High carbohydrate is preferable to high lipid parenteral nutrition in healthy dogs undergoing prolonged sedation

Parenteral nutrition (PN) is commonly used in intensive care units (ICUs) and is associated with earlier hospital outcome. However, there is scarcity of information about the metabolic effects of PN caloric distribution for dogs. Considering the high tolerance of dogs to lipids and, also, that hospitalized animals usually present insulin resistance, PN formulation with high fat instead high glucose can provide metabolic benefits in this specie. This study evaluated two PN protocols, based on high lipid or high carbohydrate in 12 healthy dogs under sedation/ventilation during 24 h. For baseline data, blood samples were collected 24 h before the study beginning. After fasting, the dogs were anesthetized and put under mechanical ventilation without energy support for 12 h to obtain: daily energy expenditure (DEE), respiratory quotient (RQ), oxygen consumption (VO2), carbon dioxide production (VCO2), lactate, glucose, cholesterol, and triglycerides concentrations. After, the dogs were allocated into two groups: lipid-based energy group (LEG) and carbohydrate-based energy group (CEG). Both groups received the PN infusions at a rate of 3 mL/kg/h for 12 h. Blood tests were performed 12, 24, and 48 h after infusion's completion. VO2 increased after PN in LEG, increasing energy expenditure compared to CEG. RQ remained close to 1 in CEG, indicating carbohydrate preferential consumption. Triglycerides increased in both groups after propofol infusion, remaining higher in LEG until the end of the evaluation. Glycaemia increased in CEG compared to baseline. In conclusion, both PN protocols can be used in healthy animals undergoing prolonged sedation protocols. However, high lipid PN had higher VO2 and DEE, and resulted in higher triglycerides concentrations and lower glycaemia indexes than carbohydrate, making high carbohydrate PN preferable to high lipid PN. Therefore, for use in critically ill patients, the data obtained in this study should be extrapolated, taking into consideration the specificity of each case.

False positive Aspergillus galactomannan assay results caused by specific parenteral nutrition

In September 2022, the proportion of clinically false positive results with high index values for the galactomannan (GM) assay increased dramatically in our hospital and remained high until November 2022. We aimed to identify the possible causative agent that led to the dramatic increase in false positivity in GM assay. A case-control-control study was conducted, and patients admitted to two intensive care units between September and November 2022 were included. We defined each time point at which the GM assay was conducted in a patient as an episode and classified episodes into strong-positive (≥10.0 index; case), positive (control), and negative (<0.5 index; control) groups. We compared the medications administered in three groups and measured GM levels in relevant medications, including parenteral nutrition (PN). In total, 118 episodes in 33 patients were classified into three groups. There were 46 negative, 23 positive, and 49 strong-positive episodes, and there was a significant difference in the use of Winuf® PNs (P < .001) between the three groups. Forty episodes (82%) in the strong-positive group received Winuf®, compared with three (6.5%) in the negative group and one (4.3%) in the positive group (P < .001). All samples of Winuf® PNs used in the five patients whose GM results were repeatedly strong-positive were strongly positive for GM. False positivity in GM assay can be caused by the administration of specific PNs. A thorough investigation of prescribed medications should be considered when there is an abrupt increase in the proportion of strong-positive or positive GM results.

Severe hypertriglyceridaemia in clinically ill horses: diagnosis, treatment and outcome

REASONS FOR PERFORMING STUDY

Sporadic measurement of serum triglycerides in depressed and inappetant clinically ill horses revealed severe hypertriglyceridaemia without visible evidence of lipaemia on several occasions, leading to the inclusion of serum triglyceride concentrations in the routine serum biochemistry evaluation of our hospital. Since then, more cases have been identified and treated for hypertriglyceridaemia, raising questions about the prevalence, predisposing factors and significance of these findings.

HYPOTHESES

1) Severe hypertriglyceridaemia without visible opacity of the serum occurs more commonly in clinically ill and inappetant horses than previously described and 2) appropriate treatment using i.v. dextrose and/or partial parenteral nutrition would decrease serum triglycerides to normal limits and might result in improved appetite and attitude of the patient.

METHODS

The laboratory computer database from 2000 and 2001 was searched for increased serum triglycerides (> 5.65 mmol/l) in any horse breed, ponies and miniature breeds excluded. Data analysed included subject details, diagnosis, clinical and laboratory parameters, treatment, response to treatment and outcome.

RESULTS

Severe hypertriglyceridaemia was identified in 13 horses, with serum triglyceride concentrations 6.17-18.29 mmol/l, while none showed visible lipaemia. All horses had clinical and laboratory findings consistent with systemic inflammatory response syndrome and all but one had an increased serum creatinine concentration. Treatment with i.v. dextrose and/or partial parenteral nutrition resulted in decrease of the serum triglycerides to normal limits.

CONCLUSIONS

Severe hypertriglyceridaemia occurs in inappetant and clinically ill horses without evidence of serum opacity more commonly than previously described. The presence of systemic inflammatory response syndrome might predispose horses to hypertriglyceridaemia, while the increased creatinine concentration might be a predisposing factor or result of the condition. Horses identified in our study readily responded to treatment and appetite and attitude improved coincident with decrease of the serum triglycerides to normal limits.

POTENTIAL RELEVANCE

Hypertriglyceridaemia could perpetuate inappetance and depression in clinically ill horses and potentially predispose to fatty infiltration of the liver and other organ systems.

