Antifungal treatment of small animal veterinary patients

Pharmacokinetics of intraarticular liposomal amphotericin B in goats (Capra aegagrus hircus)

Lameness is a significant welfare concern in goats. Amphotericin B is used via intraarticular (IA) administration in models to study experimentally induced lameness in large animals. The main objective of this study was to estimate plasma pharmacokinetic (PK) parameters for amphotericin B in goats after a single IA administration. Liposomal amphotericin B was administered to ten Kiko-cross goats at a dose of 10 mg total (range: 0.34-0.51 mg/kg) via IA administration into the right hind lateral distal interphalangeal joint. Plasma samples were collected over 96 h. Amphotericin B concentrations were measured via liquid chromatography/mass spectrometry (LC-MS/MS). A non-compartmental analysis was used to derive PK parameters. Following single IA administration, maximum plasma concentration was estimated at 54.6 ± 16.5 ng/mL, and time to maximum concentration ranged from 6 to 12 h. Elimination half-life was estimated at 30.9 ± 16.5 h, and mean residence time was 45.1 ± 10.4 h. The volume of distribution after IA administration was 13.3 ± 9.4 L/kg. The area under the curve was 1481 ± 761 h*ng/mL. The achieved maximum concentration was less than the observed concentrations for other species and routes of administration. Further research is needed into the pharmacodynamics of IA liposomal amphotericin B in goats to determine specific research strategies.

Osteomyelitis by Microsporum canis and Staphylococcus spp. in cat (Felis catus) - case report

BACKGROUND

Staphylococcus spp and Microsporum canis are zoonotic microorganisms which can cause infections and systemic diseases. The bone infection is usually caused by invasion of pathogen through the hematologic route. Mixed osteomyelitis caused by bacteria and fungi is rare, and to date, there have been no reports of mixed osteomyelitis with Staphylococcus spp. and Microsporum canis.

CASE PRESENTATION

This essay reports an atypical presentation of mixed osteomyelitis (Staphylococcus spp. and Microsporum canis) in a domestic cat. A 15-month-old female Persian cat was presented to a veterinary service; the main complaint was the appearance of a nodule in the mandibular ventral rostral region. A radiographic exam performed on the animal showed proliferative and osteolytic bone lesions. The patient was submitted to a biopsy for histopathological evaluation, along with bacterial and fungal cultures. Results showed mixed osteomyelitis by Staphylococcus spp. and Microsporum canis. Microbial Sensitivity Test was performed to choose a more suitable treatment. Two surgical procedures were executed to resect and curette the lesion, and treatments with anti-inflammatory, antibiotic, and antifungal drugs were established, showing a positive clinical evolution. After 8 months of treatment, the patient's owner moved to a different city, and the animal was seen by other veterinarians, who followed along with the same treatment. However, due to complications and a diminishing quality of life over 4 years of diagnosis, the patient was euthanized.

CONCLUSION

Given the above, mixed osteomyelitis is difficult to treat and can cause losses of life quality resulting death, especially in infections where M. canis is the agent causing the disease. Bacterial osteomyelitis is more frequently reported. But the lack of investigation of microorganisms other than bacteria, such as fungal cases, may imply in underdiagnosed cases. Treatment of osteomyelitis can be difficult considering the difficulties in isolating the pathological agent, resistance to the drug used, prolonged treatment time, and cost.

Short Review on the Biological Activity of Cyclodextrin-Drug Inclusion Complexes Applicable in Veterinary Therapy

Cyclodextrins (CDs) are a family of carrier molecules used to improve the pharmacokinetic parameters of therapeutic molecules. These cyclic oligosaccharides have medical and pharmaceutical applications by being able to form inclusion complexes with molecules that are poorly soluble in water. The benefits of these complexes are directed towards improving the chemical and biological properties-i.e., solubility, bioavailability, stability, non-toxicity and shelf life of drug molecules. Since the 1960s, the first inclusion complexes used in therapeutics were those with α-, β- and γ-CD, which proved their usefulness, but had certain degrees of particularly renal toxicity. Currently, to correct these deficiencies, β-CD derivatives are most frequently used, such as sulfobutylether-β-CD, hydroxypropyl-β-CD, etc. Therefore, it is of interest to bring to the attention of those interested the diversity of current and potential future clinical applications of inclusion complexes in veterinary medicine and to present the contribution of these inclusion complexes in improving drug efficacy. The most important biological activities of β-CD complexed molecules in the veterinary field are summarized in this short review.

