Dietary supplementation of micro-encapsulated sodium butyrate in healthy horses: effect on gut histology and immunohistochemistry parameters.

BACKGROUND: As colic and intestinal disorders are a major concern in horses, the aim of the present study was to investigate the effect of dietary supplementation of butyrate, known to have a diverse array of beneficial effects on intestinal health. The effect of micro-encapsulated sodium butyrate supplementation on gut histology and immunohistochemistry parameters was studied in 14 healthy warmblood horses destined for slaughter in two separate periods. Horses were fed a low fiber - high starch diet, designed to induce subsequent starch overflow in the large intestine, aiming to create a mild challenge for large intestinal health. Treatment included supplementation with either micro-encapsulated sodium butyrate (Excential Butycoat®, Orffa, Werkendam, the Netherlands) or placebo (containing only coating material). The horses were fed for 20 consecutive days at a dosage of 0.4 g/kg BW (body weight). At day 21, the horses were slaughtered and intestinal samples were collected for determination of gut pH, villus length, crypt depth and area % of CD3+ and CD20+ cells. RESULTS: Horses on the butyrate supplemented diet had significantly reduced crypt depths in the right dorsal colon compared to placebo-fed horses (P < 0.001). However, a treatment x period interaction (P = 0.002) was discovered regarding this parameter, which could not be explained by the authors. Further investigation into the number of KI67+ cells in the RDC crypts did not reveal any significant differences between treatments (P = 0.650), indicating that the reduction in crypt depth in butyrate-fed horses could not be explained by a significant difference in cellular proliferation. Intestinal pH, villus length and expression of intestinal CD3+ and CD20+ cells were not significantly affected by treatment at any intestinal level. CONCLUSIONS: Our data indicate that supplementation of micro-encapsulated sodium butyrate to the equine diet did not influence gut histology (with the exception of a decrease found in the crypts of the RDC) or immunohistochemistry parameters in healthy horses. Further research is warranted to investigate the impact of butyrate supplementation in horses with intestinal disease.

Variability of serum concentrations of cystatin C and urinary retinol-binding protein, neutrophil gelatinase-associated lipocalin, immunoglobulin G, and C-reactive protein in dogs.

BACKGROUND: Markers of kidney dysfunction and damage have potential to detect chronic kidney disease (CKD) in early stages. However, data on long-term variation of these markers in healthy dogs is lacking and is crucial for the interpretation of results. HYPOTHESIS/OBJECTIVES: To determine temporal variations of serum cystatin C (sCysC) and urinary retinol-binding protein (uRBP), neutrophil gelatinase-associated lipocalin (uNGAL), immunoglobulin G (uIgG), and C-reactive protein (uCRP) in healthy dogs. ANIMALS: Eight clinically healthy adult Beagles were evaluated. METHODS: Longitudinal observational study. Serum cystatin C was determined by particle-enhanced nephelometric immunoassay. Urinary retinol-binding protein, uNGAL, uIgG and uCRP were determined by ELISA and concentrations were indexed to urinary creatinine. Within- and between-dog variance components (VC) and within-dog coefficients of variation (CV) were determined from blood and urine collected at eight time points over 1.5 years. RESULTS: Urinary C-reactive protein (uCRP) concentrations were consistently below the detection limit (5.28 ng/mL). Mean ± within-dog standard deviation for sCysC, uRBP/c, uNGAL/c and uIgG/c was 0.15 ± 0.01 mg/L, 0.09 ± 0.03 mg/g, 2.32 ± 2.03 µg/g and 12.47 ± 10.98 mg/g, respectively. Within-dog CV for sCysC, uRBP/c, uNGAL/c and uIgG/c was 8.1%, 33.7%, 87.2% and 88.1%, respectively. CONCLUSIONS AND CLINICAL IMPORTANCE: Serum cystatin C, uRBP/c, uNGAL/c and uIgG/c exhibit a wide range of long-term within-dog variability. Researchers and veterinarians might need to take this into account when interpreting their results. To assess their diagnostic and predictive ability, future studies need to establish reference ranges for healthy dogs and dogs with CKD.