Parenterally fed neonatal piglets have a low rate of endogenous arginine synthesis from circulating proline

Parenterally fed neonatal piglets cannot synthesize sufficient arginine to maintain arginine status, presumably due to the intestinal atrophy that occurs with parenteral feeding. Parenteral feeding-induced atrophy can be reduced by the infusion of glucagon-like peptide 2 (GLP-2). GLP-2 infusion was hypothesized to increase the rate of endogenous arginine synthesis from proline, the major arginine precursor, in parenterally fed piglets receiving an arginine-deficient diet. Male piglets, fitted with jugular vein catheters for diet and isotope infusion, and femoral vein catheters for blood sampling (d 0), were allocated to a continuous infusion of either GLP-2 (n = 5; 10 nmol x kg(-1) x d(-1)) or saline (n = 5) for 7 d. Piglets received 2 d of a complete diet, followed by 5 d of an arginine-deficient [0.60 g x kg(-1) x d(-1)] diet. Piglets received primed, constant infusions of [guanido-(14)C]arginine to measure arginine flux (d 6) and [U-(14)C]proline (d 7) to measure proline conversion to arginine. Plasma arginine concentrations and arginine fluxes indicated a similar whole-body arginine status. Piglets receiving GLP-2 showed improvements in intestinal variables, including mucosal mass (P < 0.01) and villus height (P < 0.001), and a greater rate of arginine synthesis (micromol x kg(-1) x h(-1)) from proline (11.6 vs. 6.3) (P = 0.03). Mucosal mass (R(2) = 0.71; P = 0.002) and villus height were correlated (R(2) = 0.66; P = 0.004) with arginine synthesis. This study was the first to quantitate arginine synthesis in parenterally fed neonates and showed that although GLP-2 infusion increased arginine synthesis in a manner directly related to mucosal mass, this increased arginine synthesis was insufficient to improve whole-body arginine status in piglets receiving a low arginine diet.

Parenteral nutrition in foals: a retrospective study of 45 cases (2000--2004)

REASONS FOR PERFORMING STUDY

Adequate nutritional support of sick foals in critical care is an important aspect of treatment. When enteral feeding is contraindicated, parenteral nutrition (PN) provides a source of energy and protein. However, no study has critically assessed the use of PN in a large group of foals.

OBJECTIVE

The administration of PN to clinically ill foals was examined retrospectively to determine the effects of PN formulation and variables on the incidence of PN-associated complications and outcome.

HYPOTHESES

There was no effect of PN formula on 1) the occurrence or type of complications; 2) of PN formula on outcome; 3) of disease severity on the occurrence or type of complications; and 4) of disease severity on outcome.

METHODS

Medical records of 45 foals, presented to the Marion duPont Scott Equine Medical Center, which received PN, were reviewed for the years 2000-2004.

RESULTS

The indications for PN were recumbency, depression or gastrointestinal conditions. Formulation of PN was not associated with the development of complications, and there was no association of PN formula with patient survival. Disease severity was positively associated with the development of PN complications and the occurrence of PN complications was associated with an increased risk of nonsurvival.

CONCLUSION AND POTENTIAL RELEVANCE

The use of lipid-containing PN solutions facilitates the delivery of energy to the critically-ill foal without increasing the risk of deleterious side effects. Severely ill foals are more prone to develop complications associated with PN and to have a poor outcome.

Parenteral nutrition: uses, indications, and compounding

Decreased caloric and other nutrient intake can complicate the course of both mild and serious illness. With proper case selection, providing parenteral nutrition (PN) can improve clinical outcome, reduce hospitalization time, and reduce the cost of patient care. Many pharmacy facilities can compound PN formulations; with proper staff training and patient monitoring resources, PN can be administered in many veterinary practices. This article discusses the components of PN formulations as well as the criteria for rational selection of patients to receive PN.

Parenteral nutrition: formulation, monitoring, and complications

Because decreased caloric and nutrient intake can complicate the course of both mild and serious illness, parenteral nutrition (PN) is an important feeding modality for patients unable to receive adequate enteral nutrition. Although the effectiveness of PN has not been proven in animals, human studies have shown that using PN in appropriately selected cases can improve clinical outcome, reduce hospitalization time, and even reduce the overall cost of patient care. PN formulations for animals are readily available through pharmacies. This article provides practitioners with basic information on calculating and using PN in patients. Information is also provided on monitoring patients receiving PN as well as ways to identify and overcome common complications in animals receiving PN.

Prospective evaluation of a peripherally administered three-in-one parenteral nutrition product in dogs

OBJECTIVES

Peripheral parenteral nutrition is an option for short-term nutritional support in dogs which cannot be supported with enteral nutrition. The objective of this study was to examine the use of a three-in-one, 840 mOsmol/l peripheral parenteral nutrition product containing amino acids, lipids and glucose in separate compartments in dogs.

METHODS

Nine dogs were administered the three-in-one product, and two dogs were administered the amino acid part of the product, via a peripheral vein. Dogs were monitored for mechanical and metabolic complications.

RESULTS

Mechanical complications (apparent thrombus or thrombophlebitis) caused failure of infusion at a median of 36 hours. None of the dogs appeared to develop catheter-related sepsis. Using a 10-hour infusion period appeared to decrease the incidence of line failure. Mild and clinically non-significant hyperglycaemia was the only metabolic complication. In four of the dogs, serum folate, cobalamin and homocysteine concentrations were determined before and after peripheral parenteral nutrition administration. Oral and parenteral administration of methionine has been previously associated with lowered serum folate concentrations. Low serum folates and the subsequent hyperhomocysteinaemia have been associated with venous endothelial damage and venous thrombus in other species. Serum cobalamin also affects homocysteine metabolism. Median serum folate, cobalamin and homocysteine concentrations were not affected by the short-term administration of this three-in-one product.

