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  • Author or Editor: Christopher K. Cebra x
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Abstract

Objectives—To test whether generalized Streptococcus zooepidemicus infection could be induced by intratracheal inoculation in llamas and to characterize this infection.

Animals—6 test and 3 control llamas.

Procedure—Test llamas received 1 of 3 dosages of S zooepidemicus by intratracheal injection, whereas control llamas received sterile culture medium. Physical examination variables and results of clinicopathologic analyses of blood, peritoneal fluid, and tracheal wash fluid were compared in test llamas between, before, and during the development of bacteremia and with control llamas. Bacteriologic culture was performed on all collected body fluids and tissue specimens that were collected at necropsy. Tissue specimens that were collected at necropsy were examined histologically.

Results—Infection induced fever, anorexia, and signs of depression. Five of 6 infected llamas developed specific signs of inflammation in the thorax or abdomen, bacteremia, neutrophilic leukocytosis with toxic changes and high band neutrophil cell counts, hyperfibrinogenemia, and high peritoneal fluid WBC counts and protein concentrations. On development of bacteremia, llamas had significant decreases in serum iron (from 118 ± 25 to 6 ± 4 µg/ml) and increases in serum glucose (from 131 ± 5 to 253 ± 48 mg/dl) concentrations.

Conclusions and Clinical RelevanceStreptococcus zooepidemicus spreads rapidly to other body compartments after intratracheal inoculation in llamas. Fever, anorexia, and signs of depression are the most consistent clinical signs, although other signs are possible. Clinicopathologic analysis of body fluids yields evidence of inflammation. Infection by S zooepidemicus can be proven by bacteriologic culture of body fluids before death or of tissue specimens after death. (Am J Vet Res 2000:61;1525–1529)

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in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association

Abstract

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 μg/ 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.

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in American Journal of Veterinary Research

Abstract

Objective—To determine blood glucose clearance in 2 species of New World camelids after IV challenge and to examine mechanisms of this clearance.

Animals—5 adult female llamas and 5 adult gelded alpacas.

Procedure—After food was withheld for 12 hours, camelids received 0.5 g of glucose/kg of body weight by rapid IV infusion. Serum concentrations of glucose, nonesterified fatty acids, cortisol, and insulin, and plasma concentrations of lactate were determined before and 0, 1, 2, 3, 4, 5, 15, 30, 60, 90, 120, 180, and 240 minutes after infusion. Ratios of insulin to glucose and insulin to cortisol were calculated for each time point.

Results—Postinfusion glucose concentrations were significantly higher in llamas than alpacas for the first 15 minutes and remained significantly higher than baseline values in both species for 180 minutes. Lactate and cortisol concentrations did not change significantly; nonesterified fatty acid concentrations decreased in both species 30 minutes after infusion. Baseline insulin concentrations were < 6 μU/ml in both species and increased only to 10.1 ± 0.7 μU/ml in llamas. Insulin concentrations did not change significantly in alpacas.

Conclusions and Clinical Relevance—Llamas and alpacas clear glucose more slowly than other domestic species after challenge, mainly because of a weak insulin response and slow cellular uptake. This response may impair the assimilation of exogenous glucose as well as make llamas and alpacas prone to diabetes-like disorders when an abundance of endogenous or exogenous glucogenic agents are present. (Am J Vet Res2001;62:682–686)

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in American Journal of Veterinary Research

Abstract

Objectives—To determine whether feed restriction induces hepatic lipidosis (HL) in llamas and to evaluate the metabolic changes that develop during feed restriction.

Animals—8 healthy adult female llamas.

Procedure—Llamas were fed grass hay at a rate of 0.25% of their body weight per day for 13 to 28 days. Llamas were monitored by use of clinical observation, serum biochemical analyses, and ultrasound-guided liver biopsies.

Results—All 8 llamas lost weight and mobilized fat. Five llamas developed HL, including 4 that were nursing crias. During the period of feed restriction, mean serum concentration of bile acids and activities of aspartate aminotransferase (AST), sorbitol dehydrogenase (SDH), and γ-glutamyl transferase (GGT) were significantly higher in llamas that developed HL, compared with llamas that did not. Mean insulin-to-cortisol concentration ratios were lower in llamas with HL before and up to 7 days of feed restriction, compared with those that did not develop HL.

Conclusions and Clinical Relevance—HL in llamas may be induced by severe feed restriction, particularly in the face of increased energy demand. Llamas with weight loss attributable to inadequate dietary intake may develop biochemical evidence of hepatopathy and HL. Increases in serum concentration of bile acids and activities of GGT, AST, and SDH may indicate the development of HL in llamas and identify affected animals for aggressive therapeutic intervention. (Am J Vet Res 2001;62:1081–1087)

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in American Journal of Veterinary Research

Abstract

Objective—To determine the minimum alveolar concentration (MAC) of sevoflurane in spontaneously breathing llamas and alpacas.