How does dietary particle size affect carnivore gastrointestinal transit: A dog model.

The effect of dietary particle size on gastrointestinal transit in carnivores has not been studied and might offer more insight into their digestive physiology. This study evaluated the effect of two dietary particle sizes (fine = 7.8 mm vs. coarse = 13 mm) of chunked day-old chicks on transit parameters in dogs. Six beagle dogs were fed both dietary treatments in a crossover design of 7 days with transit testing on the fifth day. Transit parameters were assessed using two markers, that is a wireless motility capsule (IntelliCap® ) and titanium oxide (TiO2 ). Dietary particle size did not affect gastric emptying time (GRT), small bowel transit time (SBTT), colonic transit time (CTT) and total transit time (aTTT) of the capsule (p > .05). There was no effect of dietary particle size on TiO2 mean retention time (MRT) (p > .05). The time of last TiO2 excretion (MaxRT) differed (p = .013) between diets, being later for the coarse diet. Both MRT (R = 0.617, p = .032) and MaxRT (R = 0.814; p = .001) were positively correlated to aTTT. The ratio MRT/aTTT tended towards a difference between diets (p = .059) with the coarse diet exceeding fine diet values. Results show that the difference between capsule measurements and TiO2 is larger for the fine than the coarse diet suggesting that the capsule becomes more accurate when dietary particle size approaches marker size. Dietary particle size might have affected transit parameters but differences are too small to claim major physiological consequences.

First detailed nutritional survey in a referral companion animal population.

Optimal nutrition in every life stage and certainly in diseased animals will contribute greatly to improve overall health and quality of life. The 5th VA guidelines have been designed to help veterinarians to implement a nutritional assessment into every patient, every time it comes into their practice. This nutritional survey in referral patients was conducted by one person skilled in acquiring detailed nutritional information and evaluating nutritional status. Two goals were set as follows: first to gain more insight into the nutritional status and management of referred patients and second to gain more insight in the nutritional recommendations given by the treating veterinarian. Using an online survey program, a detailed nutritional survey was designed using the 5th VA guidelines as a roadmap. Ultimately, 100 surveys were completed using referral patients with following results: only 15% of referred patients were cats; obesity occurrence was high with 53% of cats and 35% of dogs being overweight or obese; eleven per cent of animals had an abnormal MCS; and five of seven dogs with an abnormal MCS dogs died within 6 months. Several nutritional risk factors were undiagnosed and consequently untreated in these patients. Therefore, continued efforts must be made to educate practicing veterinarians into using the nutritional guidelines. The routine use of these guidelines by veterinarians will ultimately improve the nutritional status of all companion animals and might reduce the prevalence of diseases where poor nutrition or management has a contributing role.

Food-specific sublingual immunotherapy is well tolerated and safe in healthy dogs: a blind, randomized, placebo-controlled study.

BACKGROUND: Food allergies are increasing in prevalence but no treatment strategies are currently available to cure dogs with food allergy. Over the past decade, experimental food allergen-specific sublingual immunotherapy (FA-SLIT) has emerged as a potential treatment for food allergies in human medicine. However, FA-SLIT has not been investigated in dogs. Therefore, the objective of this study was to prospectively evaluate the safety, tolerability and dispenser sterility of FA-SLIT in healthy dogs before testing it in food allergic dogs. Eight experimental healthy beagle dogs, never orally exposed to peanut, were randomized in two groups to receive SLIT with peanut or placebo for 4 months. Subjects were monitored daily for local and systemic adverse effects. Blood samples for complete blood count and serum biochemistry, and urine for urinalysis were collected and the dogs' body weight was recorded at day 0, 35 and 119 of the SLIT treatment. Sera for the determination of peanut-specific IgG and IgE were collected at day 0, 35, 49, 70, 91, 105 and 119. Intradermal tests were performed before (day 0) and after (day 119) the experiment. The content of each dispenser used to administer treatment or placebo was tested for sterility after usage. In order to assess the presence or absence of sensitization, dogs were challenged 6 months after the end of the study with 2000 µg of peanut extract daily for 7 to 14 days. RESULTS: All dogs completed the study. The treatment did not provoke either local or systemic side-effects. Peanut-specific IgG significantly increased in treatment group. Even though a significant increase in peanut-specific IgE was also seen, intradermal tests were negative in all dogs before and after the experiment, and the challenge test did not trigger any adverse reactions in the treated dogs, which shows the protocol did not cause sensitization to peanut, but nevertheless primed the immune system as indicated by the humoral immune response. All dispenser solutions were sterile. CONCLUSIONS: Our results demonstrate that the used peanut-SLIT protocol is well tolerated and safe in healthy dogs. Further studies should evaluate tolerability, safety and efficacy in dogs with food allergy.

