Anthelmintic resistance in a herd of alpacas (Vicugna pacos)

A herd of alpacas was examined because of a history of severe endoparasitism, anemia, hypoproteinemia, and weight loss. Resistance of gastrointestinal nematodes to albendazole, fenbendazole, and doramectin was documented. This report suggests that anthelmintic resistance may be an emerging problem in South American camelids in North America.     

Neurological causes of diaphragmatic paralysis in 11 alpacas (Vicugna pacos)

Background: Diaphragmatic paralysis is a relatively uncommon medical condition in animals not reported in alpacas. Objectives: Describe the signalment, physical examination, diagnostic testing, clinical, and histopathologic findings related to diaphragmatic paralysis in alpacas. Animals: Eleven alpacas with spontaneous diaphragmatic paralysis. Methods: A retrospective study examined medical records from a 10‐year period and identified 11 alpacas with confirmed diaphragmatic paralysis admitted to Washington State University and Colorado State University Veterinary Teaching Hospitals between September 2003 and October 2009. Results: The 11 alpacas ranged in age from 2 to 12 months. Fluoroscopic imaging confirmed the presence of bilateral diaphragmatic paralysis in the 7 alpacas that were imaged. Arterial blood gas analyses showed hypercapnea, hypoxemia, and low oxygen saturation. Seven alpacas died or were euthanized between 2 and 60 days after onset of respiratory signs. Histopathologic examination of tissues found phrenic nerve degeneration in the 6 alpacas that were necropsied and additional long nerves examined demonstrated degeneration in 2 of these animals. Two animals had spinal cord lesions and 2 had diaphragm muscle abnormalities. No etiologic agent was identified in the alpacas. Conclusions and Clinical Importance: The etiology for diaphragmatic paralysis in these alpacas is unknown. A variety of medical treatments did not appear to alter the outcome.     

Rumen‐protected methionine supplementation and fibre production in alpacas (Vicugna pacos)

Sulphur‐containing amino acids are a crucial requirement for fibre production and may be supplemented in the diet of fibre‐producing animals to stimulate fibre growth. The alpaca fibre industry is a developing industry in Australia with high variability in fibre production. To date, there is no evidence whether supplementing the diet of alpacas with sulphur amino acids improves fibre production. We hypothesised that supplementation with the rumen‐protected sulphur amino acid, methionine would increase fibre growth in alpacas. Three groups of eight huacaya alpaca wethers were fed daily a maintenance diet supplemented with 0, 2 or 4 g of rumen‐protected methionine for 7 weeks. Fibre samples were taken at the beginning and end of the study with a blood sample taken by jugular venipuncture prior to feeding on the first day of each week. Methionine supplementation had no effect on fibre diameter (p = 0.92), fibre length (p = 0.91) or fibre yield (p = 0.33). The change of season over the study affected plasma glucose (p < 0.001), plasma urea nitrogen (p < 0.001) and fibre diameter (p < 0.001). The indifference between groups may be due to the maintenance diet supplying sufficient levels of methionine, the lack of genetic potential of the experimental animals to respond to additional methionine or that the supplemental methionine was not protected in alpacas and deaminated for glucose production.     

Demodex spp. infestation and suspected demodicosis of alpacas (Vicugna pacos) in New Zealand

Extract

Ectoparasites known to cause skin lesions in alpacas (Vicugna pacos) include the mites Sarcoptes scabiei, Chorioptes bovis and Psoroptes spp., and the lice Microthoracius mazzai and Bovicola breviceps (Cicchino et al. 1998 Cicchino, AC, Munoz, Cobenas ME, Bulman, GM, Diaz, JC and Laos, A. 1998. Identification of Microthoracius mazzai (Phthiraptera: Anoplura) as an economically important parasite of alpacas. Journal of Medical Entomology, 35: 922–930.  [Google Scholar]; Foster et al. 2007 Foster, A, Jackson, A and D'alterio, GL. 2007. Skin diseases of South American camelids. In Practice, 29: 216–223. [Crossref], [Web of Science ®] , [Google Scholar]). Occasionally, Demodex spp. infestations have been reported or mentioned as incidental fi ndings in llamas (Lama glama) (Atlee et al. 1997 Atlee, BA, Stannard, AA, Fowler, ME, Willemse, T, Ihrke, PJ and Olivry, T. 1997. The histology of the normal llama skin. Veterinary Dermatology, 8: 165–176. [Crossref], [Web of Science ®] , [Google Scholar]) and alpacas (Foster et al. 2007 Foster, A, Jackson, A and D'alterio, GL. 2007. Skin diseases of South American camelids. In Practice, 29: 216–223. [Crossref], [Web of Science ®] , [Google Scholar]). So far, only Sarcoptes scabiei (McKenna et al. 2005 McKenna, PB, Hill, FI and Gillett, R. 2005. Sarcoptes scabiei infection on an alpaca (Lama pacos. New Zealand Veterinary Journal, 53: 213–213. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]), Chorioptes bovis (Arthur 1997 Arthur, DG. 1997. Diseases of lamoids in New Zealand. Surveillance, 24(1): 29–30.  [Google Scholar], non-peer reviewed) and Bovicola breviceps (Palma et al. 2006 Palma, RL, McKenna, PB and Aitken, P. 2006. Confirmation of the occurrence of the chewing louse Bovicola (Lepikentron) breviceps (Insecta: Phthiraptera: Trichodectidae) on alpacas (Lamas pacos) in New Zealand. New Zealand Veterinary Journal, 54: 253–254. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]) have been recorded on lamoids in New Zealand. Here, we report the first record of Demodex spp. infestation of an alpaca in New Zealand.     

