Allotransplantation of Transgenic Mouse Ovaries Expressing Enhanced Green Fluorescent Protein under the Control of the Murine Phosphoglycerate Kinase 1 Promoter

The aim of this study was to generate a transgenic mouse that ubiquitously expressed enhanced green fluorescent protein (EGFP) under the control of the murine phosphoglycerate kinase 1 promoter by allotransplantation of transgenic mouse ovaries. The EGFP transgenic mice expressed green fluorescence in many organs, and the fluorescence was detected as early as the embryonic stage. Ovaries from the EGFP transgenic mice were allotransplanted into recipients and these mice were mated with normal male mice. Histological sections of EGFP‐allotransplanted ovaries from the recipient mice showed the well development and formation at follicles and corpora lutea. The green fluorescence was clearly detectable at the allotransplanted section of the ovaries, which had fused with the normal ovary. The average size of the first litter from these mice was 6.8 ± 1.2 pups per recipient, and 17.8% of the pups expressed EGFP. These results demonstrated that allotransplantation of transgenic ovaries can restore a normal reproductive lifespan and can be used to generate a ubiquitously expressing EGFP animal model.     

Laboratory measures of hemostasis and fibrinolysis after intravenous administration of epsilon-aminocaproic acid in clinically normal horses and ponies

OBJECTIVE: To determine whether epsilon-aminocaproic acid (EACA) administered IV affects hemostasis and fibrinolysis in clinically normal horses and ponies. ANIMALS: 20 clinically normal adult horses and ponies. PROCEDURES: Blood samples were collected 24 hours before (baseline) and 1 and 5 hours after i.v. administration of a low dose (30 mg/kg) or high dose (100 mg/kg) of EACA. Platelet count, fibrinogen concentration, prothrombin time, partial thromboplastin time (PTT), D-dimer concentration, alpha2-antiplasmin activity, and thrombin-antithrombin complex concentration were measured. Values at 1 and 5 hours were compared with baseline values. RESULTS: hour after administration of a low dose of EACA, mean fibrinogen concentration was significantly lower than baseline concentration. Mean PTT was significantly shorter than the baseline value 5 hours after administration of a low dose of EACA. One hour after administration of 100 mg of EACA/kg, mean alpha2-antiplasmin activity was significantly higher than baseline activity. Mean fibrinogen concentration was significantly lower than baseline concentration 1 and 5 hours after administration of a high dose of EACA. Mean PTT was significantly shorter than the baseline value 5 hours after administration of a high dose of EACA. CONCLUSIONS AND CLINICAL RELEVANCE: i.v. administration of 30 and 100mg of EACA/kg to clinically normal horses significantly modified some laboratory measures of hemostasis, consistent with its known antifibrinolytic effects. Although enhanced clot maintenance and diminished bleeding were not directly assessed, the clinical use of EACA may benefit some patients.     

Assessment of the effects of feed restriction and amino acid supplementation on glucose tolerance in llamas

OBJECTIVE: To assess the effects of prolonged feed deprivation on glucose tolerance, insulin secretion, and lipid homeostasis in llamas. ANIMALS: 9 adult female llamas. PROCEDURE: On each of 2 consecutive days, food was withheld from the llamas for 8 hours. Blood samples were collected before and 5, 15, 30, 45, 60, 120, and 240 minutes after IV injection of dextrose (0.5 g/kg) for determination of plasma insulin and serum glucose, triglyceride, and nonesterified fatty acid concentrations. Between experimental periods, the llamas received supplemental amino acids IV (185 mg/kg in solution). The llamas were then fed a limited diet (grass hay, 0.25% of body weight daily) for 23 days, after which the experimental procedures were repeated. RESULTS: Feed restriction decreased glucose tolerance and had slight effects on insulin secretion in llamas. Basal lipid fractions were higher after feed restriction, but dextrose administration resulted in similar reductions in serum lipid concentrations with and without feed restriction. Insulin secretion was decreased on the second day of each study period, which lessened reduction of serum lipid concentrations but did not affect glucose tolerance. CONCLUSIONS AND CLINICAL RELEVANCE: Despite having a comparatively competent pancreatic response, feed-restricted llamas assimilated dextrose via an IV bolus more slowly than did llamas on full rations. However, repeated administration of dextrose reduced insulin secretion and could promote hyperglycemia and fat mobilization. These findings suggested that veterinarians should use alternative methods of supplying energy to camelids with long-term reduced feed intake or consider administering agents to improve the assimilation of glucose.     

Assessment of the effects of exogenous long-acting insulin on glucose tolerance in alpacas

OBJECTIVE: To evaluate the effects of long-acting insulin on glucose clearance in alpacas. ANIMALS: 8 adult castrated alpacas. PROCEDURE: On 2 days, food was withheld from alpacas for 8 hours. Alpacas were randomly allocated to receive an SC injection of long-acting insulin (0.4 U/kg) or saline (0.9% NaCI) solution 1 hour before the first of 3 administrations of glucose (at 60, 480, and 1,200 minutes after treatment) on day 1 and the alternate treatment and procedure on day 2. Plasma glucose concentration was determined before and 15, 45, 120, and 240 minutes after each glucose administration, and fractional turnover rates were calculated. The data were compared between alpacas with and without insulin administration and among the 3 glucose administrations for each day. RESULTS: Compared with sham-treated alpacas, insulin-treated alpacas had significantly lower blood glucose concentrations from 180 to 600 minutes after treatment; they also had glucose concentrations significantly below baseline values from 120 to 480 minutes, at which time the mean glucose concentration was in the hypoglycemic range. Also, mean fractional turnover of glucose was significantly higher in insulin-treated alpacas from 105 through 300 minutes. CONCLUSIONS AND CLINICAL RELEVANCE: Compared with known effects of regular insulin in alpacas, the action of long-acting insulin was of slower onset but longer lasting; its administration may induce hypoglycemia, even in alpacas that receive glucose. To maintain the hypoglycemic effect, long-acting insulin may have to be administered more than once daily and blood glucose concentration should be monitored to avoid hypoglycemic complications in alpacas.     

