Susan J. Tornquist

Coccidioidomycosis in dogs and cats: A review

The dimorphic fungi Coccidioides immitis and Coccidioides posadasii are the causative agents of coccidioidomycosis. Dogs and cats residing in and visiting endemic areas are at risk of exposure to infectious arthrospores. The primary infection is pulmonary and frequently results in chronic cough. Disseminated disease is common and causes cutaneous, osseous, cardiac, ocular, nervous system, or other organ disease. Radiographic changes include a variable degree of interstitial pulmonary infiltration, hilar lymphadenopathy, and osseous lesions. Serological titers support the diagnosis, but definitive diagnosis relies on identification of Coccidioides in cytological or tissue samples. Coccidioidomycosis should be considered in any dog or cat that has been potentially exposed during the previous 3 years and is presented with chronic illness, respiratory signs, lameness, lymphadenopathy, nonhealing cutaneous lesions, or neurological, ocular, or cardiac abnormalities.

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.

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.

Collection and analysis of peritoneal fluid from healthy llamas and alpacas

OBJECTIVE To describe a technique for abdominocentesis in camelids and report peritoneal fluid biochemical and cytologic findings from healthy llamas and alpacas. DESIGN Prospective study. Animals-17 adult llamas and 5 adult alpacas. PROCEDURES Right paracostal abdominocentesis was performed. Peritoneal fluid was collected by gravity flow into tubes containing potassium-EDTA for cell count and cytologic evaluation and lithium heparin for biochemical analysis. Blood samples were collected via jugular venipuncture into heparinized tubes at the same time. Cytologic components were quantified. Fluid pH and concentrations of total carbon dioxide, sodium, potassium, chloride, lactate, and glucose were compared between peritoneal fluid and venous blood. RESULTS All but 3 camelids had peritoneal fluid cell counts of < 3,000 nucleated cells/microL, with < 2,000 neutrophils/microL and < 1,040 large mononuclear cells/microL. All but 1 had peritoneal fluid protein concentrations of > or = 2.5 g/dL. Peritoneal fluid of camelids generally contained slightly less glucose, lactate, and sodium and roughly equal concentrations of potassium and chloride as venous blood. CONCLUSIONS AND CLINICAL RELEVANCE Peritoneal fluid was collected safely from healthy camelids. Compared with blood, peritoneal fluid usually had a low cell count and protein concentration, but some individuals had higher values. Electrolyte concentrations resembled those found in blood. High cell counts and protein concentrations found in peritoneal fluid of some healthy camelids may overlap with values found in diseased camelids, complicating interpretation of peritoneal fluid values.

Investigation of Mycoplasma haemolamae infection in crias born to infected dams

THE haemotropic mycoplasma Mycoplasma haemolamae adheres to the surface of red blood cells of llamas and alpacas. It is variably associated with anaemia and sometimes with other clinical signs such as depression, fever and weight loss. Many infected camelids do not develop clinical or laboratory abnormalities (Tornquist and others 2002, 2009). Infected camelids that are immunosuppressed, stressed or concurrently infected with other organisms are more likely to show clinical signs and to have organisms visible on blood smears (Hutchison and others 1992, Barrington and others 1997, Lascola and others 2009). It appears that many camelids, once infected, remain chronic carriers regardless of whether they are treated with antibiotics (Tornquist and others 2002, 2009). The development of a PCR-based assay in 2001 has facilitated the study of M haemolamae and has begun to clarify some aspects of infection and response to treatment, although the organism has still not been successfully cultivated in vitro. The PCR assay is a sensitive and specific method for identifying early infections as well as subclinical infections (Tornquist and others 2009). The mode of transmission of M haemolamae has not been determined, although biting insect vectors are suspected or confirmed in other haemotropic mycoplasma infections (Messick 2004, Woods and others 2005, Almy and others 2006, Willi and others 2007). In utero transmission has also been suspected, on the basis of the presence of organisms in …

Clinical Pathology of Llamas and Alpacas

Clinical laboratory data including hematology, hemostasis, biochemical, and cytologic findings contribute to diagnosis and monitoring of numerous conditions in camelids. Establishment of reference intervals and descriptions of normal components of fluids in these species have improved our ability to interpret test results.