Predictive equations of selenium accessibility of dry pet foods.

The trace element selenium is essential to both dogs and cats. Dry diets are formulated with a large range of ingredients, which may vary in selenium concentration and accessibility. This paper reports equations to predict the average in vitro selenium accessibility from dry pet foods based on essential dietary nutrient concentrations, including crude protein, amino acids and crude fat. Predictive equations were made using stepwise linear regression for extruded and pelleted diets. The equations can be used to aid diet formulation to optimize selenium accessibility within the diet and to prevent selenium deficiency or toxicity.

A commercially available immunoglobulin E-based test for food allergy gives inconsistent results in healthy ponies.

REASONS FOR PERFORMING STUDY: Commercial immunoglobulin E (IgE)-based tests are available for diagnosis of food allergies and are commonly used in equine practice. However, these tests have been proven unreliable as a screening method in man and other species, but not critically evaluated in equids. Therefore, a commercially available IgE-based test for horses was evaluated. OBJECTIVES: To evaluate the consistency of the results obtained with a commercially available IgE-based test for food allergy diagnosis in ponies (Phase I) and to subject ponies to a provocation trial with the presumed allergens (Phase II). STUDY DESIGN: Allergen screening followed by experimental food provocation trials in healthy ponies. METHODS: Blood samples of 17 healthy Shetland ponies were taken at 2 different time points, sent blinded to a commercial laboratory for screening of common food allergens and the results were evaluated for consistency (Phase I). Ponies that were positive for food allergens were consecutively challenged orally with each allergen separately for 14 days (Phase II). A washout period of one week was applied in ponies with multiple positive results. Clinical parameters and serum amyloid A were monitored during the provocation trial. RESULTS: Only 7/17 ponies were negative on the IgE-based test at the 2 time points, 3 had positive results twice but only one tested positive twice for the same food allergen. No abnormalities were noted during the provocation trials. CONCLUSIONS: This study demonstrated that this IgE-based test is not a reliable screening tool for food allergy in healthy equids.

The effect of feeding, storage and anticoagulant on feline serum cystatin C.

Serum cystatin C (sCysC) is a possible marker for early detection of chronic kidney disease (CKD) in cats. In contrast with serum creatinine (sCr), feline sCysC is not affected by age, breed or sex. However, further biological and clinical validation is required. The objectives of this study were: (1) to investigate if food intake and circadian rhythm affect feline sCysC; (2) to determine the stability of sCysC under different storage conditions, and (3) to investigate if plasma concentrations of CysC (pCysC) differed from sCysC. A crossover study with 10 healthy laboratory cats fed the same commercial dry food was performed to study the influence of feeding and diurnal variation. Storage effects and comparison of pCysC with sCysC were determined using healthy cats (n = 3 and n = 10, respectively) and cats with CKD (n= 4 and n = 17, respectively). A significant daily sCysC variation was seen. Pre- and postprandial sCysC and sCr concentrations did not change significantly. Serum CysC significantly increased during storage at room temperature. After freezing, sCysC significantly decreased after 5 and 12 months at both -20 °C and -72 °C. Plasma CysC was significantly lower than sCysC. These findings suggest that it is not mandatory to fast cats before evaluation of sCysC and sCr. Samples were stable during routinely used storage conditions. Based on these findings, freezing for more than 5 months is not recommended, although additional studies are required to evaluate the clinical relevance of decreased sCysC after prolonged storage. Plasma and serum CysC cannot be compared directly.

