Prevalence of Mycoplasma haemolamae infection in Peruvian and Chilean llamas and alpacas.

Mycoplasma haemolamae is a hemotropic mycoplasma that affects red blood cells of llamas (Lama glama) and alpacas (Lama pacos). It is variably associated with anemia, and most infections are subclinical. Development of a polymerase chain reaction assay has facilitated detection of this infection in llamas and alpacas in the United States and other countries. Whether the infection occurs in camelids in South America has previously been unknown. The current study documents a 15.8% infection rate among 76 Peruvian llamas, a 19.3% infection rate among Peruvian alpacas at one site, and a 9.26% infection rate in 108 Chilean alpacas from selected herds. All of the camelids tested appeared to be clinically healthy. No gender or species predilection was found. Only 1 positive camelid younger than 18 months was found. Infection is not associated with anemia, and the mean packed cell volume (PCV) in positive Peruvian camelids was slightly higher than the mean PCV in negative Peruvian camelids. In the Chilean alpacas, the positive alpacas had a slightly lower PCV than the negative alpacas, although the mean PCV was not in the anemic range in any of the groups.

Use of a polymerase chain reaction assay to study response to oxytetracycline treatment in experimental Candidatus Mycoplasma haemolamae infection in alpacas.

OBJECTIVE: To develop a PCR assay for Candidatus Mycoplasma haemolamae (CMhl) infection in alpacas and use it to study the efficacy of oxytetracycline treatment and development of a subclinical carrier state. ANIMALS: 8 healthy adult alpacas. PROCEDURES: Alpacas initially had negative results for CMhl in blood samples via PCR assay and were experimentally infected with CMhl; 4 were treated with oxytetracycline, and 4 were not treated. All were monitored regularly via PCR assay, blood smear examination, PCV, rectal temperature, and physical examination. At 6 months after treatment, all alpacas were immunosuppressed by administration of dexamethasone and tested for CMhl. RESULTS: 7 of 8 alpacas had positive PCR assay results 4 to 6 days after experimental infection. When organisms were detectable on a blood smear, they were seen 2 to 6 days after positive results of PCR assay. Infection was often associated with mild anemia that was usually transient. No alpacas became hypoglycemic. Oxytetracycline treatment was not associated with faster clearance of organisms or resolution of anemia, and 4 of 4 treated alpacas still had positive results of PCR assay when immunosuppressed 6 months later; 0 of 3 nontreated alpacas had positive results of PCR assay following immunosuppression. Transient fever was detected in 3 alpacas during immunosuppression. CONCLUSIONS AND CLINICAL RELEVANCE: The PCR assay was more sensitive than blood smear examination for detection of infection. Clinical signs, anemia, and fever were not necessarily associated with infection. Oxytetracyline administration did not consistently clear CMhl infection. Although treated with oxytetracycline, infected alpacas remained chronic carriers.

Comparison between manual and automated total nucleated cell counts using the ADVIA 120 for pleural and peritoneal fluid samples from dogs, cats, horses, and alpacas.

BACKGROUND: Analysis of body fluids includes an estimate of total nucleated cell count (TNCC). Automated methods may enhance the accuracy and timeliness of TNCC results. OBJECTIVE: The purpose of this report was to assess the ability of the ADVIA 120 hematology analyzer to accurately count nucleated cells in pleural and peritoneal fluids from animals, compared with manual counts. METHODS: Pleural and peritoneal fluids submitted in EDTA tubes to our laboratory over a 17-month period were used in the study. TNCC/microL was determined by a manual method, using a hemocytometer, and by an automated method, using the ADVIA 120. Correlation of results was determined by Passing-Bablok regression, Bland-Altman plots, and Pearson correlation analysis. RESULTS: Samples from dogs (n=36), cats (n=36), horses (n=59), and alpacas (n=11) were analyzed. High correlation in TNCC between methods was found for peritoneal fluid (n=93, r=.959), pleural fluid (n=49, r=.966), and all fluids combined (n=142, r=.960) (P<.001). Variation between methods was greater in samples with TNCCs<1000/microL (r=.62, P<.001). The ADVIA systematically overestimated the number of cells in all fluid samples by 95 cells/microL (confidence interval=19.2-190.5/muL). CONCLUSION: The ADVIA 120 reliably determines TNCC in pleural and peritoneal effusions and can be recommended for routine veterinary laboratory analysis.