Small animal deworming protocols, client education, and veterinarian perception of zoonotic parasites in western Canada

Abstract

Questionnaires were mailed to veterinarians in western Canada to determine dog and cat deworming protocols and the association between perceived zoonotic risk and perceived prevalence of endoparasites and deworming protocols. Of the responding veterinarians (545), 13% and 39% recommended deworming protocols consistent with established guidelines for puppies and kittens, respectively. Mixed animal practitioners and high-perceived prevalence of Toxocara cati were associated with increased appropriate kitten deworming (P < 0.01 and P = 0.04, respectively). High-perceived zoonotic concern of Toxocara canis was associated with increased appropriate puppy deworming (P = 0.01). Sixty-eight percent of veterinarians noted an established hospital deworming protocol, although only 78% followed the protocol. Forty-four percent of veterinarians stated they discussed with all clients the zoonotic risk of animal-derived endoparasites, whereas the remainder discussed it only under particular circumstances or not at all. Most small animal deworming protocols recommended in western Canada begin too late to inhibit endoparasite shedding. Increased educational efforts directed at veterinarians are warranted.

Full text

CVJ / VOL 48 / MARCH 2007 269
Article
Small animal deworming protocols, client education, and veterinarian
perception of zoonotic parasites in western Canada
Jason W. Stull, Anthony P. Carr, Bruno B. Chomel, Roy D. Berghaus, David W. Hird
Abstract — Questionnaires were mailed to veterinarians in western Canada to determine dog and cat deworming
protocols and the association between perceived zoonotic risk and perceived prevalence of endoparasites and
deworming protocols. Of the responding veterinarians (545), 13% and 39% recommended deworming protocols
consistent with established guidelines for puppies and kittens, respectively. Mixed animal practitioners and high-
perceived prevalence of Toxocara cati were associated with increased appropriate kitten deworming (P , 0.01 and
P = 0.04, respectively). High-perceived zoonotic concern of Toxocara canis was associated with increased appropri-
ate puppy deworming (P = 0.01). Sixty-eight percent of veterinarians noted an established hospital deworming
protocol, although only 78% followed the protocol. Forty-four percent of veterinarians stated they discussed with
all clients the zoonotic risk of animal-derived endoparasites, whereas the remainder discussed it only under par-
ticular circumstances or not at all. Most small animal deworming protocols recommended in western Canada begin
too late to inhibit endoparasite shedding. Increased educational efforts directed at veterinarians are warranted.
Résumé — Protocoles de vermifugation chez les petits animaux, éducation des clients et perception de
l’importance des parasites zoonotiques par les vétérinaires de l’ouest du Canada. Des questionnaires ont été
postés à des vétérinaires de l’ouest du Canada afin d’établir des protocoles de vermifugation chez les chiens et les
chats et de déterminer l’association entre le risque zoonotique perçu, la perception de la prévalence des endoparasites
et les protocoles de vermifugation. Sur les 545 vétérinaires répondants, 13 % et 39 % ont respectivement recommandé
des protocoles de vermifugation compatibles avec les normes établies pour les chiots et les chatons. Les vétérinaires
de pratique mixte et une perception élevée de la prévalence de Toxocara cati étaient associés à une augmentation des
pratiques appropriées de vermifugation (P , 0,01 et P = 0,04, respectivement). Une préoccupation zoonotique
élevée de Toxocara canis était associée à une augmentation de protocoles appropriés de vermifugation des chiots
(P = 0,01). Soixante-huit pour cent des vétérinaires inscrivaient un protocole de vermifugation établi par l’hôpital
alors que seulement 78 % le suivaient. Quarante-quatre pour cent des vétérinaires mentionnaient qu’ils discutaient
des risques zoonotiques reliés aux endoparasites des animaux avec leurs clients alors que les autres en discutaient
uniquement lors de circonstances particulières ou pas du tout. La majorité mentionnait que les protocoles de
vermifugation des petits animaux utilisés dans l’ouest du Canada commençaient trop tard pour éviter l’excrétion
des endoparasites. De plus grands efforts d’éducation à l’intention des vétérinaires sont justifiés.