Presence and molecular characterisation of Giardia and Cryptosporidium in alpacas (Vicugna pacos) from Peru

The presence of Giardia and Cryptosporidium was investigated in 274 faecal samples of alpacas (Vicugna pacos) from 12 herds from Peru by immunofluorescence microscopy and PCR amplification and sequencing of fragments of the ssu-rRNA and β-giardin genes from Giardia spp., as well as the ssu-rRNA gene from Cryptosporidium spp. A total of 137 samples (50.0%) were positive for Giardia spp., and 12 samples (4.4%) for Cryptosporidium spp. In ten samples (3.6%), co-infection by both pathogens was found. Herd prevalence was found to be 91.7% (11/12 herds) for Giardia and 58.3% (7/12 herds) for Cryptosporidium. Regarding the age of the animals, although Giardia was detected in animals as young as 1 week, the prevalence increased with age, reaching 80% by 8 weeks. Similarly, the highest percentage of Cryptosporidium detection (20%) was also found in the 8 week-old group. By PCR, 92 of the 274 analysed samples were positive for Giardia. Sequencing of the amplicons showed the existence of Giardia duodenalis assemblage A in 67 samples; G. duodenalis assemblage E in 24 samples; and inconsistent results between the two molecular markers used in a further sample. Cryptosporidium was only detected by PCR in 3 of the 274 samples; Cryptosporidium parvum was identified in two samples and Cryptosporidium ubiquitum in one sample. This study is the first performing molecular characterisation of both parasites in Peruvian alpacas, and the first report of C. ubiquitum in this host. The identification of G. duodenalis assemblage A, C. parvum and C. ubiquitum, suggests that zoonotic transmission of these enteropathogens between alpacas and humans is possible.     

Volatile fatty acid profile for grass hay or alfalfa hay fed to alpacas (Vicugna pacos)

The purpose of this study was to determine the diurnal composition and concentration of volatile fatty acids (VFA) and to determine VFA composition and concentration differences between stomach compartment 1 (C1) and caecum of alpacas fed grass and alfalfa hay. The study was divided into two experiments. In Experiment 1 (EXP 1), 10 male alpacas (3+ years old, 65 kg BW) were divided into two groups, housed in drylot pens, provided ad libitum water and fed alfalfa (AH) or grass hay (GH) for 30 days. The alpacas were slaughtered and the digestive tract collected, divided into sub‐tract sections, weighed and digesta sampled for pH, dry matter (DM) and NDF. Volatile fatty acid composition and concentration were determined on C1 and caecal material. Four adult male (3+ years old, 60 kg BW), C1 fistulated alpacas were housed in metabolism crates and divided into two forage groups for Experiment 2 (EXP 2). Alpacas were fed the forages as in EXP 1. Diurnal C1 VFA samples were drawn at 1, 3, 6, 9, 12, 18 and 24 h post‐feeding. There were no differences between forages for tract weight, C1 and caecum digesta DM or NDF. Differences were noted (p < 0.05) for pH between forages and sub‐tract site. Volatile fatty acids concentrations were different (p < 0.05) for forage and site, and total VFA was higher for AH than GH (110.6 and 79.1 mm ) and C1 than caecum (40.7 and 27.6 mm ). Proportion of VFA was significant (p < 0.05) for forage and site, C1 acetate highest for GH (84.8 vs. 74.0 mm ) and caecum acetate 83.7 and 76.2 mm for GH and AH respectively. These data demonstrate the level of VFA produced in C1 and the caecum of alpacas and the diurnal VFA patterns. Composition of VFA is similar to other ruminant species.     

Pharmacokinetics of ceftiofur crystalline free acid after single and multiple subcutaneous administrations in healthy alpacas (Vicugna pacos)