Level of energy restriction alters body condition score and morphometric profile in obese Shetland ponies.

Due to the high prevalence of obesity in some horses and ponies (especially in the leisure horse sector), effective and safe weight loss strategies are required. The present study evaluated the effect of two different energy restriction rates on physical, morphometric and welfare parameters in 18 obese (body condition score [BCS] 7-9/9) Shetland geldings. The trial was divided into three periods: (1) a 4 week adaptation period, during which the maintenance energy intakes to maintain a stable obese bodyweight were determined (100% MERob); (2) a 16.5-week weight loss period during which the ponies were randomly divided into three groups (n = 6/group) comprising a control group (CONTROL), moderate energy restricted (MOD), and severe energy restricted (SEV) groups that were respectively fed at 100%, 80% and 60% of their individual MERob; and (3) a 3 week follow up period in which the ponies were again fed at their outset individual 100% MERob. Between the start and end of the weight loss period, significant pairwise differences between the three treatment groups were seen for bodyweight, BCS, heart girth, belly girth, and relative ultrasound fat depth at the level of loin and ribs at several time points (P < 0.05). The higher energy restriction was associated with a faster decrease in BCS, tail head, and heart plus belly girth, but no gastric ulcers or stereotypic behaviours were seen.

Secreted phospholipase A2 inhibitor modulates fatty acid composition and reduces obesity-induced inflammation in Beagle dogs.

Secreted phospholipase A2 inhibitor (sPLA2i) has been reported to have an anti-inflammatory function by blocking the production of inflammatory mediators. Obesity is characterized by low-grade inflammation and oxidative stress. The aim of this study was to investigate the effects of dietary supplementation of sPLA2i on inflammation, oxidative stress and serum fatty acid profile in dogs. Seven obese and seven lean Beagle dogs were used in a 28-day double blind cross-over design. Dogs were fed a control diet without supplemental sPLA2i or an sPLA2i supplemented diet. The sPLA2i diet decreased plasma fibrinogen levels and increased the protein:fibrinogen ratio in obese dogs to levels similar to those of lean dogs fed the same diet. Obese dogs had a higher plasma concentration of the lipophilic vitamin A with potential antioxidative capacity and a lower ratio of retinol binding protein 4:vitamin A compared to lean dogs, independent of the diets. A higher proportion of myristic acid (C14:0) and a lower proportion of linoleic acid (C18:2n-6) were observed in the dogs fed with the sPLA2i diet compared to dogs fed with the control diet. Furthermore, a higher ratio of n-6 to n-3, a lower proportion of n-3 polyunsaturated fatty acids and lower omega-3 index were observed in obese compared to lean dogs. The results indicate that obese dogs are characterized by a more 'proinflammatory' serum fatty acid profile and that diet inclusion of sPLA2i may reduce inflammation and alter fatty acid profile.

The cat as a model for human obesity: insights into depot-specific inflammation associated with feline obesity.

According to human research, the location of fat accumulation seems to play an important role in the induction of obesity-related inflammatory complications. To evaluate whether an inflammatory response to obesity depends on adipose tissue location, adipokine gene expression, presence of immune cells and adipocyte cell size of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) were compared between lean and obese cats. Additionally, the present study proposes the cat as a model for human obesity and highlights the importance of animal models for human research. A total of ten chronically obese and ten lean control cats were included in the present study. Body weight, body condition score and body composition were determined. T-lymphocyte, B-lymphocyte, macrophage concentrations and adipocyte cell size were measured in adipose tissue at different locations. Serum leptin concentration and the mRNA expression of leptin and adiponectin, monocyte chemoattractant protein-1, chemoligand-5, IL-8, TNF-alpha, interferon-gamma, IL-6 and IL-10 were measured in blood and adipose tissues (abdominal and inguinal SAT, and omental, bladder and renal VAT). Feline obesity was characterised by increased adipocyte cell size and altered adipokine gene expression, in favour of pro-inflammatory cytokines and chemokines. Consequently, concentration of T-lymphocytes was increased in the adipose tissue of obese cats. Alteration of adipose tissue was location dependent in both lean and obese cats. Moreover, the observed changes were more prominent in SAT compared with VAT.