(Traduit par Docteur André Blouin)
Can Vet J 2007;48:269–276
Introduction
E
ndoparasites are commonly encountered in small ani-
mal veterinary medicine (1). Reports of endoparasite
prevalence in domestic small animals range from 5% to 70%
worldwide (1–7), with similar findings in Canada (8–12,
unpublished data — Stull, 2003); differences in study location,
year conducted, status of animal ownership, and methodology
are responsible for the wide range in published endoparasite
prevalence. Clinical signs in infected animals vary from none
(13,14) to severe (fatal anemia, emaciation). The life cycles
of endoparasites commonly encountered early in life, such as
Toxocara canis (15,16), Toxocara cati (17), and Ancylostoma
caninum (16) are well documented. The Centers for Disease
Control and Prevention (18) recommends treatments at 2,
School of Veterinary Medicine, University of California, One Shields Ave., Davis, California 95616, USA (Stull, Chomel, Berghaus,
Hird); Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan,
52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4 (Carr).
Address all correspondence and reprint requests to Dr. Jason Stull; e-mail: Jason.Stull@dhhs.state.nh.us
Dr. Stull’s current address is Public Health Veterinarian, Department of Health and Human Services/Bureau of Disease Control,
29 Hazen Drive, Concord, New Hampshire 03301-6504, USA.
This study was funded in part by Bayer Pharmaceuticals.

270 CVJ / VOL 48 / MARCH 2007
A R T I C LE
4, 6, and 8 wk of age for puppies and 3, 5, 7, and 9 wk of age
for kittens to prevent establishment of T. canis, T. cati, and
A. caninum infections. Given a relatively lower risk of acquisi-
tion of roundworms and hookworms in kittens than in puppies,
6 wk of age has been noted as an acceptable age for commencing
deworming in kittens (19). Concurrent treatment of the bitch
every 2 wk during the 8-week postwhelping period is important
to eliminate reactivated larvae (20) and horizontal transmis-
sion from shedding neonates (21). Prophylactic treatment is
recommended during the postwhelping/neonatal time period,
since negative fecal examinations may be misleading. Regular
treatment/screening for endoparasites is warranted, because
repeated infection can occur throughout life (22). Similar
neonate and adult deworming guidelines are endorsed by the
Companion Animal Parasite Council (23).
In addition to the hazards endoparasites pose to the animal
community, humans can be infected. Manifestations of these
zoonotic diseases vary with the causative agent, but include
visual (24), neurologic (25), dermatologic (26), respiratory
(27), and enteric disorders (28), all of which have a dramatic
impact on human health and the economy (29). Seroprevalence
studies have documented substantial exposure to Toxocara in
Canadians (30–32); however, as neither this disease nor its
associated syndromes (visceral larval migrans — VLM, ocular
larval migrans — OLM) are reportable by law, it is difficult
to determine the true incidence in the population. Estimates
suggest 10 000 cases of VLM and 700 cases of OLM occur
each year in the United States (29). Several factors predispose
humans to zoonotic transmission, including pica (25), dog
ownership/contact (24,25,33), socio-economic status, and
geographic location (34).
Despite the high prevalence of zoonotic endoparasites in
domestic small animals, the significant public health risk they
pose, and ease of parasite removal through appropriate deworm-
ing protocols, previous studies have indicated poor veterinary
compliance in applying appropriate deworming protocols
(35–37). Although some studies have examined small animal
deworming protocols, veterinarian-perceived parasite prevalence
(37), and perceived zoonotic risk (37,38), it is not entirely
understood why poor deworming-compliance persists and how
to correct it. Previous studies examining deworming protocols
were limited geographically (37) and temporally (35,36), so it
cannot be assumed that the findings from these studies are valid
today in other locations. Furthermore, although studies have
examined veterinarian-perceived risk and veterinarian-perceived
prevalence of various endoparasites, none has determined their
association with recommended deworming protocols. Attaining
a better understanding of current deworming practices and
potential risk factors for deviation from an appropriate protocol
will enable targeted education of the veterinary community and
aid in the identification of further areas of research.
