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Beynen AC, 2017. Diet and doggy breath

Creature Companion 2017; October: 30-31.
Anton C. Beynen
Diet and doggy breath
Bad breath is a common condition in companion dogs and an annoying problem for owners.
Mouth odor is usually caused by bacteria that produce volatile sulfur compounds with offensive
smell. The bacteria can be controlled by regular toothbrushing and professional cleaning, which
improves breath in most cases. Suitable dry foods and treats can further help combat stinky
breath. The marketplace offers products for fresh breath, but their efficacy is usually unknown
To evaluate breath-freshening foods and treats, oral malodor in dogs has to be quantified. Human
perception, by sniffing and scoring of mouth air, represents the real-life situation. Mouth air can
also be examined with a sulfur monitor. The results of sniff and sulfur tests are reasonably
interchangeable as they move in tandem. Worsening bad breath goes hand in hand with
increasing plaque and calculus on the tooth surface and with more severe gum inflammation.
The type of diet and certain dental chews can influence dog breath. Experiments showed that
large-sized kibbles with enhanced teeth contact can improve breath smell. Dogs given chew treats
in addition to their base diet had less offensive breath. The abrasiveness of dental kibbles and
chews brings about mechanical removal of dental plaque. There is no solid evidence that herbal
bacteria killers in dog food contribute to control of oral malodor.
On a scale of 0 to 10, with 0 indicating no noticeable malodor and 10 representing extremely
intensive malodor, an effective dental diet or chew may improve average breath odor by about
one scale unit. The improvement is perceivable by dog owners, but seems small, while many
individual animals will respond below average. Nevertheless, effective dental diets and treats help
freshen breath between toothbrushing.
Halitosis and dental disease
Halitosis can have an oral or non-oral etiology. Hydrogen sulfide and methylmercaptan, produced by
certain bacteria in the oral cavity, are seen as the most common reason for bad breath. Oral
malodor in dogs is quantified by human perception or by measuring breath volatile sulfur
compounds. Sensory assessment is the gold standard as it simulates everyday practice.
Sensory ratings and breath sulfur concentrations are linearly related, but the explained variation is
only about 50% (1, 2). Increasing degrees of dental plaque, calculus and gingivitis are associated with
higher breath scores (3) and sulfur concentrations (4). Dental prophylaxis in dogs reduces breath
sulfur (5), but mechanical removal of plaque by daily toothbrushing has a durable impact (2, 6).
Canine periodontal disease unquestionably leads to halitosis.
Food texture
In a double-blinded, cross-over trial with 7-day periods, 20 dogs were fed a reference dry food or a
veterinary dental diet (7). The dental food consisted of large, abrasive, more fibrous kibbles with
enhanced resistance to crumbling on chewing, thus providing mechanical plaque control. On a 0-10
scale, mean baseline sensory malodor score was 2.6. The dental diet induced a statistically
significant improvement of 0.5 units. When compared with the same reference food, the dental food
has been shown to reduce dental plaque by 19% after one week (8) and by 39% after six months (9).
For four months, dogs were fed one of three diets: the above-mentioned textural kibbles, a canned
food or a mixture (10). Compared with the wet food, the kibbles alone or as inclusion were found to
reduce halitosis. No reference was made to score values and blinding of scoring.
Herbal supplements
Switching from a control diet to the same diet with an extract of green tea leaves diminished breath
sulfur in dogs and cats after 7 weeks (11, 12). There also was a decrease in gingivitis and plaque-
derived Porphyromonas, which produces volatile sulfur compounds. However, the studies lacked
control groups and reported breath sulfur concentrations are improbably high.
In a cross-over experiment with 30-day periods, 32 dogs were fed a dry food without or with herbal
supplement (13). To formulate the test food, chicken meal in a commercial diet was replaced by
6.5% of a complex herb mixture and fish meal. Breath hydrogen sulfide and methylmercaptan were
markedly reduced by the test diet, but the presented concentrations are improbably low.
Mixing Streptococcus salivarius tablets with the morning meal of dogs lowered malodor scores (14).
In oral gas, hydrogen sulfide and methylmercaptan were undetectable throughout. Possibly, the
tablets were swallowed intact and affected extra-oral halitosis.