Review of Novel Oral Amphotericin B Formulations for the Treatment of Parasitic Infections

Amphotericin B (AmpB) is a polyene macrolide antibiotic used in the treatment of blood-borne parasitic and fungal infections. However, its use, particularly in the developing world, has been limited by dose-dependent kidney toxicity, other systemic-related toxicity issues following injection, the inconvenience of parenteral administration, and accessibility. Oral formulation approaches have focused on the dual problem of solubility and permeability of AmpB, which is poorly water soluble, amphoteric and has extremely low oral bioavailability. Therefore, to enhance oral absorption, researchers have employed micellar formulations, polymeric nanoparticles, cochleates, pro-drugs, and self-emulsifying drug delivery systems (SEDDS). This paper will highlight current uses of AmpB against parasitic infections such as leishmaniasis, preclinical and clinical formulation strategies, applications in veterinary medicine and the importance of developing a cost-effective and safe oral AmpB formulation.

Strategies for managing marine disease

The incidence of emerging infectious diseases (EIDs) has increased in wildlife populations in recent years and is expected to continue to increase with global environmental change. Marine diseases are relatively understudied compared with terrestrial diseases but warrant parallel attention as they can disrupt ecosystems, cause economic loss, and threaten human livelihoods. Although there are many existing tools to combat the direct and indirect consequences of EIDs, these management strategies are often insufficient or ineffective in marine habitats compared with their terrestrial counterparts, often due to fundamental differences between marine and terrestrial systems. Here, we first illustrate how the marine environment and marine organism life histories present challenges and opportunities for wildlife disease management. We then assess the application of common disease management strategies to marine versus terrestrial systems to identify those that may be most effective for marine disease outbreak prevention, response, and recovery. Finally, we recommend multiple actions that will enable more successful management of marine wildlife disease emergencies in the future. These include prioritizing marine disease research and understanding its links to climate change, improving marine ecosystem health, forming better monitoring and response networks, developing marine veterinary medicine programs, and enacting policy that addresses marine and other wildlife diseases. Overall, we encourage a more proactive rather than reactive approach to marine wildlife disease management and emphasize that multidisciplinary collaborations are crucial to managing marine wildlife health.

The antimicrobial and immunomodulatory effects of Ionophores for the treatment of human infection

Ionophores are a diverse class of synthetic and naturally occurring ion transporter compounds which demonstrate both direct and in-direct antimicrobial properties against a broad panel of bacterial, fungal, viral and parasitic pathogens. In addition, ionophores can regulate the host-immune response during communicable and non-communicable disease states. Although the clinical use of ionophores such as Amphotericin B, Bedaquiline and Ivermectin highlight the utility of ionophores in modern medicine, for many other ionophore compounds issues surrounding toxicity, bioavailability or lack of in vivo efficacy studies have hindered clinical development. The antimicrobial and immunomodulating properties of a range of compounds with characteristics of ionophores remain largely unexplored. As such, ionophores remain a latent therapeutic avenue to address both the global burden of antimicrobial resistance, and the unmet clinical need for new antimicrobial therapies. This review will provide an overview of the broad-spectrum antimicrobial and immunomodulatory properties of ionophores, and their potential uses in clinical medicine for combatting infection.

Novel approach of dermatophytosis eradication in shelters: effect of Pythium oligandrum on Microsporum canis in FIV or FeLV positive cats

Background

Shelters and similar facilities with a high concentration and fluctuation of animals often have problems with various infections, which are usually difficult to solve in such environments and are very expensive to treat. This study investigated the eradication of Microsporum canis, the widespread cause of zoonotic dermatophytosis in shelters, even in immunosuppressed feline leukaemia virus or feline immunodeficiency virus positive cats.

Results

Our study showed the increased effectiveness of an alternative topical therapy for affected animals using the mycoparasitic fungus Pythium oligandrum, which is gentler and cheaper than the standard systemic treatment with itraconazole, and which can also be easily used as a preventative treatment. A decrease in the number of M. canis colonies was observed in cats treated with a preparation containing P. oligandrum 2 weeks after the start of therapy (2 cats with P-1 score, 2 cats with P-2 score, 5 cats with P-3 score) compared with the beginning of the study (9 cats with P-3 score = massive infection). The alternative topical therapy with a preparation containing P. oligandrum was significantly more effective compared with the commonly used systemic treatment using itraconazole 5 mg/kg in a 6-week pulse. After 16 weeks of application of the alternative topical therapy, the clinical signs of dermatophytosis were eliminated throughout the whole shelter.

