Experimental equine herpesvirus-1 infection in llamas (Lama glama).

Three llamas (Lama glama) were experimentally infected intranasally with an isolate of equine herpesvirus-1 (EHV-1) from the brain of an alpaca that had experienced severe neurologic signs. Two of the 3 llamas developed severe neurologic disorders following inoculation; 1 died, and 1 was euthanized in a moribund state. The third llama showed only mild neurologic signs. The euthanized llama had preexisting antibodies to EHV-1, and the remaining 2 llamas were seronegative (virus neutralization titer less than 6) at the time of inoculation. One of the seronegative llamas died acutely without production of detectable antibodies, and the other developed antibodies typical of a primary immune response. The EHV-1 virus was recovered only from a sample of the thalamus of the llama that died acutely. Histopathologic lesions were observed in the brain and retina of the dead and euthanized animals. This study verifies the pathogenic potential of EHV-1 for llamas.     

Foot-and-mouth disease virus in the llama (Lama glama): diagnosis, transmission, and susceptibility

Foot-and-mouth disease virus (FMDV) was shown to be transmitted from either cattle to llamas, llamas to swine (interspecies), or llamas to llamas (intraspecies). Response to FMDV varied greatly in the 6 llamas studied; 3 llamas developed generalized clinical disease with mild pyrexia, 2 after intradermolingual inoculation, and 1 after exposure to a calf infected with FMDV serotype A24. Another contact llama developed vesicular lesions on all 4 extremities but no oral lesions. Two contact llamas, in separate study groups, did not seroconvert or develop clinical signs of FMDV infection. All 4 llamas showing clinical disease developed virus-neutralizing antibodies against FMDV A24 and antibodies against the virus-infection-associated antigen. Virus-neutralizing antibody titers remained elevated for over 200 days postinoculation or exposure. Antibodies to virus-infection-associated antigen were detected several days after virus-neutralizing antibody appeared and became weaker 100-125 days post-FMDV exposure in 3 of the 4 clinically affected llamas. One inoculated llama was still positive for virus-infection-associated antigen at 360 days after inoculation. Foot-and-mouth disease virus A24 was not detected from esophageal-pharyngeal fluid specimens beyond 8 days postexposure using in vitro techniques.     

Passive transfer of colostral immunoglobulin G in neonatal llamas and alpacas

OBJECTIVE: To evaluate precolostral hypogammaglobulinemia in neonatal llamas and alpacas, to determine when postcolostral peak serum IgG concentrations develop, to determine whether differences in postcolostral serum IgG concentrations between llamas and alpacas exist, and to determine postcolostral half-life of serum IgG in llamas and alpacas. DESIGN: Prospective observational study. ANIMALS: 29 llama and 10 alpaca crias. PROCEDURE: Blood samples were collected prior to suckling and on days 1, 2, and 3 after parturition and analyzed for serum IgG concentration by use of a commercial radial immunodiffusion assay. Additional samples were collected on days 8, 13, and 18 from 8 crias to determine mean half-life of IgG. RESULTS: Llamas and alpacas are born severely hypogammaglobulinemic. Mean serum IgG concentrations for day-1, -2, and -3 samples for llamas were 1,578 mg/dl, 1,579 mg/dl, and 1,401 mg/dl, respectively, and for alpacas were 2,024 mg/dl, 1,806 mg/dl, and 1,669 mg/dl, respectively. Peak serum immunoglobulin concentration developed between days 1 and 2. Mean half-life of IgG for all crias was 15.7 days. CONCLUSIONS AND CLINICAL RELEVANCE: Although increased mortality has been linked to failure of passive transfer, it is clearly possible to raise crias that have low serum immunoglobulin concentrations. Llamas and alpacas do not differ significantly with respect to immunoglobulin absorption or IgG concentration in neonates. The optimal sampling time for passive transfer status is between 1 and 2 days.     