Dental chews
Addition of different types of dental chews to a dry diet reduced breath sulfur in dogs (6, 15, 16).
Prior to testing, the dogs’ teeth were scaled and polished. There were 17-30 dogs per treatment,
which lasted 4 weeks. Average control sulfur concentrations corresponded with 3.6 on a 0-10
sensory scale (2) while chew-mediated lowering was 1.6 units (Note). In another study (17),
undefined halimeter scores pointed to a smaller chew effect on halitosis.
Feeding a dental chew six days per week has been shown to maintain low breath sulfur for up to 21
months (15). A once-daily chew regimen appears to control oral malodor as it preserved a low, flat
diurnal pattern of breath sulfur (18). All the chews that improved halitosis also reduced
accumulation of dental deposits, just like severity of gingivitis (6, 15-17).
Topical (19-22) or pill (5) administration of various antimicrobials reduced halitosis levels in dogs.
Within the range of 2 to 8 (on a 0-10 scale) for organoleptic halitosis scores, a difference in volatile
sulfur compound concentration in dog breath of 1 ppb equals a score change of 0.041 unit as based
on the linear regression line (2). After 4 weeks of feeding a dry diet without or with dental chew, the
group-mean control versus test sulfur concentrations were 125 versus 102 (6), 160 versus 126 (15)
and 128 versus 70 ppb (16). The mean chew effect of 38.3 ppb lowering corresponds with a decrease
of the halitosis score by 1.57 unit (38.3 x 0.041).
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3. Simone AJ, Logan EI, Livgren R, Suelzer M. Oral malodor in beagles: association with indicators of
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9. Logan EI, Finney O, Hefferren JJ. Effects of a dental food on plaque accumulation and gingival
health in dogs. J Vet Dent 2002; 19: 15-18.
10. Clarke DE. Plaque and calculus accumulation in respect to feeding canned diets, and Hills t/d diet
as a treat compared to 100% of the diet. Proc 12th Ann Vet Dent Forum 1998, pp 122-123.
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14. Matsumoto H, Okusa T, Yoshimatsu H, Mochizuki Y, Teshima T, Koyama H. A basic study of the
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ResearchGate has not been able to resolve any citations for this publication.
Full-text available
Halitosis is a common complaint involving social and communicational problems in humans and also affects the pet-owner relationship. In this randomized placebo-controlled crossover clinical evaluation, we assessed the effectiveness of a dedicated dietary supplement to improve chronic halitosis in 32 dogs of different breeds and ages. This protocol describes how to evalute the presence of oral volatile suphur compunds, e.g. methyl mercaptan, hydrogen sulfide and dimethyl sulfide, by means of a portable gas chromatograph device coupled with a syringe, which was used to collect the breath, and a dedicated software, which allows the operator to monitor each compound concentration during each measurement, in a relatively short time (8 min). A significant modification of halitosis parameters was observed after 30 days since the beginning of treatment (p <0.05), while a long-lasting effect was still observed even 20 days after the suspension of the treatment. Portable gas chromatograph, which is also widely used in clinical practice, can be therefore used to confirm and control halitosis in humans and animals. Even though human and animal species present some differences, this innovative and alternative therapy for halitosis management might be extended to human clinical practice as an adjuvant dietary approach.
Full-text available
Objective: To evaluate the effectiveness of a topically applied gel containing essential oils (menthol and thymol) and polyphenolic antioxidants (phloretin and ferulic acid) for reducing halitosis in dogs. Animals: 20 dogs. Procedures: A blinded crossover clinical trial was conducted. Dogs received a dental cleaning and examination (periodontal examination including periodontal probing and assessments of plaque, calculus, and gingivitis). Owners then applied a gel (active or placebo) to oral soft tissues twice daily for a 4-week period. Teeth of the dogs were cleaned again, and owners applied the other gel for a 4-week period. Clinicians scored halitosis immediately after the initial cleaning and at 4 and 8 weeks, and owners scored halitosis weekly. Results: Halitosis assessment by clinicians revealed that both groups had improvement in halitosis scores. Two dogs were removed because of owner noncompliance. In the active-to-placebo group (n = 9), halitosis was significantly reduced during application of the active gel but increased during application of the placebo. Seven of 9 owners reported increased halitosis when treatment was changed from the active gel to the placebo. In the placebo-to-active group (n = 9), halitosis decreased during application of the placebo and continued to decrease during application of the active gel. Seven of 9 owners reported a decrease in halitosis with the active gel. Conclusions and clinical relevance: An oral topically applied gel with essential oils and polyphenolic antioxidants applied daily after an initial professional dental cleaning decreased oral malodor in dogs.
