Pharmacokinetics of nebulized terbinafine in Hispaniolan Amazon parrots (Amazona ventralis)

A RETROSPECTIVE EVALUATION OF MORBIDITY AND MORTALITY IN ASSOCIATION WITH INFESTATION BY THE MITE STERNOSTOMA TRACHEACOLUM IN AN AVIARY-HOUSED POPULATION OF GOULDIAN FINCHES (CHLOEBIA GOULDIAE)

The Rhynonyssid mesostigmatic mite, Sternostoma tracheacolum, is a well-documented endoparasitic hematophagous arthropod of the respiratory tracts of multiple avian species, particularly Estrildid finches and canaries. In this retrospective study, 175 medical and 278 pathology records for the Gouldian finch (Chloebia gouldiae) population (N = 377) at the San Diego Zoo between 2013 and 2021 were analyzed to evaluate the effectiveness of ivermectin-based prophylaxis. A multivariable negative binomial regression model was constructed to evaluate the population effects of monthly treatments on morbidity or mortality associated with respiratory mites. While controlling for other factors in the model, the prophylactic treatment did not significantly reduce the monthly rate of mite-associated morbidity or mortality (IRR = 1.017, 95% CI: 0.997-1.036, P = 0.0759); however, low proportions of the population were prophylactically treated over time. Different factors were significant when separately evaluating adjusted associations with respiratory morbidity and mortality. The findings suggest increased rates of respiratory morbidity for each successive year of the study period (IRR = 1.180, 95% CI: 1.046-1.342, P = 0.0090) and increased rates of mite-associated mortality occurring annually between May and October (IRR = 1.697, 95% CI: 1.034-2.855, P = 0.0404) compared to the wet winter season. Our findings highlight the need to continually evaluate and optimize treatment regimens in zoological collections. Further investigations into this host-parasite relationship and potential treatments and preventive therapies are warranted.

A Critical Review on the Dosing and Safety of Antifungals Used in Exotic Avian and Reptile Species

Antifungals are used in exotic avian and reptile species for the treatment of fungal diseases. Dose extrapolations across species are common due to lack of species-specific pharmacological data. This may not be ideal because interspecies physiological differences may result in subtherapeutic dosing or toxicity. This critical review aims to collate existing pharmacological data to identify antifungals with the most evidence to support their safe and effective use. In the process, significant trends and gaps are also identified and discussed. An extensive search was conducted on PubMed and JSTOR, and relevant data were critically appraised. Itraconazole or voriconazole showed promising results in Japanese quails, racing pigeons and inland bearded dragons for the treatment of aspergillosis and CANV-related infections. Voriconazole neurotoxicity manifested as seizures in multiple penguins, but as lethargy or torticollis in cottonmouths. Itraconazole toxicity was predominantly hepatotoxicity, observed as liver abnormalities in inland bearded dragons and a Parson's chameleon. Differences in formulations of itraconazole affected various absorption parameters. Non-linearities in voriconazole due to saturable metabolism and autoinduction showed opposing effects on clearance, especially in multiple-dosing regimens. These differences in pharmacokinetic parameters across species resulted in varying elimination half-lives. Terbinafine has been used in dermatomycoses, especially in reptiles, due to its keratinophilic nature, and no significant adverse events were observed. The use of fluconazole has declined due to resistance or its narrow spectrum of activity.

Inhaled Antifungal Agents for Treatment and Prophylaxis of Bronchopulmonary Invasive Mold Infections

Pulmonary mold infections are life-threatening diseases with high morbi-mortalities. Treatment is based on systemic antifungal agents belonging to the families of polyenes (amphotericin B) and triazoles. Despite this treatment, mortality remains high and the doses of systemic antifungals cannot be increased as they often lead to toxicity. The pulmonary aerosolization of antifungal agents can theoretically increase their concentration at the infectious site, which could improve their efficacy while limiting their systemic exposure and toxicity. However, clinical experience is poor and thus inhaled agent utilization remains unclear in term of indications, drugs, and devices. This comprehensive literature review aims to describe the pharmacokinetic behavior and the efficacy of inhaled antifungal drugs as prophylaxes and curative treatments both in animal models and humans.