Conclusion

The complete elimination of the clinical signs of dermatophytosis in all cats indicates that this therapy will be useful for the management and prevention of zoonotic dermatophytosis in animal shelters.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-021-03001-w.

A preliminary study of the plasma concentrations of orally administered fluconazole in alpacas (Vicugna pacos)

Alpacas residing in the region endemic for Coccidioides spp. are susceptible to serious, disseminated coccidioidomycosis that may result in death. There is currently no oral antifungal dose recommendation for this species. We used a steady-state study design to assess the pharmacokinetics of oral generic fluconazole in alpacas dosed q 24 h for 14 days. Cohorts of 2-3 animals received fluconazole from 6 to 15 mg/kg/day, and pharmacokinetic analysis was performed after each group of animals in order to make dose adjustments for the next group. The final three animals were used as confirmation of our dose recommendation. The median T_max was 7 h, and the median C_max was 1.25 µg/ml per mg/kg dose. The mean dose-normalized 24-h AUC was 41.7 µg h/ml per mg/kg dose (CV = 72%). Based on these results, we recommend alpacas receive a starting dose of oral fluconazole at 10-15 mg/kg/day based on the fluconazole AUC in humans (313-625 µg h/ml). Testing to ascertain putative therapeutic plasma concentrations and monitoring of serum transaminases should be performed.

Diagnostic and therapeutic management of Cryptococcosis in a kitten with practical considerations to veterinary pediatric therapeutic approach

A 3-months-old male domestic kitten was referred for repeated seizures. Analysis revealed Cryptococcus neoformans. Levetiracetam and fluconazole were administered without significant clinical improvements and without negativization. Hypothesizing resistance, therapy was switched to amphotericin B. Seizure disappeared. Haematological controls highlighted transitory increasing of CK, BUN, ALP and cholesterol. PCR repeated two weeks after the treatment was negative for Cryptococcus neoformans. Nowadays the cat is 5 years old, and no seizures occurred since the age of 5 months.

Clinical, clinicopathologic, and hepatic histopathologic features associated with probable ketoconazole-induced liver injury in dogs: 15 cases (2015-2018)

OBJECTIVE

To characterize clinical, clinicopathologic, and hepatic histopathologic features and outcome for dogs with probable ketoconazole-induced liver injury.

ANIMALS

15 dogs with suspected ketoconazole-induced liver injury that underwent liver biopsy.

PROCEDURES

Medical record data were summarized regarding signalment, clinical signs, clinicopathologic and hepatic histopathologic findings, concurrent medications, ketoconazole dose, treatment duration, and outcome.

RESULTS

Median age and body weight were 8.2 years (range, 5 to 15 years) and 13.0 kg (28.6 lb; range, 8.2 to 38.0 kg [18.0 to 83.6 lb]), respectively. The most common breed was Cocker Spaniel (n = 5). All dogs received ketoconazole to treat cutaneous Malassezia infections. Median daily ketoconazole dose was 7.8 mg/kg (3.5 mg/lb; range, 4.4 to 26.0 mg/kg [2.0 to 11.8 mg/lb]), PO. Treatment duration ranged from 0.3 to 100 cumulative weeks (intermittent cyclic administration in some dogs); 6 dogs were treated for ≤ 10 days. Common clinical signs included lethargy, anorexia, and vomiting. All dogs developed high serum liver enzyme activities. Hepatic histopathologic findings included variable lobular injury, mixed inflammatory infiltrates, and conspicuous aggregates of ceroid-lipofuscin-engorged macrophages that marked regions of parenchymal damage. Five dogs developed chronic hepatitis, including 3 with pyogranulomatous inflammation. Of the 10 dogs reported to have died at last follow-up, survival time after illness onset ranged from 0.5 to 165 weeks, with 7 dogs dying of liver-related causes.

CONCLUSIONS AND CLINICAL RELEVANCE

Findings for dogs with hepatotoxicosis circumstantially associated with ketoconazole treatment suggested proactive monitoring of serum liver enzyme activities is advisable before and sequentially after initiation of such treatment.