Full-text available
Canine oral malodor is a common complaint among dog owners. The aim of this study was to test the effect of an antimicrobial herbal palatal mucoadhesive tablet on oral malodor in dogs. Twelve dogs suffering from oral malodor participated in the study. Palatal mucoadhesive tablets were prepared with or without the herbal medicinals: Echinacea (Echinacea angustifolia), Mastic gum (Pistacia lentiscus), Lavender (Lavandula angustifolia) and Sage (Salvia officinalis). Measurement included odor judge scores (two judges) and volatile sulfide compounds (VSC) readings by a sulfide monitor (Halimeter®). Application of the palatal adhesive tablets containing herbal formulation resulted in a 60% reduction in oral malodor scores and 73% in VSC levels. These results suggest that the palatal mucoadhesive tablets containing herbal formulation may serve as an effective means of treatment for oral malodor in dogs.
Asaccharolytic pigmented Porphyromonas strains were isolated from the plaque of dogs with gingivitis and periodontitis. Various species of Porphyromonas , including P. endodontalis , P. gingivalis , P. circumdentaria and unclassified species, were detectable. Canine Porphyromonas were sensitive to Japanese green tea extract (JGTE). We examined the effects of dietary JGTE on periodontal diseases. A special diet was prepared on the basis of the minimum inhibitory concentration (MIC: 0.8 mg/ml) of JGTE to several canine Porphyrmonas species. Growth of all Porphyromonas isolates was inhibited at this concentration. After 2 mths, the percentage of canine Porphyromonas significantly decreased in the plaque microbiota. Concurrently with the observed decrease in percentage of these bacteria, gingival inflammation was inhibited. However. no change in the calculus index was recorded during the observation period. Levels of oral malodour varied among the dogs and diet with JGTE was effective in the inhibition of oral malodour. We concluded that JGTE was effective in the inhibition of canine periodontal diseases. Keywords: green tea extract; canine Porphyromonas : periodontal disease
OBJECTIVE To determine whether consumption of a single dental treat with specific mechanical properties and active ingredients would provide a 24-hour effect on dental plaque bacteria and halitosis in dogs. ANIMALS 10 dogs of various breeds from a privately owned colony that had received routine dental scaling and polishing 4 weeks before the study began. PROCEDURES Dogs were randomly assigned to receive 1 placebo or dental treat first. A 4-week washout period was provided, and then dogs received the opposite treatment. Oral plaque and breath samples were collected before and 0.5, 3, 12, and 24 hours after treat consumption. Volatile sulfur compounds (VSCs) concentration was measured in breath samples. Total aerobic, total anaerobic, Porphyromonas gulae, Prevotella intermedia–like, Tannerella forsythia , and Fusobacterium nucleatum bacterial counts (measured via bacterial culture) and total live bacterial counts, total live and dead bacterial counts, and bacterial vitality (measured via quantitative real-time PCR assay) were assessed in plaque samples. RESULTS Compared with placebo treat consumption, dental treat consumption resulted in a significant decrease in breath VSCs concentration and all plaque bacterial counts, without an effect on bacterial vitality. Effects of the dental treat versus the placebo treat persisted for 12 hours for several bacterial counts and for 24 hours for breath VSCs concentration. CONCLUSIONS AND CLINICAL RELEVANCE Although clinical benefits should be investigated in larger scale, longer-term studies, results of this study suggested that feeding the evaluated dental treat may help to decrease oral bacterial growth in dogs for 12 hours and oral malodor for 24 hours. A feeding interval of 12 hours is therefore recommended.
