Validation of the FAMACHA© system in South American camelids.

Haemonchus contortus resistant to multiple anthelmintics threaten the viability of the small ruminant industry in areas where this parasite is prevalent. In response to this situation, the FAMACHA© system was developed and validated for use with small ruminants as a way to detect clinical anemia associated with haemonchosis. Given that H. contortus and multiple anthelmintic resistance is a similar problem in camelids, the FAMACHA© system might also provide the same benefits. To address this need, a validation study of the FAMACHA© system was conducted on 21 alpaca and llama farms over a 2-year period. H. contortus was the predominant nematode parasite on 17 of the 21 farms (10 alpaca and 7 llama farms) enrolled in the study, based on fecal culture results. The FAMACHA© card was used to score the color of the lower palpebral (lower eye lid) conjunctiva on a 1-5 scale. Packed cell volume (PCV) values were measured and compared to FAMACHA© scores using FAMACHA© score cutoffs of ≥3 or ≥4 and with anemia defined as a PCV ≤15%, ≤17%, or≤20%. PCV was significantly associated with FAMACHA© score, fecal egg count (FEC), and body condition score (BCS), regardless of the FAMACHA© cutoff score or the PCV% chosen to define clinical anemia (p<0.01 in all cases). The use of FAMACHA© scores ≥3 and PCV ≥ 15% indicating anemia provided the best sensitivity (96.4% vs 92.9% for FAMACHA© ≥4), whereas FAMACHA scores ≥ 4 and PCV ≤20% provided the best specificity (94.2% vs 69.1% for FAMACHA© ≥3). The data from this study support the FAMACHA© system as a useful tool for detecting clinical anemia in camelids suffering from haemonchosis. Parameters for making treatment decisions based on FAMACHA© score in camelids should mirror those established for small ruminants.

Pathology of Haemonchus contortus in New World camelids in the southeastern United States: a retrospective review.

Most small ruminant farms in tropical climates are plagued by Haemonchus contortus, a hematophagous, abomasal parasite. Heavy burdens of this parasite can cause anemia, hypoproteinemia, weight loss, and mortality in susceptible animals. Haemonchus contortus is becoming a major health concern in New World camelids as well, namely llamas (Llama glama) and alpacas (Vicugna pacos), yet little research has been conducted regarding its prevalence or pathology in these species. Herein, we present a retrospective review of llamas and alpacas that were admitted to The University of Georgia Veterinary Teaching Hospital and Athens Diagnostic Laboratory between the years 2002 and 2013. Antemortem fecal egg count (FEC) estimates performed on 30 alpacas were negatively correlated with hematocrit, hemoglobin, and red blood cell count. Total protein was not significantly correlated with FEC. On postmortem examination, 55 of 198 camelids, including 2 from the aforementioned antemortem review, were infected with H. contortus, with llamas (42.6%) having a significantly higher infection rate than alpacas (22.2%). In 15.7% of the total cases, the parasite was the major cause of death. Common gross lesions included peritoneal, thoracic, and pericardial effusions, visceral pallor, subcutaneous edema, and serous atrophy of fat. Histologic lesions included centrilobular hepatic necrosis, hepatic atrophy, lymphoplasmacytic inflammation of the mucosa of the third gastric compartment (C3), extramedullary hematopoiesis in both the liver and spleen, and the presence of nematodes in C3. Our study emphasizes the importance of H. contortus diagnosis and herd monitoring in New World camelids, particularly llamas.

Comparison of three point-of-care blood glucose meters for use in adult and juvenile alpacas.

OBJECTIVE: To compare the performance of 3 point-of-care glucose meters in adult and juvenile alpacas with that of a laboratory-based analyzer. DESIGN: Evaluation study. ANIMALS: 35 adult alpacas and 21 juvenile alpacas. PROCEDURES: Whole blood samples obtained via jugular venipuncture were tested with all 3 point-of-care glucose meters; plasma samples were also tested with 1 of those meters. Glucose concentrations determined by use of the point-of-care meters were compared with results from the laboratory-based analyzer. RESULTS: Plasma glucose concentrations determined by use of the laboratory-based analyzer ranged from 36 to 693 mg/dL. Over the entire range of glucose concentrations tested, the Lin concordance correlation coefficient (agreement) was significant and excellent for all comparisons. Concordance decreased for 1 glucometer when testing whole blood samples over a narrower range of glucose concentrations (50 to 200 mg/dL). Bias was typically small (< 10 mg/dL) for 3 of the 4 comparisons but considerable for 1 meter with the use of whole blood. The limits of agreement were wide for all comparisons over the entire range of glucose concentrations tested but decreased to within acceptable limits when the narrower glucose range (50 to 200 mg/dL) was analyzed for 3 of the comparisons. For samples with a PCV < 25%, bias and the limits of agreement were greater for one of the meters tested. CONCLUSIONS AND CLINICAL RELEVANCE: Discrepancies between point-of-care glucose meters and reference techniques can be considerable in alpacas, emphasizing the importance of assessing individual meter performance in a target population.

One-stage prothrombin time, activated partial thromboplastin time, thrombin time, fibrin degradation product concentration, and antithrombin activity in healthy adult alpacas.

