Myocardial energy deprivation plays a causal role in the development of heart failure. A cardiac protection blend (CPB) of nutrients including medium chain triglycerides, fish oil and other key nutrients was developed to slow the progression of canine myxomatous mitral valve disease (MMVD). A six-month dietary intervention demonstrated efficacy of CPB in slowing MMVD progression. Untargeted metabolomic analysis of serum from these dogs identified 102 differential metabolites (adjusted P < 0.05). The ratios of omega-6 to omega-3 fatty acid (FA) changed from 2.41 and 1.46 in control and CPB groups at baseline to 4.30 and 0.46 at 6 months respectively. A 2.7-fold increase of α-aminobutyrate, a myocardial modulator of glutathione homeostasis, was found in CPB dogs compared to 1.3-fold increase in control dogs. Arginine and citrulline, precursors of nitric oxide biosynthesis, were both increased 2-fold; caprate, a medium chain FA, was increased 3-fold; and deoxycarnitine, precursor of carnitine biosynthesis, was increased 2.5-fold in CPB dogs. Margarate and methylpalmitate decreased in response to CPB, a potential benefit in MMVD dogs as positive correlations were found between changes in both these FAs and left atrial diameter (r = 0.69, r = 0.87 respectively, adjusted P < 0.05). Sphingomyelins with very long chain saturated FAs associated with decreased risk of heart failure in humans were increased in MMVD dogs fed the CPB diet. Our data supports the hypothesis that CPB improves FA utilization and energetics, reduces oxidative stress and inflammation in MMVD dogs. More studies are needed to understand the roles of specific metabolites in MMVD.

SummaryCommon beans (Phaseolus vulgarisL.) are a nutrient-dense, low glycemic index food that supports healthy weight management in people and was examined for dogs. The objectives of this study were to evaluate the apparent total tract digestibility (ATTD) and nutrient utilisation of navy (NB) and black (BB) bean-based diets in overweight or obese companion dogs undergoing a weight loss intervention. A nutritionally complete, dry extruded dog food was used as the control (CON) diet and two isocaloric, nutrient matched bean diets, containing either 25% w/w cooked BB or NB powder formed the test diets. Diets were fed to adult, overweight companion dogs for either four weeks (short-term study, n = 30) or for twenty-six weeks (long-term study, n = 15) at 60% of maintenance calories for ideal weight. Apparent weight loss increased over time in both the short- and long-term studies (p < 0.001) but was not different between the three study groups: apparent weight loss was between 4.05% – 6.14% for the short-term study and 14.0% – 17.9% in the long-term study. The ATTD was within expected ranges for all groups, whereby total dry matter and crude protein ATTD was 7–8% higher in the BB diet compared to CON (P < 0.05), crude fat ATTD was similar across all diets, and nitrogen free extract ATTD was 5–6% higher in both BB and NB compared to CON (P < 0.05). Metabolisable energy was similar for all diets, and ranged from 3,434–3,632 kcal/kg. At the end of each study period, dogs had haemoglobin levels ≥12 g/dl, packed cell volume ≥36%, albumin ≥2.4 g/dl, ALP ≤ 300 IU/l and all median values for each group were within defined limits for nutritional adequacy. This investigation demonstrated that BB and NB diets were safe, digestible, and supported weight loss in calorically restricted, overweight or obese, adult companion dogs.

Monk parrots (Myiopsitta monachus) were hand-fed over two chick seasons spanning of 2010 to 2011. Information from the growth curve of chicks hand-fed in 2010 was used to develop a feeding protocol for the 2011 season (Protocol-2011). This protocol addressed the problems of delayed followed by excessive growth experienced by parrots hand fed in 2010. Monk parrots that were hand-fed in 2011 following the new protocol experienced delayed growth after 20 days of age. However, some Monk parrots were fed in excess of Protocol-2011 and did not experience a major delay in growth. The energy requirement equations used to construct Protocol-2011 were low when compared to adult Monk parrot maintenance energy requirements. The data suggest that growing birds do not require approximately twice their adult maintenance energy requirements, as is the case for growing dogs. Additionally, there appear to be fluctuations in energy needs as Monk parrots grow. A major increase in energy needs occurred between days 18 and 23 posthatching, which corresponds to feather development and growth in Monk parrot chicks. Thus, multiple equations estimating energy requirements, rather than just one equation, are likely needed from hatching to fledging in order to ensure adequate energy is provided to chicks. More research on the energy requirements of growing Monk parrots, especially around the time of fledging and weaning, is needed to improve hand-fed methods and potentially the adult health of hand-fed birds.

