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Research in Veterinary Science
journal homepage: www.elsevier.com/locate/rvsc
Functional foods in pet nutrition: Focus on dogs and cats
Alessandro Di Cerbo
, Julio Cesar Morales-Medina
, Beniamino Palmieri
, Federica Pezzuto
, Gonzalo Flores
, Tommaso Iannitti
Department of Medical, Oral and Biotechnological Sciences, Dental School, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy
Centro de Investigación en Reproducción Animal, CINVESTAV-Tlaxcala, CP 90000, AP 62, Mexico
Department of Surgery and Surgical Specialties, University of Modena, Modena, Italy
University of Modena and Reggio Emilia, Italy
Department of Veterinary Medicine, Pathology and Veterinary Clinic Section, University of Sassari, Sassari, Italy
Lab. Neuropsiquiatría, Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, 14 Sur 6301, San Manuel, 72570, Puebla, Mexico
KWS BioTest, Marine View Oﬃce Park, Portishead, Somerset BS20 7AW, UK
Functional foods provide health beneﬁts if they are consumed on a regular basis as part of a varied diet. In this
review, we discuss the availability and role of functional foods in pet nutrition with a focus on dogs and cats.
Indeed, functional foods modify gastrointestinal physiology, promote changes in biochemical parameters,
improve brain functions and may reduce or minimize the risk of developing speciﬁc pathologies. This evidence
derives largely from clinical studies while only limited evidence is available from studies in dogs and cats.
Therefore, functional food consumption should be further investigated in pet nutrition to understand how
dietary interventions can be used for disease prevention and treatment.
Novel foods and food components have been identiﬁed as “func-
tional”because they provide health beneﬁts beyond the provision of
essential nutrients, such as vitamins, minerals, water, proteins, carbo-
hydrates and fats (Hasler, 2000). The role of functional foods has been
investigated in dogs (Canis familiaris) and cats (Felis catus) in order to
better understand their metabolism, thus optimising companion animal
nutritional and health status (Swanson et al., 2003). After a long history
of coexistence, the most common pets in modern societies are dogs and
cats. Dogs and cats present signiﬁcant diﬀerences in digestive-related
processes but, while cats are carnivorous, dogs appear to be omnivorous
like human beings (Bosch et al., 2015). Dogs share some carnivorous
traits with cats as both lack salivary amylase, have a short gastro-
intestinal tract and are unable to synthesize vitamin D (National
Research Council, 2006). In contrast, there are 3 genes, AMY2B, MGAM
and SGLT1 that have evolved only in dogs during domestication and are
involved in starch digestion and glucose uptake (Axelsson et al., 2013).
Another characteristic of the dogs digestive system is that they can
synthesise several essential nutrients such as niacin, taurine and
arginine (Bosch et al., 2015). As far as cats are concerned, they can
catabolise and use amino acids as a source of energy for gluconeogen-
esis (Morris, 2002). Cats have a diet consisting of 52% protein, 36% fat
and 12% carbohydrate (Plantinga et al., 2011). Therefore, we have to
study pet nutrition considering dogs and cats separately. A human-pet
parallel exists as pet owners provide their dogs and cats with alternative
foods, such as commercially available “natural”, raw food and vegetar-
ian diets as they are considered family members (Michel, 2006). The
parallel between humans and animals is further strengthened by the
evidence that, similarly to human babies who copy adults' redundant
actions (Brugger et al., 2007; Cook et al., 2014; Lyons et al., 2007;
Topal et al., 2008), companion animals acquire the wrong eating habits
from their owners (Marshall-Pescini et al., 2012). This evidence
suggests that understanding pet nutrition is also important to study
human nutrition; however, this is not object of this article and has been
reviewed elsewhere (Di Cerbo et al., 2014).
Several studies have focused on investigating health beneﬁts of
ingredients found in commercially available functional foods in hu-
mans; these ingredients may also exert their beneﬁcial eﬀects on dogs
and cats but, at least in some cases, have not been investigated yet. The
interest in the adequacy of commercially available pet foods has been
growing worldwide (Zicker, 2008). Functional foods, strongly appre-
Received 15 September 2016; Received in revised form 10 March 2017; Accepted 15 March 2017
Corresponding author at: KWS BioTest, 47-48 Martingale Way, Marine View Oﬃce Park, Portishead, Somerset BS20 7AW, UK.
Authors contributed equally.
E-mail addresses: email@example.com (A. Di Cerbo), firstname.lastname@example.org (J.C. Morales-Medina), email@example.com (B. Palmieri), firstname.lastname@example.org (F. Pezzuto),
email@example.com (R. Cocco), gonzaloﬂores56@gmail.com (G. Flores), firstname.lastname@example.org (T. Iannitti).
Research in Veterinary Science 112 (2017) 161–166
0034-5288/ © 2017 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/BY-NC-ND/4.0/).
ciated for their health beneﬁts, include fruit and vegetables (Slavin and
Lloyd, 2012), botanicals (Guidetti et al., 2016), whole grains (Borneo
and Leon, 2012), dietary supplements including pycnogenol, collagen,
coenzyme Q10, low-molecular-weight hyaluronic acid, chondroitin
sulfate and glucosamine sulfate (Di Cerbo et al., 2015a), beverages
(Corbo et al., 2014; Shiby and Mishra, 2013), prebiotics and probiotics
(Di Cerbo et al., 2012; Di Cerbo and Palmieri, 2015; Di Cerbo et al.,
2013; Iannitti and Palmieri, 2010; Ricciardi et al., 2014; Romano et al.,
2014; Blaiotta et al., 2016) [probiotics eﬃcacy in canine and feline
welfare has been reviewed elsewhere (Grzeskowiak et al., 2015)]. Most
of these functional foods can improve satiety (Delzenne and Kok, 2001;
Reimer et al., 2012) and reduce postprandial glucose and insulin
concentrations (Delzenne and Kok, 2001), thus reducing diabetes-
related comorbities. Inulin and oligofructose, two functional foods,
can modify the intestinal microﬂora in dogs, cats (Hussein et al., 1999)
and humans (Van Loo et al., 1999). Dietary ﬁbers, which are commonly
found in pet foods (de Godoy et al., 2009), can modify the intestinal
microﬂora by promoting commensal bacteria growth (Tungland, 2003).
Decrease in gastric emptying, blood cholesterol concentrations
(Brennan and Cleary, 2005), gastric transit time, dilution in diet calorie
density as well as increase in satiety (Rebello et al., 2013), glucose
uptake rate (Jenkins et al., 2008) and fecal excretion (Wenk, 2001) can
also be ascribed to dietary ﬁbers.