BACKGROUND: Alpacas are increasingly presented to veterinarians for evaluation and care. Reports of alpaca reference intervals for one-stage prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time (TT), concentration of fibrin degradation products (FDP), and antithrombin (AT) activities are scarce or nonexistent. OBJECTIVE: The aim of this study was to determine values for blood coagulation times (PT, aPTT, and TT), FDP concentrations, and AT activities in healthy adult alpacas. METHODS: Of blood samples collected from 35 clinically healthy adult alpacas via jugular venipuncture and placed into sodium citrate and FDP tubes, 29 samples were assayable for coagulation testing. PT, aPTT, and TT were determined by physical (mechanical) clot detection; AT activity was determined using a thrombin-specific chromogenic substrate end-point assay; and FDP concentrations were determined by the slide agglutination method. RESULTS: Median values and ranges (minimum-maximum) were determined for PT (8.7 seconds, 6.6-11.2 seconds), aPTT (17.3 seconds, 11.9-22.5 seconds), TT (10.2 seconds, 5.4-16.0 seconds), and AT activity (123.3%, 104.8-144.2%). The mean concentration of FDP was <8 µg/mL. CONCLUSION: These values for coagulation times, FDP concentration, and AT activity will provide a useful starting point in the diagnostic evaluation of ill adult alpacas.

Efficacy of anthelmintics on South American camelid (llama and alpaca) farms in Georgia.

The number of South American camelid (SAC; llama and alpaca) farms is growing in the southeastern United States, and infection with gastrointestinal nematodes (GIN) is a major health concern in this region. There is widespread resistance to anthelmintic remedies in small ruminants (sheep and goats), but a paucity of information on llamas and alpacas. Anthelmintic resistance was evaluated on three SAC farms (two llama; one alpaca) in Georgia in the southern United States using fecal egg count reduction (FECR) tests. For each farm, animals were randomly assigned to 1 of 5 treatment groups based on initial fecal egg count (FEC) and number of animals available (2-5 groups, n=9-11 per treatment). Ivermectin (IVM, subcutaneous injection; 0.3mg/kg body weight (BW)) and a control group were tested on an alpaca farm, and fenbendazole (FBZ, oral; 10mg/kg BW; two farms), moxidectin (MOX oral; 0.2mg/kg BW; two farms), and levamisole (LEV, oral; 8 mg/kg BW; one farm) were added for the llama farms. Anthelmintic efficacy was determined by comparing FEC of treatment and control animals 14 days post-treatment, with resistance evaluated using the World Association for the Advancement of Veterinary Parasitology (WAAVP) guidelines. Based upon these guidelines, there was GIN resistance to IVM in both llamas and alpacas in Georgia and to FBZ on both llama farms where this drug was tested. There was MOX resistance on one llama farm using the FECR test, while there was no resistance to LEV detected in this study. These data demonstrate a serious emerging problem in the United States of llama and alpaca GIN resistant to drugs from two of the three major anthelmintic classes.

Prevalence of anthelmintic resistance on sheep and goat farms in the southeastern United States.

OBJECTIVE: To determine prevalence of anthelmintic resistance on sheep and goat farms in the southeastern United States. DESIGN: Cross-sectional study. ANIMALS: Sheep and goats from 46 farms in 8 southern states, Puerto Rico, and St Croix in the US Virgin Islands. PROCEDURES: Parasite eggs were isolated from fecal samples, and susceptibility to benzimidazole, imidathiazole, and avermectin-milbemycin anthelmintics was evaluated with a commercial larval development assay. RESULTS: Haemonchus contortus was the most common parasite on 44 of 46 farms; Trichostrongylus colubriformis was the second most commonly identified parasite. Haemonchus contortus from 45 (98%), 25 (54%), 35 (76%), and 11 (24%) farms were resistant to benzimidazole, levamisole, ivermectin, and moxidectin, respectively. Resistance to all 3 classes of anthelmintics was detected on 22 (48%) farms, and resistance to all 3 classes plus moxidectin was detected on 8 farms (17%). CONCLUSIONS AND CLINICAL RELEVANCE: Findings provided strong evidence that anthelmintic resistance is a serious problem on small ruminant farms throughout the southeastern United States. Owing to the frequent movement of animals among regions, the prevalence of resistance in other regions of the United States is likely to also be high. Consequently, testing of parasite eggs for anthelmintic resistance should be a routine part of parasite management on small ruminant farms.

Evaluation of prevalence and clinical implications of anthelmintic resistance in gastrointestinal nematodes in goats.

OBJECTIVE: To determine prevalence of resistance to all anthelmintics that are commonly used to treat gastrointestinal nematodes (GINs) in goats. DESIGN: Prospective study. ANIMALS: 777 goats. PROCEDURE: On each farm, goats were assigned to 1 of 5 treatment groups: untreated controls, albendazole (20 mg/kg [9.0 mg/lb], p.o., once), ivermectin (0.4 mg/kg [0.18 mg/lb], p.o., once), levamisole (12 mg/kg [5.4 mg/lb], p.o., once), or moxidectin (0.4 mg/kg, p.o., once), except on 3 farms where albendazole was omitted. Fecal samples were collected 2 weeks after treatment for determination of fecal egg counts (FECs), and percentage reductions were calculated by comparing data from anthelmintic-treated and control groups. Nematode populations were categorized as susceptible, suspected resistant, or resistant by use of guidelines published by the World Association for the Advancement of Veterinary Parasitology. RESULTS: Resistance to albendazole was found on 14 of 15 farms, and resistance to ivermectin, levamisole, and moxidectin was found on 17, 6, and 1 of 18 farms, respectively. Suspected resistance to levamisole and moxidectin was found on 4 and 3 farms, respectively. Resistance to multiple anthelmintics (albendazole and ivermectin) was found on 14 of 15 farms and to albendazole, ivermectin, and levamisole on 5 of 15 farms. Mean overall FEC reduction percentages for albendazole, ivermectin, levamisole, and moxidectin were 67, 54, 94, and 99%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Anthelmintic resistance in GINs of goats is highly prevalent in the southern United States. The high prevalence of resistance to multiple anthelmintics emphasizes the need for reexamination of nematode control practices.