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REGULAR ARTICLES
Risk factors associated with clinical dermatophilosis
in smallholder sector cattle herds of Zimbabwe at the Amblyomma
variegatum and Amblyomma hebraeum interface
Daud Nyosi Ndhlovu &Patrick Julius Masika
Received: 19 June 2014 /Accepted: 18 November 2014 /Published online: 3 December 2014
#Springer Science+Business Media Dordrecht 2014
Abstract A cross-sectional study was conducted to investi-
gate factors for clinical dermatophilosis herd-level positivity
in smallholder dip tanks from Gokwe (Chemawororo,
Gwanyika), Kwekwe (Koronika) and Chegutu (Chivero),
Zimbabwe, between September 2013 and April 2014. A total
of 185 herds were clinically examined for disease and tick
infestation. Data on herd and potential herd level risk factors
were collected using a structured questionnaire. A herd was
classified as clinically positive if an animal satisfied any of the
following criteria: small lesions characterised by hairs
clumping like a small paint brush, clear exudative
circumscribed lesions with scabs of at least 1 cm in diameter
and confluent progressive exudative scab lesions affecting
significant parts of the animal’s body. Amblyomma
variegatum and Amblyomma hebraeum ticks were identified
in situ with further laboratory confirmation. The potential
herd-level risk factors for clinical dermatophilosis were tested
using multiple logistic regression with herd infection status
(positive, negative) being the binomial outcome and risk
factors being predictors. Of the herds examined, clinical bo-
vine dermatophilosis was detected in 45 % (84/185, 95 %
confidence interval (CI) 38.2, 52.6 %) of the herds. The herd
prevalence ranged from 6.9 % (95 % CI 0.00, 16.7) to 56.7 %
(95 % CI 43.8, 69.6) with Chivero and Chemawororo dip
tanks recording the lowest and highest prevalence, respective-
ly. Herds infested with A. variegatum were associated with
higher odds (OR=6.8, 95 % CI 1.71, 27.10) of clinical
dermatophilosis while the association was not significant
(p>0.05) in A. hebraeum-infested herds. A history of having
bought cattle (OR = 3.5, 95 % CI 1.09, 11.12) compared to not
buying was associated with increased herd clinical positivity
status. It was concluded that management practices aimed at
movement and tick control would help reduce the prevalence
of clinical dermatophilosis in cattle herds.
Keywords Fisher’s exact test .Ticks .Exudative .Univariate
Introduction
Amblyomma variegatum, a three-host tick, is one of the most
important and widely distributed of the Amblyomma ticks
(Stachurski et al. 2010). All stages of the tick infest cattle,
sheep and goats. The distribution of this tick extends from
north-western Zimbabwe, the central highveld and on the
eastern border of the country, to central and northern Mozam-
bique (Estrada-Peňaetal.2008) which also reported its ab-
sence from drier arid areas. Adults of this tick are present
throughout the year on cattle and buffalo although infestations
are heavier during the wet warm months (Ahoussou et al.
2010). In Zimbabwe, the most commonly occurring
Amblyomma species is Amblyomma hebraeum, which in the
adult stage is parasitic on cattle and other medium- to large-
sized ungulates, leopards and ostriches (Walker et al. 2003).
The distribution of A. hebraeum is from central Zimbabwe
southwards into South Africa, eastern Swaziland, southern
Mozambique and eastern Botswana (Walker et al. 2003).
A. hebraeum is the principal vector of heart-water in Zimba-
bwe; however, it is replaced by A. variegatum in the northern
parts of the country (Estrada-Peňaetal.2008). Of importance
when considering A. hebraeum and A. variegatum in Zimba-
bwe is the fact that these two species have an area of overlap
(Peter et al. 1998). It was reported that in an area of overlap,
D. N. Ndhlovu
Department of Clinical Veterinary Studies, Faculty of Veterinary
Science, University of Zimbabwe, P.O. MP 167,
Mt Pleasant, Harare, Zimbabwe
D. N. Ndhlovu :P. J. Masika (*)
Agricultural and Rural Development Research Institute (ARDRI),
University of Fort Hare, Private Bag X1314, Alice 5700,
Republic of South Africa
e-mail: Pmasika@ufh.ac.za
Trop Anim Health Prod (2015) 47:353–360
DOI 10.1007/s11250-014-0727-x
A. variegatum completely replaces A. hebraeum over a period
of 3 years (Norval et al. 1994).
