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Abstract

OBJECTIVE

To evaluate the level of agreement (LOA) between direct and oscillometric blood pressure (BP) measurements and the ability of oscillometric measurements to accurately detect hypotension in anesthetized chimpanzees (Pan troglodytes).

ANIMALS

8 captive, adult chimpanzees.

PROCEDURES

During prescheduled annual examinations, each chimpanzee underwent general anesthesia and patient monitoring for their examination, echocardiography for a concurrent study, and measurement of direct BP with the use of tibial artery catheterization and oscillometry with the use of a cuff placed around a brachium and a cuff placed around the second digit of the contralateral forelimb for the present study. Bland-Altman plots were generated to compare results for direct and oscillometric BP measurements. Mean bias and 95% LOAs were calculated for oscillometric measurements of systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and mean arterial pressure (MAP) for each cuff site. Sensitivity and specificity in detecting hypotension were also determined for each cuff site.

RESULTS

There were 74 paired direct and brachial oscillometric measurements of each, SAP, MAP, and DAP and 66 paired direct and digit oscillometric measurements of each, SAP, MAP, and DAP. Only brachial oscillometric measurements of MAP had adequate sensitivity (78%) and specificity (95%) to accurately detect hypotension, and this technique also had the least mean bias (0.8 mm Hg; 95% LOA, –29 to 31 mm Hg).

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that brachial oscillometric measurement of MAP provided reasonable agreement with tibial arterial direct MAP measurement and performed well in diagnosing hypotension in anesthetized chimpanzees.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To compare numbers of L cells in intestinal samples and blood concentrations of glucagon-like peptide (GLP)-1 between neonatal and mature alpacas.

Sample—Intestinal samples from carcasses of 4 suckling crias and 4 postweaning alpacas for immunohistochemical analysis and blood samples from 32 suckling crias and 19 healthy adult alpacas for an ELISA.

Procedures—Immunohistochemical staining was conducted in accordance with Oregon State University Veterinary Diagnostic Laboratory standard procedures with a rabbit polyclonal anti–GLP-1 primary antibody. Stained cells with staining results in ileal tissue were counted in 20 fields by 2 investigators, and the mean value was calculated. For quantification of GLP-1 concentrations, blood samples were collected into tubes containing a dipeptidyl peptidase-4 inhibitor. Plasma samples were tested in duplicate with a commercial GLP-1 ELISA validated for use in alpacas.

Results—Counts of stained cells (mean ± SD, 50 ± 18 cells) and plasma GLP-1 concentrations (median, 0.086 ng/mL; interquartile range, 0.061 to 0.144 ng/mL) were higher for suckling alpacas than for postsuckling alpacas (stained cells, 26 ± 4 cells; plasma GLP-1 concentration, median, 0.034 ng/mL; interquartile range, 0.015 to 0.048 ng/mL).

Conclusions and Clinical Relevance—Older alpacas had lower numbers of L cells in intestinal tissues and lower blood concentrations of GLP-1 than those in neonates. These findings suggested that there may be a decrease in the contribution of GLP-1 to insulin production in adult alpacas, compared with the contribution in neonates.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To test the ability of a nested PCR assay to detect Eimeria macusaniensis at various stages of infection in alpacas.

Animals—4 healthy adult alpacas with no detectable E macusaniensis.

Procedures—Alpacas were inoculated with 2 × 104 sporulated oocysts. Serial fecal samples collected during the next 38 days were tested via sucrose flotation and PCR assay.

Results—Oocyst passage was detected via fecal flotation in all 4 alpacas 31 to 35 days after inoculation. Three had positive results for PCR assays on samples obtained 7 to 14 days after inoculation. One alpaca subsequently was removed from the study because of weight loss and inappetence. Two remaining alpacas had positive PCR reactions 28 and 31 days after inoculation, up to 7 days before oocysts appeared in the feces. All fecal samples with positive results for flotation also had positive results for PCR assay.

Conclusions and Clinical Relevance—The PCR assay was able to detect early (7 to 14 days) and late (28 to 31 days) prepatent infection. These positive results suggested that the assay could have been detecting DNA unassociated with oocysts or detecting shedding earlier than has been previously recognized. The gap between the early and late detection periods may not be evident in alpacas receiving a larger or continuous inoculum, as might occur with natural infection. Use of a PCR assay for analysis of fecal samples may be valuable for detection of E macusaniensis during the prepatent period, thus aiding in the identification and control of infected animals.

Full access
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)

Full access
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)

Full access
in American Journal of Veterinary Research

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)

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE To investigate use of the plethysmographic variability index (PVI) and perfusion index (PI) for evaluating changes in arterial blood pressure in anesthetized tigers (Panthera tigris).

ANIMALS 8 adult tigers.

PROCEDURES Each tiger was anesthetized once with a combination of ketamine, midazolam, medetomidine, and isoflurane. Anesthetic monitoring included assessment of PI, PVI, direct blood pressure measurements, anesthetic gas concentrations, esophageal temperature, and results of capnography and ECG. Mean arterial blood pressure (MAP) was maintained for at least 20 minutes at each of the following blood pressure conditions: hypotensive (MAP = 50 ± 5 mm Hg), normotensive (MAP = 70 ± 5 mm Hg), and hypertensive (MAP = 90 ± 5 mm Hg). Arterial blood gas analysis was performed at the beginning of anesthesia and at each blood pressure condition.