Proliferation capacity of T-lymphocytes is affected transiently after a long-term weight gain in Beagle dogs.

Across species obesity is associated with several disorders but in companion animals little information is available on the impact of chronic obesity on immune competence. The aim of the present study was to investigate whether weight gain and stable obese bodyweight affects the immune cell response. Obesity was induced in eight adult healthy beagle dogs (weight gain group; WGG) by a weight gain period (WGP) of 47 weeks, which was immediately followed by a period (stable period: SP) of stable obesity of 26 weeks. Eight adult healthy beagle dogs were included as a control group (CG) and remained at their ideal bodyweight throughout the entire study. Body composition was measured at five intervening time-points. Concentration of serum leptin and inflammatory cytokines, functionality of lymphocytes and phagocytic activity of neutrophils and monocytes were evaluated at ten intervening time-points. Serum leptin concentration was rising during the WGP in the WGG but went to lower concentrations during the SP. At the end of long-term weight gain, a decreased mitogen-induced proliferation of T-lymphocytes was noted but this alteration seemed to be transient after stabilization of bodyweight. This finding may imply an altered immune response for dogs with different energy balances. However, no systemic low grade inflammation or alteration in other immune cell functions was observed. Consequently it is suggested that the change in energy balance during the onset of obesity (becoming obese versus being obese), evokes an additional obesity-related disorder in dogs, i.e. impaired T-lymphocyte immune function.

Animal fibre: the forgotten nutrient in strict carnivores? First insights in the cheetah.

As wild felids are obligate carnivores, it is likely that poorly enzymatically digestible animal tissues determine hindgut fermentation, instead of plant fibre. Therefore, faecal concentrations of short-chain fatty acids (SCFA, including branched-chain fatty acids, BCFA), indole and phenol were evaluated in 14 captive cheetahs, fed two different diets differing in proportion of poorly enzymatically digestible animal tissue. Using a cross-over design, the cheetahs were fed exclusively whole rabbit or supplemented beef for 1 month each. Feeding whole rabbit decreased faecal propionic (p < 0.001) and butyric (p = 0.013) acid concentrations, yet total SCFA was unaltered (p = 0.146). Also, a remarkably higher acetic acid to propionic acid ratio (p = 0.013) was present when fed whole rabbit. Total BCFA (p = 0.011) and putrefactive indole (p = 0.004) and phenol (p = 0.002) were lower when fed whole rabbit. Additionally, serum indoxyl sulphate, a toxic metabolite of indole, was analysed and showed a quadratic decrease (p = 0.050) when fed whole rabbit. The divergent SCFA ratios and the decrease in putrefaction when fed whole rabbit could be caused by the presence of undigested tissue, such as skin, bone and cartilage, that might have fibre-like functions. The concept of animal fibre is an unexplored area of interest relevant to gastrointestinal health of captive cheetahs and likely other felids.

Biological effects of short-term salmon oil administration, using distinct salmon oil sources in healthy dogs.

OBJECTIVES: To assess the short-term effects of feeding distinct salmon oil sources in healthy dogs. METHODS: A diet containing chicken fat as major fat source was fed to 17 dogs for 14 days. For the next 14 days, dogs received one of two diets, both with 1% of chicken fat exchanged for 1% salmon oil; Norwegian or Scottish salmon oil, harvested using a distinct procedure. Finally, all dogs were fed chicken fat again for 14 days. RESULTS: Salmon oil increased serum phospholipid total n-3 polyunsaturated fatty acids, eicosapentaenoic and docosahexaenoic acid and decreased total n-6 polyunsaturated fatty acids and n-6:n-3. The phospholipid fatty acid profile returned to initial values within 2 weeks of discontinuing salmon oil administration. Blood coagulation, acute phase response and plasma immunoglobulin concentrations were not affected by salmon oil and no differences were detected for the measured indices between the two salmon oils. CLINICAL SIGNIFICANCE: Low-dose salmon oil administration alters serum phospholipid fatty acid profile within 2 weeks, but without affecting selected immunologic and coagulation indices. Salmon oil sources from different sources and harvested using a distinct procedure did not induce different effects, most probably because of their similar fatty acid profiles.