Bovine dermatophilosis is an important disease of cattle in
Africa, and it was first reported in Belgian Congo in 1915
(Oppong 1996). It has been reported in most countries in the
continent of Africa (Hamid and Musa 2009). Bovine
dermatophilosis is a tick-associated disease caused by an
actinomycete bacterium, Dermatophilus congolensis (Molia
et al. 2008; Gebreyahannes and Gebresselassie 2013),
characterised by an exudative acute or chronic dermatitis
which could be localised or generalised (Admassu and Alemu
2011). The lesions vary in severity: from small lesions which
make hair stand like a small paint brush, to clear
circumscribed scabs over 1 cm in diameter and finally to more
confluent progressive lesions (Hadrill and Walker 1994).
Stewart (1972) describes a carrier state in cattle; in such a
state, the lesions are not easily observed and it was concluded
that carrier animals were the chief means of survival for
D. congolensis.AccordingtoEstrada-Peňaetal.(2007), the
saliva of A. variegatum contributes to the pathogenesis of
bovine dermatophilosis. The disease can occur in tick-free
animals, but it is more severe in those that are infested by
the A. variegatum ticks (Stachurski et al. 2010). Walker (1996)
stated that A. variegatum’s role in the development of
dermatophilosis was through immunosuppression. The tick
was postulated to secrete an immunosuppressing agent in its
saliva or waste metabolites that were toxic to the host. Eco-
nomically, bovine dermatophilosis is important due to mor-
bidity and mortality, damage to hides and its effect on draught
animal power (Ahoussou et al. 2010;Bayisaetal.2012). In
other parts of Africa, it has frustrated the introduction of exotic
breeds to improve meat and milk production (Koney 1996).
The treatment of bovine dermatophilosis is mainly through
the use of penicillin, streptomycin and dihydrostreptomycin
given intramuscularly (Hamid and Musa 2009). Awad et al.
(2008) indicated that a double dose of long-acting tetracy-
clines given a day apart gave better results than a single dose.
Penicillin could be used in combination with streptomycin to
produce a cure while gentamycin was reportedly the most
effective antibiotic (Hamid and Musa 2009). Acaricides have
been reported to be the best option for the control of bovine
dermatophilosis (Hadrill and Walker 1994). Amitraz-based
acaricides applied on the predilection sites of A. variegatum
ticks on cattle reduced the prevalence of dermatophilosis
(Morrow et al. 1993,1996) as did deltamethrin. The method
of tick control is important in the control of bovine
dermatophilosis. Chatikobo et al. (2001) reported that plunge
dipping could in fact increase the spread of the disease while
hand spraying reduced the risk of spread.
In Zimbabwe, research on bovine dermatophilosis has been
conducted focusing on its control, prevalence and distribution
(Chatikobo et al. 2001,2004,2009). The aim of the current
study was to identify potential herd-level risk factors related to
bovine dermatophilosis and its association with A. variegatum
and A. hebraeum ticks at selected dip tanks where the two
ticks have been reported to interface. Knowledge of these risk
factors will assist animal health decision-makers in the control
and management of bovine dermatophilosis.
Materials and methods
Study sites
The study sites were at four dip tanks where co-existence/
interface of the two species of A. hebraeum and A. variegatum
was reported by Peter et al. (1998)(Table1).
Study design and selection of individual herds
A cross-sectional study was conducted between September
2013 and April 2014. The study animals (herds) were purpo-
sively selected (Dohoo et al. 2003). A sample of 30 to 60
stockowners was systematically selected per dip tank. This
figure was arrived at considering financial and material re-
sources. Stockowners served as proxies for the herds. That is,
herds belonging to selected stockowners became the primary
sampling units. One hundred and eighty five (185) herds with a
total of 1788 cattle were sampled. On the day of sampling,
stockowners were interviewed by the principal investigator
and by two district veterinarians using a pretested structured
questionnaire written in English. The interviews were conduct-
ed in the local Shona and siNdebele languages. The questions
sought information on herd-level factors such as herd size,
keeping of cattle confined in kraals at night, materials that
were used to construct the kraals, source of drinking water,
how long farmers had been keeping cattle, history of purchase
of cattle in the past 3 years, personal methods of tick control, if
farmers treated their cattle for diseases, knowledge of and on
the treatment of bovine dermatophilosis, how the stockowners
rated dipping service delivery, and dipping sessions attended in
the past 12 months (verified from stock cards).