CLINICAL SIGNIFICANCE

Using the product for 24 hours/day may require catheter replacement due to line failure. Other than line failure, which may be improved by 10- to 12-hour infusion times, this product was found to be safe and practical for short-term peripheral parenteral nutrition in dogs.

Rattlesnake envenomation in 12 New World camelids

BACKGROUND

Rattlesnake envenomation of New World camelids is a seasonal problem with often dramatic clinical signs.

HYPOTHESIS

The purpose of this study was to identify the clinical signs, laboratory results, treatment methods, and outcome for rattlesnake envenomation in New World camelids.

ANIMALS

Medical records from 1988 to 2004 were searched for New World camelids presented for rattlesnake bite or clinical signs suspected to be related to recent envenomation. Twelve records were identified.

METHODS

From these records a retrospective study was performed.

RESULTS

Nine camelids presented for acute disease (2/9 arrived dead), whereas 3 presented for subacute onset of disease. Swelling of the lips, head and neck, tachypnea, dyspnea, tachycardia, and lethargy were the most common presenting signs. Snake bites were most commonly located to the muzzle (10/12). Common complete blood count (CBC) and serum biochemical abnormalities were neutrophilia, lymphopenia, increased muscle enzyme activity, hypoalbuminemia, hyperglycemia, hypokalemia, and thrombocytopenia. Treatment included combinations of intravenous fluid therapy, antimicrobials, anti-inflammatory drugs, tetanus prophylaxis, tracheostomy, supplemental oxygen, antivenom, total parenteral nutrition, and nursing care. Five of the 10 animals with acute onset of clinical signs survived, and all animals with subacute presentation died. The mortality rate for New World camelids with severe local tissue reaction and systemic signs of envenomation was 58%.

CLINICAL IMPORTANCE

New World camelids that sustain rattlesnake envenomation and severe facial swelling precluding prehension and mastication have a guarded prognosis for survival. Aggressive treatment is recommended to optimize the chances of survival. Animals with less severe local tissue reaction and absence of systemic signs have a better prognosis.

Clinical application of parenteral nutrition in the treatment of five ponies and one donkey with hyperlipaemia

Five ponies and one donkey with hyperlipaemia that occurred secondarily to a variety of primary clinical conditions were treated with lipid-free partial parenteral nutrition comprising equal volumes of 50 per cent glucose and 15 per cent amino acids. The infusion supplied energy and protein at rates of 2.6 kJ/kg per hour and 34.3 mg/kg per hour, respectively. In all six cases there was a prompt and sustained decrease in serum concentrations of triglyceride. In four of the six cases a good response to treatment of the primary condition was also seen and the subjects were discharged successfully. In the remaining two cases, poor clinical response of the primary condition resulted in euthanasia, although hyperlipaemia was nevertheless resolved. The main complication of parenteral nutrition was hyperglycaemia.

Early Enteral Nutrition in Young Dogs Suffering from Haemorrhagic Gastroenteritis

The purpose of this study was to investigate clinical and metabolic effects of combined parenteral and oral nutrition compared with parenteral nutrition in young dogs with haemorrhagic gastroenteritis in a prospective clinical study. Dogs with acute gastroenteritis received either parenteral nutrition (group PN, n = 9) or combined parenteral and early enteral nutrition (group EN, n = 10). Infusions were compounded from amino acids, lipids, glucose and electrolyte/glucose solutions [149 g/l glucose, 20 g/l triglycerides, 40 g/l amino acids and 4009 kJ metabolizable energy/l (957 kcal ME/l)], and supplemented with potassium, phosphate and trace elements. Group EN received additionally a hydrolysed diet (74 kJ/kg BW(0.75) on day 2 and 148 kJ/kg BW(0.75) on days 3 and 4). Glucose, triglycerides, protein, albumin, fibrinogen, urea, creatinine, alkaline phosphatase, glutamate dehydrogenase and glutamate pyruvate transaminase were measured before and during the infusions, haematological traits only before the infusions. Statistics included two-factorial anova and subsequent t-test or Wilcoxon test (P < 0.05). All dogs of group EN survived compared with seven of nine patients in group PN. Most dogs in the EN group vomited within half an hour after introduction of oral feeding on day 2 but tolerance for food increased on days 3 and 4. The general health status and faecal and blood parameters of the surviving dogs were similar (P > 0.05) between the groups. In all dogs leucocytes increased during the treatment period, haematocrit and haemoglobin levels declined. Infusions increased blood glucose and triglycerides (P < 0.05); however, no adverse signs were observed. Early enteral nutrition was possible after a short period of adaptation, however, vomiting can be a severe problem. The evaluation of clinical benefits of early enteral nutrition in young dogs with haemorrhagic gastroenteritis requires further investigations.

Effect of parenteral vitamin E and selenium supplementation on immune status of dogs vaccinated with subunit and somatic antigens against Taenia hydatigena

Thirty clinically healthy dogs were divided into five equal groups; Gs 1 and 2 were vaccinated with subunit and somatic antigens (Ags) respectively in combination with vitamin E and selenium (Vit E/Se) supplement, Gs 3 and 4 were vaccinated with subunit and somatic Ags respectively and group 5 was kept unvaccinated as control positive. Dogs in the vaccinated-Vit E/Se supplemented groups had a significantly greater (P < 0.05) serum Se and alpha-tocopherol than un-supplemented Gs. Best immune response against T. hydatigena was observed in the Vit E/Se supplemented groups, as evidenced by increase production of antibody titer and IgG concentration in comparison with either vaccinated un-supplemented or control groups. Moreover, the highest protection level against T. hydatigena infection was observed in groups 1 and 2 (83.3%), while was 66.7% and 50% in groups 3 and 4 respectively. Subunit Ag was more efficient than somatic Ag in improving the immune status of dogs. Vit E and Se proved to be immuno-potentiating to dogs vaccinated with subunit and somatic Ags and increased the possibility for the protection against T. hydatigena infection.

