Dietary fish oil and flaxseed oil suppress inflammation and immunity in cats

Nutrient Digestive Bypass: Determinants and Associations with Stool Quality in Cats and Dogs

The effect of digestive bypass macronutrients and age on stool quality (moisture and firmness) in dogs and cats is not well understood. Data were analyzed from digestibility tests (n = 2020, 361 dogs and 536 cats) including dry and wet product types. Both food and feces were measured for moisture and nutrients according to standard protocols; stool firmness was graded. Linear mixed modeling was used to evaluate the associations between nutrient bypass, age and stool quality. Bypass protein increased stool moisture (dog, cat p < 0.0001) and decreased firmness (dog p = 0.01, cat p < 0.0001), while bypass fiber decreased stool moisture and increased firmness (dog, cat p < 0.0001 for both). Both species manifested a negative quadratic effect of advanced age on stool firmness (dog p < 0.0001 and cat p = 0.02). However, the association of advanced age (quadratic effect) with metabolizable energy required to maintain body weight was different between species; dogs had a positive association (p = 0.028), while it was negative for cats (p < 0.0001). Taken together, these data may aid in the development of food formulations for companion animals, which can better meet changing nutritional needs across life stages.

The balance of n-6 and n-3 fatty acids in canine, feline, and equine nutrition: exploring sources and the significance of alpha-linolenic acid

Both n-6 and n-3 fatty acids (FA) have numerous significant physiological roles for mammals. The interplay between these families of FA is of interest in companion animal nutrition due to the influence of the n-6:n-3 FA ratio on the modulation of the inflammatory response in disease management and treatment. As both human and animal diets have shifted to greater consumption of vegetable oils rich in n-6 FA, the supplementation of n-3 FA to canine, feline, and equine diets has been advocated for. Although fish oils are commonly added to supply the long-chain n-3 FA eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), a heavy reliance on this ingredient by the human, pet food, and equine supplement industries is not environmentally sustainable. Instead, sustainable sourcing of plant-based oils rich in n-3 α-linolenic acid (ALA), such as flaxseed and camelina oils, emerges as a viable option to support an optimal n-6:n-3 FA ratio. Moreover, ALA may offer health benefits that extend beyond its role as a precursor for endogenous EPA and DHA production. The following review underlines the metabolism and recommendations of n-6 and n-3 FA for dogs, cats, and horses and the ratio between them in promoting optimal health and inflammation management. Additionally, insights into both marine and plant-based n-3 FA sources will be discussed, along with the commercial practicality of using plant oils rich in ALA for the provision of n-3 FA to companion animals.

Technological Benefits Associated with the Use of Spray-Dried Animal Plasma in Fish-Based Chunks for Canned Pet Food

Spray-dried animal plasma (SDAP) and wheat gluten (WG) are common binders in wet pet food that provide amino acids and energy, as well as texture and cohesiveness due to their gelling strength, water retention and fat emulsion properties. Binder use is a valuable tool especially in recipes based on ingredients with low technological properties such as fish by-products containing spines and scales and soft texture after cooking. Two basal recipes for chunks in gravy were produced to evaluate experimental treatments. One basal recipe used a mixture of salmon and tuna by-products as the only animal protein sources without binders or with a 20 g/kg inclusion of SDAP or WG. The other basal recipe mimicked a more typical commercial recipe containing meat animal ingredients and a 40 g/kg salmon by-product to develop experimental treatments with and 0, 10, 20, 30 or 40 g/kg inclusions of SDAP. Dry matter, protein, and viscosity were evaluated in raw emulsions. After a 1 h retorting at 121 °C, hardness was measured in emulsions and in cooked chunks, juiciness, and Texture Profile Analysis (TPA) were assessed. Results demonstrated the viability of producing quality chunks in gravy containing only fish by-products including 20 g/kg of SDAP, which significantly increased hardness, elasticity, cohesiveness, and juiciness. There was a positive linear correlation of increased SDAP inclusion rate in the commercial recipe for most of the quality parameters evaluated. Based on these results, the inclusion of SDAP in fish recipes can help manufacturers achieve technological quality control targets for commercial wet pet food and may help producers to successfully formulate new recipes for wet pet food products using fish by-products as the sole animal protein source.

Short-term changes in dietary fat levels and starch sources affect weight management, glucose and lipid metabolism, and gut microbiota in adult cats

A 2 × 2 factorial randomized design was utilized to investigate the effects of fat level (8% or 16% fat on a fed basis) and starch source (pea starch or corn starch) on body weight, glycolipid metabolism, hematology, and fecal microbiota in cats. The study lasted for 28 d and included a low fat and pea starch diet (LFPS), a high fat and pea starch diet, a low fat and corn starch diet, and a high fat and corn starch diet. In this study, hematological analysis showed that all cats were healthy. The apparent total tract digestibility of gross energy, crude protein, and crude fat was above 85% in the four diets. After 28 d, cats fed the high fat diets (HF) gained an average of 50 g more than those fed the low fat diets (LF). The hematological results showed that the HF diets increased the body inflammation in cats, while the LFPS group improved the glucolipid metabolism. The levels of glucose and insulin were lower in cats fed the LF diets than those in cats fed the HF diets (P < 0.05). Meanwhile, compared with the LF, the concentrations of total cholesterol, triglyceride, and high-density lipoprotein cholesterol in serum were greater in the cats fed the HF diets (P < 0.05). Additionally, both fat level and starch source influenced the fecal microbiota, with the relative abundance of beneficial bacteria, such as Blautia being significantly greater in the LFPS group than in the other three groups (P < 0.05). Reducing energy density and using pea starch in foods are both valuable design additions to aid in the management of weight control and improve gut health in cats. This study highlights the importance of fat level and starch in weight management in cats.