Chiral conazole fungicides - (Enantioselective) terrestrial bioaccumulation and aquatic toxicity

Five conazole fungicides (CFs) (epoxiconazole, tebuconazole, myclobutanil, uniconazole (P), rac-uniconazole, and diniconazole) were tested in order to provide additional information on i) the effects of CFs on the nematode Caenorhabditis elegans and on the aquatic insect Chironomus riparius under acute exposure scenarios and in multi-generation exposure studies, taking advantage of the short life cycle of nematodes and ii) on the bioaccumulation (earthworm Eisenia andrei) profiles of CFs including also the enantiomer-specific assessment of degradation in soils and uptake/elimination by earthworms. Acute toxicity was considered low following the exposure of up to 2.5 mg of CFs per liter of the test medium. In a multigeneration study on nematodes, all five generations exposed to epoxiconazole were significantly negatively affected in terms of reproductive efficiency, and the severity of effects increased from F0 to F1 generation and was sustained thereafter. Adverse effects were also observed in the case of uniconazole (P) and diniconazole, and similarly to epoxiconazole, the effects occurred within the active life of the pesticides and were assumed to be based on their half-lives in soil (e.g., 53.3 to 691 days for uniconazole and diniconazole in our study) and in sediment/water. Bioaccumulation of diniconazole and uniconazole by earthworms varied between soils (Lufa 2.1 ≥ Lufa 2.4 > sandy soil > Lufa 2.2) and compounds (diniconazole > uniconazole) and was enantioselective. Earthworms preferentially accumulated R-uniconazole as a result of faster elimination of the S-form, which was evidenced from the enantiomer-specific uptake/elimination rate constants derived from the bioaccumulation profiles. Our results suggest that multigeneration exposure studies can advantageously be used for assessing the long-term and trans-general effects of pesticides. Also, the enantioselectivity in bioaccumulation observed for both uniconazole and diniconazole suggests that enantioselectivity in the fate and effects should be considered when exploring ways for safer and sustainable use of chiral pesticides.

Oral administration of voriconazole with surgical fungal plaque debridement for the treatment of sinonasal aspergillosis with cribriform plate lysis in three dogs

CASE DESCRIPTION

3 dogs with chronic sinonasal signs (sneezing, nasal discharge, or epistaxis [or a combination of signs]) were examined.

CLINICAL FINDINGS

For all 3 dogs, CT revealed variable degrees of nasal turbinate destruction and frontal sinus involvement with cribriform plate lysis. Fungal plaques were detected during rhinoscopy or sinusoscopy. Results of fungal culture (2 dogs) or cytologic examination of a plaque specimen (1 dog) supported a diagnosis of sinonasal aspergillosis.

TREATMENT AND OUTCOME

All dogs underwent surgical rhinotomy or sinusotomy (or both) for fungal plaque debridement followed by oral treatment with voriconazole and periodic physical examinations, clinicopathologic analyses, and assessments of serum drug concentrations for a period ≥ 22 weeks. All dogs had considerable to complete reduction of their clinical signs and tolerated voriconazole treatment with minimal adverse effects. Adverse effects included development of reversible neurotoxicosis (associated with high serum voriconazole concentration) and mildly high serum liver enzyme activities. The dosage of voriconazole administered to achieve therapeutic serum concentrations (2.5 to 3.3 mg/kg [1.1 to 1.5 mg/lb], PO, q 12 h) was substantially lower than dosages suggested by previously published studies in dogs. The 3 dogs remained clinically normal or had mild clinical signs after voriconazole discontinuation for follow-up times of 6 to 15 months.

CLINICAL RELEVANCE

Findings in these 3 dogs indicated that surgical fungal plaque debridement followed by oral treatment with voriconazole may be an effective treatment option for dogs with sinonasal aspergillosis and cribriform plate lysis. Further evaluation of this treatment regimen with repeated CT examinations and longer follow-up times is warranted.

Upper Airway Obstruction Due to Primary Laryngeal Blastomycosis in a Dog

A 9 yr old female spayed Labrador retriever presented for progressive dyspnea. Inspiratory stridor and inspiratory and expiratory dyspnea were present, consistent with an upper airway obstruction. A laryngeal exam revealed severe thickening of the arytenoid cartilages and masses associated with the arytenoids. A tracheostomy tube was placed, and the masses were biopsied. Histopathology showed pyogranulomatous inflammation secondary to Blastomyces dermatitidis. The dog was initially treated with amphotericin B and terbinafine in the hospital until the airway obstruction resolved and the tracheostomy tube could be removed. The dog experienced complete recovery after long-term treatment with itraconazole and terbinafine. This is the first report of laryngeal obstruction secondary to primary laryngeal blastomycosis in a dog. Blastomycosis should be considered for cases of obstructive laryngeal disease, and a good outcome can be achieved with antifungal treatment.