Peroxidative protection of parenteral admixture by D-alpha-tocopherol

High lipid:low dextrose (HL:LD) parenteral admixtures (PAs) are becoming commonplace in the nutritional support of veterinary patients. Lipid peroxidation before administration appears to be an unwanted sequela of high lipid content in PAs that can lead to oxidative injury of biologic membranes in vivo. The purpose of this in vitro study was to measure hydroperoxides in HL:LD PAs and to determine the optimal dose of d-alpha-tocopherol to minimize peroxidation in these PAs during a 24-hr period. Detectable concentrations of hydroperoxides were present in all PAs. D-alpha-tocopherol appeared to significantly minimize peroxidation of HL:LD PAs in vitro. These results have clinical implications for parenteral feeding in critically ill patients.

Absorption and metabolism of alpha-ketoglutarate in growing pigs

The portal appearance of enteral alpha-ketoglutarate (AKG) and the effect of enteral or parenteral AKG on portal net appearance of glucose, short-chain fatty acids, alanine, aspartate, glutamate, glutamine, proline and insulin were investigated in three growing pigs. During the experimental samplings the pigs were fed hourly with a standard feed mix with 5% glucose (control), 5% AKG (enteral) or no feed additive but continuously infused with AKG into the mesenteric vein in an amount equivalent to 5% of feed intake (parenteral). The arterial plasma concentration of AKG increased (p < 0.05) following both enteral (from 16+/-2 to 22+/-3 micromol/l) and parenteral (from 16+/-2 to 425+/-27 micromol/l) administration of AKG. With the enteral treatment 4+/-1% of the AKG could be accounted for in the portal vein, however, with the parenteral treatment 86+/-5% could be accounted for in the portal vein. The arterial plasma concentration of proline increased (p < 0.05) with the enteral treatment (365 +/- 3 to 443 +/- 39 micromol/l), but was not affected by the parenteral treatment (p > 0.10). The plasma concentration glutamine decreased (p < 0.05) with the parenteral treatment only. The portal net appearance of proline showed a numerical increase with the enteral treatment but no other affects on arterial concentrations or portal net appearance were found. A small accompanying study showed that only small amounts of enteral AKG was present in the small intestine. It was therefore concluded that enteral AKG has a low availability to peripheral tissues either because it is absorbed and metabolized in the stomach and duodenum or because it is metabolized by microbes in the stomach. The study showed that AKG is metabolized differently following enteral and parenteral application in growing pigs.

Esophageal and gastric feeding tubes in ICU patients

Providing nutrition to critically ill patients is important to the healing process. This article will focus on selection and placement of nasoesophageal, nasogastic, esophagostomy, and gastrostomy tubes. Advantages and disadvantages of these tubes will be discussed, as well detailed instructions on the placement of the aforementioned tubes.

Route of nutrient delivery

Nutritional intervention early in the course of critical illness in humans and animals can have a significant impact on morbidity and mortality. Enteral delivery of nutrients is less technically demanding, more physiologic, and less expensive than parenteral nutrition. Furthermore, as complete bowel rest during critical illness can be associated with detrimental intestinal structural and functional changes ultimately resulting in bacterial translocation from the gut, direct delivery of nutrients to the gastrointestinal tract is preferred in patients with sufficient gastrointestinal function to allow digestion and absorption of nutrients. Once the decision to "feed the gut" has been established, there are several routes of enteral nutrient delivery available. A sound knowledge of gastrointestinal function, anticipated duration of enteral support, and co-moribund conditions will help the clinician tailor a plan of nutrient delivery that optimally meets each patient's needs. This article will review available routes of nutrient delivery to the gastrointestinal tract, and discuss indications and contraindications for each.

Parenteral and enteral routes of feeding in neonatal piglets require different ratios of branched-chain amino acids

The requirements for total branched-chain amino acids (BCAA), isoleucine, leucine and valine, in neonatal piglets receiving parenteral and enteral nutrition was determined recently. The optimum ratio among BCAA during different routes of feeding is not yet known. In this study, the ratio of BCAA during parenteral and enteral feeding was tested using the indicator amino acid oxidation (IAAO) technique. Male Yorkshire piglets (n=24) received amino acid-based diets containing adequate nutrients for 5 d. Phenylalanine oxidation and kinetics were determined from a 4-h primed, constant infusion of L-[1-14C]-phenylalanine on d 6 and 8. On d 6, all piglets received a BCAA diet which met 75% of the total BCAA requirement, based on our previous research, with a ratio of 1:1.8:1.2 of isoleucine/leucine/valine. On d 8, the piglets were randomly assigned to receive one of the 3 test diets supplemented with isoleucine (+isoleucine), leucine (+leucine) or valine (+valine) to meet 100% of requirement, with the remaining two BCAA at 75% of requirement. The difference in phenylalanine oxidation (% of dose) between d 6 and 8 was used as an indicator of BCAA adequacy. In enterally fed piglets, the change in the percentage of the dose oxidized was minimal for all 3 test diets (mean=1.15%). In parenterally fed piglets, the difference in phenylalanine oxidation (% of dose) between d 6 and 8 was +isoleucine (12.6%), +leucine (2%) and +valine (6.6%). The ratio of 1:1.8:1.2 of isoleucine/leucine/valine is appropriate for enteral feeding, but during parenteral feeding, isoleucine was first limiting and valine was second limiting.

