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.

Systemic coccidioidomycosis in a llama cria native to Missouri

A 3-mo-old male llama was examined because of a 4-wk history of lethargy and ill thrift. Clinical examination revealed subcutaneous masses in the left prescapular and right inguinal regions, mild ataxia, a slight head tilt to the right, and right ear droop. The cria died before clinical workup was complete. At autopsy, there was generalized lymphadenomegaly, a hepatic nodule, a midbrain mass causing rostral compression of the cerebellum, and internal hydrocephalus. Microscopic findings included pyogranulomatous lymphadenitis, meningoencephalitis, hepatitis, and bronchopneumonia. Intralesional fungal spherules, most consistent with Coccidioides spp., were identified in the lymph nodes, lung, and brain. Fungal culture, single-nucleotide variation genotyping real-time PCR, and DNA sequencing confirmed Coccidioides posadasii. The dam of the cria was native to Arizona and had been moved to Missouri ~2.5 y previously. Agar gel immunodiffusion assay of the herd revealed that only the dam was positive for Coccidioides spp.; 6 herdmates were negative. Computed tomography of the dam revealed multiple nodules within the lungs and liver, which were presumed to be an active coccidioidomycosis infection. This case of systemic coccidioidomycosis in a llama native to Missouri was presumably acquired by vertical transmission from the dam.

Coccidioidomycosis in llamas and alpacas diagnosed at the University of California, Davis (1990-2016)

Given the predisposition of South American camelids to coccidioidomycosis, we sought to describe the disease presentation in alpacas and llamas and identify potential risk factors for these species. The records of 224 llamas and alpacas that were tested for Coccidioides infection using immunodiffusion serology at the Coccidioidomycosis Serology Laboratory of the University of California, Davis, between 1990 and 2016 were examined; of those, 46 alpacas and 42 llamas had positive test results. The remaining 99 alpacas and 37 llamas were used as control groups. We found that male llamas were at increased risk for Coccidioides infection when compared with female llamas and when compared with male alpacas. South American camelids living within California were at higher risk for infection than camelids living in other states. Alpacas were more likely than llamas to have subclinical infections. We documented five cases of abortion or neonatal mortality attributable to coccidioidomycosis in alpacas. Our study demonstrates that South American camelids are susceptible to Coccidioides infection in areas where the disease is endemic, lending support to the importance of vigilance for this disease in alpacas and llamas and suggesting a possible role for these animals as sentinel species.

LAY SUMMARY

We examined cases of Valley Fever and described the disease and risk factors for llamas and alpacas. Male llamas were at increased risk for infection as were animals living within California. Five alpacas had miscarriages or neonatal deaths as a result of Valley Fever infections.

Sensitivity of Serologic Testing for Dogs Diagnosed with Coccidioidomycosis on Histology: 52 Cases (2012-2013)

Coccidioidomycosis, or Valley Fever, is a fungal infection caused by Coccidioides spp., soil-living fungi endemic to the southwest region of the United States. The infection can cause various diseases including respiratory, neurologic, cardiac, dermatologic, and ocular disease as well as osteomyelitis in dogs and many other mammals. Obtaining a definitive diagnosis can be challenging. Serology is commonly used as a screening diagnostic test for disease, but both false-negative and false-positive results have been reported. Fifty-two cases of coccidioidomycosis diagnosed via histopathology were retrospectively evaluated. The sensitivity of serology in the study population was determined to be 87% for immunoglobulin G and 46% for immunoglobulin M. The cases were evaluated for an association between negative serology results and anatomic location of disease, but these variables were found to be independent. This study reports the sensitivity of serology for canine coccidioidomycosis and highlights the importance of using multiple diagnostic tests for definitive diagnosis of infection.

Coccidioidomycosis in alpacas in the southwestern United States

An anonymous web-based survey of alpaca owners was used to learn more about the clinical presentation, diagnosis, and treatment of coccidioidomycosis in alpacas in the United States. Thirty-seven owners, with 1,117 alpacas, completed the survey. Over 4% of alpacas included in the study were diagnosed with coccidioidomycosis between 2005 and 2016 (5 post mortem, 46 clinically). Immunodiffusion titers ranged from 1:4 to ≥1:256 in sick animals. Alpacas residing in Arizona counties with a high incidence of human disease were 5.8 times more likely to contract coccidioidomycosis than animals residing in other areas of the state. Treatment was reported in 23 alpacas, and 78% of those animals died or were euthanized. Necropsy records from a veterinary diagnostic laboratory in Tucson, AZ were reviewed to estimate the severity of disease in this species. Nine cases identified for review died of disseminated coccidioidomycosis; the disease was extensive in most animals, with the lungs, lymph nodes, and liver the most frequently affected. Alpacas appear to be highly susceptible to severe illness as a result of infection by Coccidioides spp., frequently resulting in death. More research is needed to better understand the epidemiology, clinical signs, and treatment protocols for coccidioidomycosis in alpacas.

Ocular Surface Disease in New World Camelids

This article discusses the anatomy, physiology, and common disease affecting the ocular surface of New World camelids, llamas, and alpacas.

Camelidae

New world (NW) camelids, alpaca, llama, vicuña, and guanaco, and old world (OW) camelids, Bactrian and dromedary camels are related and have many of the same anatomical features and disease susceptibilities though they are also very different. Only the free-ranging population of wild Bactrian camel is endangered. Bactrian camels held in zoos are generally of domestic origin. Vicuña are listed as vulnerable. In addition to those camelids held in captivity, there are domesticated populations of camelids (except vicuña and guanaco) maintained throughout the world. Most are fairly hardy animals, but there are some specific disease concerns. Domesticated llamas and alpacas have become hobby pets and thus management and genetic issues are an increasing source of disease. These include obesity, vitamin and mineral deficiencies and intoxications, metabolic derangements, and congenital malformations (particularly in the young). Domesticated animals are also more prone to degenerative arthropathy and dental disease as they age than wild camelids. Ovarian hydrobursitis is an important source of infertility in dromedaries. Important infectious diseases include coccidiosis, bovine viral diarrhea virus, alpaca fever, and meningeal worm of NW camelids, trypanosomiasis and camelpox in OW camels, and foot and mouth disease in Bactrian camels and NW camelids. These and other disease processes are discussed in this chapter.

The habitat of Coccidioides spp. and the role of animals as reservoirs and disseminators in nature

BACKGROUND

Coccidioidomycosis, a potentially fatal fungal infection, is considered an emergent mycotic disease because of the increased incidence of fungal infections registered over recent years. Infection occurs through the inhalation of arthroconidia from two main species of Coccidioides: Coccidioides immitis and C. posadasii, which are both endemic to arid and semi-arid regions of North America. Coccidioides species not only infect humans but can also infect other mammals (land, aquatic, wild or domestic), reptiles and birds.

OBJECTIVE

To obtain information regarding the habitat of Coccidioides spp. and the animals infected by this fungus and to identify the role that infected animals play as reservoirs and disseminators of this fungus in nature.

MATERIALS

A literature review was conducted to identify the habitat of Coccidioides spp. and the infected non-human animal species targeted by this fungus.

RESULTS AND CONCLUSIONS

This review allows us to suggest that Coccidioides spp. may be classified as halotolerant organisms; nevertheless, to perpetuate their life cycle, these organisms depend on different animal species (reservoirs) that serve as a link with the environment, by acting as disseminators of the fungi in nature.