Obesity has been associated with an increased inflammatory response and insulin resistance due to adipose tissue-derived adipokines and increases in C-reactive protein (CRP). Dogs appear to be similar to other species with the exception of adiponectin, which might not be affected by obesity status. Serum long-chain polyunsaturated fatty acid concentrations have been positively and negatively associated with serum adipokines. The aim of the study was to examine the relationship between leptin, CRP, adiponectin, and insulin to body condition score (BCS) and to the long-chain omega-3 fatty acids in serum lipoproteins, including alpha-linolenic acid, eicosapentaenoic acid (EPA), docosapentanenoic acid (DPA), and docosahexaenoic acid (DHA) as a reflection of dietary omega-3 status in the Labrador Retriever. Seventy-seven Labrador Retrievers were evaluated for BCS, percent fasting serum lipoprotein fatty acid concentrations, as well as serum leptin, adiponectin, insulin, and CRP. A multivariable general linear regression model was constructed to examine the association between the dependent variables leptin, CRP, adiponectin, and insulin and the predictor variables of BCS, age, and sex, as well as concentrations of alpha-linolenic acid, EPA, DHA, and DPA. Adiponectin concentration was positively associated with age (P<0.0008), EPA (P=0.027) and negatively associated with DHA (P=0.008). Leptin concentration was positively associated with an increased DHA (P=0.009), BCS (P<0.0001), age (P=0.02), and decreased DPA (P=0.06). Insulin concentration was only associated with BCS (P<0.0001), and no meaningful associations were found for CRP. Longer chain omega-3 fatty acids may play a role in regulating adiponectin concentrations in dogs. However, because insulin concentrations were associated only with BCSs, further examination of the role of adiponectin in canine obesity is warranted. EPA and DPA may reduce the overall inflammatory state in dogs as these omega-3 fatty acids reflect increased adiponectin (increased EPA and decreased DHA) and decreased leptin (decreased DHA and increased DPA).

Common beans (Phaseolus vulgaris, L.), are a safe and digestible source of macro- and micro-nutrients for dogs and supply phytochemicals that are associated with improving human and animal health. In this study, we utilized a targeted and non-targeted metabolomic approach to evaluate dietary cooked navy bean powder (25% weight/weight) as part of the canine food metabolome. GC- and LC-MS were used to evaluate the effects of a navy bean diet on serum biochemistry and chemical composition of feces and urine in clinically healthy adult dogs (n=10), compared to a control diet (n=11). The navy bean diet was higher in 2-piperdinecarboxylic acid, s-methyl cysteine, beta-sitosterol, gamma-tocopherol, sucrose, and fructose. Companion dogs consuming the 25% navy bean diet for one month had lower serum cholesterol and showed changes in fecal and urine metabolites that were consistent with modulation of lipid and carbohydrate metabolism. Metabolite biomarkers of bean intake were identified in canine diets and urine. These data support the continued investigation of the potential for bean-based diets to improve companion dog health and the utility of nutritional metabolomics in companion animal studies.