Nutrition for critical gastrointestinal illness: feeding horses with diarrhea or colic

Horses with GI diseases such as colic and diarrhea are often intolerant of adequate enteral nutrition. Nutritional intervention should be an early part of therapeutic management in such cases. Protein and energy malnutrition in critically ill horses can have deleterious effects, including poor wound or incisional healing, reduced immunity, and weight loss. Early enteral or parenteral support should be provided to supply resting DE requirements in the equine ICU.

Study of the clinical effects of postoperative parenteral nutrition in 15 horses

Several clinical variables were compared in two groups of 15 horses recovering from resection and anastomosis of a strangulated small intestine; 15 were treated with parenteral nutrition and 15 were starved routinely. There was some evidence that parenteral nutrition had a short-lived adverse effect on both the catheter sites and gastric emptying, but there were no marked adverse clinical effects and no evidence of any improvement in the horses' condition.

Response of dogs to short-term infusions of carbohydrate- or lipid-based parenteral nutrition

Parenteral nutrition (PN) is used to support intensive care patients. The risk for adverse metabolic effects depends on the composition of infused solutions and the duration of application. The present study in dogs compares metabolic and endocrine effects of two infusion solutions, with either triglycerides or glucose being the major energy sources, administered in a comparatively short infusion period (10 h/day). PN was administered for 9 days to two groups of five adult dogs to meet energy maintenance requirements. In group PN-LIP 61% of the total energy was derived from lipids and 22% from carbohydrates, compared with 21 and 62% in group PN-GLUC. Among routine haematology and clinical chemistry the plasma levels of glucose, triglycerides, insulin, insulin-like growth factor-I (IGF-I), glucagon, 3,5,3'-triiodothyronine and thyroxin were measured in non-infused dogs and at 2, 4, 6, and 8 h after the start of infusion at days 2 and 8 of the study. Infusions protocols did not cause gross metabolic aberrations. During the actual infusions glucose, triglyceride and insulin concentrations were elevated, each depending on the infusion solution. Concentrations of IGF-I, glucagon, 3,5,3'-triiodothyronine, thyroxin and cortisol did not change significantly. In conclusion short infusion periods of 10 h per day were tolerated by healthy dogs without adverse signs, which could improve practicability of PN also in clinical cases.

Laparoscopic-assisted enterostomy tube placement and full-thickness biopsy of the jejunum with serosal patching in dogs

OBJECTIVE

To develop laparoscopic-assisted techniques for enterostomy feeding tube placement and full-thickness biopsy of the jejunum in dogs.

ANIMALS

15 healthy dogs. PROCEDURE Dogs were anesthetized, and positive pressure ventilation was provided. A trocar cannula for the laparoscope was inserted on the ventral midline caudal to the umbilicus. For enterostomy tube placement, a second trocar cannula was placed lateral to the right rectus abdominis muscle, and a Babcock forceps was used to grasp the duodenum and elevate it to the incision made for the cannula. The duodenum was sutured to the abdominal wall, and a feeding tube was inserted. For jejunal biopsy, a third trocar cannula was placed lateral to the left rectus abdominis muscle. A portion of jejunum was elevated to the incision for the second or third cannula, and a full-thickness biopsy specimen was obtained. A second specimen was obtained from another portion of jejunum, and retention sutures for the 2 biopsy sites were tied so that serosal surfaces of the biopsy sites were apposed to each other. Dogs were euthanatized 30 days after surgery.

RESULTS

The enterostomy tube was properly positioned and functional in all 8 dogs that underwent laparoscopic-assisted enterostomy tube placement, and sufficient samples for histologic examination were obtained from all 7 dogs that underwent laparoscopic-assisted jejunal biopsy. None of the dogs had any identifiable problems after surgery.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that in dogs, laparoscopic-assisted procedures for enterostomy tube placement and jejunal biopsy are an acceptable alternative to procedures performed during a laparotomy.

Retrospective evaluation of partial parenteral nutrition in dogs and cats

The purpose of this retrospective study was to evaluate the use of partial parenteral nutrition (PPN) in dogs and cats. The medical records of all dogs and cats receiving PPN between 1994 and 1999 were reviewed to determine signalment, reasons for use of PPN, duration of PPN administration, duration of hospitalization, complications, and mortality. Complications were classified as metabolic, mechanical, or septic. One hundred twenty-seven animals (80 dogs and 47 cats) were included in the study, accounting for 443 patient days of PPN. The most common underlying diseases were pancreatitis (n = 41), gastrointestinal disease (n = 33), and hepatic disease (n = 23). Median time of hospitalization before initiation of PPN was 2.8 days (range, 0.2-10.7 days). Median duration of PPN administration was 3.0 days (range, 0.3-8.8 days). Median duration of hospitalization was 7 days (range, 2-20 days). In the 127 animals receiving PPN, 72 complications occurred. These included metabolic (n = 43), mechanical (n = 25), and septic (n = 4) complications. The most common metabolic complication was hyperglycemia (n = 19), followed by lipemia (n = 17) and hyperbilirubinemia (n = 6). Most complications were mild and did not require discontinuation of PPN. Ninety-three (73.2%) of the 127 patients were discharged. All 4 animals with septic complications were discharged from the hospital. The presence, type, and number of complications did not impact the duration of hospitalization or outcome. However, animals that received supplemental enteral nutrition survived more often than those receiving PPN exclusively. Although PPN seems to be a relatively safe method of providing nutritional support, future studies are warranted to determine its efficacy.