We examined the effect of catechin diet on gingivitis in cats. Gingival inflammation, oral malodor, and percentage of Porphy-romonas were decreased after feeding of diet with catechin compounds. We sug-gest that feline gingivitis can be controlled by phytomedical activities of catechin in pet food. Twenty nine cats affected with gingivitis were fed either a catechin diet of 0.8 mg/g or 0.4 mg/g of catechin or a control diet and assessed for gingival inflamma-tion, oral malodor, and percentage of the genus Porphyromonas present. The catechin diet showed an anti-inflammatory effect, a deodorant effect, and a decrease in Porphy-romonas compared with the control diet. This suggests that the catechin in diet has the potential to reduce gingivitis resulting from the bacterial growth and virulence factors in cats.
An independent study was conducted to determine and quantify the oral care benefits of a daily edible dental chew in dogs as measured by plaque and calculus control, gingival indices, and oral malodor. A "clean mouth" test model was used comparing a commercial dry diet and a commercial dry diet plus one dental chew per day. The dental chew tested was representative of a retail canine dental chew. The test dental chew was a green-colored dental dog chew with a flexible texture that can be readily chewed by dogs. They are made with a knuckle bone shape on one end and a toothbrush shape on the other end. Sixty adult dogs were allocated in either control or test groups based on plaque stratification and studied for 28-days. The test group (30 dogs) received a dry diet and 1 dental chew each day. The control group (30 dogs) received the same dry diet only. At the end of the study, measurements of plaque and calculus accumulation and evaluations of oral malodor and gingival heath were performed. Adding a dental chew to the diet resulted in statistically significant reductions in plaque and calculus accumulation, and oral malodor while improving gingival indices.
Periodontal disease is an oral disease common in middle-aged dogs and cats, with halitosis being the most common sign. There are many commercial products containing chlorhexidine, cetylpyridinium chloride (CPC), zinc salts and essential oils for controlling halitosis and periodontal disease. CPC is a quaternary ammonium compound and has a broad spectrum antimicrobial activity. In this study, oral spray (OS) and gel (OG) containing CPC was applied to the dogs’ teeth twice daily for 3 weeks, and their effect in controlling periodontal disease and halitosis was examined. In the 3-week study, OS and OG were significantly effective in controlling plaque, calculus, and halitosis. Therefore, the OS and OG containing CPC were effective in controlling periodontal disease and halitosis in dogs.
Sixteen toy breed dogs completed a parallel, 70-day two-period, cross-over design clinical study to determine the effect of a vegetable dental chew on gingivitis, halitosis, plaque, and calculus accumulations. The dogs were randomly assigned into two groups. During one study period the dogs were fed a non-dental dry diet only and during the second study period were fed the same dry diet supplemented by the daily addition of a vegetable dental chew. Daily administration of the dental chew was shown to reduce halitosis, as well as, significantly reduce gingivitis, plaque and calculus accumulation and therefore may play a significant role in the improvement of canine oral health over the long-term.
To measure production of volatile sulfur compounds (VSC) responsible for halitosis on the crown surface of the maxillary fourth premolar of dogs with gingivitis. 28 dogs owned by veterinary students who complained that their dogs had halitosis. Clinical dental indices (plaque index, calculus index, and gingival index) were measured on the most diseased maxillary fourth premolar tooth. Production of VSC from the crown surface of the tooth was recorded by use of a portable sulfide monitor. Measurements were performed several times on each dog over a 2-month period, resulting in 98 series of measurements. Dogs with heavy amounts of plaque or calculus (plaque and calculus indices of 2 or 3) had significantly higher VSC readings than did dogs with no visible plaque and calculus accumulation. Significant (P = 0.0008) correlation was found between VSC measurements and plaque index, and significant correlations were found between VSC measurements and calculus index (P = 0.00118) and gingival index (P = 0.00475). VSC production recorded on the crown of maxillary fourth premolar teeth of dogs with gingivitis is significantly correlated with the amount of plaque and calculus accumulation and with severity of gingivitis. VSC measurements on tooth surfaces could be used as a site-specific method to assess, in conjunction with clinical dental variables, effectiveness of dental hygiene products.