Objective—To determine whether feeding activated
charcoal, Yucca schidigera, and zinc acetate would
ameliorate the frequency and odor characteristics of
flatulence in dogs.
Design—In vitro screening of active agents followed
by a randomized controlled trial.
Animals—8 adult dogs.
Procedure—A fecal fermentation system was used
to assess the effects of activated charcoal, Yucca
schidigera, and zinc acetate alone and in combination
on total gas production and production of hydrogen
sulfide, the primary determinant of flatus malodor in
dogs. All 3 agents were subsequently incorporated
into edible treats that were fed 30 minutes after the
dogs ate their daily rations, and the number, frequency,
and odor characteristics of flatulence were measured
for 5 hours, using a device that sampled rectal
gases and monitored hydrogen sulfide concentrations.
Results—Total gas production and number and frequency of flatulence episodes were unaffected by any
of the agents. Production of hydrogen sulfide in vitro
was significantly reduced by charcoal, Yucca schidigera,
and zinc acetate by 71, 38, and 58%, respectively,
and was reduced by 86% by the combination of
the 3 agents. Consumption of the 3 agents was associated
with a significant decrease (86%) in the percentage
of flatulence episodes with bad or unbearable
odor and a proportional increase in the percentage
of episodes of no or only slightly noticeable odor.
Conclusions and Clinical Relevance—Results suggest that activated charcoal, Yucca schidigera, and
zinc acetate reduce malodor of flatus in dogs by altering
the production or availability of hydrogen sulfide in
the large intestine. (J Am Vet Med Assoc 2001;218:
Objective—To develop a noninvasive method for the
in vivo assessment of flatulence in dogs.
Animals—8 adult dogs.
Procedure—Rectal gases were collected via a perforated
tube held close to each dog's anus and attached
to a monitoring pump fitted with a sensor that recorded
hydrogen sulfide concentrations every 20 seconds.
Patterns of flatulence were monitored for 14
hours after feeding on 4 days, and within- and
between-dog variation was assessed over 4 hours on
4 consecutive days. Rate of hydrogen sulfide production
(flatulence index) and frequency and number of
emissions were evaluated as potential indicators of
flatus characteristics. An odor judge assigned an odor
rating to each flatulence episode, and the relationship
between that rating and hydrogen sulfide concentration
Results—Flatulence patterns varied within and
between dogs. Variation was most pronounced for flatulence
index; mean coefficients of variance within
dogs over time and between dogs on each day were
75 and 103%, respectively. Flatus with hydrogen sulfide
concentrations > 1 parts per million could be
detected by the odor judge, and severity of malodor
was highly correlated with hydrogen sulfide concentration.
Odor ratings were accurately predicted by use of
the equation 1.51 × hydrogen sulfide concentration0.28.
Conclusions and Clinical Relevance—The technique
described in this report appears to provide sensitive,
reliable, and relevant data and will enable further
studies of the factors that influence flatulence in
dogs. Use of this technique also has the potential to
aid in investigations of colonic physiology and pathology.
(Am J Vet Res 2001;62:1014–1019).