Monk parrots (Myiopsitta monachus) are susceptible to atherosclerosis, a progressive disease characterized by the formation of plaques in the arteries accompanied by underlying chronic inflammation. The family of n-3 fatty acids, especially eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA), have consistently been shown to reduce atherosclerotic risk factors in humans and other mammals. Some avian species have been observed to convert α-linolenic acid (18:3n-3, ALA) to EPA and DHA (Htin et al. in Arch Geflugelk 71:258–266, 2007; Petzinger et al. in J Anim Physiol Anim Nutr, 2013). Therefore, the metabolic effects of including flaxseed oil, as a source of ALA, in the diet at three different levels (low, medium, and high) on the lipid metabolism of Monk parrots was evaluated through measuring plasma total cholesterol (TC), free cholesterol (FC), triacylglycerols (TAG), and phospholipid fatty acids. Feed intake, body weight, and body condition score were also assessed. Thus the dose and possible saturation response of increasing dietary ALA at constant linoleic acid (18:2n-6, LNA) concentration on lipid metabolism in Monk parrots (M. monachus) was evaluated. Calculated esterified cholesterol in addition to plasma TC, FC, and TAG were unaltered by increasing dietary ALA. The high ALA group had elevated levels of plasma phospholipid ALA, EPA, and docosapentaenoic acid (DPAn-3, 22:5n-3). The medium and high ALA groups had suppressed plasma phospholipid 20:2n-6 and adrenic acid (22:4n-6, ADA) compared to the low ALA group. When the present data were combined with data from a previous study (Petzinger et al. in J Anim Physiol Anim Nutr, 2013) a dose response to dietary ALA was observed when LNA was constant. Plasma phospholipid ALA, EPA, DPAn-3, DHA, and total n-3 were positively correlated while 20:2n-6, di-homo-gamma-linoleic acid (20:3n-6Δ7), arachidonic acid (20:4n-6), ADA, and total n-6 were inversely correlated with dietary en% ALA.

Vet Med Today: Timely Topics in Nutrition 1241 H and nutrition-minded consumers have a considerable interest in and demand for natural food products, including natural foods for their pets. Natural pet food is the fastest growing segment of the pet food industry in the United States, compared with the science, grocery, and overall pet specialty segments. Sales of natural pet foods increased from $2.0 billion in 2008 to $3.9 billion in 2012. Interest in natural pet foods and ingredient sourcing was fueled by the 2007 recall of pet food products adulterated with melamine and related derivatives as a result of the inclusion of Chinese-sourced wheat gluten, rice gluten, and corn gluten. Consequently, consumer awareness of pet food safety and the inclusion of specific ingredients in pet foods were heightened, which resulted in increased demand by consumers and pet food manufacturers for traceability of pet food ingredients, specifically with regard to country of origin. The rapid growth in the demand for natural pet foods is also propelled by the unsubstantiated belief of many consumers that diets consisting of meat, whole grains, and fewer by-products offer better nutritional options for their dogs and cats. A preference for recognizable ingredients (eg, fruits and vegetables) listed on the label parallels consumers’ beliefs that these foods are good for the health and well-being of their pets. Understanding what constitutes a natural pet food and how to assess its quality is necessary to enable veterinarians to confidently provide nutritional advice to pet owners. The purpose of the information provided here is to clarify the definition of natural pet foods in the United States and provide guidance for assessing natural pet food products. In addition, qualityand safety-related aspects involved in delivering optimal companion animal nutrition is discussed.

Arachidonic acid (ARA) is essential in felines because conversion of dietary linoleic acid (LA) to ARA is rate-limited by low Δ6-desaturase. Dietary γ-linolenic acid (GLA) may serve as an ARA precursor by-passing this initial rate-limiting step. This possibility was investigated using twenty-six adult female domestic shorthair cats divided into three groups and fed on complete and balanced diets containing high GLA (GL), high LA (HL) or low LA (LL, control) diets, for 300 d prior to ovariohysterectomy. Plasma was obtained 1–2 d before surgery and uterine, ovarian and associated adipose tissues were reserved for lipid analysis. Fatty acid profiles of the plasma phospholipid (PL) fractions and adipose lipids were performed. In the GL group, plasma and uterine tissue PL were significantly enriched in GLA, di-homo GLA (DGLA) and ARA compared with control. However, ovarian and adipose tissue PL were only enriched in DGLA. Enrichment of uterine tissues with DGLA and ARA probably supplies the essential eicosanoid precursors for reproduction when GLA is fed consistently with an active Δ5-desaturase in uterus. By contrast, this enzyme appears less active in ovary because ARA was not higher compared with control. Earlier reports concluded that ARA was not necessary for fertilisation (an ovarian function), but required for successful pregnancy and reproduction (a uterine function). Adipose tissue DGLA may be a reservoir for ARA synthesis by other tissues upon mobilisation. Dietary GLA may meet feline ARA requirements in the absence of an animal-based preformed source of ARA.