Inhibitors of Brassinosteroid Biosynthesis and Signal Transduction

Chemical inhibitors are invaluable tools for investigating protein function in reverse genetic approaches. Their application bears many advantages over mutant generation and characterization. Inhibitors can overcome functional redundancy, their application is not limited to species for which tools of molecular genetics are available and they can be applied to specific tissues or developmental stages, making them highly convenient for addressing biological questions. The use of inhibitors has helped to elucidate hormone biosynthesis and signaling pathways and here we review compounds that were developed for the plant hormones brassinosteroids (BRs). BRs are steroids that have strong growth-promoting capacities, are crucial for all stages of plant development and participate in adaptive growth processes and stress response reactions. In the last two decades, impressive progress has been made in BR inhibitor development and application, which has been instrumental for studying BR modes of activity and identifying and characterizing key players. Both, inhibitors that target biosynthesis, such as brassinazole, and inhibitors that target signaling, such as bikinin, exist and in a comprehensive overview we summarize knowledge and methodology that enabled their design and key findings of their use. In addition, the potential of BR inhibitors for commercial application in plant production is discussed.

Therapy of Non-Dermatophytic Mycoses in Animals

This review focuses on aspects of antimycotic therapy specific to veterinary medicine. In the first part, drug availability, limited mostly by economic consideration but also by clinical applicability and specific adverse effects, is described for polyenes, 5 fluorocytosine, azoles, echinocandins and terbinafine. In the second part, current knowledge and experience in the treatment of selected fungal infections are overviewed. These mycoses include disseminated mold infections in small animals (dogs and cats) and avian species, upper respiratory tract infections of small animals (sino-nasal and sino-orbital aspergillosis) and horses (guttural pouch mycosis), eumycetoma, infections caused by dimorphic fungi, (blastomycosis, histoplasmosis, coccidioidomycosis, paracoccidioidomycosis and sporothrichosis) and by yeasts and yeast-like microorganism (Cryptococcus spp. and Malassezia pachydermatis).

Candidate prognostic indicators in cats with histoplasmosis treated with antifungal therapy

Objectives The aim of this study was to retrospectively identify candidate prognostic indicators in cats with histoplasmosis treated with antifungal therapy. Methods Medical records of cats diagnosed with histoplasmosis were reviewed. Candidate prognostic indicators were assessed for an association with survival to hospital discharge and survival to 1 and 6 months after diagnosis. Potential indicators included easily obtained data at the time of the initial hospital visit derived from cat signalment, historical information, physical examination, laboratory data, form of disease and initial treatment. Results Approximately 88% of cats survived to discharge, with 77% and 67% surviving to 1 and 6 months, respectively. Clinical variables significantly associated with death at more than one outcome time point included the presence of dyspnea, adventitial lung sounds, fungemia, neurologic disease, neutropenia, lymphopenia, multiple cytopenias (anemia, neutropenia, thrombocytopenia), hyperbilirubinemia and increased creatinine kinase activity. Cats that did not survive were more likely to have received corticosteroids, oxygen supplementation and required hospitalization. In addition, cats that did not survive required significantly longer hospitalization. There was no significant difference between initial antifungal drug and survival. Conclusions and relevance Potential prognostic indicators were associated with more severe respiratory, hepatic, hematologic or neurologic disease. Prospective investigation concerning clinical indicators of disease severity of these body systems is indicated.

Long term survival of a dog with disseminated Aspergillus deflectus infection without definitive treatment

Canine disseminated fungal infection by Aspergillus species carries a guarded to grave prognosis as they often rapidly progress and are refractory to treatment with many euthanased soon after diagnosis. This case report describes a 2.5 year old female spayed German Shepherd Dog diagnosed with disseminated Aspergillus deflectus infection for which definitive treatment was declined by the owners. With only palliative management the dog survived three years and two months before succumbing to chronic kidney disease.