Whole grains, whose main sources are wheat, corn, oats, barley and
rye (Slavin et al., 2001), are rich in dietary ﬁbers, trace minerals,
vitamin B and E (Fardet, 2010), bioactive compounds, e.g. tocotrienols,
lignans and polyphenols, lipotropes and methyl donors, such as choline,
methionine, betaine, inositol and folate and antinutrients; these are
deﬁned as compounds that interfere with the absorption of nutrients
such as phytic acid, tannins and saponins endowed with antioxidant
and anti-carcinogenic eﬀects (Fardet, 2010; Jones and Engleson, 2010;
Jonnalagadda et al., 2011; Slavin et al., 2001). Cereal grain is mainly
used (~90%) in animal feeding and its nutritional composition ranges
from 21% to 27% of total dietary ﬁber, 12%–16% of crude protein and
Studies of functional foods and functional food-containing diets in dogs.
Functional food/diet containing functional foods Health beneﬁts References
FOS alone or in combination with MOS plus poultry by-product meal, brewers rice,
poultry fat, beet pulp, dehydrated egg, sodium chloride, potassium chloride,
choline chloride, vitamin premix and mineral premix
↑ileal immunoglobulin A,
↓fecal total indole and phenol concentrations
Swanson et al., 2002
Oligofructose ↓levels of Clostridium perfringens Flickinger et al.,
Poultry fat combined with 12% stabilized rice bran
Defatted rice bran diet combined with poultry fat, beef tallow, or poultry
fat:soybean oil (50:50)
↑food intake and palatability
↓plasma phospholipid total monounsaturated fatty acids
Spears et al., 2004
Peas ↓glycemic index value Adolphe et al., 2012
104·80 μmol retinol (100,000 IU vitamin A) ↑bone growth Morris et al., 2012
Corn, beet pulp, yeast, ﬁsh oil, minerals, dried yeast (Bio MOS), FOS, Yucca
schidigera, Vitamin A (15,000 IU), Vitamin D3 (1080 IU), Vitamin E (180 mg),
choline chloride (1000 mg), copper chelate of amino acids hydrate (20 mg), DL-
methionine (500 mg), taurine (1500 mg), L-carnitine (500 mg), extract rich in
natural tocopherols (44.3 mg), Rosmarinus oﬃcinalis (0.84 mg), Grifola frondosa
(270 mg), Curcuma longa (263 mg), Carica papaya (151 mg), Punica granatum
(103 mg), Aloe vera (92 mg), Polygonum L. (82 mg), Haematococcus pluvialis
(74 mg), Solanum lycopersicum (25 mg), and Vitis vinifera (19 mg)
↓Body Condition Score, d-ROMs, hematocrit, and platelets
Pasquini et al., 2013
Antioxidants, phytotherapic compounds, vitamins, and trace elements ↑metabolic activity (free thyroxine and testosterone) and a
consequent positive eﬀect on fertility and thyroid activity
↑semen motility and vitality
Ponzio et al., 2013
Fish hydrolyzed proteins, rice carbohydrates, Melaleuca alternifolia (0.00343%), Tilia
platyphyllos scapoli et cordata (0.0147%), Allium sativum L. (0.0245%), Rosa
canina L. (0.098%) and zinc (0.00479%)
↓mean score intensity of all chronic otitis externa-associated
symptoms (occlusion of ear canal, erythema, discharge quantity
Di Cerbo et al., 2014,
Ascophyllum nodosum,Cucumis melo,Carica papaya, Aloe vera, Astaxanthin from
Haematococcus pluvialis,Curcuma longa,Camellia sinensis, Punica granatum, Piper
nigrum, Poligonum spp.,Echinacea purpurea, Grifola frondosa, Glycine max, and
Omega 3 and Omega 6 unsaturated fatty acids
↑platelet number and CD4/CD8 ratio, ↓Treg and Th1 cells Cortese et al., 2015
Rice carbohydrates, Grifola frondosa,Curcuma longa,Carica papaya, Punica granatum,
Aloe vera, Polygonum cuspidatum, Solanum lycopersicum, Vitis vinifera,Rosmarinus
oﬃcinalis, and an Omega 3 and Omega 6 ratio of 1:0.8
Sechi et al., 2015
Fish meal, propolis (0.0161%), Salvia oﬃcinalis (0.0087%), egg albumen (lysozyme
0.0078%), dehydrated orange extract (bioﬂavonoids 0.0077%), Thymus vulgaris
(0.0127%), and Ribes nigrum (0.0040%)
↓halitosis volatile sulfur compounds (methyl mercaptan,
hydrogen sulﬁde and dimethyl sulﬁde)
Di Cerbo et al.,
Fish proteins, rice carbohydrates (carbohydrates: 75–80%; starch: 65–70%; beta-
glucans: < 0.1%), Cucumis melo (300 mg/kg), Ascophyllum nodosum (40,000 mg/
kg), Astaxanthin from Hematococcus pluvialis (49 mg/kg), Aloe vera (135 mg/kg),
Carica papaya (135 mg/kg), Punica granatum (70 mg/kg), Camellia sinensis
(70 mg/kg), Polygonum cuspidatum (7 mg/kg), Curcuma longa (102 mg/kg), Piper
nigrum (30 mg/kg), zinc (137 mg/kg), and an Omega 3 and Omega 6 ratio of
↓mean intensity of tear production, conjunctival inﬂammation,
corneal keratinization, corneal pigment density and mucus
Destefanis et al.,
Rice carbohydrates, Punica granatum (0.0457%), Valeriana oﬃcinalis (0.026%),
Rosmarinus oﬃcinalis (0.000044%), Tilia spp. (0.0635%), tea extract (0.031%)
and L-tryptophan (0.0329%)
↑clinical and behavioral symptoms related to general anxiety Di Cerbo et al., 2016
Punica granatum (457 mg/kg), Valeriana oﬃcinalis (260 mg/kg), Rosmarinus
oﬃcinalis (0.44 mg/kg), Tilia spp. (635 mg/kg), tea extract (392 mg/kg), and L-
tryptophan (329 mg/kg), L-theanine (310 mg/kg), Omega 6 (12.5 g/kg), Omega
3 (16 g/kg), Vitamin A (18,500 UI/kg), E (120 mg/kg), C (250 mg/kg), choline
chloride (1000 mg/kg), zinc sulfate monohydrate (137 mg/kg), cupric chelate
glycine hydrate (39 mg/kg) and DL-methionine (500 mg/kg)
↑serotonin, dopamine and β-endorphin plasma concentrations
↓noradrenaline and cortisol plasma concentrations and d-ROMs
Sechi et al., 2017
BAP, biological antioxidant potential; BDNF, brain-derived neurotrophic factor; d-ROMs, derivatives of reactive oxygen metabolites; FOS, fructooligosaccharides; MOS, mannan-
A. Di Cerbo et al. Research in Veterinary Science 112 (2017) 161–166
18%–22% of crude fat (Kahlon, 2009). Corn is another valuable ﬁber
source since it possesses no detrimental eﬀects on palatability and
nutrient digestibility, also lowering the glycemic response in adult dogs
(de Godoy et al., 2009). Although corn ﬁber contains phenolic
compounds with known antioxidant, anti-mutagenic and cholesterol-
lowering eﬀects (Wilson et al., 2000) that can reduce the incidence of
colon cancer in humans (Lamy et al., 2014), these eﬀects have not been
investigated in dogs and cats. Therefore, further studies are warranted.