The objective of this study was to utilize questionnaires
mailed to all small and mixed animal veterinarians in western
Canada to determine current recommended small animal
deworming protocols and to compare these protocols with
established guidelines. Data were collected on veterinarian-
perceived prevalence and veterinarian-perceived zoonotic con
-
cern of several endoparasites to determine if associations existed
between recommended deworming protocols, client education,
and veterinarian perceptions.
Materials and methods
In order to examine current recommended small animal
deworming protocols and the association between veterinarian-
perceived zoonotic risk, veterinarian-perceived prevalence of
endoparasites, and deworming protocols, a questionnaire was
mailed to all small and mixed animal veterinarians practicing
in western Canada.
Selection of study sample
In January 2003, all practicing veterinarians coded in the
Canadian Veterinary Medical Association (CVMA) database
as small or mixed animal practitioners, residing in British
Columbia (BC), Alberta (AB), Saskatchewan (SK), or Manitoba
(MB), (n = 2145) were mailed a cover letter, questionnaire, and
postage-paid return envelope. In these provinces all practic-
ing veterinarians are automatically members of the CVMA.
Questionnaires returned before August 2003 were eligible for
inclusion in the study. No attempt was made to follow-up
nonrespondents.
Survey questionnaire
The questionnaire consisted of 4 sections: 1) demographic
information, 2) recommended deworming protocols, 3) client
education, and 4) frequency of diagnosis and zoonotic concern
of specific parasites. Demographic information was obtained
through questions regarding number of years in practice, type of
practitioner (small or mixed animal), number of veterinarians at
their current clinic, and number of small animals they examined
each week. Information pertaining to deworming protocols and
Table 1. Demographics of responding veterinarians
(western Canada, 2003)
Result
Sample (Number [%]
Variable size unless noted)
Province 545
Alberta 201 (36.9)
British Columbia 244 (44.8)
Manitoba 52 (9.5)
Saskatchewan 41 (7.5)
Not stated 7 (1.3)
Practice type 545
Small animal 379 (69.5)
Mixed animal 162 (29.7)
Not stated 4 (0.8)
Years in practice 534 15.3 (9.7)
a
Small animal caseload/wk 501 (35, 50, 75)
b
Practice size 503 2.8 (2.0)
a
(Number of veterinarians)
Age of puppy/kitten at first exam 539
, 6 wk 11 (2.0)
6–7 wk 276 (51.2)
. 7 wk 252 (46.8)
a
Mean (s)
b
Quartiles

CVJ / VOL 48 / MARCH 2007 271
A R T I C LE
client education was obtained by asking the following questions:
1) “what age do you routinely first see puppies/kittens”, “when
do you recommend deworming puppies — place a check next
to all ages” (week intervals were provided for ages 1–16 wk
and month intervals were provided for 5–12 mo), or “never,”
or “as needed based on fecal examination;” 2) “when do you
recommend deworming adult dogs” (The same deworming
questions were asked for kittens/cats); 3) “do you recommend
routine deworming of nursing bitches/queens;” 4) “does your
practice have an established deworming protocol;” 5) “is the
protocol given in this survey that of the practice or your per-
sonal protocol,” and 6) “how often do you speak to your clients
regarding the zoonotic potential of cat/dog worms (helminths).”
Information regarding frequency of diagnosis and zoonotic
concern of specific parasites was acquired by asking veterinar-
ians, “in your experience, rank the frequency of diagnosis of the
following parasites in young and adult cats and dogs (1-never,
5-very common) and your concern regarding each as a potential
zoonotic hazard (1-no concern, 3-significant concern).” The
following parasites were listed for ranking: T. canis, T. cati,
A. caninum, Trichuris vulpis, Toxoplasma gondii, Giardia lamblia,
Dipylidium caninum, and Echinococcus spp.
Data analysis
Data on recommended deworming protocol, client educa-
tion, and demographics were divided into biologically relevant
categories that, where possible, would provide relatively equal
numbers in each group: recommended age of 1st deworming
puppies (# 3 wk, . 3 wk, never); kittens (# 6 wk, . 6 wk,
never); client education regarding zoonotic disease (with all
clients, only with those clients at increased risk, only when
prompted by the client, when worms are diagnosed, never); and
demographics (practitioner type [small, mixed], number of years
in practice [, 4, 4–6, 7–9, 10–15, 16–20, . 20], number of
veterinarians in the practice [# 3, . 3], and number of small
animals examined per week [# 35, 36–50, 51–75, . 75]). Age
at 1st deworming was considered appropriate if complying with
established guidelines (puppy # 3 wk, kitten # 6 wk). Pearson’s
x
2
test for independence (39) and a x
2
test for trend were used
as appropriate to sequentially evaluate the existence of an asso-
ciation between recommended age category at 1st deworming
and demographic information, veterinarian-perceived parasite
prevalence, and veterinarian-perceived parasite zoonotic concern.