Clinical examination of animals and sample collection
All cattle belonging to participating stockowners were placed
in a race and clinically examined. The herd was initially
visually inspected for any signs of bovine dermatophilosis.
Clinically ill cattle were restrained in a race and a thorough
physical examination was conducted. There was a predefined
case definition for bovine dermatophilosis. This definition
was based on the literature (Samui and Hugh-Jones 1990;
Hadrill and Walker 1994) and also on the experiences of the
investigating veterinarians. Cattle were classified as follows:
positive, if their clinical presentation complied with the case
definition for bovine dermatophilosis, or negative, if clinical
354 Trop Anim Health Prod (2015) 47:353–360
presentation did not conform to the case definition. The case
definition embraced an animal whose clinical presentation
satisfied any of the following three criteria: small lesions
characterised by hairs clumping like a small paint brush, clear
exudative circumscribed lesions with scabs of at least 1 cm in
diameter and confluent progressive exudative scab lesions
affecting significant parts of the animal’sbody.Presenceor
absence of A. variegatum and A. hebraeum was also recorded,
and the ticks were identified in situ using their characteristic
ornate markings (Walker et al. 2003). Tick inspections were
conducted on at least five animals and tick samples collected
and stored in 70 % ethanol for further verification at the
University of Zimbabwe Parasitology laboratory. A herd was
considered to be dermatophilosis positive if one animal in the
herd presented with clinical signs that conformed to the case
definition. With regards to tick infestation, a herd was consid-
ered to be A. variegatum or A. hebraeum positive if one
animal in the herd was infested with either of the ticks.
Statistical analysis
The potential risk factors, stockowner and animal biodata
were captured using the Epi Info software make view ques-
tionnaire utility (Epi Info TM version 3.5.3 database and
statistics software for public health professionals 2012). Sta-
tistical analysis was performed using Stata/SE 11.2 for Win-
dows (StataCorp, College Station, Texas, USA). Fisher’sex-
act test was used in univariate analysis to evaluate the associ-
ation between the outcome, bovine dermatophilosis (yes or
no) and categorical risk factors. Variables with a pvalue <0.25
in univariate analysis were recruited into the binary logistic
regression. In the multivariable logistic regression, the model
was built as follows: the outcome was the binomial herd-level
clinical dermatophilosis positivity status (negative herd=0,
positive herd=1) and the explanatory variables with pvalues
<0.25, identified in the univariate analysis, were fit into the
model. The model was manually constructed using forward
selection applying the maximum likelihood estimation proce-
dure and statistical significance contribution of individual
predictors (or group of predictors). The logistic regression
model was assessed for goodness of fit using the Hosmer-
Lemeshow test while its predictive ability was determined
using the receiver operating characteristic (ROC) curve
(Dohoo et al. 2003).
Results
Herd clinical bovine dermatophilosis prevalence
Bovine dermatophilosis clinical positivity was detected in
45 % (84/185, 95 % confidence interval (CI) 38.2, 52.6 %)
of the herds that were investigated. The herd prevalence
ranged from 6.9 % (95 % CI 0.00, 16.7) to 56.7 % (95 % CI
43.8, 69.6) with Chivero and Chemawororo dip tanks record-
ing the lowest and highest prevalence, respectively (Table 2).
The proportion of positive herds was significantly lower
(p<0.05) at Chivero than at other dip tanks. Prevalence at
the other three dip tanks did not differ significantly (p>0.05).
Using the Fisher’s exact test in univariate analysis (Table 3),
A. variegatum was significantly (p<0.05) associated with the
occurrence of clinical dermatophilosis while association of the
latter with A. hebraeum was not significant (p>0.05).
A. variegatum ticks infested 69. 7 % (129/185, 95 % CI
63.0, 76.4) of the herds while 28.1 % (52/185, 95 % CI
21.6, 34.6) were infested by A. hebraeum.
Tab le 3shows the results of univariate analysis and de-
scriptive statistics of 12 variables from the structured
interviewer-administered questionnaires. Eight variables that
had a p<0.25 in univariate analysis, that is, bought cattle (yes
vs no), herd size (small, medium, large), knowledge of
dermatophilosis, age category of affected cattle, treating cattle
for diseases, A. variegatum (present vs absent), dip atten-
dance, purchase of own acaricide and dip tank, were fitted
into the multivariable logistic regression model.