Rice bran is an excellent source of essential amino acids since it is
particularly rich in sulfur-containing amino acids, micronutrients such
as magnesium, manganese and B vitamins (Ryan, 2011), bioactive
molecules such as tocopherols, tocotrienols, polyphenols like ferulic
acid and α-lipoic acid, phytoesterols, γ-oryzanol and carotenoids such
as carotene, lycopene, lutein and zeaxanthin, all of which have strong
antioxidant, anti-inﬂammatory and chemopreventive properties in
management and prevention of chronic diseases such as cardiovascular
disease, type-2 diabetes, and obesity (Ryan, 2011). In addition, rice
bran oil contains a good fatty acid proﬁle including mostly mono- and
poly-unsaturated fatty acids [oleic acid (38.4%), linoleic acid (34.4%)
and α-linolenic acid (2.2%)] and about 1.5% γ-oryzanol, all of which
have a strong antioxidant capacity, as observed in rodents, rabbits, non-
human primates and humans (Cicero and Derosa, 2005). During pet
food heat processing, the Maillard reaction, i.e. a non-enzymatic
browning and ﬂavoring reaction (van Rooijen et al., 2013), reduces
the bioavailability of essential amino acids such as lysine (Friedman,
1996). Therefore, pet food can supply less lysine than the animal may
require thus needing the addition of a dietary supplement to integrate
such deﬁciency. Understanding the nutritional beneﬁts of functional
foods currently available is of key importance to provide dogs and cats
with the correct diet to keep them healthy. For this reason, softwares
are available online to allow the consumer to choose the appropriate
pet food based on the desired ingredients and diet (BlueBuﬀalo;
2. Aim and searching criteria
The aim of this review is to discuss the availability and use of
functional foods in dogs and cats. We searched Pubmed/Medline using
the keywords “dogs”,“cats”,“functional”,“food”,“nutraceutical”and
“diet”alone or combined. Selected papers from 1941 to 2017 were
chosen based on their content.
3. Functional foods and dog nutrition
Several studies focused on the role of functional foods in dog
nutrition (Adolphe et al., 2012; Cortese et al., 2015; Destefanis et al.,
2016; Di Cerbo et al., 2016; Di Cerbo et al., 2014; Di Cerbo et al.,
2015b; Di Cerbo et al., 2017; Fahnestock et al., 2012; Pasquini et al.,
2013; Ponzio et al., 2013; Sechi et al., 2015; Sechi et al., 2017; Spears
et al., 2004; Swanson et al., 2002; Tidu et al., 2013) are summarized in
Table 1. For instance, in adult male beagles, oligofructose-enriched diet
decreased fecal ammonia and Clostridium perfringens concentrations,
while total aerobes increased, thus ameliorating the overall dog health
(Flickinger et al., 2003). Fructooligosaccharides (FOS), were used alone
or in combination with mannan-oligosaccharide in dogs fed on a meat-
based diet (Swanson et al., 2002). Dogs showed greater ileal immu-
noglobulin A concentration, whereas they displayed lower fecal total
indole and phenol concentrations, if compared with untreated controls.
A further study tested a 6-month maintenance diet (FOS as well as corn,
ﬁsh meal, processed proteins of chicken, poultry fat, beet pulp, yeast,
ﬁsh oil, minerals, dried yeast (Bio mannan-oligosaccharides), Yucca
schidigera, Vitamin A, D3 and E, choline chloride, copper chelate of
amino acids hydrate, DL-methionine, taurine, L-carnitine and tocopher-
ols, Grifola frondosa,Curcuma longa,Carica papaya,Punica granatum,
Aloe vera,Polygonum L.,Haematococcus pluvialis,Solanum licopersicum,
and Vitis vinifera) on oxidative stress markers in 12 adult dogs (Pasquini
et al., 2013). These dogs presented oxidative imbalance in the form of
increased derivatives of reactive oxygen metabolites (d-ROMs) and
reduced biological antioxidant potential (BAP; a spectrophotometric
test that evaluates blood plasma antioxidant potential by measuring its
ferric reducing ability) and retinol. At 6 months, a signiﬁcant reduction
in d-ROMs, primarily hydroperoxides and platelets, as well as an
increase in both retinol and BAP was observed, suggesting a restored
oxidative balance. This evidence supports the idea that an adequate diet
may be crucial to achieve a good oxidative balance in dogs. Conversely,
oxidative imbalance may occur after consuming a high glycemic index
meal (Adolphe et al., 2012). In order to test this hypothesis, the authors
compared postprandial responses of 4 complex carbohydrate sources
(barley, corn, peas and rice) vs. a simple carbohydrate (glucose) in 6
dogs reporting that peas had the lowest glycemic index value (29%)
compared to barley and rice (51 and 55%, respectively) and could be
considered as part of a balanced diet. A further study by Ponzio et al.
(2013) evaluated the eﬀects of a speciﬁc diet (hydrolyzed ﬁsh protein,
hydrolyzed potato protein, dried yeast, FOS, vitamin E, ascorbic acid,
vitamin B12, niacin, vitamin A, calcium pantothenate, riboﬂavin,
pyridoxine hydrochloride, thiamine mononitrate, folic acid, choline
chloride, DL-methionine, L-carnitine, Yucca schidigera extract, beta-
carotene, Lepidium meyenii, and Tribulus terrestris) on reproduction in
14 fertile male dogs, divided in 4 age groups (1–2 years, 3–4 years,
5–7 years, and 8–10 years), over a 4-month period, which was preceded
by a 3 months pre-treatment period with their usual diet (Ponzio et al.,
2013). A constant improvement in metabolic activity (free thyroxine
and testosterone) was observed within 45 days since the beginning of
the diet enriched with antioxidants with a consequent positive eﬀect on
fertility and thyroid activity. Qualitative analysis of semen showed a
signiﬁcant increase in motility and vitality in dogs aged between 2 and
7. These results suggest that a diet enriched with antioxidants can be
used to achieve a better reproductive performance. The canine model
has been used to investigate the relationship among cognitive impair-
ment in aging, brain-derived neurotrophic factor (BDNF) and diet, but
also among behavioral disturbances, neuroendocrine parameters mod-
iﬁcation and diet (Behavioral, SANYpet S.p.A., Padua, Italy) (Di Cerbo
et al., 2017; Fahnestock et al., 2012; Sechi et al., 2015; Sechi et al.,
2017). These studies showed that dogs receiving two diﬀerent anti-
oxidant- and botanical-enriched diets (rice, ﬁsh meal, vegetable fats
and oils, ﬁsh oil, beet pulp, minerals, dehydrated yeast, FOS, Yucca
schidigera,Grifola frondosa,Curcuma longa,Carica papaya,Punica
granatum,Aloe vera,Polygonum cuspidatum,Haematococcus pluvialis,
Solanum lycopersicum,Vitis vinifera,and Rosmarinus oﬃcinalis) presented
signiﬁcantly higher BDNF (Sechi et al., 2015), lower d-ROMs and
normalized neuroendocrine parameter levels as well as an overall
improvement in behavioral disturbances and their related clinical signs
(rice ﬂour, ﬁsh protein hydrolysate, potato protein hydrolysate, miner-
als, Punica granatum,Valeriana oﬃcinalis,Rosmarinus oﬃcinalis,Tilia
spp.,Crataegus oxyacantha L. tea extract, and L-tryptophan), if com-
pared to animal fed on a control diet (Di Cerbo et al., 2017; Sechi et al.,
2017). This evidence suggests that dietary intervention might be a
valuable alternative for treatment of cognitive deﬁcits and behavioral
disturbances in dogs.