A x
2
test for trend was used to determine if perceived zoonotic
concern or perceived prevalence of T. canis or T. cati was asso-
ciated with recommended age of 1st deworming in puppies or
kittens, respectively. Logistic regression was performed separately
for puppies and kittens, using appropriate age of 1st deworming
as a dichotomous outcome and T. canis/cati perceived preva-
lence, perceived zoonotic concern, and demographic variables
determined to be of interest by univariate analysis as covariates.
Veterinarian-perceived prevalence and veterinarian-perceived
zoonotic risk data were summarized by calculating mean ranks
and 95% confidence intervals for each parasite. Comparisons
in veterinarian perceptions were made between small and mixed
animal practitioners by using the Mann-Whitney test (40). All
analyses were performed by using a statistical computer software
program (SPSS version 12 for Windows; SPSS, Chicago, Illinois,
USA) with P-values , 0.05 considered statistically significant
for all analyses.
Table 2. Veterinarian-recommended deworming protocols for dogs and cats
(western Canada, 2003)
Dog Cat
Sample Number Sample Number
Age category size (%) size (%)
Young (1–16 wk of age) 529 543
Prophylactically $ once 500 (94.5) 507 (93.4)
Following positive fecal examination 29 (5.5) 36 (6.6)
Juvenile (5–12 mo of age) 494 495
Prophylactically $ once 254 (51.4) 248 (50.1)
Following positive fecal examination 223 (45.1) 227 (45.9)
Not recommended 17 (3.5) 20 (4.0)
Adult (. 12 mo of age) 523 536
Prophylactically $ once/y 340 (65.0) 350 (65.3)
Following positive fecal examination 178 (34.0) 182 (34.0)
Not recommended 5 (1.0) 4 (0.7)
Figure 1. Veterinarian-recommended age of first kitten/puppy
deworming (n = 529; western Canada, 2003).
a
Centers for Disease Control and Prevention recommendation
b
Recommend deworming only following a positive fecal
examination

272 CVJ / VOL 48 / MARCH 2007
A R T I C LE
Results
Of the 2145 surveys mailed, 638 were returned, of which 545
(25% of all mailed surveys) met the study criteria (small/mixed
animal veterinary practitioners in western Canada) and were
completed to an extent suitable for analysis. The 4 provinces had
different survey return proportions (AB: 26.3% [201/764], BC:
28.7%, [244/849], MB: 20.8% [52/250], SK: 14.5% [41/282];
P , 0.001). Seven respondents did not list the province in
which they practiced.
Demographics
Four hundred and thirty-eight different veterinary practices were
represented. The number of responding veterinarians varied
among provinces, practice type, years in practice, weekly small
animal caseload, clinic size, and age at which kittens/puppies
were typically first examined (Table 1).
Deworming protocols and client education
Veterinarian-recommended deworming protocols varied
(Table 2). The majority (94.5%) of veterinarians, responding to
questions regarding puppy deworming protocols, recommended
prophylactically deworming puppies at least once between
1–16 wk of age (Figure 1); mean 6.1 wk [standard deviation (s) =
2.0]. The mean frequency of deworming puppies during the first
16 wk of life was 3.5 treatments (s = 1.7). Sixty-six (13.2%) of
the respondents recommended both 1st deworming at # 3 wk
and $ 3 treatments during the first 16 wk of life.
Similar trends were noted in recommended kitten deworm-
ing protocols (Table 2). The majority of respondents (93.4%)
recommended prophylactically deworming kittens at least once
(Figure 1); mean 6.6 wk (s = 2.0), with a mean frequency of 3.1
(s = 1.6) treatments during the first 16 wk of life. Nearly half
of the respondents (48.3%; 245/507) recommended deworm-
ing kittens at # 6 wk of age. One hundred and ninety-seven
(38.9%) of the respondents recommended both 1st deworming
at # 6 wk and $ 3 treatments during the first 16 wk of life.