Multivariable logistic regression model for herd-level bovine
dermatophilosis infection
The multivariable logistic regression model revealed study
site, bought cattle, A. variegatum (yes vs no) and treatment
of cattle for diseases as independently associated with herd
dermatophilosis positivity (Table 4). The Hosmer-Lemeshow
goodness-of-fit test showed that the model fit the data (χ
2
=
Tabl e 1 Locations where A. hebraeum and A. variegatum co-exist (Peter et al. 1998)
Province District Location Agro-ecological zone Latitude Longitude
Midlands Gokwe south Gwenyika 3 −18° 24′S29°12′E
Midlands Gokwe south Chemawororo (Nyaje) 3 −18° 19′S28°47′E
Midlands Kwekwe Koronika 3 −18° 07′S29°26′E
Mashonaland West Chegutu Chivero 2 −18° 21′S30°36′E
Trop Anim Health Prod (2015) 47:353–360 355
4.06, d.f.8,p=0.85). The model had a good predictive ability
(area under curve=0.96).
Discussion
A limitation of this study was the reliance on clinical signs as a
proxy for infection with bovine dermatophilosis and the use of
purposive sampling. Regardless, the results from the study do
provide a picture of risk factors for bovine dermatophilosis in
the smallholder sector of Zimbabwe; purposive sampling is a
recognised epidemiological sampling method (Dohoo et al.
2003). Further, the investigators had long years of experience
encountering bovine dermatophilosis cases in the field which
in this case was a positive factor. Other studies have been
conducted by Nyman et al. (2007), Waage and Vatn (2008),
and Dippel et al. (2009) where only clinical signs were used as
the outcome in efforts to determine potential herd- or
individual-level risk factors for the animal health conditions.
These studies were carried out to determine potential
herd/individual animal-level risk factors for clinical mastitis
andlamenessinsheepandcattle.
The observed variation in prevalence of dermatophilosis
between some dip tanks can be attributed to management
factors and agro-ecological factors. Chivero dip tank which
had the lowest prevalence (6.9 %) is in agro-ecological zone 2
while the other three study sites with prevalence ranging from
48.1 to 56.7 % were in zone 3; for these latter three sites, the
differences in prevalence were not statistically significant.
Agro-ecological zone 2 is characterised by intensive farming
and moderate rainfall while zone 3 is characterised by semi-
intensive farming and moderate to erratic rainfall (Hove et al.
2008). The presence of higher temperatures in zone 3 together
with moderate rain could provide an ideal environment for the
germination and propagation of D. congolensis zoospores as
compared to the colder zone 2. The other reason for the
difference could be the fact that the proportion of tick-
infested cattle differed per study site particularly between
Chemawororo and Chivero. Chivero had more cattle
infested with A. hebraeum than those with A. variegatum
and vice versa for Chemawororo dip tank. Chatikobo et al.
(2004,2009) have reported on the potential association be-
tween A. variegatum and bovine dermatophilosis as such that
the difference in herd infestations by these two ticks could
explain the differences in dermatophilosis herd prevalence.
These findings were also in agreement with those of Admassu
and Alemu (2011) who reported that dermatophilosis was
more prevalent in A. variegatum-infested cattle. The preva-
lence values in the current study differed from those of other
works. Dalis et al. (2009) in Nigeria reported a clinical prev-
alence of dermatophilosis-like cases, of 17 %, which dropped
down to 8.7 % after laboratory examination. In Ethiopia,
AdmassuandAlemu(2011)reported1.04%laboratory
dermatophilosis positivity. The differences in the prevalence
observed between the current study and the other studies
could be attributed to cattle management differences and
agro-ecological factors. The other reason for the differences
could be that in the other studies, dermatophilosis positivity
was confirmed through laboratory tests, which was not the
case in the current study. Nath et al. (2010)reportedthatthe
isolation of D. congolensis was in most cases difficult; this can
lead to low prevalence detected at the laboratory. In the current
study, the case definition was strictly adhered to so as to
exclude cases of lumpy skin disease, sweating sickness,
parafilariasis, ringworm and scab.