Fermentation of animal components in strict carnivores: a comparative study with cheetah fecal inoculum.

The natural diet of felids contains highly digestible animal tissues but also fractions resistant to small intestinal digestion, which enter the large intestine where they may be fermented by the resident microbial population. Little information exists on the microbial degradability of animal tissues in the large intestine of felids consuming a natural diet. This study aimed to rank animal substrates in their microbial degradability by means of an in vitro study using captive cheetahs fed a strict carnivorous diet as fecal donors. Fresh cheetah fecal samples were collected, pooled, and incubated with various raw animal substrates (chicken cartilage, collagen, glucosamine-chondroitin, glucosamine, rabbit bone, rabbit hair, and rabbit skin; 4 replicates per substrate) for cumulative gas production measurement in a batch culture technique. Negative (cellulose) and positive (casein and fructo-oligosaccharides; FOS) controls were incorporated in the study. Additionally, after 72 h of incubation, short-chain fatty acids (SCFA), including branched-chain fatty acids (BCFA), and ammonia concentrations were determined for each substrate. Glucosamine and glucosamine-chondroitin yielded the greatest organic matter cumulative gas volume (OMCV) among animal substrates (P < 0.05), whereas total SCFA production was greatest for collagen (P < 0.05). Collagen induced an acetate production comparable with FOS and a markedly high acetate-to-propionate ratio (8.41:1) compared with all other substrates (1.67:1 to 2.97:1). Chicken cartilage was rapidly fermentable, indicated by a greater maximal rate of gas production (R(max)) compared with all other substrates (P < 0.05). In general, animal substrates showed an earlier occurrence for maximal gas production rate compared with FOS. Rabbit hair, skin, and bone were poorly fermentable substrates, indicated by the least amount of OMCV and total SCFA among animal substrates (P < 0.05). The greatest amount of ammonia production among animal substrates was measured after incubation of collagen and rabbit bone (P < 0.05). This study provides the first insight into the potential of animal tissues to influence large intestinal fermentation in a strict carnivore, and indicates that animal tissues have potentially similar functions as soluble or insoluble plant fibers in vitro. Further research is warranted to assess the impact of fermentation of each type of animal tissue on gastro-intestinal function and health in the cheetah and other felid species.

Short-term increase of body weight triggers immunological variables in dogs.

Overweight in dogs is, as in other companion animals, a major risk factor for several metabolic disorders. However, it is not yet known whether immunity is challenged by increased body weight in dogs. The aim of this study was to investigate the effect of a short-term increase in body weight on immunological variables in adult healthy beagle dogs. Sixteen dogs, divided into a control group (CG) and weight gain group (WGG), were included. During a period of 13 weeks, the CG was fed at maintenance energy requirement (MER), whereas the WGG received a double amount of food. After 13 weeks, blood samples were taken for immunological and biochemical analyses. Weight gain and increased body condition score in the WGG were accompanied by a significant higher leptin concentration. Weight gain increased the number of lymphocytes and immunoglobulins A and M and was responsible for a higher proliferation of peripheral blood mononuclear cells (PBMC). Short-term increase of body weight thus seems to trigger immunological variables in dogs.

Propionate absorbed from the colon acts as gluconeogenic substrate in a strict carnivore, the domestic cat (Felis catus).