Derivation of the Omega-3 Index from EPA and DHA Analysis of Dried Blood Spots from Dogs and Cats

The Omega-3 Index (O3I) is the red blood cell (RBC) eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) content expressed as a percentage of total RBC fatty acids. Although a validated biomarker of omega-3 status in humans, little is known about the O3I status of dogs and cats; species in which omega-3 fatty acids have known health benefits. The purpose of this study was to develop equations to predict the O3I in these species from a dried blood spot (DBS) analysis. Random blood samples from 33 dogs and 10 cats were obtained from a community veterinary clinic. DBS and RBC samples were analyzed for fatty acid composition. For both species, the R2 between the DBS EPA + DHA value and the O3I was >0.96 (p < 0.001). The O3I was roughly 75% lower in dogs and cats than in humans. We conclude that the O3I can be estimated from a DBS sample, and the convenience of DBS collection should facilitate omega-3 research in these companion animals.

A review of flaxseed lignan and the extraction and refinement of secoisolariciresinol diglucoside

Lignan is a class of diphenolic compounds that arise from the condensation of two phenylpropanoid moieties. Oilseed and cereal crops (e.g., flaxseed, sesame seed, wheat, barley, oats, rye, etc.) are major sources of plant lignan. Methods for commercial isolation of the lignan secoisolariciresinol diglucoside (SDG) are not well reported, as most publications describing the detection, extraction, and enrichment of SDG use methods that have not been optimized for commercial scale lignan recovery. Simply scaling up laboratory methods would require expensive infrastructure to achieve a marketable yield and reproducible product quality. Therefore, establishing standard protocols to produce SDG and its derivatives on an industrial scale is critical to decrease lignan cost and increase market opportunities. This review summarizes the human health benefits of flaxseed lignan consumption, lignan physicochemical properties, and mammalian lignan metabolism, and describes methods for detecting, extracting, and enriching flaxseed lignan. Refining and optimization of these methods could lead to the development of inexpensive lignan sources for application as an ingredient in medicines, dietary supplements, and other healthy ingredients.

Dietary Betaine Interacts with Very Long Chain n-3 Polyunsaturated Fatty Acids to Influence Fat Metabolism and Circulating Single Carbon Status in the Cat

Simple Summary

The domestic cat can metabolize and thrive on a range of intakes of different dietary polyunsaturated fatty acids (PUFA). However, changes in the intake of PUFA have relatively unknown effects on concentrations of other fatty acids and metabolites. Similarly, the effect of increasing dietary betaine (which is a single carbon donor) on circulating concentrations of metabolites and fatty acids is relatively unreported. As might be expected, increasing intake of specific dietary fatty acids resulted in an increased concentration of that fatty acid and moieties containing that fatty acid. Dietary betaine increased concentration of many compounds associated with single carbon metabolism (e.g., dimethyl glycine, sarcosine, methionine) and many PUFA such as the n-6 PUFA linoleic acid (LA) and arachidonic acid (ARA) and the n-3 fatty acids α-linolenic acid (αLA), and docosahexaenoic acid (DHA). Dietary betaine interacted with the addition of dietary fish oil to dampen diet-induced increase of ARA while potentiating the increase of circulating DHA occurring with increased DHA dietary intake. Dietary betaine and fish oil also combined to reduce the circulating concentration of the renal toxin 3-indoxyl sulfate, suggesting a positive effect on the gut microbiota. These data suggest a positive effect of a daily betaine intake which exceeds 60 mg per kg body weight. The data also support an added benefit of a combined EPA+DHA daily intake of greater than 26 mg/kg body weight as well as a daily intake of 75 mg/kg body weight of alpha linolenic acid.

Abstract

Six foods were used to evaluate the interaction of dietary betaine and n-3 PUFA in the cat. There was no ingredient added to the control food to specifically increase betaine or n-3 fatty acids. The experimental design was a 3 × 2 factorial (fatty acids were varied from the control food which had no added source of n-3 fatty acids, flax was included as a source of 18 carbon n-3, or menhaden fish oil as a source of EPA and DHA). Foods were then formulated using these three foods as a base with added betaine or without added betaine. Forty eight cats were used in this study. Equal numbers of cats were allotted by age and gender to each of the six dietary treatments. The cats were offered food amounts to maintain weight and consumed the food to which they were assigned for the length of the study (60 days). Metabolomics, selected circulating analytes and fatty acids were analyzed at the beginning and end of the feeding period. There was an increase in single carbon metabolites (betaine, dimethyl glycine, and methionine) with the consumption of dietary betaine. Betaine also increased the concentration of specific PUFA (ARA, αLA, DHA, and the sum of all circulating PUFA). The combination of dietary betaine and fish oil resulted in a reduction of circulating 3-indoxyl sulfate which suggests a renal benefit from their combined dietary presence.