Evaluation of glucose tolerance and insulin sensitivity in Ilama crias

OBJECTIVE: To investigate glucose tolerance and insulin sensitivity in llama crias. ANIMALS: 7 llamas (age range, 14 to 30 days). PROCEDURE: On each of 2 sequential days, crias were administered glucose (0.5 g/kg) via rapid i.v. injection. On 1 day (randomly determined for each cria), regular insulin (0.2 U/kg) or 0.9% NaCl solution (0.002 mL/kg) was administered i.v. 15 minutes after glucose administration. Blood samples were collected before (baseline) and at 5, 15, 30, 45, 60, 90, 120, 180, and 240 minutes after glucose administration for determination of plasma glucose and insulin concentrations; fractional turnover rates and plasma half-life of glucose were calculated. The data were compared over time and between days (ie, between glucose treatments with and without insulin administration). RESULTS: A peak plasma glucose concentration of 342 +/- 47 mg/dL was detected at 5 minutes after glucose administration and llamas cleared glucose from plasma within 60 minutes; at 15 minutes, plasma insulin concentration attained a peak value of 33 +/- 13 microU/mL (ie, triple the baseline value). During the 15- to 45-minute interval, fractional turnover rate of glucose was 1.10 +/- 0.24%/min and plasma half-life was 65.7 +/- 13.4 minutes. Insulin significantly increased glucose turnover and resulted in hypoglycemia within 75 minutes of administration. CONCLUSIONS AND CLINICAL RELEVANCE: Healthy immature llamas have glucose tolerance and insulin sensitivity superior to that of adults. However, whether sick crias retain the pancreatic sufficiency and tissue responsiveness that are likely responsible for the rapid glucose clearance in healthy individuals is not known.     

Vaccination-related anthrax in three llamas

Two llama calves died 3 days after inoculation with anthrax vaccine. Concurrent administration of ivermectin and other biologics may have enhanced the infectivity of the Sterne strain vaccine of Bacillus anthracis. This experience suggests that the Sterne strain of anthrax vaccine can induce fatal disease when given to young llamas and should be used only with extreme care and in face of strong "at risk" situations.     

Encephalitic listeriosis in two adult llamas (Lama glama): clinical presentations, lesions and immunofluorescence of Listeria monocytogenes in brainstem lesions

Encephalitic listeriosis was diagnosed in 2 adult llamas. Both had a multifocal suppurative encephalitis with mixed lymphocytic and neutrophilic perivascular infiltrates. Listeria monocytogenes was cultured from the brain stem of 1 llama using cold enrichment techniques; the other llama was culture negative. Formalin-fixed and paraffin embedded sections of brainstem lesions from both affected animals were labeled with a fluorescein-conjugated, anti-L. monocytogenes antibody. Using this technique, intralesional L. monocytogenes were identified in both llamas.     

Yeast Flora in Oropharyngeal and Rectal Mucous Membranes of Healthy and Critically Ill Neonatal Foals

Little is known about the normal or pathologic yeast flora in healthy and critically ill neonatal foals. The aims of this study were to evaluate the yeast flora colonizing the mucous membranes of the digestive tract (oropharynx and rectum mucous membranes) of healthy and hospitalized foals and to find out risk factors involved in yeast colonization of foals referred to a neonatal intensive care unit. A total of 240 swabs were collected from 21 healthy (group A) and 39 sick (group B) foals. In 14 of the 60 foals, yeast was isolated in at least one sample (23.3%): 3 of the 21 foals (14.3%) were positive in group A and 11 of 39 foals (28.2%) were positive in group B. The yeasts were isolated from rectal swabs obtained from none in healthy foals, whereas 5 of the 39 sick foals were positive; however, this difference was not statistically significant. No significant difference was also detected regarding oropharyngeal swabs between healthy (3/21) and sick (10/39) foals. The risk factors significantly associated with the isolation of yeasts from rectal swabs were female sex, treatment with oral antibiotics, and stressful diagnostic–therapeutic procedures. The only risk factor significantly associated with the isolation of yeast from oropharyngeal swabs was the treatment with antacids and gastroprotectants. The results show that fungi present in the gastrointestinal tract of neonatal foals were mainly environmental yeasts and suggested the absence of a stable fungal colonization. Candida was the genus frequently isolated in hospitalized foals, just as it is isolated in critically ill human neonates.     