Halitosis is a condition aﬀecting both dogs and humans impacting
their relationships (Di Cerbo et al., 2015b). A randomized placebo-
controlled cross-over clinical evaluation assessed the eﬀectiveness of a
dedicated diet (Forza10 OralActive, SANYpet S.p.A., Padua, Italy) in
improving chronic halitosis in 16 dogs of diﬀerent breeds and ages (Di
Cerbo et al., 2015b). Brieﬂy, it was possible to evaluate the eﬃcacy of
the diet (rice, ﬁsh meal, vegetable fats and oils, ﬁsh oil, beet pulp,
minerals, dehydrated yeast, FOS, Yucca schidigera, propolis, Salvia
oﬃcinalis, lysozyme, bioﬂavonoids, Thymus vulgaris, and Ribes nigrum)
on oral volatile sulfur compounds, e.g. methyl mercaptan, hydrogen
sulﬁde and dimethyl sulﬁde, using gas chromatography, which eval-
uated the concentration of the aforementioned compounds over
30 days. A signiﬁcant decrease in halitosis-related sulfur compounds
A. Di Cerbo et al. Research in Veterinary Science 112 (2017) 161–166
was observed. Moreover, such improvement was still evident at 20 days
post interruption of the diet supporting the long-lasting eﬃcacy of the
compound. Di Cerbo and coworkers observed a pivotal role of a
functional diet (hydrolyzed proteins of ﬁsh and vegetable origin,
minerals, used as glidants, Melaleuca alternifolia,Tilia platyphyllos
scapoli et cordata,Allium sativum L.,Rosa canina L., and zinc) in relieving
chronic otitis externa-associated symptoms limiting the need of phar-
macological therapy to treat this condition (Di Cerbo et al., 2016). In
this study, 15 adult dogs of diﬀerent breeds and ages, aﬀected by
chronic otitis externa, received a functional diet along with pharmaco-
logical therapy (OTOMAX, 8 drops a day for 7 days). The nutraceutical
diet, endowed with anti-inﬂammatory and antioxidant activities, sig-
niﬁcantly decreased the mean score intensity of all symptoms (occlu-
sion of ear canal, erythema, discharge quantity, and odor) after 90 days
of intervention. In this evaluation, dogs received the pharmacological
treatment for the ﬁrst 8 days of diet supplementation, while they
received diet alone for the remaining 82 days. This result is of
signiﬁcant relevance in light of the growing of antimicrobial resistance
to pharmacological therapy and represents a starting point for devel-
oping functional foods endowed with antibacterial activity. A further
study investigated the eﬀect of an immune-modulating diet (IMMD) or
standard diet (SD) combined with anti-Leishmania pharmacological
therapy (meglumine antimoniate and allopurinol), in 2 groups of 20
dogs (IMMD and SD groups) of diﬀerent breeds and ages, aﬀected by
canine Leishmaniasis (CL), at 0, 3, 6 and 12 months (Cortese et al.,
2015). The IMMD restored the levels of regulatory T cells that are
reduced during CL, if compared to dogs receiving the SD, at 3, 6 and
12 months. At 6 and 12 months, dogs fed on the IMMD also showed a
decrease in T helper cells comparable to the levels observed in healthy
dogs. This evidence suggests that a speciﬁc diet can regulate the
immune response in dogs aﬀected by CL during pharmacological
treatment. The same immune-modulating diet resulted particularly
eﬀective in reducing the overall mean intensity of tear production,
conjunctival inﬂammation, corneal keratinization, corneal pigment
density and mucus discharge which are the most common symptoms
of canine keratoconjunctivitis sicca (Destefanis et al., 2016).
Pet food palatability has also been object of study since this feature
is of key importance in terms of suitability and safety. Spears et al.
(2004) examined palatability of a dry canine diet and its eﬀect on
digestion of stabilized rice bran by determining fecal characteristics,
food intake, selected immune mediators and blood lipid characteristics
(Spears et al., 2004). In the ﬁrst experiment, the authors compared the
palatability of 4 diets containing poultry fat (Test diet 1) or soybean oil
(Test diet 2) combined with either 12% stabilized (Test diet 3) or
defatted rice bran (Test diet 4) which were fed on 20 dogs for 4 days.
Food intake improved in dogs fed on Test diet 1 combined with 12%
stabilized rice bran. In the second experiment, 36 beagles received 6
diets containing 12% stabilized or defatted rice bran diet combined
with poultry fat, beef tallow, or poultry fat:soybean oil (50:50). Dogs on
a defatted rice bran diet showed signiﬁcantly lower plasma phospho-
lipid total monounsaturated fatty acids with respect to those on a
stabilized rice bran diet. They observed that stabilized rice bran was
well tolerated in dogs with no detrimental eﬀect on nutrient digest-
ibility and fecal characteristics and without promoting changes in
inﬂammatory and immune responses. Moreover, stabilized rice bran
diet presented better palatability compared to the defatted rice bran
4. Functional foods and cat nutrition
Compared to dogs, cats are carnivorous animals with diﬀerent
nutritional needs (Legrand-Defretin, 1994). Thus, speciﬁc functional
foods have been investigated in cat nutrition, as summarized in Table 2.
In a randomized, double-blind, controlled clinical trial involving 55 cats
with chronic diarrhea, the eﬃcacy of either a high (10%) or low fat
(23%) highly digestible diet (soy ﬂakes, soy protein isolate, turkey and
turkey by-product meal, corn starch, oat meal, oat ﬁber, beef tallow,
vitamins and minerals) was evaluated by assessing the fecal score (FSa).
All cats responded to the diets tested with an increase in FSa within the
ﬁrst week, achieving a maximum response to diet supplementation
within 3 weeks. Furthermore, one third of the cats developed normal
stools. No signiﬁcant diﬀerences were observed in response to both
diets, indicating that dietary fat amount is not a key factor in dietary
management of cats with diarrhea (Laﬂamme et al., 2011).