Necrotizing hepatitis associated with enteric salmonellosis in an alpaca

Salmonella typhimurium was isolated from the feces of an alpaca suffering anorexia and weight loss. Multifocal necrotizing and suppurative hepatitis consistent with bacterial infection was found in the liver biopsies. Enteric salmonellosis may be associated with milder physical and clinicopathological changes in camelids than in other large animal species.     

Potential pathogens in feces from unweaned llamas and alpacas with diarrhea

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 < or = 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.     

Pathogenesis of Streptococcus zooepidemicus infection after intratracheal inoculation in llamas

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 microg/ml) and increases in serum glucose (from 131+/-5 to 253+/-48 mg/dl) concentrations. CONCLUSIONS AND CLINICAL RELEVANCE: Streptococcus 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.     

Reproductive performance of Thoroughbred mares on six commercial stud farms

The records of 1630 mare years from 6 Thoroughbred stud farms in south eastern Australia were analysed for the years 1981 to 1986. Overall pregnancy and foaling rates were 83.9% and 69.3%, respectively. When calculated per served oestrous cycle, pregnancy and foaling rates were 54.7% and 43.1%, respectively. Pregnancy and foaling rates were higher (P < 0.001) for mares 3 to 10 years of age than for older mares. There was no difference in the pregnancy rates of maiden, barren and foaling mares. The foaling rate was significantly higher (P < 0.001) in mares that became pregnant during the first served oestrous cycle (77.8%) than in mares that needed two served oestrous cycles to become pregnant (65.4%). Of all diagnosed pregnancies, 19.5% were not completed. Pregnancy loss was lower (P < 0.05) in maiden (12.4%) than in barren (19.7%) or foaling (20.9%) mares. Twins were diagnosed in 7.8% of all pregnancies. If one conceptus was lost without external interference, 84.1% of pregnancies went to term. If one conceptus was manually crushed, 55.9% of pregnancies were maintained. If prostaglandin was used to terminate twin pregnancies, 60% of mares so treated produced foals the following year.     

A comparison of coulometric titration and potentiometric determination of chloride concentration in rumen fluid

Abstract: The concentration of chloride ions in rumen fluid is a useful measure of obstructive gastrointestinal disease in ruminants and camelids. However, rumen fluid is very different from other biological fluids in its bacterial populations, consistency, and concentrations of various anions. Two methods of determining the chloride concentration in biological fluids were compared using centrifuged and filtered rumen fluid containing different amounts of sodium chloride. Although coulometric titration and potentiometric electrode analysis yielded results that had a strong linear relationship, the results of potentiometry were consistently and significantly higher, by about 20 mEq/L. This difference was investigated further by analyzing a series of fluids containing different concentrations of sodium acetate. Acetate was detected as chloride (0.21 chloride molecules per acetate molecule) by potentiometry but not by coulometric titration. Therefore, the acetate concentration of rumen fluid was the most likely cause of the discrepancy between tests in the original trial. In conclusion, the coulometric procedure may be more accurate than the potentiometric procedure for measuring rumen chloride when the concentrations of possible confounding ions are unknown.     

Effects of exogenous insulin on glucose tolerance in alpacas

OBJECTIVE: To evaluate the effects of exogenous insulin on clearance of exogenous glucose in alpacas. ANIMALS: 7 adult castrated male alpacas. PROCEDURE: Prior to each of 2 trials, food was withheld for 8 hours. Glucose (0.5 g/kg of body weight) was then administered by rapid IV infusion. During 1 of the trials, regular insulin (0.2 U/kg, IV) was also administered 15 minutes later. Blood was collected immediately before (0 minutes) and 15, 20, 25, 30, 45, 60, 90, 120, 180, and 240 minutes after glucose administration. Plasma concentrations of glucose and lactate were determined, and glucose fractional turnover rate and plasma half-life were calculated. RESULTS: Insulin treatment caused a significant increase in fractional turnover rate of glucose and plasma lactate concentration. Plasma glucose concentrations were less in insulin-treated alpacas from 30 minutes after glucose administration (15 minutes after insulin administration) until the conclusion of each trial, compared with nontreated alpacas. In addition, plasma glucose concentration in insulin-treated alpacas returned to baseline values 1 hour sooner than in the nontreated group. CONCLUSIONS AND CLINICAL RELEVANCE: Glucose uptake in alpacas improves after insulin treatment, suggesting that administration of exogenous insulin will increase the therapeutic and decrease the pathologic effects of exogenous glucose administered to hypoglycemic alpacas. However, alpacas and other New World camelids should be monitored carefully during treatment with glucose or insulin, because these species appear to be partially insulin resistant.