Veterinarians’ recommendations were similar for juvenile
(5–12 mo) and adult (. 12 mo) cats and dogs (Table 2). Half
of the responding veterinarians recommended prophylacti-
cally deworming juveniles during this 8-month period, with a
frequency that ranged from 1 to 8 treatments (mean dog 2.2
[s = 1.7]; mean cat 2.0 [s = 1.3]). Results were similar for adult
dogs and cats, with most veterinarians (dog: 65.0% [340/523];
cat 65.3% [350/536]) recommending prophylactic deworming
with mean yearly frequencies of 2.0 (s = 1.0) and 2.5 (s = 1.3)
in dogs and cats, respectively. Seventy-two percent (364/507)
of the respondents recommended deworming nursing bitches/
queens. Most responding veterinarians (68.5%; 369/539) stated
the clinic at which they worked had an established deworming
Table 3. Perceived prevalence
a
of specific endoparasites in young and adult dogs
and cats by small animal veterinarians (western Canada, 2003)
Young Adult
Sample Mean Sample Mean
Parasite size Rank 95% CI size Rank 95% CI
Toxocara canis 353 3.6
b
3.5–3.8 335 2.2
b
2.1–2.3
Toxocara cati 354 3.3
b
3.2–3.4 331 2.1
b
2.1–2.2
Dipylidium caninum 340 2.4 2.3–2.5 330 2.7 2.6–2.9
Giardia lamblia 351 2.4
b
2.3–2.5 340 2.5
b
2.4–2.6
Other roundworms 288 2.1
b
2.0–2.2 260 1.6
b
1.5–1.7
Ancylostoma caninum 333 1.8 1.7–1.8 315 1.8 1.7–1.9
Trichuris vulpis 338 1.6 1.6–1.7 318 1.6 1.5–1.7
Toxoplasma gondii 342 1.4 1.4–1.5 324 1.5 1.4–1.5
Echinococcus 338 1.3 1.3–1.4 319 1.3
b
1.3–1.4
a
Perceived prevalence was ranked by veterinarians from 1 (never) to 5 (very common)
b
Significant difference (P , 0.05) in median rank between small (Table 3) and mixed (Table 4) animal
practitioners (Mann-Whitney test)
Table 4. Perceived prevalence
a
of specific endoparasites in young and adult dogs
and cats by mixed animal veterinarians (western Canada, 2003)
Young Adult
Sample Mean Sample Mean
Parasite size Rank 95% CI size Rank 95% CI
Toxocara canis 144 3.8
b
3.6–4.0 137 2.5
b
2.3–2.7
Toxocara cati 143 3.6
b
3.4–3.8 136 2.4
b
2.3–2.6
Dipylidium caninum 136 2.4 2.2–2.6 138 2.8 2.6–3.1
Giardia lamblia 140 2.2
b
2.0–2.3 135 2.2
b
2.1–2.4
Other roundworms 121 2.7
b
2.5–2.9 120 2.1
b
1.9–2.3
Ancylostoma caninum 131 1.9 1.7–2.1 130 1.9 1.8–2.1
Trichuris vulpis 136 1.8 1.7–2.0 131 1.7 1.6–1.8
Toxoplasma gondii 136 1.5 1.4–1.6 134 1.6 1.5–1.7
Echinococcus 135 1.5 1.3–1.6 133 1.8
b
1.6–2.0
a
Perceived prevalence was ranked by veterinarians from 1 (never) to 5 (very common)
b
Significant difference (P , 0.05) in median rank between small (Table 3) and mixed (Table 4) animal
practitioners (Mann-Whitney test)

CVJ / VOL 48 / MARCH 2007 273
A R T I C LE
protocol; however, only 78.3% of these claimed to follow the
protocol.
Given identical clinic name, city, and province, 35% of the
respondents (192/545) worked at the same clinic as at least 1
other respondent (19% [85/438] of the clinics were represented
more than once). Of those respondents working at the same
clinic as another respondent, 38% (73/192) stated they followed
an established clinic-wide deworming program. Comparison
of the protocols from these respondents (age of 1st deworming
puppies) revealed only 36% (26/73) were in fact identical.