In a further study, inclusion of 26% full-fat rice bran in a puriﬁed cat
diet led to a signiﬁcantly lower mean whole blood taurine concentra-
tion, if compared with controls fed on a puriﬁed diet containing 26%
corn starch (Stratton-Phelps et al., 2002). The lower taurine concentra-
tion observed in cats fed on the rice bran diet was due to increased fecal
excretion of conjugated bile acids in addition to changes in hindgut
microbiota due to the indigestible protein fraction of rice bran able to
degrade taurine (this amino acid is not degraded under physiological
conditions). Based on this outcome, a higher concentration of dietary
taurine (> 0.05%) should be included in feline diets that contain rice
bran. Cats can self regulate food selection and intake to balance
macronutrient intake regardless of diﬀerences in moisture content
and textural properties of commercial cat diets (Hewson-Hughes
et al., 2013).
Even under artiﬁcial selection (domestication), where humans
largely determine the diet of the animal, evidence suggests that, when
provided with a choice of foods with diﬀerent nutritional proﬁles, cats
consume diﬀerent quantities of diﬀerent foods to balance their nutrient
intake. This was shown by Hewson-Hughes and co-authors (Hewson-
Hughes et al., 2013) by feeding 45 cats on 2 diﬀerent commercial diets
(wet diet: Sheba®chunks in jelly, Turkey and Chicken variety, Wd; dry
diets: (Whiskas®TOP, Chicken variety, Dd) in diﬀerent combinations (1
wet +3 dry; 1 dry +3 wet; 3 wet + 3 dry). Diets were oﬀered
simultaneously and separated by a phase in which diets were oﬀered
sequentially in 3-day cycles. This study shows a convergence upon the
same dietary macronutrient composition within each experiment as
well as over the course of the 3-day cycles. Moreover, despite
diﬀerences in dietary options, the macronutrient composition of the
diets was remarkably similar across all experiments. Besides composi-
tion, acceptance and digestibility of nutrients are other key factors that
need to be taken into account in cat nutrition. Since apple pomace has a
low digestibility (Fekete et al., 2001), it was mixed with a meat-based
diet at an inclusion level of 10, 20, and 40% and fed to 9 adult neutered
European shorthaired obese cats (Fekete et al., 2001). Inclusion of
apple pomace (10 or 20% of the diet) did not decrease food palatability,
reduced the energy density, slightly changed the digestibility of fat, and
considerably decreased the digestibility of crude protein. Energy
density decreased proportionally to the percentage of apple pomace
added to the diet. Unfortunately, at a 40% inclusion rate, a lower food
intake was observed. Therefore, inclusion of palatable ﬁbrous compo-
nents at a restricted inclusion rate in the diet of obese cats represents a
good way to reduce food energy content and maintain a physiological
level of food intake.
5. The pet food market
Adequacy and safety of food supply are of great interest to
consumers (Buchanan et al., 2011). Generally, pet owners do not refuse
to provide foods that can support health and wellness of their animals,
but at the same time, doubt their safety. For instance, incorporation of
corn and wheat that have documented antioxidant and anticancer
activity (Wood et al., 1994) into pet foods has been perceived as
negative by a subgroup of pet owners who believe that they are of lower
quality or of poor nutritional value for dogs and cats, despite them
matching the Association of American Feed Control Oﬃcials (AAFCO)
standards (Carter et al., 2014). Pet owners have shown increased
interest in holistic, natural diets containing wholesome ingredients,
such as oats (Avena sativa) and barley (Hordeum vulgare), which can
A. Di Cerbo et al. Research in Veterinary Science 112 (2017) 161–166
reduce the risk of obesity (Jones and Engleson, 2010) and prevent
diabetes mellitus (the greater the intake of whole grains is, the lower
the fasting insulin levels are likely to be) (Pereira et al., 2002). Besides
food nutrition-related beneﬁts, safety issues should also be taken into
account. In recent years, pet food safety has represented a substantial
challenge because of the direct impact of food contaminations on both
animals and humans (FDA, 2005). Such contaminations could also lead
to nutritional deﬁciencies despite a correct diet formulation. However,
the eﬀect of contaminations (caused, for instance, by microorganisms)
of pet foods on animal health has not been extensively investigated due
to the multitude of possible sources of contamination (LeJeune and
Hancock, 2001). Moreover, most commonly used pet foods in the UK
employ products of unknown animal origin including bovine, porcine
and chicken DNA in various proportions and combinations often not
explicitly indicated on the product labels (Maine et al., 2015). There-
fore, the pet food industry still has various challenges to overcome in
order to provide better nutriments to dogs and cats.
Due to a reduction in the number of family components in
industrialized countries, the role of pets such as dogs and cats as
‘family members’has gained increasing importance (Shepherd, 2008),
and their health and well-being have become a prominent challenge for
their owners (Buchanan et al., 2011). As a matter of fact, companion
animals, most commonly dogs and cats, provide a positive impact on
humans' emotional (Allen et al., 1991; Serpell, 1991) and physical
health (Friedmann and Thomas, 1995; Headey, 1999). Due to the
diﬃculty understanding pet food labels, consumers' education becomes
a key issue for the marketing of functional foods. In addition, research
on pet food is still scarce. Accurate claims on food labels help
consumers select products that satisfy their desire to promote animal
care and improve their pets' health. Food scientists and healthcare
professionals should therefore work together to improve consumers'
education by accurately characterizing new scientiﬁc developments or
achievements in nutrition. The ultimate success of functional pet foods
will depend on delivering bioactive components in a predictable, safe
and functional manner to eﬀectively reduce the risk of disease and
support the domestic animal's body. Future basic and applied nutri-
tional research should further explore the role and mechanism of
functional foods in dogs and cats.
The authors declare that they have no competing interests.
This article was not supported by any funding.
This article was not supported by grants. JCMM and GFA acknowl-
edge CONACyT for membership.
Adolphe, J.L., Drew, M.D., Huang, Q., Silver, T.I., Weber, L.P., 2012. Postprandial
impairment of ﬂow-mediated dilation and elevated methylglyoxal after simple but
not complex carbohydrate consumption in dogs. Nutr. Res. 32, 278–284 (New
Allen, K.M., Blascovich, J., Tomaka, J., Kelsey, R.M., 1991. Presence of human friends
and pet dogs as moderators of autonomic responses to stress in women. J. Pers. Soc.
Psychol. 61, 582–589.
Axelsson, E., Ratnakumar, A., Arendt, M.L., Maqbool, K., Webster, M.T., Perloski, M.,
Liberg, O., Arnemo, J.M., Hedhammar, A., Lindblad-Toh, K., 2013. The genomic
signature of dog domestication reveals adaptation to a starch-rich diet. Nature 495,
Blaiotta, G., Murru, N., Di Cerbo, A., Succi, M., Coppola, R., Aponte, M., 2016.