Parenteral nutrition for horses with gastrointestinal disease: a retrospective study of 79 cases

Parenteral nutrition is advocated for sick foals and horses, although there is no report which has critically evaluated its benefits in this species. Therefore, the hypothesis that parenteral nutrition (PN) is beneficial for horses with severe gastrointestinal disease was investigated in a retrospective study. Records from 79 treatment courses in horses with gastrointestinal disease were reviewed for the years 1992-2000. The fatality rate (48.1%) was attributed to the severity of the primary disease. Complications due to PN were recorded and hyperglycaemia was the most common complication associated with PN. The number of laparatomies, proportion of horses that received lipid emulsion and the daily cost were higher in nonsurvivors than in survivors. The length of PN course was longer in survivors, although glucose peak was observed later in nonsurvivors after initiation of PN. The content of vitamins in PN solution and plasma protein at the beginning of PN were higher for survivors, while the volume of plasma administered was significantly larger in nonsurvivors. In horses with inflammatory diseases, the rate of glucose infusion and the amount of vitamins administered were higher than in horses with nonstrangulated obstruction. The proportion of horses that received lipid emulsion was higher among those with nonstrangulated and strangulated obstruction than in the group with inflammatory conditions. Because of the diverse group of diseases and the variability in the clinical signs, evaluating the effect of PN on disease outcome was not possible. A prospective study to compare horses with similar clinical conditions treated and not treated with PN is needed to evaluate fully the benefits of PN, and to establish guidelines for patient selection for PN.

Chronic restraint via tail immobilization of mice: effects on corticosterone levels and other physiologic indices of stress

Chronic venous cannulation in mice is an acceptable and useful technique for repeated blood sampling or continuous intravenous administration of substances, for which mild restraint of the animal may be necessary. Because chronic restraint has drawn considerable attention in the animal welfare community, the purpose of this study was to evaluate physiologic indices of stress in mice restrained by using an established tail restraint method. Serum corticosterone levels and body, thymus, adrenal, and spleen weights on days 2, 5, 8, and 12 were compared between tail-restrained and unrestrained mice. There were no significant differences between the two groups at the time points evaluated. Corticosterone levels were highest on day 8 for both groups and were significantly different from those on days 2 (P<0.009) and 5 (P<0.04) for restrained mice and on day 2 (P<0.02) for unrestrained mice. Levels in both groups declined by day 12, suggesting habitation. Weight loss was observed in all mice whether restrained or unrestrained. Significant differences in body, thymus, adrenal, and spleen weights were not evident between restrained and unrestrained mice. This study provides important information for balancing issues of prolonged restraint, animal well-being, and research goals.

Nitrogen balance in clinically normal dogs receiving parenteral nutrition solutions

OBJECTIVE

To determine nitrogen balance in clinically normal dogs receiving parenteral nutrition solutions.

ANIMALS

8 clinically normal female Beagles.

PROCEDURE

Dogs were randomly assigned to receive 4 treatments in random order. Treatment A consisted of IV administration of nonlactated Ringer's solution. Treatments B, C, and D consisted of IV administration of isocaloric parenteral solutions containing 0, 1.36, and 2.04 g of amino acids/kg of body weight/d, respectively, for 7 consecutive days. Urine and feces were collected on days 5, 6, and 7 of each treatment period, and Kjeldahl analysis was used to determine nitrogen balance.

RESULTS

Mean nitrogen balance was negative with treatments A and B but was not significantly different from 0 with treatments C and D. Dogs had the lowest nitrogen balance values and lost the most weight while receiving treatment A. Dogs were able to conserve protein and had higher nitrogen balance values when receiving treatment B, compared with treatment A. Dogs lost the least amount of weight while receiving treatment D. Regression analysis indicated that an IV amino acid intake of 2.32 g/kg/d (95% confidence interval, 2.00 to 2.81 g/kg/d), as supplied by the commercial product used in this study, would result in zero nitrogen balance in clinically normal dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that IV amino acid requirement of clinically normal dogs is approximately 2.3 g/kg/d.

Nutritional support for treatment of hepatic lipidosis in a llama

A 3-year-old female llama that was 3 months into her first lactation and 10 weeks pregnant was evaluated for anorexia of 24 hours' duration. On physical examination, the llama was in lateral recumbency, bradycardic, tachypneic, and hyperthermic. Palpation per rectum confirmed the presence of a possible dry fecal mass in the spiral colon. A tissue biopsy specimen of the liver was obtained, and histologic examination revealed moderate diffuse lipid accumulation within the hepatocytes. Lactated Ringer's solution was administered for rehydration, and partial parenteral nutrition was then initiated. Hepatic lipidosis is a disease characterized by abnormal accumulation of lipid in the liver and is associated with high mortality in camelids. Anorexia associated with hepatic lipidosis promotes further lipid mobilization and fatty infiltration of the liver. Partial parenteral nutrition with enteral supplementation may be used to maintain adequate energy intake and minimize further lipid mobilization. The distinctive metabolism of camelids may require higher amino acid supplementation relative to nonprotein calories in parenteral solutions than those traditionally provided to other species. Treatment with insulin may be effective

Effects of luminal nutrient absorption, intraluminal physical stimulation, and intravenous parenteral alimentation on the recovery responses of duodenal villus morphology following feed withdrawal in chickens