The effect of α-linolenic acid from a flaxseed (FLX)-enriched diet on plasma lipid and fatty acid metabolism and possible atherosclerosis risk factors was studied in Monk parrots (Myiopsitta monachus). Twenty-four Monk parrots were randomly assigned to diets containing either 10% ground SUNs or 10% ground FLXs. Feed intake was calculated daily. Blood samples, body condition scores and body weights were obtained at -5 weeks, day 0, 7, 14, 28, 42 and 70. Plasma samples were analysed for total cholesterol, free cholesterol, triacylglycerols and lipoproteins. Phospholipid subfraction fatty acid profiles were determined. By day 70, the FLX group had significantly higher plasma phospholipid fatty acids including 18:3n-3 (α-linolenic acid), 20:5n-3 (eicosapentaenoic acid) and 22:6n-3 (docosahexaenoic acid). The sunflower group had significantly higher plasma phospholipid levels of 20:4n-6 (arachidonic acid). By day 70, the high-density lipoprotein (HDL) peak shifted resulting in significantly different HDL peak densities between the two experimental groups (1.097 g/ml FLX group and 1.095 g/ml SUN group, p = 0.028). The plasma fatty acid results indicate that Monk parrots can readily convert α-linolenic acid to the long-chain omega-3 derivatives including docosahexaenoic acid and reduce 20:4n-6 accumulation in plasma phospholipids. The reason for a shift in the HDL peak density is unknown at this time.

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.

Objective-To evaluate the combined effects of a dietary fiber and carnitine supplement using a commercially available canned dog supplement on satiety, weight loss, and lipid metabolism.Design-A randomized, crossover design (satiety study) and randomized complete block design (weight loss study) Sample Population-12 (satiety study) and 7 (weight loss study) adult female overweight/obese Beagles.Procedures-Two studies were conducted. In the satiety study, dogs were fed 1.2 times maintenance energy amounts of either high dietary fiber/high carnitine (HF/C) or low dietary fiber/low carnitine (LF/C) supplemented diet twice a day using a 3 hour interval and food intake was monitored. Blood samples were obtained at 0, 45, and 120 min postprandially for peptide YY determination. For the weight loss study, 60 % of maintenance energy amounts of either the HF/C or LF/C diet were fed for 42 days. Blood samples were collected at days 1, 28, and 42 to determine plasma lipid metabolites and peptide YY.Results-The HF/C diet decreased both the amount of food and energy intakes at 3 hour post-feeding, suggesting improved 3 hour post-meal satiety. This combination supplement also increased postprandial plasma beta-hydroxybutyrate at day 42 and was associated with greater body fat and weight loss without alteration of plasma peptide YY, triglyceride, total cholesterol, and lipoprotein-cholesterol concentrations.Conclusions and Clinical Relevance-The combination of dietary fiber/carnitine from a commercially available canned supplement demonstrated the potential to decrease begging behavior between meals due to increased 3 hour post-meal satiety. This combination supplement also supported improved body weight reduction and increased fat utilization without altering plasma triglyceride, lipoprotein-cholesterol and cholesterol concentrations.

Echoes are frequently seen in the urinary bladder of cats during abdominal ultrasound. These have been attributed to hematuria, pyuria, crystalluria, and lipid. However, sonographic findings have not been previously correlated with urinalysis. We prospectively evaluated 40 clinically normal cats via ultrasound, serum chemistry, and urinalysis. Thin layer chromatography was performed on the urine to determine the amount (mg) of lipid subfractions including diacylglycerol, triglyceride, phospholipid, free fatty acid, cholesterol, and cholesterol ester. Ninety percent (36/40) of the cats in our population had sonographic echoes suspended in the urinary bladder, with most having a subjective score of mild echoes (n = 20). None of the sonographic echoes were gravity dependent or caused distal acoustic shadowing, reverberation, or twinkle artifact. Of the cats with sonographic echoes in the urine, 66% (24/36) had no significant findings on urinalysis other than the presence of lipid. The total amount of subjective sonographic echoes was not significantly related to the total amount of fat measured on thin layer chromatography or the number of lipid droplets seen on urinalysis. An increased amount of urine diacylglycerol was significantly associated with clumping of echoes (P = 0.02) and the amount of lipid droplets seen on urinalysis (P = 0.04). An association between increased amounts of urine diacylglycerol and the amount of echoes seen on ultrasound approached significance (P = 0.05). Findings from this study support previously published theories that sonographic echoes within the urinary bladder of clinically normal cats may be due to urine lipid.

