, further studies are needed to assess the efficacy and safety of the drug during prolonged treatment and the clinical relevance of its accumulation.

Ultrastructure of the gastro intestinal tract of healthy Japanese quail (Coturnix japonica) using light and scanning electron microscopy

The Japanese quail (Coturnix japonica) are popular both as an alternative protein source and as a model of choice for scientific research in several disciplines. There is limited published information on the histological features of the intestinal tract of Japanese quail. The only comprehensive reference is a book published in 1969. This study aims to fill that niche by providing a reference of general histological features of the Japanese quail, covering all the main sections of the intestinal tract. Both light and scanning electron microscope (SEM) images are presented. Results showed that the Japanese quail intestinal tract is very similar to that of the chicken with the exception of the luminal koilin membrane of the gizzard. Scanning electron microscopic photomicrographs show that in the Japanese quail koilin vertical rods are tightly packed together in a uniform manner making a carpet-like appearance. This differs in chicken where the conformations of vertical rods are arranged in clusters.

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.

Reproductive Disorders in Commonly Kept Fowl

Backyard poultry and other commonly kept fowl species are often kept for their ability to lay eggs. Reproductive disease is common in fowl species. Despite being classified as food-producing species, they can be considered valuable pets, and the demand for adequate veterinary care is constantly increasing. The clinician should be familiar with the different abnormalities and the potential treatment options. Fowl species have been traditionally an anatomic, physiologic, and experimental model for avian medicine; however, information about treatment options is often limited and extrapolated from other species.