Dechant, J. E., Rowe, J. D., Byrne, B. A., Wetzlich, S. E., Kieu, H. T., Tell, L. A. Pharmacokinetics of ceftiofur crystalline free acid after single and multiple subcutaneous administrations in healthy alpacas (Vicugna pacos). J. vet. Pharmacol. Therap.  36 , 122–129. Six adult male alpacas received one subcutaneous administration of ceftiofur crystalline free acid (CCFA) at a dosage of 6.6 mg/kg. After a washout period, the same alpacas received three subcutaneous doses of 6.6 mg/kg CCFA at 5‐day intervals. Blood samples collected from the jugular vein before and at multiple time points after each CCFA administration were assayed for ceftiofur‐ and desfuroylceftiofur‐related metabolite concentrations using high‐performance liquid chromatography. Pharmacokinetic disposition of CCFA was analyzed by a noncompartmental approach. Mean pharmacokinetic parameters (±SD) following single‐dose administration of CCFA were C_max (2.7 ± 0.9 μg/mL); T_max (36 ± 0 h); area under the curve AUC_0→∞ (199.2 ± 42.1 μg·h/mL); terminal phase rate constant λz (0.02 ± 0.003/h); and terminal phase rate constant half‐life t_1/2λz (44.7 h; harmonic). Mean terminal pharmacokinetic parameters (±SD) following three administrations of CCFA were C_max (2.0 ± 0.4 μg/mL); T_max (17.3 ± 16.3 h); AUC_0→∞ (216.8 ± 84.5 μg·h/mL); λz (0.01 ± 0.003/h); and t_1/2λz (65.9 h; harmonic). The terminal phase rate constant and the T_max were significantly different between single and multiple administrations. Local reactions were noted in two alpacas following multiple CCFA administrations.     

Pulmonary alveolar microlithiasis in an alpaca (Vicugna pacos)

Pulmonary alveolar microlithiasis (PAM) is a rare, familial disease of unknown aetiology characterised by intra‐alveolar formation and accumulation of microliths. Multiple formalin‐fixed tissues were submitted from a 5‐month‐old female alpaca that died suddenly without significant clinical signs. No gross abnormalities were observed on postmortem examination. Histological findings included PAM and severe centrilobular hepatic necrosis. Although the hepatic lesion was the likely cause of death, PAM was an incidental finding that has not been reported previously in alpacas. An overview of PAM, including pathogenesis and histopathological characteristics, are discussed in relation to the concurrent hepatic disease in the present case.     

Diaphragmatic hernia in a two-year-old alpaca (Vicugna pacos)

A 2-yr-old male intact alpaca (Vicugna pacos) was admitted for a 4-day history of anorexia and colic. Five months prior, the alpaca had undergone surgical removal of a duodenal trichophytobezoar and had recovered uneventfully. The alpaca died under anesthesia, and diaphragmatic herniation of the third gastric compartment (C3) was diagnosed at necropsy. A defect was identified in the left dorsal hemidiaphragm accompanied by herniation of 80% of C3 and the aboral portion of the second gastric compartment into the pericardial sac. The smooth margins and dorsal location of the diaphragmatic defect suggested a congenital origin. Diaphragmatic herniation is uncommon in camelids, and only one other case has been reported. Due to the dorsal location of the diaphragmatic defect in this animal, positioning during the previous surgery may have initiated a partial entrapment of gastric compartments, leading to a more complete incarceration between when the animal was discharged and presented again.     

Vitamin D doses for alpacas (Lama pacos)

OBJECTIVE: To assess the effectiveness of cholecalciferol (D3) doses for maintaining adequate vitamin D status in crias and adult female alpacas at pasture. DESIGN: A field experiment during winter and early spring in a herd on a farm in South Australia. ANIMALS AND PROCEDURE: Crias, usually less than 6 months of age and female alpacas, aged 2 to 6 years, were given a single subcutaneous dose of 0, 1000 or 2000 IU D3/kg body weight. Plasma concentrations of 25-hydroxycholecalciferol (25-OH D3), phosphorus, calcium and vitamins A and E and alkaline phosphatase activity were measured at intervals over a period of 16 weeks after treatment. RESULTS: Crias not given a vitamin D supplement had reduced growth rate during winter and one animal showed clinical signs of rickets. Vitamin D treatment had no effect on the body weight of mature females. Vitamin D supplements increased the 25-OH D3 and phosphorus concentrations in plasma of both crias and adult females; alkaline phosphatase activity was not affected by treatment. CONCLUSION: It is suggested that for alpacas in southern Australia a subcutaneous dose of 1000 IU D3/kg body weight to crias in late autumn and again in mid winter and to adult females in mid winter should prevent vitamin D inadequacy.     

Rickets in alpacas (Lama pacos) in New Zealand

Rickets was diagnosed in two weaner alpacas showing ill thrift and lameness during the winter of 1992, from a flock at AgResearch Flock House. Affected alpacas had abnormally shaped ribs with occasional healing fractures, irregular thickening of growth plates and metaphyseal haemorrhages. The mean serum phosphorus concentrations of the alpacas fell during June and July, even though lambs grazing the same pasture had normal serum phosphorus concentrations and the phosphorus concentration of the pasture was considered adequate. Vitamin D deficiency may also have contributed to the osteodystrophy. The alpacas had a thick fleece during the winter, and diurnal Vitamin D3 synthesis resulting from solar irradiation is likely to have been minimal, especially considering the reduced sunshine hours recorded during the 1992 winter. Surviving alpacas recovered after treatment with monosodium phosphate and an oral Vitamin D supplement.