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.

Hematologic effects of subcutaneous administration of recombinant human granulocyte colony-stimulating factor (filgrastim) in healthy alpacas

OBJECTIVE To determine the effects of SC administration of filgrastim on cell counts in venous blood and bone marrow of healthy adult alpacas. ANIMALS 10 healthy alpacas. PROCEDURES Alpacas were randomly assigned to receive treatment with filgrastim (5 microg/kg, SC; n=5) or an equivalent volume of physiologic saline (0.9% NaCl) solution (5) once a day for 3 days. Blood samples were obtained via jugular venipuncture 1 day prior to treatment and once a day for 5 days commencing 24 hours after the first dose was administered. Complete blood counts were performed for each blood sample. Bone marrow aspirates were obtained from the sternum of each alpaca 48 hours before the first treatment was administered and 72 hours after the third treatment was administered. Myeloid-to-erythroid cell (M:E) ratio was determined via cytologic evaluation of bone marrow aspirates. RESULTS In filgrastim-treated alpacas, substantial increases in counts of WBCs and neutrophils were detected within 24 hours after the first dose was administered. Band cell count and percentage significantly increased 24 hours after the second dose. Counts of WBCs, neutrophils, and band cells remained high 48 hours after the third dose. Red blood cell counts and PCV were unaffected. The M:E ratio also increased significantly after treatment with filgrastim. CONCLUSIONS AND CLINICAL RELEVANCE Filgrastim induced rapid and substantial increases in numbers of circulating neutrophils and M:E ratios of bone marrow in healthy alpacas. Therefore, filgrastim may be useful in the treatment of camelids with impaired bone marrow function.

Evaluation of serum amyloid A and haptoglobin concentrations as prognostic indicators for horses with inflammatory disease examined at a tertiary care hospital

OBJECTIVE To evaluate use of serum amyloid A (SAA) and haptoglobin concentrations as prognostic indicators for horses with inflammatory disease in regard to euthanasia, complications, and hospitalization duration and cost. ANIMALS 20 clinically normal horses and 53 horses with inflammatory disease. PROCEDURES Total WBC count, neutrophil count, and fibrinogen, SAA, and haptoglobin concentrations were determined for clinically normal horses and horses with suspected inflammatory disease. Clinicopathologic values at admission were compared to test the use of SAA and haptoglobin concentrations in predicting euthanasia, complications, and hospitalization duration and cost. Haptoglobin and SAA concentrations of 22 horses were monitored during hospitalization to test the use of serial measurements in predicting survival and complications. RESULTS Neutrophil count and SAA and haptoglobin concentrations were significantly different at admission for horses with inflammatory disease, compared with those for clinically normal horses. Horses with colitis and peritonitis had significantly higher SAA and haptoglobin concentrations than clinically normal horses. A moderate positive correlation (r = 0.355) between hospitalization duration and haptoglobin concentration was identified. Horses with an increase in SAA concentration between 24 and 72 hours after admission, compared with admission SAA concentration, were significantly more likely (OR, 7.0; 95% confidence interval, 1.1 to 45.9) to be euthanized or develop complications. CONCLUSIONS AND CLINICAL RELEVANCE Concentrations of SAA and haptoglobin at admission were not significantly correlated with outcome in horses with inflammatory conditions. Acute-phase proteins likely have more utility in serial analysis rather than testing at a single time point for horses with inflammatory conditions.

Diagnostic Sampling and Gross Pathology of New World Camelids

This article provides an overview of tests and appropriate samples to send to a Veterinary Diagnostic Laboratory for the diagnosis of common diseases of New World Camelids (NWC) such as abortions, congenital anomalies, anemia, enteritis, endoparasitism, gastric ulcer, hepatic lipidosis, encephalitis, pneumonia, dermatosis, neoplasia and cryptococcosis. Unique anatomic features of NWC and common findings encountered during gross necropsy examination are briefly reviewed.