Comparison of the pharmacokinetic profiles of two different amphotericin B formulations in healthy dogs

This study was conducted to compare the pharmacokinetic profiles of conventional (Fungizone^® ) and liposomal amphotericin B (AmBisome^® ) formulations in order to predict their therapeutic properties, and evaluate their potential differences in veterinary treatment. For this purpose, twelve healthy mixed breed dogs received both drugs at a dose of 0.6 mg/kg by intravenous infusion over a 4-min period in a total volume of 40 ml. Blood samples were collected at 0, 0.5, 1, 1.5, 2, 3, 4, 8, 12, 24, 48, 72 and 96 hr after dosing, and concentrations of drug in plasma were determined by high-performance liquid chromatography (HPLC). Pharmacokinetics was described by a two-compartment model. Although both formulations were administered at the same doses (0.6 mg/kg), the plasma pharmacokinetics of liposomal amphotericin B differed significantly from those of amphotericin B deoxycholate in healthy dogs (p < .05). Liposomal amphotericin B showed markedly higher peak plasma concentrations (approximately ninefold greater) and higher area under the plasma concentration curve values (approximately 14-fold higher) compared to conventional formulation. It is concluded that AmBisome^® reached higher plasma concentration and lower distribution volume and had a longer half-life compared to Fungizone^® , and therefore, AmBisome^® is reported to be an appropriate and effective choice for the treatment of systemic mycotic infections in dogs.

Pharmacokinetics and Relative Bioavailability of Orally Administered Innovator-Formulated Itraconazole Capsules and Solution in Healthy Dogs

Background

Itraconazole is commonly used for treatment of systemic and cutaneous mycoses in veterinary medicine. Two formulations, capsule and solution, are used interchangeably in dogs. However, marked differences in bioavailability have been reported in other species. Similar investigations have not been performed in dogs.

Objective

To determine and compare pharmacokinetics of itraconazole in dogs after oral administration of commercially available capsule and solution formulations intended for use in humans.

Animals

Eight healthy, adult, purpose‐bred dogs.

Methods

Dogs received approximately 10 mg/kg of innovator‐formulated itraconazole solution and capsule PO in randomized, crossover design with a 10‐day washout period. To ensure maximal absorption, solution was administered to fasted dogs, whereas capsules were co‐administered with food. Blood samples were collected at predetermined time points, and plasma drug concentrations were measured using high‐pressure liquid chromatography. Pharmacokinetic parameters were determined with compartmental analysis.

Results

The mean relative bioavailability of the capsule was 85% that of the solution, but drug absorption was variable, and overall drug concentrations were similar between formulations. Mean elimination half‐lives of both formulations were nearly identical at approximately 33 hours. Regardless of formulation, simulations suggest that a loading dose of 20 mg/kg, followed by 10 mg/kg once every 24 hours, will result in plasma concentrations considered to be adequate in most dogs.

Conclusions and Clinical Importance

Contrary to findings reported in other species, overall drug exposures after capsule and solution administration are not substantially different in dogs. Despite some pharmacokinetic differences between itraconazole capsule and solution, formulation‐specific dosages do not appear to be necessary.

Ventricular pneumocephalus, cervical subarachnoid pneumorrhachis, and meningoencephalitis in a dog following rhinotomy for chronic fungal rhinitis

CASE DESCRIPTION

A 5-year-old 35.8-kg (78.8-lb) neutered male Labrador Retriever was evaluated for chronic nasal discharge associated with a fungal infection. The dog had previously been prescribed antimicrobials and antifungal treatment, but owner compliance was lacking.

CLINICAL FINDINGS

Bilateral mucopurulent nasal discharge, mild ulceration of the left nasal commissure, and hyperkeratosis of the dorsal nasal planum were present. Computed tomography revealed destruction of the intranasal structures, focal lysis of the cribriform plate, and invasion of a soft-tissue mass into the frontal cortex. Rhinoscopy revealed a large pale mass in the caudal aspect of the right nasal passage; a biopsy sample was consistent with Aspergillus sp on histologic evaluation.

TREATMENT AND OUTCOME

Initial treatment included medical management with an antifungal agent. Approximately 3 months later, a large fungal granuloma in the right frontal sinus was removed and debridement was performed via dorsal rhinotomy. One month after surgery, the dog was evaluated for signs of cervical pain and altered mentation. An MRI and CSF analysis were performed; diagnoses of ventricular pneumocephalus, subarachnoid pneumorrhachis, and meningoencephalitis were made. Management included oxygen therapy and administration of antimicrobials, analgesics, and antifungal medications. On follow-up 9 months after initial evaluation, neurologic deficits were reportedly resolved, and the dog was doing well.