Detection of lysozyme in llama, sheep, and cattle tears

OBJECTIVE: To determine whether the tears of llamas, sheep, and cattle contain lysozyme and compare lysozyme concentrations in tears among these species. ANIMALS: 40 llamas, 5 sheep, and 36 cattle. PROCEDURE: Electrophoresis, western blot immunoassay for lysozyme, a spectrophotometric assay to detect tear lysozyme by its ability to lyse a suspension of Micrococcus lysodeiticus, and a microtiter plate colorometric assay were performed. RESULTS: A 13.6-kd protein band was detected by use of electrophoresis and western blot immunoassay in llama and sheep tears but not cattle tears. Results of spectrophotometric assay suggested that llama and sheep tears had high concentrations of lysozyme, whereas cattle tears had low concentrations. Results of the microtiter plate colorometric assay suggested that llama tears had high concentrations of lysozyme, whereas concentrations in sheep and cattle tears were lower. CONCLUSIONS AND CLINICAL RELEVANCE: Lysozyme concentrations in tears may vary among species and this variability may contribute to differing susceptibilities to ocular diseases such as infectious keratoconjunctivitis.     

Coccidia of the llama, Lama glama, in Colorado and Wyoming.

Fecal samples were collected from 144 llamas, Lama glama, on four premises in northern Colorado and southern Wyoming. Feces were examined for the presence of coccidial oocysts; Eimeria alpacae was found in 55.6%, Eimeria lamae in 67.3% and Eimeria macusaniensis in 1.4% of the samples. An adult female llama was found to be infected with Eimeria macusaniensis at necropsy. This is the first report of these species of coccidia in the llama.     

Hyperlipemia and Ketonuria in an Alpaca and a Llama

An alpaca and a llama in late stages of gestation were evaluated for lethargy, anorexia, and recumbency. Both camelids had cloudy, white, turbid serum, elevated serum triglyceride (1564, 5658 mg/dL, respectively) and cholesterol (158, 297 mg/dL, respectively) concentrations, and ketonuria. Signs of fetal stress were evident ultrasonographically in the alpaca, and a live cria was delivered by Cesarean section performed under general anesthesia. The alpaca developed severe metabolic acidosis, hepatic lipidosis, and acute renal failure secondary to renal lipidosis and died 36 hours after admission despite medical therapy. Histopathology revealed renal and hepatic lipidosis and neutrophilic pancreatitis. The cria died 72 hours after birth. The llama responded to IV electrolyte, dextrose, and regular crystalline insulin therapy. The pregnancy was maintained, and the llama was discharged from the hospital 20 days after admission. Two months after discharge, the llama gave birth to a live, 5 kg cria. Findings of hypertriglyceridemia, hypercholesterolemia, elevated sorbitol dehydrogenase activity, metabolic acidosis, azotemia, and ketonuria occurred in these two camelids. Based on this report, camelids appear to be similar to both horses and cattle in their response to severe energy imbalances in late gestation.     

Seasonal changes in serum calcium, phosphorus, and vitamin D concentrations in llamas and alpacas

OBJECTIVE: To evaluate the interaction of season and age on serum calcium, phosphorus, and vitamin D3 concentrations in llamas and alpacas. ANIMALS: 23 clinically normal llamas and 7 alpacas. PROCEDURES: Animals were assigned to 1 of the 3 following groups on the basis of age at the start of the study: adult (age, > or = 24 months; n = 8), yearling (> 12 but < 20 months; 5), and neonate (< 6 months; 17). Twelve serum samples were obtained at monthly intervals. Calcium, phosphorus, and vitamin D3 concentrations were measured, and the calcium-to-phosphorus concentration (Ca:P) ratio calculated. Effect of season and age on each of these variables was determined. RESULTS: Vitamin D3 concentrations varied significantly as a function of season; the highest and lowest concentrations were detected September through October and February through March, respectively. The seasonal decrease in vitamin D3 concentration was significantly greater in neonates and yearlings, compared with adults. Serum phosphorus concentration decreased as a function of age, with the most significant seasonal change detected in the neonate group. The Ca:P ratio in neonates varied between 1.1 and 1.3 except during winter months when it increased to > or = 2.0. CONCLUSIONS AND CLINICAL RELEVANCE: Mean vitamin D3 concentration varied by > 6 fold in neonatal and yearling llamas and alpacas and > 3 fold in adult animals as a function of season. These results support the hypothesis that seasonal alterations in vitamin D3 concentrations are a key factor in the development of hypophosphatemic rickets in llamas and alpacas.     