Design—Prospective study.

Animals—6 healthy adult llamas and 6 healthy adult alpacas.

Procedure—Anesthesia was induced with sevoflurane delivered with oxygen through a mask. An endotracheal tube was inserted, and a port for continuous measurement of end-tidal and inspired sevoflurane concentrations was placed between the endotracheal tube and the breathing circuit. After equilibration at an end-tidal-to-inspired sevoflurane concentration ratio > 0.90 for 15 minutes, a 50-Hz, 80-mA electrical stimulus was applied to the antebrachium until a response was obtained (ie, gross purposeful movement) or for up to 1 minute. The vaporizer setting was increased or decreased to effect a 10 to 20% change in end-tidal sevoflurane concentration, and equilibration and stimulus were repeated. The MAC was defined as the mean of the lowest end-tidal sevoflurane concentration that prevented a positive response and the highest concentration that allowed a positive response.

Results—Mean ± SD MAC of sevoflurane was 2.29 ± 0.14% in llamas and 2.33 ± 0.09% in alpacas. Conclusions and Clinical Relevance—The MAC of sevoflurane in llamas and alpacas was similar to that reported for other species. (J Am Vet Med Assoc 2003;223:1167–1169)

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To identify potential pathogens in feces from llama and alpaca crias with diarrhea.

Design—Prospective observational study.

Animals—45 unweaned crias with diarrhea.

Procedure—Fecal samples were evaluated for Eimeria spp, Giardia spp, Cryptosporidium spp, enteric viruses, and Salmonella spp. A questionnaire yielded information concerning herd management and presence of other affected camelids.

Results—28 crias were ≤ 31 days old, 11 were 32 to 62 days old, and 6 were 63 to 210 days old. Potential pathogens were isolated from feces from 32 of the 45 crias. A total of 39 potential pathogens were obtained, including coronavirus (n = 19 crias; 42%), Giardia spp (8; 18%), Eimeria spp (6; 13%), Cryptosporidium spp (4; 9%), rotavirus (1; 2%), and nematode ova (1; 2%). Salmonella spp were not isolated. Most crias from which potential pathogens were isolated were identified during outbreaks of diarrhea involving other camelids, although only coronavirus was isolated from crias identified during outbreaks involving adult camelids. Coronavirus was detected throughout the year, whereas protozoa were most commonly isolated during the fall and winter.

Conclusions and Clinical Relevance—Results suggest that a variety of potential pathogens may be isolated from young crias with diarrhea. Many crias shed coronavirus, which may also have been affecting older camelids. Protozoa were isolated most often during wetter months, suggesting that crias born during these months may have greater exposure to protozoal pathogens. (J Am Vet Med Assoc 2003;223: 1806–1808)

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in Journal of the American Veterinary Medical Association

Abstract

Case Description—20 alpaca crias (13 females and 7 males) were examined for diarrhea (n = 20), weight loss (15), and poor appetite (5). Fourteen crias were between 8 and 18 days of age at time of admission.

Clinical Findings—Cryptosporidiosis was diagnosed in all crias. Common biochemical abnormalities included acidemia, hyperlactemia, azotemia, and hyperglycemia and increases in aspartate transaminase and γ-glutamyltransferase activities. Serum sodium and chloride concentrations were high or low. Other potential gastrointestinal tract pathogens were identified in only 7 crias.

Treatment and Outcome—Supportive care was instituted, including IV administration of fluids with partial parenteral administration of nutrients (n = 19 crias), antimicrobials (19), supplemental orally administered nutrients (11), administration of plasma (10), and insulin treatment (9). Other palliative treatments used by attending clinicians were sucralfate, flunixin meglumine, vitamin A/D/E/B complex, antiparasitic agents, antidiarrheal agents, and azithromycin. Three crias with inadequate urine production and severe azotemia were treated with furosemide administered IV as a bolus or as a constant-rate infusion. Treatment resulted in a successful outcome in 16 of 20 crias. Weight loss and refractory azotemia were common in nonsurvivors but not in surviving crias.

Clinical Relevance—Findings suggested that Cryptosporidium spp may be a diarrheal pathogen of unweaned alpaca crias that may be more widespread than has been recognized and can become endemic on some farms. Metabolic derangements were unpredictable and should be determined by biochemical analysis before fluid and electrolyte replacement is initiated. Cryptosporidiosis has zoonotic potential, and the infection can be self-limiting in alpacas receiving supportive treatment.

Full access
in Journal of the American Veterinary Medical Association