Pathology of coccidioidomycosis in llamas and alpacas

Abstract

Coccidioidomycosis is a fungal disease caused by either Coccidioides immitis or Coccidioides posadasii. Anecdotal evidence suggests that camelids are particularly susceptible to this disease and that a relatively large percentage of pneumonias in these animals are caused by Coccidioides spp. In a search of 21 y (1992-2013) of records from the California Animal Health and Food Safety Laboratory, we found 79 cases of coccidioidomycosis diagnosed in camelids; 66 (84%) had pneumonia and 13 (16%) had lesions only in organs other than the lungs. The organs most frequently affected were lung (84%) and liver (78%). Coccidioides spp. were the cause of pneumonia in 66 of 362 (18%) camelid cases during the study period. The lesions in affected organs were multifocal-to-coalescing pyogranulomas, which in most cases were visible grossly. Ten of the 12 formalin-fixed, paraffin-embedded lung samples tested by a universal Coccidioides spp. PCR assay were positive (4 C. immitis, 2 C. posadasii); the species could not be determined in 4 of the 10 cases positive by PCR. Coccidioidomycosis is an important cause of pneumonia in camelids in California, and can be caused by either C. immitis or C. posadasii.

Coccidioidomycosis in alpacas in the southwestern United States

“…Although we were able to identify far fewer necropsy reports for alpacas with coccidioidomycosis compared to another review (Fernandez et al, 2018), we did identify similar trends. Our review identified a similar rate of dissemination to the liver (67% compared to 78%), and spleen and kidney (33% compared to 47% each).…”

“…There is very limited published information on coccidioidomycosis in South American camelids in general and on alpacas in particular, with only two publications detailing cases in this species, and only one animal for which there is antemortem information published (Coster et al., ; Fernandez et al., ). Both series reported widespread disease in most animals.…”

“…The frequency of cardiac involvement seen in the necropsy reports was not anticipated. Cardiac lesions in disseminated cases of coccidioidomycosis are reported in both people and dogs, although with less frequency than these alpacas (Chan et al., ; Shubitz, Matz, Noon, Reggiardo, & Bradley, ), or in camelids in California (Fernandez et al., ). A similar review of canine coccidioidomycosis reports, also from Arizona Veterinary Diagnostic Laboratory, found that 28% had evidence of the disease in the heart and/or pericardium (Shubitz et al., ), while this population of alpacas had a rate of 56%.…”

“…Domestic livestock such as cattle and sheep are susceptible to infection, although clinical illness is rare. South American camelids (SAC), on the other hand, appear to be prone to widespread disseminated illness (Fernandez, Hidalgo, Hodzic, Diab, & Uzal, ; Shubitz, ).…”

“…based on reports in llamas plus conversations with pathologists, veterinarians, and animal owners in southern Arizona (Coster, Ramos‐Vara, Vemulapalli, Stiles, & Krohne, ; Fowler, Pappagianis, & Ingram, ; Maddy, ; Muir & Pappagianis, ). A review of necropsies performed on camelids in California between 1992 and 2013 found that 4% of the animals died from coccidioidomycosis; the fungus was found in extrapulmonary tissue in most of these animals (Fernandez et al., ). There is one case report of coccidioidomycosis causing spontaneous abortion in an alpaca with infection of the placenta and foetus.…”