Forty-four percent (238/539) of respondents reported that
they actively discussed with all clients the zoonotic risk of small
animal-derived endoparasites. Few (9.8%) reported actively
discussing the zoonotic risk with only those at greatest risk
(households with children, young animals, and immunocompro-
mised individuals), while 40.3% utilized passive discussions with
their clients, including discussing “only when prompted by the
client” and “when worms were diagnosed.” Three respondents
(0.6%) reported never discussing the zoonotic risk of cat/dog
helminths.
Veterinarian-perceived parasite prevalence and
zoonotic concern
Median veterinarian-perceived prevalence significantly dif-
fered between small and mixed animal practitioners for several
parasites (Tables 3 and 4). Within practitioner type (small or
mixed), significant differences in perceived parasite prevalence
were noted between age groups (young verses adult animals)
and between parasites (Tables 3 and 4). Toxocara canis and
T. cati were considered of greatest prevalence in young patients,
while D. caninum was considered of greatest prevalence in adult
patients. Ancylostoma caninum was infrequently diagnosed.
Mean/median veterinarian-perceived zoonotic concern signifi-
cantly differed between several of the parasites and type of prac-
titioner (Table 5). Roundworms (T. canis and T. cati), Giardia,
and T. gondii were considered to be of moderate-significant
zoonotic concern.
Associations between demographics,
veterinarians’ perceptions, and deworming
protocols
Univariate analysis revealed number of years in practice, small
animal weekly caseload, and use of an established clinic-wide
deworming protocol were independent of age of 1st deworming
in kittens and puppies (Table 6). Puppy and kitten deworming
protocols recommended by recent graduates (, 4 y) did not
significantly differ from those of other veterinarians (x
2
; P = 0.3
and P = 0.2, respectively). Type of practitioner and practice
size were independent of age of 1st deworming in puppies, but
they were associated with age of 1st deworming in kittens, with
smaller clinics (# 3 veterinarians) and mixed animal practitio-
ners associated with higher proportions of deworming # 6 wk
of age. Province was associated with age of 1st deworming in
puppies, but not kittens.
Veterinarian-perceived prevalence and veterianarian-perceived
zoonotic risk of several parasites were significantly associated
with recommended deworming protocols in dogs and cats
(x
2
test for trend; P , 0.05). Increased perceived prevalence of
T. canis in young animals was linearly associated with increased
proportion of 1st deworming puppies # 3 wk of age. This
association did not remain significant in the multivariate model
(adjusting for province, practitioner type, practice size, and
zoonotic concern — Table 7). A similar trend was noted for
perceived zoonotic risk of T. canis with puppy deworming, but
remained significant when adjusting for these variables. Trends
were also noted in perceived prevalence and zoonotic concern
of T. cati in 1st deworming of kittens # 6 wk of age. When
adjusting for variables identified during univariate analysis, per-
ceived prevalence of T. cati remained significant, while zoonotic
concern was marginally significant (Table 8). The association
between practitioner type and appropriate kitten deworming
also remained significant in this model.
Discussion
As compared with established puppy (2, 4, 6, and 8 wk of age)
and kitten (3, 5, 7, 9 wk or 6, 9, 10 wk) deworming protocols
(18,19), over 85% of the puppy and 60% to 90% (depending
on acceptable age: # 6 wk, # 3 wk, respectively) of the kitten
deworming protocols recommended by responding veterinarians
were inappropriate. These proportions were similar to those in
previous studies (36,37,41). The proportion of veterinarians
prophylactically deworming (without a fecal examination) at
least once during the first 16 wk of life was greatly increased,
93% to 95%, from previous studies, 33% (35) and 46% (36).
Given the high proportion of congenitally infected puppies and
false negative fecal examinations, prophylactic deworming is
recommended for young animals (18,20,42). Toxocariasis may
fail to be diagnosed due to low sensitivity of the fecal test (up to
50% in 1 study [43]), often due to low egg production, which
is common in animals less than 4 wk of age (44).