Atherosclerosis is a disease that occurs in many avian species commonly presented to veterinarians. Many risk factors for atherosclerosis are well defined in mammals but not in avian species. Dietary nutrients can play a large role in reducing the severity and prevalence of atherosclerosis in both avian and mammalian species. Information on the effect of dietary nutrients on atherosclerosis in Falconiformes and other birds of prey is extremely limited as no studies were identified by the authors. Dietary cholesterol can be fed to induce the development of atherosclerosis in avian species that consume nonanimal protein. Diets containing high levels of omega-3 fatty acids reduce the prevalence and severity of atherosclerosis, with fish oil being more effective than α-linolenic acid. The presence of dietary cholesterol results in higher levels of dietary protein, increasing the prevalence and severity of atherosclerosis, but if dietary cholesterol is absent, there is a subsequent decrease in atherosclerosis. Pectin in the diet decreased the occurrence of atherosclerosis but also decreased the availability of nutrients owing to faster ingesta passage rates. Feed restriction has also been found to decrease the prevalence of atherosclerosis in birds. It should be noted that many studies have found nutrient interaction effects on the development of atherosclerosis, with some being “neutralizing” or negative, so caution should be observed when manipulating avian diets. The objective of this article is to review the effects of dietary nutrients on atherosclerosis.

Rice bran chemical profiles differ across rice varieties and have not yet been analysed for differential chemopreventive bioactivity. A diverse panel of seven rice bran varieties was analysed for growth inhibition of human colorectal cancer (CRC) cells. Inhibition varied from 0% to 99%, depending on the variety of bran used. Across varieties, total lipid content ranged 5-16%, individual fatty acids had 1.4- to 1.9-fold differences, vitamin E isoforms (alpha-, gamma-, delta-tocotrienols, and tocopherols) showed 1.3- to 15.2-fold differences, and differences in gamma-oryzanol and total phenolics ranged between 100-275 ng/mg and 57-146 ng GAE/mg, respectively. Spearman correlation analysis was used to identify bioactive compounds implicated in CRC cell growth inhibitory activity. Total phenolics and gamma-tocotrienol were positively correlated with reduced CRC cell growth (p < 0.05). Stoichiometric variation in rice bran components and differential effects on CRC viability merit further evaluation elucidate their role in dietary CRC chemoprevention. (C) 2013 Elsevier Ltd. All rights reserved.

Dry beans (Phaseolus vulgaris L., Fabaceae) are a low glycemic index food containing protein, fiber, minerals, essential vitamins, and bioactive compounds and have not been evaluated for inclusion in commercial canine diets. The objective of this study was to establish the apparent total tract digestibility and safety of cooked navy bean powder when incorporated into a canine diet formulation at 25% (wt/wt) compared with a macro- and micro-nutrient matched control. Twenty-one healthy, free-living, male and female adult dogs of different breeds were used in a randomized, blinded, placebo controlled, 28-d dietary intervention study. Apparent total tract energy and nutrient digestibility of the navy bean powder diet were compared with the control diet. Digestibilities and ME content were 68.58 and 68.89% DM, 78.22 and 79.49% CP, 77.57 and 74.91% OM, 94.49 and 93.85% acid hydrolyzed fat, and 3,313 and 3,195 kcal ME/kg for the navy bean diet and control diet, respectively. No differences were observed between the groups. No increased flatulence or major change in fecal consistency was observed. Navy bean powder at 25% (wt/wt) of total diet was determined to be palatable (on the basis of intake and observation) and digestible in a variety of dog breeds. No changes were detected in clinical laboratory values, including complete blood counts, blood biochemical profiles, and urinalysis in either the bean or control diet groups. These results indicate that cooked navy bean powder can be safely included as a major food ingredient in canine diet formulations and provide a novel quality protein source, and its use warrants further investigation as a functional food for chronic disease control and prevention.