Dietary Ground Flaxseed Increases Serum Alpha-Linolenic Acid Concentrations in Adult Cats

We evaluated effects of dietary ground flaxseed on fecal and serum alpha-linolenic acid (ALA) concentrations, nutrient digestibility, and stool quality in female and male adult cats (n = 20 (8 males, 12 females); 3.95 ± 1.49 years of age (mean ± SD); 3.88 ± 0.82 kg BW). We hypothesized that adding ground flaxseed would increase serum ALA compared with feeding no flax, without changing nutrient digestibility. Cats were fed as-is 2.6% added-flaxseed (flax, n = 10) or no-flax (control, n = 10) diets (2.66 vs. 0.78% ALA of total fatty acids; crude protein 35%, fat 20%, fiber 3% as-fed) twice daily to maintain body weight for 28 days. Fecal collections were conducted on days 23−27 for total-tract nutrient digestibility, stool quality (scale 1−5; 1 = watery diarrhea, 5 = hard, dry, crumbly) and long-chain fatty acid (LCFA) analyses. Blood was collected on days 0, 14, and 28 for serum LCFA and chemistry analysis. Digestibility and fecal data were analyzed by ANOVA (SAS v9.4, Cary, NC, USA) and a repeated measures ANOVA for serum ALA. Flax-fed cats, compared with control-fed, had greater (p < 0.05) serum ALA after 14 days (4.00 vs. 0.71 µg/mL) and 28 days (7.83 and 3.67 µg/mL). No differences were observed in stool quality, and dry matter, protein, fat, and ALA digestibility. However, metabolizable energy was greater in the flax vs. control diet (4.18 vs. 3.91 kcal/g; p < 0.05). Overall, these data demonstrate that ground flaxseed added to cat diets increases serum ALA within 14 days, with no detriments to nutrient digestibility. We conclude that flaxseed can be used as a bioavailable source of ALA in cat diets.

Tailoring freshwater diets towards boosted immunity and pancreas disease infection robustness in Atlantic salmon post smolts

The aim of the current study was to investigate how freshwater diets impact on immunity in Atlantic salmon smolts in freshwater, during transfer to seawater and in post smolts during the seawater stage with and without pancreas disease (PD) infection. Three specific freshwater diets were prepared: (i) A diet similar in composition to commercial salmon freshwater diets (Standard diet); (ii) A diet composed of vegetable oils (rapeseed, palm and linseed oils) mimicking the fat composition in aquatic insects - the natural diet of wild salmon in freshwater (Fatty acid diet); (iii) A diet enriched with possible immune modulating amino acids including dl-methionine, l-lysine, l-threonine and taurine (Amino acid diet). After seawater transfer, all fish were fed the same commercial diet. Head kidneys were extracted, and their leukocytes isolated from smolts right before transfer to seawater, from post smolts one and six weeks after transfer to seawater, and from post smolts in seawater after 8 weeks of ongoing PD infection. In addition, to provoke bacterial or virus induced inflammation in vitro, the individual leukocyte suspension from all fish were stimulated by lipopolysaccharide (LPS) or polyinosinic acid: polycytidylic acid (PIC). The transfer of smolts from fresh-to seawater changed the transcription of several types of genes. Particularly in isolates from fish fed the Standard or Fatty acid diet in freshwater, overall gene transcription (IL-1β, CD83, INF-γ, cox2, cd36, MGAT2, catalase) declined. However, the Amino acid diet stimulated the LPS induced gene transcription of IL-1β, CD83, Cox2, and INF-γ at this stage. In freshwater smolts, PIC stimulated leukocytes showed higher transcription level of Mx and viperin in the Fatty acid and Amino acid diet groups compared to the Standard diet group. In seawater post smolts, Mx and viperin responded similarly to PIC challenge in all diet groups. Furthermore, leukocytes isolated from PD infected fish, continued responding to PIC, regardless of freshwater diet.

Puppyhood diet as a factor in the development of owner-reported allergy/atopy skin signs in adult dogs in Finland

BACKGROUND

The increased prevalence of atopic dermatitis (AD) in dogs necessitates research in its disease etiology.

OBJECTIVES

To explore the association between puppyhood dietary exposures and prevalence of owner-reported allergy/atopy skin signs (AASS) after the age of 1 year.

ANIMALS

Four thousand and twenty-two dogs were eligible, 1158 cases, and 2864 controls.

METHODS

This cross-sectional hypothesis-driven observational study was extracted from the DogRisk food frequency questionnaire. Forty-six food items and the ratio of 4 major diet types were tested for their association with AASS incidence later in life. Potential puppyhood dietary risk factors for AASS incidence were specified using binary multivariable logistic regression. The model was adjusted for age and sex.

RESULTS

Eating raw tripe (odds ratio, 95% confidence intervals OR, 95% CI = 0.36, 0.16-0.79; P = .01), raw organ meats (OR, 95% CI = 0.23, 0.08-0.67; P = .007), human meal leftovers, and fish oil supplements as well as eating more that 20% of the diet as raw and/or <80% of the diet as dry, in general, were associated with significantly lower AASS incidence in adulthood. In contrast, dogs fed fruits (OR, 95% CI = 2.01, 1.31-3.07; P = .001), mixed-oil supplements, dried animal parts, and dogs that drank from puddles showed significantly higher AASS incidence in adulthood.