Recommended deworming protocols for juvenile and adult
dogs and cats are less well-defined, and include periodic pro-
phylactic or fecal examination-based treatments and monthly
prophylaxis (18). Nearly all surveyed veterinarians (97% to
99%) followed these guidelines. The simultaneous deworming
Table 5. Veterinarian-perceived zoonotic concern for selected
endoparasites of dogs and cats (western Canada, 2003)
Zoonotic concern
a
Parasite Sample size Mean Rank 95% CI
Toxocara canis 492 2.3 2.2–2.4
Giardia lamblia 480 2.3 2.2–2.3
Toxoplasma gondii 477 2.2 2.2–2.3
Toxocara cati 485 2.2 2.2–2.3
Echinococcus 443 1.9 1.8–2.0
Other roundworms 382 1.8 1.7–1.9
Ancylostoma caninum 427 1.5 1.5–1.6
Dipylidium caninum
c
129 1.5 1.4–1.6
Dipylidium caninum
b
314 1.4 1.3–1.4
Trichuris vulpis
c
128 1.4 1.3–1.5
Trichuris vulpis
b
296 1.3 1.2–1.3
a
Perceived zoonotic concern: veterinarians ranked each parasite according to their
“concern as a potential zoonotic hazard” from 1 (no concern) to 3 (significant
concern)
b,c
Significant difference (P , 0.05) in median rank between small and mixed
animal practitioners (Mann-Whitney test): b = value for small animal
practitioners; c = value for mixed animal practitioners

274 CVJ / VOL 48 / MARCH 2007
A R T I C LE
of nursing bitches and queens, important in decreasing shed-
ding of roundworms and hookworms, was recommended by a
higher percentage of veterinarians (72%) than previously noted
(15% to 64% [35,36]). Although the majority of veterinar-
ians acknowledged the existence of an established clinic-wide
deworming protocol at their practice, not all followed this pro-
tocol. Therefore, the education of veterinarians on appropriate
deworming protocols must be performed at the level of the
individual veterinarian.
Education is a crucial service veterinarians provide their cli-
ents. Although physicians could play a role in educating their
clients on the zoonotic potential of helminths, studies indicate
that they are even less involved and comfortable with the task
than are veterinarians (37,38). Because many of the preventive
measures important in the control of zoonotic helminth disease,
including proper disposal of feces, washing hands after handling
fecal material, and decreasing pica in children, occur outside the
veterinary clinic, client education remains vital to the control
of these diseases. Many responding veterinarians (46%) did not
actively educate clients on the zoonotic risk of small animal-
derived endoparasites, despite ranking several common small
animal helminths as having a moderate to high perceived preva-
lence and posing moderate to significant zoonotic risk. These
findings are similar to those previously reported (37,38).
Several endoparasites were perceived as moderately to
highly prevalent. Results were similar to those of other stud-
ies (1,7,8,37), identifying a number of zoonotic helminths
potentially occurring in the small animal population in west-
ern Canada with substantial frequency. Several endoparasites
(roundworms, T. gondii, and Giardia) were identified as per-
ceived by veterinarians to be of moderate-high zoonotic risk, as
previously noted (37). The overall perception of zoonotic risk
likely incorporated several factors not directly measured by the
present study, including likelihood of transmission, prevalence,
and severity of illness, and may indicate which parasites are most
likely to be discussed in conversation with clients (37).
The present study suggests that changes in puppy deworm-
ing protocols are needed throughout western Canada, in all
practice types and sizes. It is worrisome that despite previous
studies on this topic (35–37,41) and well-established guidelines
for appropriate helminth control in small animals (18,19),
recent veterinary graduates (, 4 y) did not notably differ from
other practitioners regarding deworming recommendations.