Suspected chlorpyrifos toxicosis in a llama, and plasma pseudocholinesterase activity in llamas given chlorpyrifos

Five days after treatment with chlorpyrifos, a 1.5-year-old male llama was unable to stand, had saliva flowing from its mouth, and had constricted pupils, hyperglycemia, a metabolic acidosis, and a plasma pseudocholinesterase activity of 111 IU/L. Mean (+/- 1 SD) plasma pseudocholinesterase activity of 29 healthy llamas was 233.76 +/- 51.55 IU/L. Five to 8 days after topical application of chlorpyrifos (25 mg/kg of body weight) to 3 healthy llamas, the pseudocholinesterase activity decreased to 38% to 62% of pretreatment (base-line) activity and returned to within 90% of base-line activity by the 36th to 48th day after treatment.     

Ventral Abdominal Approach for Laparoscopic Ovariectomy in Llamas

Objective —To evaluate a technique for laparoscopic ovariectomy by a ventral abdominal approach in the llama.
Study Design —Prospective evaluation.
Animal Population —Six healthy adult female llamas, aged 2 to 6 years.
Methods —Laparoscopic ovariectomy was performed with the llamas in a 30-degree Trendelenburg position. The mesovarium and proper ligament of the ovary were isolated, and two Hulka clips were placed in opposite directions across each mesovarium and proper ligament of the ovary. Ovaries were removed through either the instrument cannula or instrument portal.
Results —The ovaries, mesovarium, and proper ligaments of the ovaries were easily identified using laparoscopy by a ventral abdominal approach. The Hulka Clip Applicator was easy to use, and the Hulka Clips provided secure hemostasis of the vessels within the mesovarium. Mean duration of surgery was 35 minutes (range, 17 to 85 minutes). Two llamas were depressed after surgery but improved within 24 hours. No other complications occurred during an 18-month follow-up period.
Conclusions —Laparoscopic ovariectomy in the llama was facilitated by the use of Hulka Clips placed across the mesovarium and proper ligament of the ovary.
Clinical Relevance —Laparoscopic ovariectomy in the llama can be accomplished easily with few complications.     

The llama industry in the United States

This chapter provides an overview of the llama in the United States. It covers the animal and its history, the people who own llamas, and the business that is developing around them and describes the industry's needs from the veterinary profession in terms of health care.     

The use of equine surfactant and positive pressure ventilation to treat a premature alpaca cria with severe hypoventilation and hypercapnia

A 5-hour-old, premature alpaca cria was presented with failure to nurse, weakness, hypoglycemia, hypercapnia, and respiratory distress. The cria was treated with 3 doses of fresh, crude equine surfactant, positive pressure ventilation, and supplemental intranasal oxygen. Recovery to discharge was uneventful, and the cria regained apparently normal respiratory function. Three years after hospital discharge, the alpaca was a healthy adult.     

Camelid mucoutaneous fibropapillomas: clinicopathologic findings and association with papillomavirus

Five camelid mucocutaneous fibropapillomas with histologic features similar to equine sarcoids were diagnosed. They were characterized by a dermal fibroblastic proliferation and overlying, often ulcerated hyperplastic epidermis with thin rete pegs extending down into the dermis. Two of the tumors came from llamas and three from alpacas. Four of the animals were 6-year-old females. The fifth was a 6-year-old castrated male. The fibropapillomas were located on the nose, lip, and cheeks. One of the llama tumors waxed and waned before surgery and recurred and spread after surgery. None of the other tumors recurred. All five tumors were positive for papillomavirus (PV) DNA by polymerase chain reaction testing. Nucleotide sequence analysis of the PCR product from one of the llama fibropapillomas confirmed a unique PV. This report provides the microscopic and clinical features of fibropapillomas in camelids as well as evidence for a PV etiology.     