RESULTS Mean ± SD PI values were 1.82 ± 2.38%, 1.17 ± 0.77%, and 1.71 ± 1.51% and mean PVI values were 16.00 ± 5.07%, 10.44 ± 3.55%, and 8.17 ± 3.49% for hypotensive, normotensive, and hypertensive conditions, respectively. The PI values did not differ significantly among blood pressure conditions. The PVI value for the hypotensive condition differed significantly from values for the normotensive and hypertensive conditions. The PVI values were significantly correlated with MAP (r = −0.657). The OR of hypotension to nonhypotension for PVI values ≥ 18% was 43.6.

CONCLUSIONS AND CLINICAL RELEVANCE PVI was a clinically applicable variable determined by use of noninvasive methods in anesthetized tigers. Values of PVI ≥ 18% may indicate hypotension.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine clinical status and renal and hematopoietic function after kidney donation and identify risks associated with kidney donation in dogs.

Design—Prospective study.

Animals—14 dogs that underwent unilateral nephrectomy for kidney donation.

Procedures—Records were reviewed retrospectively to collect data regarding prenephrectomy clinicopathologic variables. Dogs were reexamined prospectively at various times after nephrectomy, and pre- and postnephrectomy CBC, serum biochemical analyses, urinalysis, and urine protein-to-urine creatinine ratio were compared. Six dogs had postnephrectomy renal volume determined ultrasonographically, and 4 of those dogs also underwent scintigraphic determination of glomerular filtration rate and renal biopsy.

Results—All dogs were clinically normal at the time of reevaluation. There were no significant differences between prenephrectomy and postnephrectomy values for BUN concentration or urine specific gravity. Mean postnephrectomy serum creatinine concentration was significantly greater than prenephrectomy concentration. Mean serum phosphorus concentration was significantly decreased after nephrectomy, and mean Hct, corpuscular volume, and corpuscular hemoglobin concentration were significantly increased after nephrectomy. Postnephrectomy renal volume was greatest in dogs < 12 months old at the time of surgery. Mean postnephrectomy glomerular filtration rate was 2.82 ± 1.12 mL/kg/ min (1.28 ± 0.51 mL/lb/min). Renal biopsy specimens obtained during and after nephrectomy were histologically normal.

Conclusions and Clinical Relevance—Renal and hematopoietic variables were within reference ranges in dogs examined up to 2.5 years after unilateral nephrectomy. Compensatory renal hypertrophy was greatest in dogs < 1 year of age at donation. Donor age, along with histocompatability, may be an important factor in selecting dogs for kidney donation.

Full access
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE

To evaluate and compare postoperative analgesic effects of grapiprant and carprofen in dogs undergoing ovariohysterectomy.

ANIMALS

42 sexually intact female healthy dogs (< 35 kg and 0.5 to 7 years old) were enrolled.

PROCEDURES

In a masked, randomized, noninferiority clinical trial, dogs received either 2 mg/kg of grapiprant or 4.4 mg/kg of carprofen orally 2 hours prior to ovariohysterectomy. Postoperative pain was assessed using the Glasgow Composite Pain Scale–Short Form (GCPS-SF) at extubation and 2, 4, 6, 8, 18, and 24 hours postextubation and compared to baseline. After each pain scoring, mechanical nociceptive testing with von Frey monofilaments (vF) was performed to assess hyperalgesia. Hydromorphone (0.05 mg/kg, IM) was administered to any dog with a GCPS-SF of ≥ 5/24. The noninferiority limit (NI) for the GCPS-SF was Δ = 3. The NI for vF was Δ = –0.2. Following noninferiority, a mixed-effect ANOVA and post hoc comparisons were made with the Tukey correction method (P < .05).

RESULTS

3 dogs required rescue analgesia and were excluded from statistical analysis. Of the remaining 39 dogs, the upper CI for GCPS-SF was below the NI of 3 and the lower CI for vF was greater than the NI of –0.2, indicating noninferiority of grapiprant as compared to carprofen. There was no difference between treatment (P = .89) nor treatment by time (P = .62) for GCPS-SF. There was no difference between groups at any time point or over time when vF were used.

CLINICAL RELEVANCE

Our study results support the use of grapiprant as an analgesic alternative to carprofen in dogs undergoing ovariohysterectomy.

Full access
in Journal of the American Veterinary Medical Association

Objective

To identify factors associated with hepatic lipidosis (HL) in llamas and alpacas.

Design

Retrospective case series.

Animals

30 llamas and 1 alpaca.

Procedures

Medical records were searched to identify llamas or alpacas in which a histologic diagnosis of HL was made. Information was retrieved on signalment, history, clinical and laboratory findings, and results of necropsy or examination of biopsy specimens. Data were analyzed using descriptive statistics and χ2 analyses.

Results

Females were affected more often than males; however, the sex distribution was not different from that of the camelid population in the diagnostic laboratory's database. Fifty-four percent of the females were pregnant, and 46% were lactating. Most affected camelids were 6 to 10 years old. Anorexia and recent weight loss were common (51.6% of camelids). An infective agent was found in only one llama, and toxins and mineral deficiencies were not identified. The most common abnormalities on serum biochemical analysis were a high concentration of bile acids, high activities of γ-glutamyltrans-ferase (GGT) and aspartate aminotransferase (AST), and hypoproteinemia. Concentrations of nonesterified fatty acids (NEFA) and β-hydroxybutyrate (β-HB) were high in those camelids in which these compounds were assayed. Twenty-nine camelids did not survive.

Clinical Implications

Sick camelids should be considered at risk for developing HL, especially those with anorexia or the metabolic demands of pregnancy and lactation. Other stresses also appear to contribute. High concentrations of NEFA, γ-HB, and bile acids; high activities of GGT and AST; and hypoproteinemia may indicate that HL has developed. (J Am Vet Med Assoc 1999;214:1368–1372)

Free access
in Journal of the American Veterinary Medical Association