The aim of this study was to clarify which of the following three factors induces villus morphological recovery best: enteral nutrient absorption, intraluminal physical stimulation, or intravenous parenteral alimentation. At 142 d, male White Leghorn chickens (Gallus gallus domesticus) were divided into eight groups of five birds each as follows: 1) access given ad libitum to a commercial layer mash diet (CP, 17.5%; ME, 2,830 kcal/kg) (control), 2) 5-d feed withdrawal (feed withdrawal), 3) 3-d feed withdrawal (3-FW), followed by refeeding the same diet as the control for 2 d (refeeding), 4) 3-FW followed by force-feeding enteral hyperalimentation (enteral), 5) 3-FW followed by force-feeding an indigestible (nonabsorbable) substance (kaolin), 6) 3-FW followed by force-feeding water for 2 d (force-fed control), 7) 3-FW followed by parenteral hyperalimentation (parenteral), and 8) 3-FW followed by no alimentation (sham control) for 2 d. In the refeeding and enteral groups, BW significantly recovered (P < 0.05), and in the parenteral group, BW tended to increase, suggesting that nutrients were enterally and parenterally absorbed, respectively. The BW in the remaining three groups showed a significant decrease (P < 0.05), indicating that kaolin could not be absorbed enterally. Compared with the feed withdrawal group, villus height, cell mitosis, and villus tip surface morphology of refeeding and enteral groups exhibited rapid villus morphological recovery. Villus morphological recovery of the enteral group appears to have been caused by enteral nutrient absorption. However, villus morphology in the kaolin treatment was not different from that in the feed withdrawal group, which suggests that intraluminal physical stimulation had no effect on villus morphological recovery. On the other hand, the parenteral group showed no effect on villus morphological recovery, which suggests that the parenteral nutrient supplied to the villi via the blood could not induce villus morphological recovery; the intestinal mucosal atrophy might have been caused by the absence of enteral nutrients, and would only be stimulated by enteral nutrient absorption. In conclusion, the present findings suggest that villus morphology is governed neither by intraluminal physical stimulation nor by parenteral alimentation, but by enteral nutrient absorption.

A pilot study of protein sparing in healthy dogs using peripheral parenteral nutrition

Total parenteral nutrition is the standard nutritional support of dogs when the enteral route is contraindicated, but it can be difficult because of cost, technical difficulties, and potential complications. Peripheral parenteral nutrition (PPN) may be a feasible option for short-term support in some cases. The objectives of this study were to determine the effect of PPN on nitrogen balance (as an indicator of the effect on protein sparing), serum folate concentrations and serum insulin-like growth factor-I (IGF - I) concentrations in fasting dogs. The effect of PPN on these parameters has not previously been reported in dogs. Using a cross-over design, three healthy adult fasting dogs were randomly assigned to three treatments: 5 per cent amino acid solution, 5 per cent glucose solution, and a control electrolyte solution. The solutions were administered into a peripheral vein at 60 ml kg(-1)per day for 4 days. The amino acid infusion resulted in a positive nitrogen balance and the glucose infusion produced less nitrogen loss than the control. Amino acid, but not glucose or electrolyte infusions, decreased serum folate concentrations. Amino acid and glucose infusions resulted in higher serum IGF -I concentrations than electrolyte infusions, although the differences were small and IGF -I decreased in all cases. In conclusion, these findings suggest that PPN increases nitrogen balance in healthy dogs undergoing short-term fasting.

Parenteral nutrition in the management of a dog with lymphocytic-plasmacytic enteritis and severe protein-losing enteropathy

Management of lymphocytic-plasmacytic enteritis in a dog with whipworm infestation, hypoproteinemia, and ascites is described. Short-term parenteral nutrition hastened normalization of serum proteins, resolution of diarrhea, and weight gain. A description of the potential benefits, limitations, and possible complications of parenteral nutrition in refractory inflammatory bowel disease is given.

Critical care nutrition: routes of feeding

Nutrition is an integral part of the management of the critically ill patient. Nutritional support can be provided by either parenteral or enteral routes. Whenever possible, enteral nutrition is the method of choice, as it reduces complication rates and improves outcome. Potential choices for enteral feeding include nasoesophageal, esophagostomy, gastrostomy, jejunostomy, and transpyloric feeding tubes. The modes of parenteral and enteral nutrition are reviewed individually, including indications and selection of appropriate routes of feeding, methods of tube placement, and benefits and risks associated with each feeding approach.

The various types of parenteral fluids and their indications

Assessment of hydration and perfusion is essential in patient evaluation. The acid-base and electrolyte disturbances that accompany many illnesses should also be considered. The duration of illness and body systems involved are also of major importance in patient evaluation. Fluid therapy is an important and potentially life-saving treatment of many and varied problems. The clinician must be able to assess the patient and determine whether the intravascular or extravascular compartments, or both, are deficient. Of primary concern is the status of the intravascular volume, then restoration of total body water and electrolytes. Fluid therapy is divided into three phases; the emergency phase, the rehydration phase, and the maintenance phase; not all patients require the three-phase therapy. The clinician must also be able to select (1) the appropriate solution to treat the volume deficit and correct the acid-base and electrolyte abnormalities and (2) the rate of administration to optimize outcome. Therefore, knowledge of electrolyte composition in plasma and of the various types of commercially available fluids is essential in order to select the appropriate therapy for the individual animal. In addition to the therapeutic aspects of fluid therapy, a knowledge of the side effects and complications of inappropriate fluid selection and rate of delivery is also important. With the individual requirements of each patient seen in a practice, the prescription approach to parenteral fluid therapy will optimize patient response to this extremely important aspect of overall patient management as well as make the practice of fluid therapy intellectually stimulating. This article has introduced the clinician to the parenteral fluids available and their indications in veterinary patients; it also contains a discussion of how to utilize preferred solutions for treatment of specific diseased states. Although there are definite "right" and "wrong" fluids to select for specific problems, there also remains individual preference in fluid choice, which is based on appropriate laboratory data and the practitioner's clinical judgment of the status of the individual patient vis-à-vis the spectrum of its disease. Recommendations for selection of different fluid types to treat similar conditions are usually based on these variables.