Surgical repair of femoral fractures in New World camelids: five cases (1996-2003)

Five New World camelids were admitted to the Western College of Veterinary Medicine between 1996 and 2003 for evaluation of femoral fractures. There were three alpacas and two llamas. Four of the animals were female and three were less than 3 months of age. Fracture configurations consisted of distal physeal fractures (three), a comminuted diaphyseal/metaphyseal fracture, and a transverse diaphyseal fracture. Fractures were diagnosed with a combination of physical examination and radiographs in all cases. All five fractures were repaired with internal fixation and three animals were discharged from the hospital with fractures that healed. One cria underwent successful internal fixation but died from pulmonary oedema during recovery from anaesthesia. Postoperative complications were rare and limited to inadequate fracture stability in one alpaca and prolonged recovery to weight bearing in another. One llama with a comminuted metaphyseal fracture, repaired with a 4.5 mm dynamic compression plate, subsequently had catastrophic failure of the bone 17 days after surgery. Overall the clients were pleased with the outcome of discharged animals. Although femoral fractures are considered rare, they pose a unique opportunity for the large animal veterinarian to successfully achieve fracture union with the aid of internal fixation.     

Systemic coccidioidomycosis in a llama cria native to Missouri

A 3-mo-old male llama was examined because of a 4-wk history of lethargy and ill thrift. Clinical examination revealed subcutaneous masses in the left prescapular and right inguinal regions, mild ataxia, a slight head tilt to the right, and right ear droop. The cria died before clinical workup was complete. At autopsy, there was generalized lymphadenomegaly, a hepatic nodule, a midbrain mass causing rostral compression of the cerebellum, and internal hydrocephalus. Microscopic findings included pyogranulomatous lymphadenitis, meningoencephalitis, hepatitis, and bronchopneumonia. Intralesional fungal spherules, most consistent with Coccidioides spp., were identified in the lymph nodes, lung, and brain. Fungal culture, single-nucleotide variation genotyping real-time PCR, and DNA sequencing confirmed Coccidioides posadasii. The dam of the cria was native to Arizona and had been moved to Missouri ~2.5 y previously. Agar gel immunodiffusion assay of the herd revealed that only the dam was positive for Coccidioides spp.; 6 herdmates were negative. Computed tomography of the dam revealed multiple nodules within the lungs and liver, which were presumed to be an active coccidioidomycosis infection. This case of systemic coccidioidomycosis in a llama native to Missouri was presumably acquired by vertical transmission from the dam.     

Humoral response to West Nile virus vaccination in alpacas and llamas

OBJECTIVE: To determine humoral responses to an equine West Nile virus (WNV) vaccine in healthy alpacas and llamas and compare responses in alpacas and llamas with responses in horses. DESIGN: Clinical trial. ANIMALS: 28 alpacas, 56 llamas, and 16 horses. PROCEDURE: Horses received 2 vaccinations at 4-week intervals, and alpacas and llamas received 3 vaccinations at 3-week intervals. Fifty-five llamas received a fourth vaccination 3 weeks after the third. Blood samples were collected immediately prior to each vaccination, 3 weeks after the last vaccination for alpacas and llamas, and 4 weeks after the last vaccination for horses and tested for virus-neutralizing antibodies. Samples from 29 randomly selected vaccinated llamas were used. RESULTS: None of the animals developed any local or systemic adverse reactions. Four of 28 (14%) alpacas, 4 of 29 (14%) llamas, and 7 of 16 (44%) horses were seropositive 3 (llamas and alpacas) or 4 (horses) weeks after administration of the first vaccination; 27 of 28 (96%) alpacas, 26 of 29 (90%) llamas, and 15 of 16 (94%) horses were seropositive after administration of the second vaccination; and all 28 alpacas and 28 of 29 (97%) llamas were seropositive 3 weeks after administration of the third vaccination. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that vaccination with the equine WNV vaccine is safe in alpacas and llamas. Administration of 3 vaccinations generally resulted in virus-neutralizing antibody titers similar to those observed following 2 vaccinations in horses; however, because it is not known what antibody titer would be protective against clinical WNV disease in alpacas or llamas, we cannot conclude that the vaccine was efficacious.