CONCLUSIONS AND CLINICAL IMPORTANCE

Puppyhood exposure to raw animal-based foods might have a protective influence on AASS incidence in adulthood, while puppyhood exposure to mixed oils, heat processed foods and sugary fruits might be a potential risk factor of AASS incidence later. The study suggests a causal relationship but does not prove it.

Botanicals Reduce Circulating Concentrations of Cholesterol and Triglycerides and Work Synergistically With Arachidonic Acid to Reduce Inflammatory Cytokines in Cats

Forty Eight cats were used to measure the effects of feeding a traditional adult cat food supplemented with either arachidonic acid (ARA), a botanical mix (botanicals) or both on circulating biochemical parameters and inflammatory cytokines. The cats were healthy adults (mean age, 3.0; range, 1.3-6.4 years). The adult cats were fed one of four foods (n = 12 per group) for 84 days (dietary changes reported as fed): a traditional adult cat food (control, 0.05% ARA no added botanicals), or control food supplemented with arachidonic acid from chicken liver (0.13% ARA when supplemented), control food supplemented with botanicals (green tea 0.5%, fenugreek 0.05%, and tulsi 0.003%), and control plus ARA (0.13% as fed) with botanicals (green tea 0.5%, fenugreek 0.05%, and tulsi 0.003%). Response variables were compared between treatments: initially, and at 84 days (end of study). The measurements were standard complete blood counts and chemistries as well as circulating cytokines. Botanical inclusion reduced (P < 0.05) circulating cholesterol and triglycerides while arachidonic acid increased (P < 0.05) their concentrations. The pro-inflammatory cytokines MCP-1, TNFα, SDF-1, Flt3L, IL-8, IL-12p40, IL-13, and IL-18 were all reduced (P < 0.05) in cats after consuming the ARA + botanicals food for 84 days with little change after consuming the other foods. Therefore, this combination of ARA and botanicals may be of value in reducing inflammation.

Treatment of the feline atopic syndrome - a systematic review

BACKGROUND

Feline allergic skin disease and asthma occur regularly in small animal practice.

OBJECTIVES

To provide evidence-based recommendations for small animal practitioners on the treatment of feline atopic syndrome (FAS).

METHODS AND MATERIALS

The authors reviewed the literature available before February 2020, prepared a detailed evidence-based literature review and made recommendations based on the evaluated evidence.

RESULTS

Sixty-six papers and abstracts were identified describing treatment interventions for FAS and evaluated to establish treatment recommendations. For many treatment options, the papers were retrospective, open studies or case reports.

CONCLUSION AND CLINICAL RELEVANCE

In this review, there was good evidence for the efficacy of systemic glucocorticoids and ciclosporin, and limited evidence for the efficacy of topical glucocorticoids, oclacitinib and allergen-specific immunotherapy in feline atopic skin syndrome. Evidence pointed to low-to-moderate efficacy for antihistamines, fatty acids and palmitoyl ethanolamide. In feline asthma, there was good evidence for the efficacy of oral and inhaled glucocorticoids, and limited evidence of moderate efficacy for allergen-specific immunotherapy. Evidence supported low-to-moderate efficacy of mesenchymal stem cells, inhaled lidocaine and oclacitinib as treatments for feline asthma. For almost all therapeutic options (with the exception of glucocorticoids and ciclosporin), more randomised controlled trials are needed.

Dietary Fatty Acids Change Circulating Fatty Acids, Microbial Putrefactive Postbiotics and Betaine Status in the Cat

Simple Summary

The cat is an obligate carnivore that is well adapted to dietary polyunsaturated fatty acids (PUFA), perhaps because of the variance resulting from normal consumption of organ meat which is high in PUFA, and storage lipid which is often relatively low in PUFA. Although able to tolerate and thrive with this variation, cats have a metabolic response to fatty acids that is relatively unknown. This study shows that dietary PUFA resulted in changing circulating concentrations of that specific PUFA. Increasing dietary eicosapentaenoic acid EPA and docosahexaenoic acid DHA (E&D) resulted in little change in total circulating PUFA as compared to increasing dietary arachidonic acid (ARA) which resulted in an increased concentration of total circulating PUFA. Cats responded to increased dietary E&D by reducing circulating cholesterol as compared to control fed cats. Increasing dietary PUFA also resulted in a decrease in circulating betaine, dimethylglycine and sarcosine in comparison to the cats consuming the control food at the end of the study. Changing dietary PUFA also changed circulating concentrations of gut microbial purification postbiotics. Increasing dietary ARA resulted in an increased concentration of indoleacetate, indolepropionate and indoleacetylglutamine in comparison to cats fed foods enhanced with increased E&D. Increasing E&D resulted in a decreased concentration of 4-ethylphenylsulfate, 3-methyl catechol sulfate and 4-vinylphenol sulfate at the end of the feeding period as compared to cats fed increased ARA or fed the unsupplemented control food. These changes suggest that support of single carbon metabolism would benefit cats with increasing dietary PUFA, that increasing E&D beneficially lowered cholesterol and that dietary PUFA influenced gut microbes resulting in changes in their postbiotics.