Commercially standardized process for probiotic “Italico”cheese production. Food
Sci. Technol. 79, 601–608.
Borneo, R., Leon, A.E., 2012. Whole grain cereals: functional components and health
beneﬁts. Food Funct. 3, 110–119.
Bosch, G., Hagen-Plantinga, E.A., Hendriks, W.H., 2015. Dietary nutrient proﬁles of wild
wolves: insights for optimal dog nutrition? Br. J. Nutr. 113 (Suppl), S40–S54.
Brennan, S.C., Cleary, L.J., 2005. The potential use of cereal (1 →3,1 →4)-β-d-glucans as
functional food ingredients. J. Cereal Sci. 42, 1–13.
Brugger, A., Lariviere, L.A., Mumme, D.L., Bushnell, E.W., 2007. Doing the right thing:
infants' selection of actions to imitate from observed event sequences. Child Dev. 78,
Buchanan, R.L., Baker, R.C., Charlton, A.J., Riviere, J.E., Standaert, R., 2011. Pet food
safety: a shared concern. Br. J. Nutr. 106 (Suppl. 1), S78–S84.
Carter, R.A., Bauer, J.E., Kersey, J.H., Buﬀ, P.R., 2014. Awareness and evaluation of
natural pet food products in the United States. J. Am. Vet. Med. Assoc. 245,
Cicero, A.F.G., Derosa, G., 2005. Rice bran and its main components: potential role in the
management of coronary risk factors. Curr. Top. Nutraceutical Res. 3, 29–46.
Cook, A., Arter, J., Jacobs, L.F., 2014. My owner, right or wrong: the eﬀect of familiarity
on the domestic dog's behavior in a food-choice task. Anim. Cogn. 17, 461–470.
Corbo, M.R., Bevilacqua, A., Petruzzi, L., Casanova, F.P., Sinigaglia, M., 2014. Functional
beverages: the emerging side of functional foods. Compr. Rev. Food Sci. Food Saf. 13,
Cortese, L., Annunziatella, M., Palatucci, A.T., Lanzilli, S., Rubino, V., Di Cerbo, A.,
Centenaro, S., Guidetti, G., Canello, S., Terrazzano, G., 2015. An immune-modulating
diet increases the regulatory T cells and reduces T helper 1 inﬂammatory response in
Leishmaniosis aﬀected dogs treated with standard therapy. BMC Vet. Res. 11, 295.
Delzenne, N.M., Kok, N., 2001. Eﬀects of fructans-type prebiotics on lipid metabolism.
Am. J. Clin. Nutr. 73, 456S–458S.
Destefanis, S., Giretto, D., Muscolo, M.C., Di Cerbo, A., Guidetti, G., Canello, S.,
Giovazzino, A., Centenaro, S., Terrazzano, G., 2016. Clinical evaluation of a
nutraceutical diet as an adjuvant to pharmacological treatment in dogs aﬀected by
Keratoconjunctivitis sicca. BMC Vet. Res. 12, 214.
Di Cerbo, A., Palmieri, B., 2015. Review: the market of probiotics. Pak. J. Pharm. Sci. 28,
Di Cerbo, A., Pezzuto, F., Palmieri, L., Palmieri, B., 2012. The use of probiotics in the end-
stage renal disease management. Minerva Biotec. 24, 155–170.
Di Cerbo, A., Pezzuto, F., Palmieri, L., Rottigni, V., Iannitti, T., Palmieri, B., 2013. Clinical
and experimental use of probiotic formulations for management of end-stage renal
disease: an update. Int. Urol. Nephrol. 45, 1569–1576.
Di Cerbo, A., Palmieri, B., Chiavolelli, F., Guidetti, G., Canello, S., 2014. Functional foods
in pets and humans. Int. J. Appl. Res. Vet. Med. 12, 192–199.
Di Cerbo, A., Laurino, C., Palmieri, B., Iannitti, T., 2015a. A dietary supplement improves
facial photoaging and skin sebum, hydration and tonicity modulating serum
ﬁbronectin, neutrophil elastase 2, hyaluronic acid and carbonylated proteins. J.
Photochem. Photobiol. B 144, 94–103.
Di Cerbo, A., Pezzuto, F., Canello, S., Guidetti, G., Palmieri, B., 2015b. Therapeutic
eﬀectiveness of a dietary supplement for management of halitosis in dogs. J. Vis. Exp.
Di Cerbo, A., Centenaro, S., Beribe, F., Laus, F., Cerquetella, M., Spaterna, A., Guidetti, G.,
Canello, S., Terrazzano, G., 2016. Clinical evaluation of an antiinﬂammatory and
antioxidant diet eﬀect in 30 dogs aﬀected by chronic otitis externa: preliminary
results. Vet. Res. Commun. 40, 29–38.
Di Cerbo, A., Sechi, S., Canello, S., Guidetti, G., Fiore, F., Cocco, R., 2017. Behavioral
Studies of functional foods and functional food-containing diets in cats.
Functional food/diet containing functional foods Health beneﬁts References
Apple pomace (10 and 20% apple pomace diet) ↓energy density
↓digestibility of crude protein
Fekete et al., 2001
Full-fat stabilized rice bran (260 g/kg) with 12.1% dry matter acid detergent ﬁber and 31.3% dry matter
neutral detergent ﬁber, casein (180 g/kg), lactalbumin 180 (g/kg), chicken fat (310.5 g/kg), taurine (3 g/
kg), vitamin mixture (10 g/kg), L-methionine (3 g/kg), L-arginine (3 g/kg), and mineral mixture (50 g/kg).
↓taurine levels in bloodstream
↑fecal excretion of conjugated bile
Stratton-Phelps et al.,
High-fat (45% calories from fat) or low-fat diet (23.8% calories from fat), soy ﬂakes and soy protein isolate,
turkey and turkey by-product meal, corn starch, oat meal, oat ﬁber, beef tallow, vitamins and minerals
↑fecal score and normal stools
Laﬂamme et al., 2011
A. Di Cerbo et al. Research in Veterinary Science 112 (2017) 161–166
disturbances: an innovative approach to monitor the modulatory eﬀects of a
nutraceutical diet. J. Vis. Exp. 119.
Fahnestock, M., Marchese, M., Head, E., Pop, V., Michalski, B., Milgram, W.N., Cotman,
C.W., 2012. BDNF increases with behavioral enrichment and an antioxidant diet in
the aged dog. Neurobiol. Aging 33, 546–554.
Fardet, A., 2010. New hypotheses for the health-protective mechanisms of whole-grain
cereals: what is beyond ﬁbre? Nutr. Res. Rev. 23, 65–134.