CONCLUSIONS AND CLINICAL RELEVANCE

This report emphasizes the importance of prompt, appropriate treatment of fungal rhinitis in dogs. Although rare, pneumocephalus and pneumorrhachis should be included as differential diagnoses for neurologic signs following treatment for this condition. In this dog, the complications were not considered severe and improved over time with supportive care.

Disseminated Chrysosporium infection in a German shepherd dog

Disseminated Chrysosporium spp. infection was diagnosed in a German shepherd dog based on a positive fungal culture and cytological findings of intralesional fungi associated with granulomatous splenitis and neutrophilic lymphadenitis. The clinical presentation that could mimic a multicentric lymphoma, including markedly enlarged lymph nodes and a very abnormal splenic appearance on ultrasound makes this case even more atypical. The patient showed rapid clinical improvement on oral posaconazole and remains clinically stable ten months after diagnosis.

Alternate-day dosing of itraconazole in healthy adult cats

The current available formulations of itraconazole are not ideal for dosing in cats. The capsular preparation often does not allow for accurate dosing, the oral solution is difficult to administer and poorly tolerated, and the bioavailability of compounded formulations has been shown to be poor in other species. The aim of this study was to evaluate every other day dosing of 100 mg itraconazole capsule in healthy adult cats. Ten healthy adult cats received a 100 mg capsule of itraconazole orally every 48 h for 8 weeks. Peak and trough serum concentrations of itraconazole were measured weekly using high-performance liquid chromatography (HPLC). Physical examination, complete blood count (CBC), and chemistry profiles were performed weekly. The dosage regimen achieved average therapeutic trough concentrations (>0.5 μg/mL) within 3 weeks. The protocol yielded no adverse effects in 8 of the 10 study cats, with affected cats recovering fully with discontinuation of the drug and supportive care. At 8 weeks, an average peak concentration of 1.79 ± 0.952 μg/mL (95% CI: 0.996-2.588) and an average trough concentration of 0.761 ± 0.540 μg/mL (95% CI: 0.314-1.216) were achieved. Overall, a 100 mg every other day oral dosage regimen for itraconazole in cats yielded serum concentrations with minimal fluctuation and with careful monitoring may be considered for treatment of cats with systemic fungal disease.

Cryptococcosis as an emerging systemic mycosis in dogs

OBJECTIVE

To review the etiology, pathogenesis, and clinical presentations of canine cryptococcosis that are of relevance to veterinary emergency and critical care veterinarians. Diagnosis, treatment, and public health considerations of the disease will also be discussed.

ETIOLOGY

Cryptococcosis is a multisystemic disease of dogs, with a predilection for the CNS, caused by encapsulated yeast species of the genus Cryptococcus. The 2 main pathogenic species are Cryptococcus neoformans and Cryptococcus gattii (previously known as C. neoformans var. gattii). Cryptococcosis is an emerging disease in North America, with C. gattii gaining prominence as a cause of serious veterinary and human disease.

DIAGNOSIS

Definitive diagnosis is made by serologic (antigen) testing, culture, and identification of the organism using light microscopy. False negatives and false positives, while uncommon, can occur in dogs using commercially available antigen tests. Cytological examination demonstrates the organism in a majority of cases, although culture is more sensitive. Specific media are required to differentiate between C. neoformans and C. gattii.

THERAPY

The most commonly used antifungal drugs to treat canine cryptococcosis are azole antifungals and amphotericin B. Some strains of Cryptococcus are resistant to antifungal drugs, especially fluconazole. Cautious use of glucocorticoids in critically affected dogs with CNS presentations can improve outcome.

PROGNOSIS

Prognosis is variable and depends on the severity of disease, underlying host immunocompetence, and financial constraints of the owner. Altered mental status in dogs with CNS cryptococcosis is a negative prognostic indicator.