Single-dose pharmacokinetics of orally administered terbinafine in bearded dragons (Pogona vitticeps) and the antifungal susceptibility patterns of Nannizziopsis guarroi

OBJECTIVE

To identify the antifungal susceptibility of Nanniziopsis guarroi isolates and to evaluate the single-dose pharmacokinetics of orally administered terbinafine in bearded dragons.

ANIMALS

8 healthy adult bearded dragons.

PROCEDURES

4 isolates of N guarroi were tested for antifungal susceptibility. A compounded oral solution of terbinafine (25 mg/mL [20 mg/kg]) was given before blood (0.2 mL) was drawn from the ventral tail vein at 0, 4, 8, 12, 24, 48, 72, and 96 hours after administration. Plasma terbinafine concentrations were measured with high-performance liquid chromatography.

RESULTS

The antifungal minimum inhibitory concentrations against N guarroi isolates ranged from 4,000 to > 64,000 ng/mL for fluconazole, 125 to 2,000 ng/mL for itraconazole, 125 to 2,000 ng/mL for ketoconazole, 125 to 1,000 ng/mL for posaconazole, 60 to 250 ng/mL for voriconazole, and 15 to 30 ng/mL for terbinafine. The mean ± SD peak plasma terbinafine concentration in bearded dragons was 435 ± 338 ng/mL at 13 ± 4.66 hours after administration. Plasma concentrations remained > 30 ng/mL for > 24 hours in all bearded dragons and for > 48 hours in 6 of 8 bearded dragons. Mean ± SD terminal half-life following oral administration was 21.2 ± 12.40 hours.

CLINICAL RELEVANCE

Antifungal susceptibility data are available for use in clinical decision making. Results indicated that administration of terbinafine (20 mg/kg, PO, q 24 to 48 h) in bearded dragons may be appropriate for the treatment of dermatomycoses caused by N guarroi. Clinical studies are needed to determine the efficacy of such treatment.

Aspergillosis in Wild Birds

The ubiquitous fungi belonging to the genus Aspergillus are able to proliferate in a large number of environments on organic substrates. The spores of these opportunistic pathogens, when inhaled, can cause serious and often fatal infections in a wide variety of captive and free-roaming wild birds. The relative importance of innate immunity and the level of exposure in the development of the disease can vary considerably between avian species and epidemiological situations. Given the low efficacy of therapeutic treatments, it is essential that breeders or avian practitioners know the conditions that favor the emergence of Aspergillosis in order to put adequate preventive measures in place.

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.

Antifungal Therapy in Birds: Old Drugs in a New Jacket

The use of antifungals in birds is characterized by interspecies and interindividual variability in the pharmacokinetics, affecting drug safety and efficacy. Oral antifungal drug absorption is a complex process affected by drug formulation characteristics, gastrointestinal anatomy, and physiology. New antifungal drug delivery systems can enhance drug stability, reduce off-target side effects, prolong residence time in the blood, and improve efficacy. Topical administration of antifungals through nebulization shows promising results. However, therapeutic output is highly influenced by drug formulation and type of nebulizer, indicating these factors should be taken into account when selecting this medication route.

Evidence-Based Advances in Avian Medicine

This article presents relevant advances in avian medicine and surgery over the past 5 years. New information has been published to improve clinical diagnosis in avian diseases. This article also describes new pharmacokinetic studies. Advances in the understanding and treatment of common avian disorders are presented in this article, as well. Although important progress has been made over the past years, there is still much research that needs to be done regarding the etiology, pathophysiology, diagnosis, and treatment of avian diseases and evidence-based information is still sparse in the literature.

Emerging and reemerging diseases of avian wildlife

Of the many important avian wildlife diseases, aspergillosis, West Nile virus, avipoxvirus, Wellfleet Bay virus, avian influenza, and inclusion body disease of cranes are covered in this article. Wellfleet Bay virus, first identified in 2010, is considered an emerging disease. Avian influenza and West Nile virus have recently been in the public eye because of their zoonotic potential and links to wildlife. Several diseases labeled as reemerging are included because of recent outbreaks or, more importantly, recent research in areas such as genomics, which shed light on the mechanisms whereby these adaptable, persistent pathogens continue to spread and thrive.