FDA, 2005. Diamond pet food recalled due to aﬂatoxin. In: Recall. Firm Press Release
Accessed december 19, Available from: www.fda.gov/Safety/Recalls/
Fekete, S., Hullar, I., Andrasofszky, E., Rigo, Z., Berkenyi, T., 2001. Reduction of the
energy density of cat foods by increasing their ﬁbre content with a view to nutrients'
digestibility. J. Anim. Physiol. Anim. Nutr. 85, 200–204.
Flickinger, E.A., Schreijen, E.M., Patil, A.R., Hussein, H.S., Grieshop, C.M., Merchen, N.R.,
Fahey Jr., G.C., 2003. Nutrient digestibilities, microbial populations, and protein
catabolites as aﬀected by fructan supplementation of dog diets. J. Anim. Sci. 81,
Friedman, M., 1996. Food browning and its prevention: an overview. J. Agric. Food
Chem. 44, 631–653.
Friedmann, E., Thomas, S.A., 1995. Pet ownership, social support, and one-year survival
after acute myocardial infarction in the Cardiac Arrhythmia Suppression Trial
(CAST). Am. J. Cardiol. 76, 1213–1217.
de Godoy, M.R., Bauer, L.L., Parsons, C.M., Fahey Jr., G.C., 2009. Select corn coproducts
from the ethanol industry and their potential as ingredients in pet foods. J. Anim. Sci.
Grzeskowiak, L., Endo, A., Beasley, S., Salminen, S., 2015. Microbiota and probiotics in
canine and feline welfare. Anaerobe 34, 14–23.
Guidetti, G., Di Cerbo, A., Giovazzino, A., Rubino, V., Palatucci, A.T., Centenaro, S.,
Fraccaroli, E., Cortese, L., Bonomo, M.G., Ruggiero, G., Canello, S., Terrazzano, G.,
2016. In vitro eﬀects of some botanicals with anti-inﬂammatory and antitoxic
activity. J. Immunol. Res. 2016, 5457010.
Hasler, C.M., 2000. The changing face of functional foods. J. Am. Coll. Nutr. 19,
Headey, B., 1999. Health beneﬁts and health cost savings due to pets: preliminary
estimates from an Australian National Survey. Soc. Indic. Res. 47, 233–243.
Hewson-Hughes, A.K., Hewson-Hughes, V.L., Colyer, A., Miller, A.T., Hall, S.R.,
Raubenheimer, D., Simpson, S.J., 2013. Consistent proportional macronutrient intake
selected by adult domestic cats (Felis catus) despite variations in macronutrient and
moisture content of foods oﬀered. J. Comp. Physiol. B Biochem. Syst. Environ.
Physiol. 183, 525–536.
Hussein, H.S., Flickinger, E.A., Fahey Jr., G.C., 1999. Petfood applications of inulin and
oligofructose. J. Nutr. 129, 1454S–1456S.
Iannitti, T., Palmieri, B., 2010. Therapeutical use of probiotic formulations in clinical
practice. Clin. Nutr. 29, 701–725.
Jenkins, A.L., Jenkins, D.J., Wolever, T.M., Rogovik, A.L., Jovanovski, E., Bozikov, V.,
Rahelic, D., Vuksan, V., 2008. Comparable postprandial glucose reductions with
viscous ﬁber blend enriched biscuits in healthy subjects and patients with diabetes
mellitus: acute randomized controlled clinical trial. Croat. Med. J. 49, 772–782.
Jones, J.M., Engleson, J., 2010. Whole grains: beneﬁts and challenges. Annu. Rev. Food
Sci. Technol. 1, 19–40.
Jonnalagadda, S.S., Harnack, L., Liu, R.H., McKeown, N., Seal, C., Liu, S., Fahey, G.C.,
2011. Putting the whole grain puzzle together: health beneﬁts associated with whole
grains—summary of American Society for Nutrition 2010 Satellite Symposium. J.
Nutr. 141, 1011S–1022S.
Kahlon, T.S., 2009. Rice bran: production, composition, functionality and food
applications, physiological beneﬁts. In: Boca Raton, U. (Ed.), Fiber Ingredients: Food
Applications and Health Beneﬁts. F Taylor & Francis Group, pp. 305 –322 (Cho, S. S.
Laﬂamme, D.P., Xu, H., Long, G.M., 2011. Eﬀect of diets diﬀering in fat content on
chronic diarrhea in cats. J. Vet. Intern. Med./Am. Coll. Vet. Intern. Med. 25,
Lamy, S., Ouanouki, A., Beliveau, R., Desrosiers, R.R., 2014. Olive oil compounds inhibit
vascular endothelial growth factor receptor-2 phosphorylation. Exp. Cell Res. 322,
Legrand-Defretin, V., 1994. Diﬀerences between cats and dogs: a nutritional view. Proc.
Nutr. Soc. 53, 15–24.
LeJeune, J.T., Hancock, D.D., 2001. Public health concerns associated with feeding raw
meat diets to dogs. J. Am. Vet. Med. Assoc. 219, 1222–1225.
Lyons, D.E., Young, A.G., Keil, F.C., 2007. The hidden structure of overimitation. Proc.
Natl. Acad. Sci. U. S. A. 104, 19751–19756.
Maine, I.R., Atterbury, R., Chang, K.C., 2015. Investigation into the animal species
contents of popular wet pet foods. Acta Vet. Scand. 57, 7.
Marshall-Pescini, S., Passalacqua, C., Miletto Petrazzini, M.E., Valsecchi, P., Prato-
Previde, E., 2012. Do dogs (Canis lupus familiaris) make counterproductive choices
because they are sensitive to human ostensive cues? PLoS One 7, e35437.
Michel, K.E., 2006. Unconventional diets for dogs and cats. Vet. Clin. North Am. Small
Anim. Pract. 36 (1269–1281), vi–vii.
Morris, J.G., 2002. Idiosyncratic nutrient requirements of cats appear to be diet-induced
evolutionary adaptations. Nutr. Res. Rev. 15, 153–168.
Morris, P.J., Salt, C., Raila, J., Brenten, T., Kohn, B., Schweigert, F.J., Zentek, J., 2012.
Safety evaluation of vitamin A in growing dogs. Br. J. Nutr. 108 (10), 1800–1809.
National Research Council, Division on Earth and Life Studies, Board on Agriculture and
Natural Resources, Committee on Animal Nutrition, Subcommittee on Dog and Cat
Nutrition, 2006. Nutrient Requirements of Dogs and Cats. National Academies Press.
Pasquini, A., Roberti, S., Meucci, V., Luchetti, E., Canello, S., Guidetti, G., Biagi, G., 2013.
Association between body condition and oxidative status in dogs. Food Nutr. Sci. 4,
Pereira, M.A., Jacobs Jr., D.R., Pins, J.J., Raatz, S.K., Gross, M.D., Slavin, J.L., Seaquist,
E.R., 2002. Eﬀect of whole grains on insulin sensitivity in overweight
hyperinsulinemic adults. Am. J. Clin. Nutr. 75, 848–855.