The effect of diets containing either 18-carbon n-3 fatty acids (FA) or 20/22-carbon n-3 FA on canine plasma and neutrophil membrane fatty acid composition, superoxide and leukotriene B 4 and B 5 production when fed at the same n-6:n-3 fatty acid ratio was investigated. Four groups of ten dogs each were fed a low fat basal diet supplemented with safflower oil (SFO), beef tallow (BTO), linseed oil (LSO), or Menhaden fish oil (MHO) for 28 days. Dietary fat provided 40.8% of energy and the n-6:n-3 of the diets were ~100:1, 9.7:1, 0.38:1, and 0.34:1 for the SFO, BTO, LSO and MHO groups, respectively. The MHO and LSO groups had increased incorporation of EPA and DPA in both the plasma and neutrophil membranes compared to the BTO and SFO groups. DHA was observed in the MHO but not in the LSO group. Neutrophils from the MHO diet fed dogs had less LTB 4 and greater LTB 5 than the other three groups. The LSO group also showed a reduction in LTB 4 and greater LTB 5 production compared to the SFO and BTO groups. Both LSO and MHO groups had lower superoxide production compared to the SFO and BTO groups. Diets containing 18 or 20/22 carbon n-3 FA fed at the same n-6:n-3 resulted in differential incorporation of long chain n-3 FA into neutrophil membranes. Thus, fatty acid type and chain length individually affect neutrophil membrane structure and function and these effects exist independent of dietary total n-6:total n-3 FA ratios.

OBJECTIVE To describe an entire litter of kittens with severe hyperlipidemia and subsequent successful, low-cost treatment that included high protein enteral support and parasite control. Previous case studies of similarly affected kittens have focused on a genetic etiology and on advanced interventions. The role of negative energy balance and additional factors influencing hyperlipidemia, as well as treatment and prognosis are discussed. CASE SUMMARY Three of 6 kittens died or were euthanized due to severe clinical signs attributable to multiorgan failure associated with subacute hyperlipidemia. The remaining 3 kittens, although subclinical, were found to have similar biochemical abnormalities, including severe anemia and hypertriglyceridemia. Flea treatment and weaning with assisted enteral support prevented the worsening of clinical signs and returned biochemical parameters to within reference intervals. UNIQUE INFORMATION PROVIDED Transient hyperlipidemia in kittens has been previously reported and successfully treated with administration of oxygen, blood transfusion, and diet change; these treatment recommendations may not always be financially feasible, resulting in euthanasia of affected kittens. In contrast, this report describes a successful, low-cost, outpatient approach of flea control, weaning, and introduction of a high protein enteral diet. It also highlights the importance of screening and treating seemingly unaffected littermates, provides new, previously unreported biochemical and histopathology findings, and proposes that negative energy balance is a significant factor in the development of transient hyperlipidemia in kittens.

Cats have limited Δ6 desaturase activity. However, γ-linolenate (GLA) feeding may by-pass the Δ6 desaturase step allowing arachidonate (ARA) accumulation via Δ5-desaturation. Alternatively, high dietary linoleate (LNA) may induce limited Δ6 desaturase also resulting in ARA accumulation. Fatty acid profiles were determined after feeding high LNA, high GLA, or adequate LNA diets. Adult female cats (n = 29) were assigned to one of three groups and fed for 8 weeks. Plasma samples were collected at weeks 0, 2, 4 and 8 for plasma triacylglycerol (TAG), total cholesterol (TC), lipoprotein (LP), and plasma and red blood cell membrane phospholipid fatty acid determinations. Time, but no diet, effects were observed for TAG, TC, and LP fractions at weeks 2 and 4 with significant increases likely due to increased dietary fat. However, all values were within feline normal limits. The GLA diet resulted in increased dihomo-γ-linolenic acid (DGLA) and ARA as early as week 2, supporting a ∆5 desaturase. Further evidence of Δ5 desaturase was found at high dietary LNA with the appearance of a novel fatty acid, 20:3 ∆7, 11, 14, apparently formed via ∆5 desaturation and chain elongation of LNA. However, Δ6 desaturase induction at high dietary LNA concentration was not observed. Cats are able to maintain plasma and red blood cell ARA when fed a practical diet containing GLA using what appears to be an active Δ5 desaturase enzyme.