Phaeohyphomycoses, emerging opportunistic diseases in animals

Emerging fungal diseases due to black yeasts and relatives in domestic or wild animals and in invertebrates or cold- and warm-blooded vertebrates are continually being reported, either as novel pathogens or as familiar pathogens affecting new species of hosts. Different epidemiological situations can be distinguished, i.e., occurrence as single infections or as zoonoses, and infection may occur sporadically in otherwise healthy hosts. Such infections are found mostly in mammals but also in cold-blooded animals, are frequently subcutaneous or cerebral, and bear much similarity to human primary disorders. Infections of the nervous system are mostly fatal, and the source and route of infection are currently unknown. A third epidemiological situation corresponds to pseudoepidemics, i.e., infection of a large host population due to a common source. It is often observed and generally hypothesized that the susceptible animals are under stress, e.g., due to poor housing conditions of mammals or to a change of basins in the case of fishes. The descriptions in this article represent an overview of the more commonly reported and recurring black fungi and the corresponding diseases in different types of animals.

Cytological, microbiological and therapeutic aspects of systemic infection in a dog caused by the fungus Phialosimplex caninus

A seven-year-old immunocompetent dog presenting with lymphadenopathy, mesenteric masses and splenic nodules was diagnosed with Phialosimplex caninus infection. Cytology of a mesenteric mass aspirate demonstrated few intact cells but numerous variably sized fungal cells and rare hyphal fragments. The identity of the cultured fungus was confirmed by DNA sequencing. Itraconazole therapy improved clinical signs, but the fungus was reisolated at follow-up. P. caninus systemic infection should be suspected in dogs presenting with lymphadenopathy and splenomegaly.

A case of Trichophyton mentagrophytes infection in a fennec fox (Vulpes zerda)

A 2-year-old male fennec fox presented with a 4 month history of nonpruritic, crusty skin lesions on the forehead, the pinnae and the tail tip. Initial investigations, including routine haematology, biochemistry profile, multiple skin scrapings, trichoscopic examination, Wood's lamp examination and fungal culture, failed to reveal any abnormalities. Histopathological examination of a first set of skin biopsies showed an interface dermatitis pattern, with lymphocyte infiltration in the basal layer, a significant lymphocytic exocytosis and occasional apoptotic basal epidermal keratinocytes; periodic acid Schiff stain did not reveal any fungal elements. On further biopsies, there was a pustular neutrophilic dermatitis, with numerous crusts containing high numbers of arthrospores and fungal hyphae. Trichophyton mentagrophytes infection was confirmed on fungal culture and PCR. The fennec fox received oral itraconazole (5 mg/kg once daily for 6 weeks) combined with a miconazole and chlorhexidine shampoo applied on affected areas once weekly, followed with an enilconazole dip. The fox improved dramatically, and a fungal culture performed at 6 weeks was negative. Unfortunately, a few days later the fennec fox developed anorexia, icterus and died. To the authors' knowledge, this is the first report of Trichophyton infection in a fennec fox and, although a postmortem examination was not performed, this is possibly the first report of fatal acute liver failure associated with itraconazole in a canid.

Terbinafine pharmacokinetics after single dose oral administration in the dog

Terbinafine is an allylamine antifungal prescribed for the treatment of mycoses in humans. It is increasingly being used in veterinary patients. The purpose of this study was to evaluate the pharmacokinetic properties of terbinafine in dogs after a single oral dose. Ten healthy adult dogs were included in the study. A single dose of terbinafine (30-35 mg/kg) was administered orally, and blood samples were periodically collected over a 24 h period during which dogs were monitored for adverse effects. Two of 10 dogs developed transient ocular changes. A high-performance liquid chromatography assay was developed and used to determine plasma terbinafine concentrations. Pharmacokinetic analysis was performed using PK Solutions(®) computer software. Area under the curve (AUC) from time 0 to 24 h was 15.4 μg·h/mL (range 5-27), maximal plasma concentration (C(max) ) was 3.5 μg/mL (range 3-4.9 μg/mL) and time to C(max) (T(max) ) was 3.6 h (range 2-6 h). The time above minimal inhibitory concentration (T > MIC) as well as AUC/MIC was calculated for important invasive fungal pathogens and dermatophytes. The T > MIC was 17-18 h for Blastomyces dermatitidis, Histoplasma capsulatum and dermatophytes (Microsporum spp. and Trichophyton mentagrophytes), while the MIC for Sporothrix schenckii and Coccidioides immitis was exceeded for 9.5-11 h. The AUC/MIC values ranged from 9 to 13 μg h/mL for these fungi. Our results provide evidence supporting the use of terbinafine as an oral therapeutic agent for treating systemic and subcutaneous mycoses in dogs.