Plantinga, E.A., Bosch, G., Hendriks, W.H., 2011. Estimation of the dietary nutrient
proﬁle of free-roaming feral cats: possible implications for nutrition of domestic cats.
Br. J. Nutr. 106 (Suppl. 1), S35–S48.
Ponzio, P.C., Canello, S., Guidetti, G., Sferra, C., Macchi, E., 2013. Correlation between
reproductive eﬃciency (semen quality and endocrine function) and dietary
supplementation in dog breeding. Veterinaria 27, 15–22.
Rebello, C.J., Liu, A.G., Greenway, F.L., Dhurandhar, N.V., 2013. Dietary strategies to
increase satiety. Adv. Food Nutr. Res. 69, 105–182.
Reimer, R.A., Maurer, A.D., Eller, L.K., Hallam, M.C., Shaykhutdinov, R., Vogel, H.J.,
Weljie, A.M., 2012. Satiety hormone and metabolomic response to an intermittent
high energy diet diﬀers in rats consuming long-term diets high in protein or prebiotic
ﬁber. J. Proteome Res. 11, 4065–4074.
Ricciardi, A., Blaiotta, G., Di Cerbo, A., Succi, M., Aponte, M., 2014. Behaviour of lactic
acid bacteria populations in Pecorino di Carmasciano cheese samples submitted to
environmental conditions prevailing in the gastrointestinal tract: evaluation by
means of a polyphasic approach. Int. J. Food Microbiol. 179, 64–71.
Romano, A., Blaiotta, G., Di Cerbo, A., Coppola, R., Masi, P., Aponte, M., 2014. Spray-
dried chestnut extract containing Lactobacillus rhamnosus cells as novel ingredient for
a probiotic chestnut mousse. J. Appl. Microbiol. 116, 1632–1641.
van Rooijen, C., Bosch, G., van der Poel, A.F., Wierenga, P.A., Alexander, L., Hendriks,
W.H., 2013. The Maillard reaction and pet food processing: eﬀects on nutritive value
and pet health. Nutr. Res. Rev. 26, 130–148.
Ryan, E.P., 2011. Bioactive food components and health properties of rice bran. J. Am.
Vet. Med. Assoc. 238, 593–600.
Sechi, S., Chiavolelli, F., Spissu, N., Di Cerbo, A., Canello, S., Guidetti, G., Fiore, F., Cocco,
R., 2015. An antioxidant dietary supplement improves brain-derived neurotrophic
factor levels in serum of aged dogs: preliminary results. J. Vet. Med. 2015, 412501.
Sechi, S., Di Cerbo, A., Canello, S., Guidetti, G., Chiavolelli, F., Fiore, F., Cocco, R., 2017.
Eﬀects in dogs with behavioural disorders of a commercial nutraceutical diet on
stress and neuroendocrine parameters. Vet. Rec. 180, 18.
Serpell, J., 1991. Beneﬁcial eﬀects of pet ownership on some aspects of human health and
behaviour. J. R. Soc. Med. 84, 717–720.
Shepherd, A.J., 2008. Results of the 2006 AVMA survey of companion animal ownership
in US pet-owning households. J. Am. Vet. Med. Assoc. 232, 695–696.
Shiby, V.K., Mishra, H.N., 2013. Fermented milks and milk products as functional
foods—a review. Crit. Rev. Food Sci. Nutr. 53, 482–496.
Slavin, J.L., Lloyd, B., 2012. Health beneﬁts of fruits and vegetables. Adv. Nutr. 3,
Slavin, J.L., Jacobs, D., Marquart, L., Wiemer, K., 2001. The role of whole grains in
disease prevention. J. Am. Diet. Assoc. 101, 780–785.
Spears, J.K., Grieshop, C.M., Fahey Jr., G.C., 2004. Evaluation of stabilized rice bran as an
ingredient in dry extruded dog diets. J. Anim. Sci. 82, 1122–1135.
Stratton-Phelps, M., Backus, R.C., Rogers, Q.R., Fascetti, A.J., 2002. Dietary rice bran
decreases plasma and whole-blood taurine in cats. J. Nutr. 132, 1745S–1747S.
Swanson, K.S., Grieshop, C.M., Flickinger, E.A., Bauer, L.L., Healy, H.P., Dawson, K.A.,
Merchen, N.R., Fahey Jr., G.C., 2002. Supplemental fructooligosaccharides and
mannanoligosaccharides inﬂuence immune function, ileal and total tract nutrient
digestibilities, microbial populations and concentrations of protein catabolites in the
large bowel of dogs. J. Nutr. 132, 980–989.
Swanson, K.S., Schook, L.B., Fahey Jr., G.C., 2003. Nutritional genomics: implications for
companion animals. J. Nutr. 133, 3033–3040.
Tidu, L., Bacciu, N., Rucco, G., Nardi, S., Santoro, M., Renaville, B., 2013. Plasma fatty
acid proﬁles during the ﬁrst year in dogs with and without hip dysplasia: preliminary
results. Trends Vet. Sci. 35–39.
Topal, J., Gergely, G., Miklosi, A., Erdohegyi, A., Csibra, G., 2008. Infants' perseverative
search errors are induced by pragmatic misinterpretation. Science 321, 1831–1834
(New York, N.Y.).
Tungland, B.C., 2003. Fructooligosaccharides and other fructans: structures and
occurrence, production, regulatory aspects, food applications, and nutritional health
signiﬁcance, oligosaccharides in food and agriculture. Am. Chem. Soc. 135–152.
Van Loo, J., Cummings, J., Delzenne, N., Englyst, H., Franck, A., Hopkins, M., Kok, N.,
Macfarlane, G., Newton, D., Quigley, M., Roberfroid, M., van Vliet, T., van den
Heuvel, E., 1999. Functional food properties of non-digestible oligosaccharides: a
consensus report from the ENDO project (DGXII AIRII-CT94-1095). Br. J. Nutr. 81,
Wenk, C., 2001. The role of dietary ﬁbre in the digestive physiology of the pig. Anim.
Feed Sci. Technol. 90, 21–33.
Wilson, T.A., DeSimone, A.P., Romano, C.A., Nicolosi, R.J., 2000. Corn ﬁber oil lowers
plasma cholesterol levels and increases cholesterol excretion greater than corn oil and
similar to diets containing soy sterols and soy stanols in hamsters. J. Nutr. Biochem.
Wood, P.J., Braaten, J.T., Scott, F.W., Riedel, K.D., Wolynetz, M.S., Collins, M.W., 1994.
Eﬀect of dose and modiﬁcation of viscous properties of oat gum on plasma glucose
and insulin following an oral glucose load. Br. J. Nutr. 72, 731–743.
Zicker, S.C., 2008. Evaluating pet foods: how conﬁdent are you when you recommend a
commercial pet food? Top. Companion Anim. Med. 23, 121–126.
A. Di Cerbo et al. Research in Veterinary Science 112 (2017) 161–166