The history of introducing new cattle into herds through
purchases placed those herds at higher odds of clinical
dermatophilosis. This introduction increased the odds of clin-
ical dermatophilosis by 3.49 (CI 1.09, 11.12). The current
findings agreed with others (Matope et al. (2010); and
Bamaiyi et al. (2014)) who reported that the purchase of
animals increased the odds of disease in the new herd. In the
Tabl e 2 Herd sizes, bovine dermatophilosis clinical cases and Amblyomma tick infestationat smallholderdip tanks of Gokwe, Kwekwe and Chegutu,
Zimbabwe
Dip tank Herds sampled Herd size Clinical cases Amblyomma tick infestation
A. variegatum A. hebraeum
Median Range Proportion (%) 95 % CI Proportion 95 % CI Proportion 95 % CI
Chemawororo 60 7 1, 26 56.7a 43.8, 69.6 73.3c 61.8, 84.9 16.7e 6.96, 26.4
Gwanyika 52 8 2, 50 48.1a 34.0, 62.1 82.7c 72.1, 93.3 17.3e 6.77, 27.9
Koronika 44 8 2, 41 52.3a 36.9, 67.6 65.9c 51.3, 80.5 52.3f 36.9, 67.6
Chivero 29 7 1, 19 6.90b 0.0, 16.7 44.8d 25.6, 64.1 34.5e 16.1, 52.9
Grand total 185 8 1, 50 45.4a 38.2, 52.6 69.7c 63.0, 76.4 28.1e 21.6, 34.6
Proportions with different letters were significantly different at p<0.05. Stockowners served as proxies for the herds
CI confidence interval
356 Trop Anim Health Prod (2015) 47:353–360
other studies, the diseases of interest were bovine and ovine
brucellosis. Chatikobo et al. (2009) reported that cattle
brought from outside were responsible for the occurrence of
dermatophilosis in some cattle herds in Kadoma in Zimba-
bwe. New introductions to herds could introduce into the
herds dermatophilosis infection or the tick A. variegatum with
which it is associated.
Treatment of cattle for various other diseases was associ-
ated with an increased odds (OR=22.9) of dermatophilosis
compared to herds where no treatment was provided. This
association was most likely due to the fact that farmers were
prompted to treat their cattle if they were showing signs of ill
health; with such treatment not being effective, this was not a
causal association. The findings were similar to those of
Nyman et al. (2007) who reported preponderance by farmers
to provide treatment as soon as their animals showed signs of
clinical mastitis; odds ratio (OR) associated with treatment in
that study was 12.5. Treatment would be expected to be
Tabl e 3 Distribution of bovine dermatophilosis-positive and dermatophilosis-negative cattle herds (n=185) according to the different risk factors and
results of univariate analysis using Fisher’s exact test
Variable Category Number Dermatophilosis OR p
+ve −ve
Bought cattle
a
Yes 92 63 29 7.4 0.00
No 93 21 72
Herd size
a
Small 128 52 76 1.92 0.004
Medium 40 18 22
Large 17 14 3
Knowledge of dermatophilosis
a
Yes 95 55 29 1.93 0.001
No 90 40 61
Age category
a
≤4 years 23 23 0 0.37 0.00
Greater than 4 years 95 36 59
Treat cattle for diseases
a
Yes 63 61 2 0.072 0.00
No 22 14 8
Dipping quality Poor 84 41 44 0.99 0.336
Adequate 74 29 45
Good 26 14 12
Dip attendance
a
Very poor 10 3 7 1.80 0.05
Poor 39 12 27
Good 136 69 67
Purchase own acaricide
a
Yes 145 70 14 1.73 0.134
No 40 75 26
Amblyomma variegatum
a
Yes 129 76 53 8.6 0.00
No 56 8 48
Amblyomma hebraeum Yes 52 25 27 1.16 0.743
No 133 59 74
Period keeping cattle 5 years and less 23 2 21 1.16 0.423
6–10 years 24 7 17
11–15 years 15 3 12
16–20 years 27 7 20
More than 20 years 96 25 71
Dip tank
a
Chivero 29 2 27 1.6 0.00
Koronika 44 23 21
Gwanyika 52 25 27
Chemawororo 60 34 26
Source of water Home borehole 10 4 6 1.0 0.970
Common borehole 64 30 34
Dam 10 4 6
River 101 46 55
OR odds ratio, +ve positive, −ve negative
a
These variables had Fisher’s exact p<0.25 and were presented to the multivariable logistic regression models
Trop Anim Health Prod (2015) 47:353–360 357
associated with odds of less than 1, as treatment is protective
(Dohoo et al. 2003).