Abstract

There is a normal variation of polyunsaturated fatty acids (PUFA) in the foods consumed both by the domestic cat and wild felines. This variation may lead to specific changes in metabolites and circulating fatty acids that influence health and response to disease. Therefore, in order to evaluate the response to these changes in dietary PUFA three foods were formulated: a complete and balanced control food (COF) with no enhanced source of added PUFA (ARA = 0.08%, EPA & DHA = 0.01%), Test food 1 (E&DF) like the COF with added eicosapentaenoic acid EPA and docosahexaenoic acid DHA (E&D = 0.36%)) from menhaden fish oil, and Test Food 2 (ARAF) like the COF with added arachidonic acid (ARA = 0.16%) from liver. All test foods had similar protein concentrations and similar vitamin and mineral concentrations while the PUFA supplemented foods had slightly higher fat concentrations. Cats (n = 36) were fed a pre-trial food for 28 days and then assigned to a group fed either the control, E&DF or ARAF for 56 days (12 cats per group). Blood samples were drawn and serum analyzed for fatty acids, albumin, urea, creatinine, cholesterol and triglycerides at the beginning of the study and after consuming the test foods for 28 and 56 days. Plasma was similarly analyzed for metabolomics. Increasing dietary E&D resulted in reduced cholesterol, betaine, dimethyl glycine, sarcosine and 4-ethylphenylsulfate. Increasing dietary ARA resulted in reduced betaine, dimethyl glycine and sarcosine and an increased concentration of indoleacetate, indolepropionate and indoleacetylglutamine. These data suggest a benefit of dietary single carbon metabolism support for cats supplemented with ARA or E&D. Moreover, the reduction in circulating cholesterol and triglycerides through dietary E&D supplementation could benefit cats with hyperlipidemia. Further research into the interrelationship between dietary PUFA and the gut microbe will benefit from the data showing that ARA increased specific positive postbiotics (i.e., indoleacetate, indolepropionate) while E&D supplementation showed the benefit of reducing some postbiotics which have been associated with reduced health (4-ethylphenylsulfate, 3-methyl catechol sulfate and 4-vinylphenol sulfate).

DHA from microalgae Schizochytrium spp. (Thraustochytriaceae) modifies the inflammatory response and gonadal lipid profile in domestic cats

The present study aimed to evaluate the inflammatory response, oxidative status and fatty acid deposition in reproductive tissues of cats supplemented with the dried microalgae Schizochytrium spp. (Thraustochytriaceae) as a DHA source. Thirty-seven cats (males, n 21; females, n 16; 11·5 (sd 0·5) months of age) were divided by sex into five groups. Treatment diets contained algae biomass at 4·0, 8·0, 12·0 or 16·0 g/kg replacing poultry fat (n-6 source). Cats were fed the respective diet for 62 d and neutered on day 58. Blood samples were collected at the beginning of the experiment (day 1), before neutering (day 58) and 4 d after surgery (day 62) for analysis of inflammation and oxidative markers. Acute-phase protein levels were altered (P < 0·01) in the postoperative period, without any treatment effect (P > 0·05). PGE2 concentrations after surgery were reduced linearly (R2 0·8706; P = 0·002) with microalgal inclusion. Blood platelet count was reduced (P = 0·001) after the surgery regardless treatment, but it was higher in the DHA group compared with control (P < 0·001). The DHA deposition (testicles, R2 0·846; ovaries, R2 0·869) and the n-6:n-3 ratio (testicles, R2 0·859; ovaries, R2 0·955) in gonads had a pattern which fitted a quadratic model. DHA from Schizochytrium spp. modifies PGE2 response after the surgery in cats. The physiological roles of the DHA in the reproduction of cats were not investigated, but its gonadal deposition after supplementation was observed.

Plant-Derived Nutraceuticals and Immune System Modulation: An Evidence-Based Overview

Immunomodulators are agents able to affect the immune system, by boosting the immune defences to improve the body reaction against infectious or exogenous injuries, or suppressing the abnormal immune response occurring in immune disorders. Moreover, immunoadjuvants can support immune system acting on nonimmune targets, thus improving the immune response. The modulation of inflammatory pathways and microbiome can also contribute to control the immune function. Some plant-based nutraceuticals have been studied as possible immunomodulating agents due to their multiple and pleiotropic effects. Being usually more tolerable than pharmacological treatments, their adjuvant contribution is approached as a desirable nutraceutical strategy. In the present review, the up to date knowledge about the immunomodulating properties of polysaccharides, fatty acids and labdane diterpenes have been analyzed, in order to give scientific basic and clinical evidence to support their practical use. Since promising evidence in preclinical studies, limited and sometimes confusing results have been highlighted in clinical trials, likely due to low methodological quality and lacking standardization. More investigations of high quality and specificity are required to describe in depth the usefulness of these plant-derived nutraceuticals in the immune system modulation, for health promoting and disease preventing purposes.