In six normal-weight and six obese cats, the metabolic effect of propionate absorbed from the colon was assessed. Two colonic infusions were tested in a crossover design with intervals of 4 weeks. The test solution contained 4 mmol sodium propionate per kg ideal body weight in a 0.2% NaCl solution. Normal saline was given as control solution. Solutions were infused into the hindgut over 30 min. Blood samples were obtained prior to and at various time points after starting the infusion. As body condition did not affect evaluated parameters, all data were pooled. Plasma glucose concentrations showed differences neither over time nor during or after infusion with propionate or control. Plasma amino acid concentrations rose over time (p < 0.001), but were similar for both infusions. Plasma propionylcarnitine rose markedly towards the end of the propionate infusion and decreased afterwards (p < 0.001), whereas 3-hydroxy-3-methylglutarylcarnitine was lower 30 (p = 0.005) and 60 min (p = 0.032) after ending propionate infusions and acetylcarnitine tended to fall at the same time points (p = 0.079; p = 0.080), suggesting inhibition of gluconeogenesis from pyruvate and amino acids, but initiation of propionate-induced gluconeogenesis. In conclusion, propionate absorbed from the colon is hypothesized to act as gluconeogenic substrate, regardless of the cat's body condition.

Blood values of adult captive cheetahs (Acinonyx jubatus) fed either supplemented beef or whole rabbit carcasses.

This study evaluated nutrient intake and relevant blood parameters of 14 captive cheetahs, randomly assigned to a meat-only diet (supplemented beef, SB) or a whole prey diet (whole rabbit, WR) for 4 weeks each. Despite a higher food intake, daily metabolizable energy intake was lower when fed WR (308 kJ BW(-1) ) compared with SB (347 kJ BW(-1) ) (P = 0.002). The ratio of protein to fat was markedly lower for WR (2.3:1) compared with SB (8.8:1), which was reflected in higher serum urea levels when fed SB (P = 0.033), and a tendency for elevated cholesterol levels when fed WR (P = 0.055). Taurine intake of cheetahs fed WR was low (0.06% on DM basis); however, analytical error during taurine analysis cannot be ruled out. Feeding WR resulted in a well-balanced mineral intake, in contrast to SB. The latter provided a low calcium:phosphorus ratio (1:2.3), thereby increasing the risk of metabolic bone disease. The high zinc content of SB (200 mg/kg DM), compared with WR (94 mg/kg DM), was reflected in higher serum zinc concentrations (P = 0.011). Feeding WR resulted in an increase in serum vitamin A (P = 0.011). Therefore, the risk of hypervitaminosis A in captive cheetahs when fed WR exclusively on a long-term basis should be evaluated. Our findings suggest that neither diet is likely to provide appropriate nutrition to captive cheetahs when fed exclusively.

Expression of P-glycoprotein in the intestinal epithelium of dogs with lymphoplasmacytic enteritis.

Inflammatory bowel disease (IBD) is an idiopathic chronic inflammatory disease of the stomach, the small intestine and/or the large intestine. Loss of integrity of the intestinal barrier may be an important factor in the pathogenesis of IBD. In dogs, lymphoplasmacytic enteritis (LPE) is one of the recognized forms of IBD. P-glycoprotein (P-gp) is a membrane-bound efflux pump constituting an important component of the intestinal barrier. Changes in P-gp expression at the level of the intestinal barrier may be important in the pathogenesis of canine LPE, as this may lead to variable protection against xenobiotics and bacterial products in the intestine. The aim of the present study was to evaluate the expression of epithelial P-gp in the intestine in dogs with LPE compared with disease-free animals. Formalin-fixed intestinal biopsy samples from 57 dogs with histopathological evidence of LPE were immunolabelled with anti-P-gp antibodies (C494 and C219). Endoscopic biopsy samples of the duodenum and colon from 16 healthy beagles were used as controls. None of the control dogs had P-gp expression in the apical membrane of duodenal enterocytes, but all had P-gp labelling at the colonic epithelial surface. Twenty out of 57 dogs with LPE had P-gp expression at the apical surface membrane of villus epithelial cells in the duodenum, jejunum and/or ileum. Six out of 16 colonic samples from dogs with LPE had decreased P-gp expression at the epithelial surface compared with controls. It is unclear whether these changes in P-gp expression in dogs with LPE are a cause or a consequence of the inflammation. The observed changes could affect bioavailability of therapeutic drugs used in LPE.