The other herd-level factors such as source of cattle drink-
ing water which is associated with the communal use of
drinking points at rivers and dams were not associated with
increased odds of herd dermatophilosis positivity in multivar-
iable logistic regression. This was in agreement with the
findings of Matope et al. (2010). This finding appeared to be
at variance with the epidemiology of diseases, which would be
expected to increase when animals congregate. Knowledge of
bovine dermatophilosis was associated with increased odds
(1.93) of herd positivity. Matope et al. (2010)reportedthat
knowledge of brucellosis was associated with reduced odds of
disease. In the current study, the increased odds could be the
result of increased awareness by farmers of the disease as an
important animal health condition. This awareness is possible
through colleagues and veterinary extension staff. Herds with
a good dipping attendance record had an increased odds
(OR= 1.8) in univariate analysis, but this was not significant
in multivariable logistic regression, of being clinically
positive to dermatophilosis than herds with a poor at-
tendance. Chatikobo et al. (2001) reported that plunge
dipping increased the risk of cattle contracting bovine
dermatophilosis, and this appears to be in agreement
with the current study since in this case, cattle were
plunge-dipped. During plunge dipping, cattle congregat-
ed and mixed with infected cattle; such herds were
likely to pick up infection via scabs that contaminate
the dip. The quality of dipping service delivery had no
association (OR 0.99) with herd-level dermatophilosis
positivity. These findings were in contrast to those of
Chatikobo et al. (2009) who postulated that poor dip-
ping services were responsible for the spread of
dermatophilosis in Zimbabwe. Farmers who purchased
their own acaricide had increased odds (OR= 1.73) in
univariate analysis, that their herds would be clinically
positive than herds belonging to farmers who did not
buy acaricides. Farmers usually purchased acaricides
that were applied by spraying or pour-on. According
to Chatikobo et al. (2001), applying acaricides through
these methods reduced the incidence of dermatophilosis;
this seems to contradict findings in the current study in
that purchase of acaricide was associated with increased
odds of disease. The increased odds associated with
purchasing acaricide could be due to the response of
farmers to poor dipping, the latter which is reportedly
(Chatikobo et al. 2009) associated with dermatophilosis.
A larger herd size had increased odds (OR= 1.92) of
having dermatophilosis although this was not significant
in multivariable logistic regression. Matope et al. (2011)
have reported similar findings with this association be-
ing significant in the multiple regression models. Large
herds increase chances of picking up the disease and
these herds are more likely to include brought in or
purchased animals. Period of keeping cattle had no
association with dermatophilosis as was A. hebraeum
tick infestation.
In conclusion, the current study showed that clinical
dermatophilosis was present in herds at all the four study sites.
Area, purchase of cattle, treatment of cattle for diseases and
infestation with A. variegatum were independently associated
with herd-level clinical dermatophilosis while A. hebraeum
Tabl e 4 Final multivariable logistic regression of herd-level factors for bovine dermatophilosis positivity in communal area cattle herds of Zimbabwe
(2013–2014)
Variable Level Multivariable logistic regression
a,b
BS.E. (B)pOR 95 % CI
Constant −3.88 1.68 0.021 ––
Study site Chivero – – –––
Koronika 3.07 1.47 0.037 21.46 1.21, 380.96
Gwanyika 1.53 1.46 0.295 4.62 0.26, 80.8
Chemawororo 2.11 1.48 0.153 8.33 0.46, 152.20
Bought cattle No –– –––
No Yes 1.25 0.59 0.035 3.49 1.09, 11.12
Amblyomma variegatum presence No – – –––
No Yes 1.91 0.71 0.007 6.80 1.71, 27.10
Treatment of cattle for diseases No –– –––
Yes 3.13 0.98 0.002 22.90 3.31, 158.38
Results are given with beta (B), standard errors (S.E.) and odds ratio (OR) with 95 % confidence intervals (CI)
a
Overall data of the model: log likelihood—42.58, LR chi
2
(7 d.f.)= 169.73, p= 0.00, number of observations= 185
b
Dependent variable: herd at least one animal clinically positive (yes/no)
358 Trop Anim Health Prod (2015) 47:353–360
was not. The implementation of strict movement control and
tick control could reduce the level of clinical dermatophilosis.
As such, spraying instead of plunge dipping should be en-
couraged in high-risk areas.
Acknowledgments The authors wish to thank the Govan Mbeki Re-
search and Development Centre at the University of Fort Hare for funding
the project and Dr Muzavazi, district veterinary officer (DVO) of
Chegutu, and Dr Mufukari, DVO Gokwe North and South, and the
stockowners for the willingness to participate in the study.
Conflict of interest The authors declare that they have no conflict of
interest.
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