Use of maropitant for the control of pruritus in non-flea, non-food-induced feline hypersensitivity dermatitis: an open-label, uncontrolled pilot study

OBJECTIVES

Non-flea, non-food-induced hypersensitivity dermatitis (NFNFIHD) is a common inflammatory and pruritic skin disease in cats. When avoidance and conventional systemic immunosuppressive treatments fail to control the clinical signs, there are limited treatment options. The aim of this study was to evaluate the efficacy and tolerability of maropitant in feline NFNFIHD.

METHODS

In an open-label, uncontrolled study, cats with proven non-seasonal NFNFIHD were treated with maropitant 2 mg/kg PO q24h for 4 weeks. Clinical lesions were evaluated with the Scoring Feline Allergic Dermatitis (SCORFAD) system and pruritus was evaluated with a 10 cm visual analogue scale (VAS) before and at the end of the study. Owners assessed global efficacy and tolerability with a 4-point scale at the end of the study. Adverse events and body weight changes were recorded.

RESULTS

Twelve cats were treated with a mean initial maropitant dose of 2.22 mg/kg PO q24h. The treatment decreased both SCORFAD and pruritus VAS (pVAS) scores in all cats except one, in which only pruritus was reduced. The efficacy and the tolerability of the treatment were judged as excellent or good by 83.3% of owners. Treatment did not cause any side effects other than, in a few cases, short-time, self-limiting sialorrhoea.

CONCLUSIONS AND RELEVANCE

Maropitant seems to be an effective, well-tolerated therapeutic option to control pruritus in cats. Caution is needed in interpreting the results as the pVAS score system has not yet been validated in cats and the trial was uncontrolled. A further, controlled study is required to confirm our findings.

Mouse Chow Composition Influences Immune Responses and Food Allergy Development in a Mouse Model

Our diet is known to substantially influence the immune response not only by support of mucosal barriers but also via direct impact on immune cells. Thus, it was of great interest to compare the immunological effect of two mouse chows with substantial differences regarding micro-, macronutrient, lipid and vitamin content on the food allergic response in our previously established mouse model. As the two mouse chows of interest, we used a soy containing feed with lower fatty acid (FA) amount (soy-containing feed) and compared it to a soy free mouse chow (soy-free feed) in an established protocol of oral immunizations with Ovalbumin (OVA) under gastric acid suppression. In the animals receiving soy-containing feed, OVA-specific IgE, IgG1, IgG2a antibody levels were significantly elevated and food allergy was evidenced by a drop of body temperature after oral immunizations. In contrast, mice on soy-free diet had significantly higher levels of IL-10 and were protected from food allergy development. In conclusion, soy-containing feed was auxiliary during sensitizations, while soy-free feed supported oral tolerance development and food allergy prevention.

A comparative study: Difference in omega-6/omega-3 balance and saturated fat in diets for Atlantic salmon (Salmo salar) affect immune-, fat metabolism-, oxidative and apoptotic-gene expression, and eicosanoid secretion in head kidney leukocytes

The aim of this study was to compare how different dietary vegetable oil n-6/n-3 ratios affect gene responses involved in inflammation, signaling pathways, fatty acid synthesis and oxidation, oxidation and apoptosis as well as eicosanoid production in salmon head kidney tissues and isolated head kidney leukocytes. Salmon smolts (200 g) were fed four different diets where the main lipid components were palm oil (n-6/n-3 ratio = 0.7), rapeseed oil (n-6/n-3 ratio = 0.9), and soybean oil (n-6/n-3 ratio = 2.4) and a high soybean oil diet with an n-6/n-3 ratio = 4. Both head kidney tissue and leukocytes isolated from head kidneys were sampled from the four diets, but from different fish. Leukocytes isolated from the head kidneys were seeded into culture wells and added lipopolysaccharide (LPS) to induce inflammatory responses. Controls without LPS were included. Head kidney leukocytes and the tissues should have the same phenotype reflecting the different diets. Interleukin 1β (IL-1β) transcription was elevated in head kidney tissue and especially in LPS treated leukocytes isolated from soybean oil (n-6/n-3 = 2.4) fed salmon, which confirmed the suitability of the in vitro model in this experiment. Leukocytes, treated with LPS, and isolated from salmon fed the soybean oil diet (n-6/n-3 = 2.4) also upregulated tumor necrosis factor alpha (tnf-α), cyclooxygenase (cox2), prostaglandin D and E synthase (ptgds, ptges), fatty acyl synthase (fas), 5 and 6 desaturases (5des, 6 des) and a fatty acid translocase protein (cd36) when compared to the other diets. The results suggest that diets with a specific n-6/n-3 ratio influence the transcription of pro-inflammatory genes and may be cross-linked to transcription of selected fatty acid metabolism genes. Salmon fed the palm oil diet (n-6/n-3 = 0.7) showed a lower expression of inflammatory genes. Instead, peroxisome proliferator activated receptor β1 (pparβ1), acyl coenzyme A (aco), apoptosis regulator (bax) and superoxide dismutase (sod) were upregulated in leukocytes in vitro, while head kidney tissue transcription of a dendritic marker (cd83) was lower than measured in tissues from fish fed the other diets. The concentration of LTB4 (10-20 ng/mL) were relatively constant in leukocyte supernatants, all diets. Head kidney leukocytes from soybean oil (n-6/n-3 = 2.4) fed fish produced LPS induced PGE2 (mean 0.5 ng/mL) while leukocytes isolated from palm oil diet (n-6/n-3 = 0.7) secreted very high amounts of LTB5 (50-70 ng/mL). In addition, equal amounts of LPS induced PGE2 and PGE3 (mean 0, 5 ng/mL) were produced, indicating that the n-6/n-3 ratio of this saturated fatty acid may have a specific impact on eicosanoid production in the head kidney of salmon.