Appropriate kitten deworming strategies are less clear, as dif-
ferent “adequate” protocols have been proposed. Regardless,
most recommended kitten deworming practices in western
Canada remain inadequate. This study identified perceived
prevalence and perceived zoonotic potential of T. canis and
T. cati as positively associated with appropriate recommended
deworming practices in puppies and kittens. Because this was a
cross-sectional study, it was impossible to determine if increased
perception of prevalence, zoonotic risk, or both, resulted in
improved deworming recommendations. However, targeted edu-
cation to the veterinary community concerning true roundworm
Table 6. Proportion of veterinarians whose recommendations followed established deworming
guidelines
a
, stratified by demographic variables (western Canada, 2003)
Puppy Kitten
Demographic Deworming Deworming
variable n # 3 wk (%)
a
P-value
b
n # 6wk (%)
a
P-value
b
Province 0.02 0.09
Alberta 182 10.4 182 42.3
British Columbia 229 19.2 230 54.3
Manitoba 47 6.4 48 43.8
Saskatchewan 39 10.3 40 45.0
Practice type 0.48 0.01
Small 338 14.8 340 44.7
Mixed 161 12.4 162 56.8
Years in practice 0.42
c
0.58
c
, 4 54 9.3 54 40.7
4–6 73 16.4 75 52.0
7–9 44 11.4 44 50.0
10–15 100 13.0 104 46.2
16–20 85 16.5 83 49.4
. 20 138 15.2 137 49.6
Small animal caseload/wk 0.90
c
0.43
c
# 35 127 12.6 127 48.0
36–50 126 12.7 126 46.8
51–75 112 18.8 115 47.0
. 75 95 10.5 94 54.3
Practice size (# veterinarians) 0.42 0.02
# 3 340 15.3 345 52.2
. 3 122 12.3 121 39.7
Use established protocol 0.33 0.41
Yes 235 12.3 233 46.4
No 267 15.4 274 50.0
a
Proportion of veterinarians recommending established deworming guidelines (18,19): # 3 wk (puppies) and # 6 wk (kittens)
b
Pearson’s x
2
test, unless noted
c
x
2
test for trend

CVJ / VOL 48 / MARCH 2007 275
A R T I C LE
prevalence and zoonotic hazard may be useful in improving
appropriate deworming practices.
The overall response proportion to our questionnaire was
25%. Due to the low response proportion, our results may
not be valid. It is expected that veterinarians with an interest,
concern, or both, for zoonotic disease deworming protocols
may have been more likely to respond to the survey than those
who were not interested or concerned. Veterinarians who are
interested in deworming protocols may be better educated in
this field, biasing the current study toward more appropriate
deworming protocols, education practices, and higher percep-
tions of parasite zoonotic risk/prevalence than actually exist.
Therefore, the true level of veterinarian knowledge concerning
small animal-derived zoonoses may be worse than this study
reports.
Although we attempted to word survey questions clearly, it
is possible that respondents may have misunderstood questions.
An example of such a misunderstanding may have occurred if
veterinarians responded to the question “when do you recom-
mend deworming puppies” with the age that they routinely first
examine puppies and are able to discuss deworming protocols.
In this instance, the distinction between a veterinarian’s recom-
mendation and daily practice may have been missed. Additional
sources of error in this study included unanswered survey
questions (left blank) for which direction of the possible error,
toward or away from the null, is unclear. There was a concern
that numerous responses from the same large clinic might bias
the results. However, despite a large percentage of clinics with
several respondents, few individuals followed the same protocol
as other veterinarians from that clinic, likely having little effect
on the results.
Early, prophylactic deworming protocols and client educa-
tion targeted at the risks and prevention of small animal-derived
zoonotic disease are critical components in controlling endo-
parasite zoonoses. Because most animals are not brought to a
veterinarian until $ 6 wk of age (as documented in this study),
it is important to reach out to clients who have pregnant or
newly born animals at home, and provide early prophylactic
treatment for endoparasites. Although puppies and kittens
may not routinely reach the veterinarian’s care until late in the
deworming schedule, veterinarians should recommend appropri-
ate deworming schedules in order to decrease the likelihood of
zoonotic disease. Veterinarians should consider measures such
as posting deworming recommendations on clinic Web sites and
conducting educational outreach to established and prospective
breeders to reach animals prior to their 1st routine examination.
This study, in accordance with previous studies (35–37,41),
documented suboptimal client education and recommended
deworming protocols in the veterinary community. Targeted
education to the veterinary community concerning roundworm
prevalence and zoonotic potential may be useful in improving
appropriate deworming practices. Further research into the
association of these perceptions and their result on deworming
protocols is warranted.
CVJ
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