Hyperosmolar hyperglycaemic syndrome in a dog resulting from parenteral nutrition overload

A dog treated for a pancreatic abscess inadvertently received 1800 ml of hyperosmolar solution within a two hour period. Blood glucose reached 44 mmol/litre and the plasma osmolality was estimated to be more than 334 mOsm/litre. Lipaemia was severe and persisted for several days. The dog developed nausea, vomiting, depression, severe hyperglycaemia, polyuria, glucosuria and hypokalaemia. These symptoms were consistent with a hyperosmolar hyperglycaemic syndrome. Treatment with insulin and intravenous fluid rapidly corrected the hyperglycaemia, electrolyte imbalances and water deficits. The dog recovered and no long-term sequelae were observed.

Nutritional support of hospitalized animals

Nutritional support of hospitalized animals is new and encouraging, although it is in need of rigorous evaluation. Principles and procedures of established value in human patients appear to be readily applied to other species, with due regard to comparative physiologic properties and medicine.

Nutrition and cancer. Recent developments

Cancer cachexia is a complex syndrome that results in involuntary weight loss, even in the face of adequate nutritional intake. The profound metabolic abnormalities associated with cancer cachexia affect a large percentage of animals with cancer even before any clinical signs are seen. This paraneoplastic syndrome results in alterations in carbohydrate, lipid, and protein metabolism that, if left untreated, decrease the animal's quality of life and lead to a poor response to cancer therapy. An understanding of the metabolic abnormalities associated with cancer cachexia is of paramount importance to the practicing veterinarian to determine an accurate prognosis and to choose the optimal type of intravenous fluids and nutritional therapy for each patient. Although research identifying the optimal diet for cancer-bearing dogs and cats is still underway, some general principles apply. The first is that the patient should receive nutritional elements orally whenever possible. When oral feeding is not possible, nasogastric, gastrostomy, and jejunostomy tube feeding are viable options. When feeding by the gastrointestinal tract is not possible, parenteral feeding is a practical alternative.

The use of parenteral nutrition in calves

Parenteral nutrition has been an important adjunct to therapy of abdominal diseases in calves, with chronic diarrhea and wasting being the most common indication. Parenteral nutrition is administered on a short-term basis to prevent further protein-energy malnutrition in debilitated calves that cannot or will not consume adequate quantities of milk. Parenteral nutrition solutions consist of a protein source (amino acids) and energy sources (glucose and lipid emulsions), supplemented as needed with balanced electrolytes and vitamins. Complications due to PPN are rare, and it is the authors' clinical impression that survivability is enhanced when PPN is employed, although enhanced survivability was not demonstrated in one controlled experimental trial.

Parenteral nutritional support in the small animal patient

Malnutrition has a direct relationship to complications associated with ineffective wound and fracture healing, inadequate immune responses, decreased tolerance to cancer therapy, muscle weakness, and certain organ dysfunctions (heart and liver). Malnutrition combined with disease, injury, or stress increases the metabolic rate in patients above that of resting. These patients are undergoing an accelerated form of starvation, which is more common than presently recognized in veterinary medicine and may be responsible for the less than optimal responses to proper therapies. Diseased or injured patients unable to digest or absorb nutrients from the gastrointestinal tract require additional medical support in the form of parenteral nutrition. Advances in parenteral solutions, products, and delivery systems make parenteral nutritional support possible in veterinary medicine, although not possible in all small animal practices. Proper patient selection, well-informed clients, dedicated technicians, and knowledgeable veterinarians are all essential in the successful implementation of parenteral nutritional support.

[Determination of methionine and tryptophan level in veterinary infusions containing amino acids]

Method has been developed for determination of methionine in veterinary infusions containing amino acid. Methionine was measured on the basis of color reaction with sodium pentacyano-nitrosyl-ferrate in alkaline solution. Reproducibility of the method was good (recovery: 95.9-101.9%, r.s.d. = 2.3%, p = 0.95, n = 6). Tryptophane was determined on the basis of its UV absorbency at 280 nm, methionine did not interfere on this wavelength. Reproducibility of tryptophane determination was with an order better than that of methionine determination (recovery: 97.7-98.3%, r.s.d. = 0.15%, p = 0.95, n = 9). Methionine could be regained from infusions that had been heated at 120 degrees C for sixty minutes in the same quantity as from infusions which had not been heated. On the other hand tryptophane could be regained with 10% positive error from the heated infusions. The error can mainly be attributed to absorbency increase of glucose which is present in the infusion.

Fluid therapy for diarrheic calves. What, how, and how much

The pathophysiologic consequences of neonatal diarrhea in calves are presented. A brief discussion of intestinal function, nutrient absorption, and osmolar effects follows. A rationale for appropriate fluid therapy is presented, and comparison of some currently marketed products are made.

Nutritional support of the foal during intensive care

Provision of adequate nutritional support to the sick neonatal foal is a vital part of intensive care; frequently, however, it is very difficult to accomplish. In this article, current recommendations concerning both enteral and parenteral nutrition are discussed.

Effect of intravenous supplements of L-methionine on milk yield and composition in cows given silage-cereal diets

Eight cows in mid lactation and receiving a diet of perennial ryegrass silage and barley (70:30 on a DM basis) were given intravenous supplements of L-methionine (8 g/d). The methionine treatment had no significant effect on milk yield, protein content or lactose content, but increased milk fat content and yield by approximately 10% (P less than 0.05).