Fishmeal supplementation during ovine pregnancy and lactation protects against maternal stress-induced programming of the offspring immune system

BACKGROUND

Prenatally stressed offspring exhibit increased susceptibility to inflammatory disorders due to in utero programming. Research into the effects of n-3 PUFAs shows promising results for the treatment and prevention of these disorders. The purpose of this study was to investigate whether maternal fishmeal supplementation during pregnancy and lactation protects against programming of the offspring's immune response following simulated maternal infection.

METHODS

In order to accomplish this, 53 ewes were fed a diet supplemented with fishmeal (FM; rich in n-3 PUFA) or soybean meal (SM; rich in n-6 PUFAs) from day 100 of gestation (gd 100) through lactation. On gd135, half the ewes from each dietary group were challenged with either 1.2 μg/kg Escherichia coli lipopolysaccharide (LPS) endotoxin to simulate a bacterial infection, or saline as the control. At 4.5 months of age the offspring's dermal immune response was assessed by cutaneous hypersensitivity testing with ovalbumin (OVA) and candida albicans (CAA) 21 days after sensitization. Skinfold measurements were taken and serum blood samples were also collected to assess the primary and secondary antibody immune response.

RESULTS

Offspring born to SM + LPS mothers had a significantly greater change in skinfold thickness in response to both antigens as well as a greater secondary antibody response to OVA compared to all treatments.

CONCLUSIONS

Supplementation during pregnancy with FM appears to protect against adverse fetal programming that may occur during maternal infection and this may reduce the risk of atopic disease later in life.

In vitro effects of oil's fatty acids on T cell function in gestational diabetic pregnant women and their newborns

BACKGROUND

The aim of this investigation was to determine the in vitro effects of linseed, olive and Nigel oils on T cell proliferation and function in gestational diabetes.

METHODS

Blood samples were collected from 40 control healthy and 32 gestational diabetic mothers and their newborns. Peripheral blood lymphocytes were isolated using a density gradient of Ficoll. T cell proliferation, interleukin-2 and -4 (IL-2, IL-4) secretion, fatty acid composition and intracellular oxidative status were investigated.

RESULTS

Mitogen (Concanavalin A) stimulated lymphocyte proliferation, IL-2 secretion, intracellular reduced glutathione levels, superoxide dismutase (SOD) and catalase activities were lower while intracellular malondialdehyde (MDA) and carbonyl proteins were higher in diabetic mothers and in their newborns as compared to their respective controls. Linseed oil induced a reduction in T-lymphocyte proliferation and IL-2 production, and alpha linolenic acid membrane enrichment in both diabetic and control groups. In the presence of Nigel oil, T-lymphocyte proliferation and IL-2 secretion, phospholipid linoleic and oleic acids were enhanced. Olive oil had no effect on lymphocyte proliferation in all groups. Linseed, olive and Nigel oils induced an increase in T cell levels of reduced glutathione levels and in activities of catalase and SOD with a concomitant decrease in MDA and carbonyl protein contents.

CONCLUSION

Linseed, olive and Nigel oils had beneficial effects on T cell functions in gestational diabetes.

Comparison of inferred fractions of n-3 and n-6 polyunsaturated fatty acids in feral domestic cat diets with those in commercial feline extruded diets

OBJECTIVE

To compare presumed fatty acid content in natural diets of feral domestic cats (inferred from body fat polyunsatrated fatty acids content) with polyunsaturated fatty acid content of commercial feline extruded diets.

SAMPLE

Subcutaneous and intra-abdominal adipose tissue samples (approx 1 g) from previously frozen cadavers of 7 adult feral domestic cats trapped in habitats remote from human activity and triplicate samples (200 g each) of 7 commercial extruded diets representing 68% of market share obtained from retail stores.

PROCEDURES

Lipid, triacylglycerol, and phospholipid fractions in adipose tissue samples and ether extracts of diet samples were determined by gas chromatography of methyl esters. Triacylglycerol and phospholipid fractions in the adipose tissue were isolated by thin-layer chromatography. Diet samples were also analyzed for proximate contents.

RESULTS

For the adipose tissue samples, with few exceptions, fatty acids fractions varied only moderately with lipid fraction and site from which tissue samples were obtained. Linoleic, α-linolenic, arachidonic, eicosapentaenoic, and docosahexaenoic acid fractions were 15.0% to 28.2%, 4.5% to 18.7%, 0.9% to 5.0%, < 0.1% to 0.2%, and 0.6% to 1.7%, respectively. As inferred from the adipose findings, dietary fractions of docosahexaenoic and α-linolenic acid were significantly greater than those in the commercial feline diets, but those for linoleic and eicosapentaenoic acids were not significantly different.

CONCLUSIONS AND CLINICAL RELEVANCE

The fatty acid content of commercial extruded feline diets differed from the inferred content of natural feral cat diets, in which dietary n-3 and possibly n-6 polyunsaturated fatty acids were more abundant. The impact of this difference on the health of pet cats is not known.

Efficacy of Cyclosporine for Chronic, Refractory Stomatitis in Cats: A Randomized, Placebo-Controlled, Double-Blinded Clinical Study

Sixteen cats with chronic stomatitis, that had previously undergone premolar-molar or full-mouth extractions, were randomly assigned a group to receive 2.5 mg/kg cyclosporine or placebo orally twice daily. Neither the clinician nor the clients were aware of the group assignments. Cats were evaluated prior to treatment and every 2 weeks for 6 weeks using a 30 point Stomatitis Disease Activity Index (SDAI) score. Mean improvement in SDAI scores among cats in the treatment group after 6 weeks was 52.7 %. This was significantly different from the mean improvement (12.2 %) of cats in the placebo group. During the 6 week study period, 7 of the 9 cats in the treatment group (77.8 %) showed a > 40 % improvement in SDAI score, while 1 of 7 cats in placebo group (14.3 %) showed a > 40 % improvement in SDAI score. This difference was statistically significant. Individual variability in the absorption of orally-administered cyclosporine was high. Trough whole-blood cyclosporine levels ranged from 32.1 ng/ml to 1,576.2 ng/ml. At the end of the 6 week observation period, there was a statistically significant difference among cats with trough whole-blood cyclosporine levels > 300 ng/ml (72.3 % improvement) compared with cats with cyclosporine levels < 300 ng/ml (28.2 % improvement). Whole-blood cyclosporine levels > 300 ng/ml were associated with significant improvement in oral inflammation in cats with chronic stomatitis that had previously undergone premolar-molar or full-mouth extraction.

The potential for enhancement of immunity in cats by dietary supplementation

This study was conducted to examine the potential benefits of dietary supplementation on the feline immune system. Forty three cats (8 or 9 per group) were fed a low protein control diet (22.7% DM basis), the same diet supplemented with yeast-derived nucleotides, salmon oil or l-arginine or a commercial moist high protein diet (53.0% DM basis) for a period of five weeks. The low protein diets were formulated using a commercial moist diet base with added fat and starch and fed ad libitum, along with water. Specific immune assays showed that supplementation with arginine caused a significant enhancement of lymphocyte proliferative responses to the T-cell mitogen PHA after 35 days (P=0.018), while supplementation with either nucleotides or salmon oil resulted in significant enhancement after both 14 (P=0.0048, P<0.0001 respectively) and 35 days (both P<0.0001). Dietary supplementation with arginine, nucleotides or salmon oil each led to significant increases in blood leucocyte phagocytic activity after both 14 (P=0.0003, P=0.0077, P<0.0001 respectively) and 35 days (P<0.0001). This indicates that a number of dietary ingredients have the ability to modulate the immune system of healthy cats possibly resulting in a greater ability to fight infection and disease.

Potential adverse effects of omega-3 Fatty acids in dogs and cats

Fish oil omega-3 fatty acids, mainly eicosapentaenoic acid and docosahexaenoic acid, are used in the management of several diseases in companion animal medicine, many of which are inflammatory in nature. This review describes metabolic differences among omega-3 fatty acids and outlines potential adverse effects that may occur with their supplementation in dogs and cats with a special focus on omega-3 fatty acids from fish oil. Important potential adverse effects of omega-3 fatty acid supplementation include altered platelet function, gastrointestinal adverse effects, detrimental effects on wound healing, lipid peroxidation, potential for nutrient excess and toxin exposure, weight gain, altered immune function, effects on glycemic control and insulin sensitivity, and nutrient-drug interactions.

Feline idiopathic inflammatory bowel disease: what we know and what remains to be unraveled

PRACTICAL RELEVANCE

Feline idiopathic inflammatory bowel disease (IBD) denotes one form of chronic enteropathy that is immunologically mediated and characterized by persistent or recurrent gastrointestinal (GI) signs and histologic inflammation. Signs of vomiting, diarrhea and weight loss generally predominate, and mucosal inflammation may occur in any portion of the GI tract (especially the small intestine). Affected cats may also have concurrent inflammation in other organs, such as the pancreas and liver, which may impact clinical disease severity.

CLINICAL CHALLENGES

The exact etiologies of this heterogeneous group of disorders have yet to be determined, though results from basic science and clinical studies suggest that interplay between genetic factors and enteric bacteria is crucial for disease development. The diagnosis is one of exclusion and requires intestinal mucosal biopsy to characterize the type and severity of the inflammatory infiltrate, and to differentiate IBD from other disorders, including alimentary lymphoma. Controversy exists concerning the relative diagnostic accuracy of endoscopic versus full-thickness specimens for the diagnosis of IBD and its differentiation from alimentary lymphoma.

AUDIENCE

This article is intended to provide veterinary practitioners with a comprehensive clinical update on idiopathic IBD in cats. It reviews the current evidence-based data, the diagnostic approach, the evolving histologic criteria, and treatment options and outcome for feline patients with this syndrome.