OVINE CYSTICERCOSIS IN THE ALBANY REGION OF WESTERN AUSTRALIA 1. Survey of Tapeworms of Rural Dogs G . de
C H ANEET, "
B.V.Sc., and J. B. WHITE,** F.R.C.V.S., F.A.C.V.Sc.
htroduction
Ovine cysticercosis has been causing concern to the meat industry in recent years because of the limitations it has placed on the export of sheep meat to the USA and Canada. Arundel (1972) has reviewed the literature on cysticercosis and in this review discusses its economic importance. Because little is known of the epizootiology of the causative parasite, Taenics ovis (Arundel 1972) it was decided to examine the problem in Western Australia. The Albany region was chosen as the centre of work because there is good tracehack from the local abattoirs to farms submitting affected sheep. The first step in the program was to survey the rural dogs in the region for tapeworms. Surveys have been carried out in Victoria of dogs (Pullar 1946a, b; Jackson and Arundel 1972), foxes (Pullar 1946a, b; Coman 1973), and dingoes (Coman 1972), but there has been no survey in Western Australia. The results of a survey of the rural dogs of the Albany region are reported here. Materials and Methods The survey commenced in October 1969, and ended in December 1971. Properties originally included in the survey were those that submitted to the Albany abattoir, lines of sheep or lambs that showed a 3% or greater incidence of Cysticercus ovis when examined by normal meat inspection procedures, and which were within 70 miles of Albany. Towards the end of the survey it was decided t o organise a pilot control program on 32 contiguous properties at Mt Manypeaks. As a prelude to this, all the dogs on these farms were tested, and the results are included in this report. The owners of properlies to be included in the survey were contacted, and were requested not to feed their dogs for 24 hours prior to the agreed time of testing. On the day of testing, all dogs on the property were purged unless they were aged, debilitated, pregnant or lactating, or less than three months of age. Purge samples were collected in the manner described by Jackson and Arundel (1972), with the exception that if a dog had failed to purge within an hour of arecoline administration, it was redosed with half the original dose of arecoline. During the visit a questionnaire was completed that recorded the size of the farm, the type of stock kept, the numbers of dogs kept, the feeding of the dogs, any anthelmintic therapy of the dogs, whether or not the
* Animal Health Laboratories, Department Jarrah Road, South Perth. ** Department of Agriculture, Albany.
of Agriculture,
Australian Veterinary Journal, Vol. 5 2 , February, 1976
dogs roamed the property and whether stray dogs were prevalent. A modification of the process described by Jackson and Arundel (1972) was used to examine purge material in the laboratory and identify any tapeworms presznt. The modifications were the use of the technique described by de Chaneet (1972) to relax tapeworms that were hard and contracted because of prolonged fixation, and the examination of the uterine morphology of all taeniid tapeworms found which had scoleces. When a scolex was not present, no attempt was made to identify the tapeworm, except in one case where, because of the morphology of gravid segments, a worm was identified as a T . ovis.
RWUltS
Questionnaire Questionnaires were completed on 138 of the 145 properties that were visited. Five of the 138 did not keep dogs. Dogs were purged on 134 of the 145 properties. Thirty-seven (26.8% ) of the 138 properties ran sheep only and 14 (10.1%) ran cattle only at the time of the visit. The majority of properties, 71 (51.5% ) ran both cattle and sheep. The sizes of the properties varied from 20 to 4,200 hectares, the average being 597 hectares. Annual rainfall on the properties varied from 102-119 cm for those on the coast to 51-64 cm for those further inland. The rainfall is predominantly seasonal, with approximately 70% falling in the winter, The numerical distribution of dogs on properties is shown in Table 1. It can be seen that the majority of properties have two dogs, the overall average being 2.4 dogs per farm. Data derived from the questionnaires on the feeding of dogs, anthelmintic therapy, whether dogs were free to roam or restrained, and prevalence of stray dogs, are shown in Table 2. One hundred and twenty-nine farmers fed some sheep meat to their dogs, though in some cases it was a small proportion of the diet, and only 31 were careful to cook all meat used as dog food. Where raw meat was being fed it was often as heads, shanks or flanks from home killed sheep, and many of the 98 farmers listed as feeding raw meat made some attempt to cook any carcase meat they fed. Offal was fed on only 44 properties, but was fed uncooked on 33 of these. Manufactured dry foods such as kibbles, pellets or meals 69
TABLE 1 Distribution of Dogs on Properties Completing Questionnaire
TABLE 3 Prevalence of Tapeworms in Dogs and on Properties ~
Number of
Number of Dogs
Properties*
Total Dogs
1 2 3 4 5 6 7
8 9 10 0
31 57 18 17 4 3 1 1 0 1 5
31 114 54 68 20 18 7 8 0 10 0
Total
138
330
*
T . serialis E . granulosus Total dogs purged successfully
Tapeworm Species Found and Zncidence The species found were Dipylidium caninum, T . ovis, T . hydatigena, T . pisiformis, T . serialis and Echinococcus granulosis. Three hundred and four dogs on 134 properties were purged successTABLE 2 Answers to Ouestionnaire Obtained on 133 Properties
Is the meat cooked?
Are dogs fed offal?
Is the offal cooked? Are dogs fed meal, kibbles, etc? Are dogs treated for tapeworms? Do dogs roam farm? Are stray dogs mevalent? * Percentages are
129 97.0%* 31 23.3% 44 33.1% 10 7.5% 68 51.1% 44 23.3% 29 21.8% 44 23.3%
No 2 1.5% 98 73.6% 77 57.9% 33 24.8% 55 41.3% 83 62.4% 98 73.6% 81 60.9%
No Answer 2
12
1 10
6 6 8
related to total pronerties with dogs (133) on which a questionnaire was completed.
70
37 27.6% 23 17.2% 36 26.8% 35 26.1% 6 4.5% 2 1.5%
T . pisiforinis
Dogs were treated for tapeworms on a regular basis (but possibly only 6-monthly) on 44 properties. Most dogs were kept under control and only 29 farmers allowed their dogs to roam at will. Stray dogs were considered prevalent on 44 properties.
Are dogs fed meat?
Properties +ve
50 16.4% 27 8.9% 46 15.1% 46 15.1% 7 2.3% 2 0.7%
T . hydatigena
were fed as part of the dug's ration on 68 properties. On none of these was the manufactured feed the sole component of the dogs' ration.
Yes
Dogs +ve
D . caninum T . ovis
Average number of dogs per property 2.4.
Question
Tapeworm
304
Total properties 134
fully, and the incidence of the various taDeworm species in the dogs and on the properties i's shown in Table 3. D. caninum was the most common species with 50 of the 304 dogs being infected. Taeniids of one species or another were found in 111 of the dogs. The most common Taeniids were T . hydatigena and T . pisiformis (46 dogs for each species). T . ovis was found in 27 dogs on 23 properties. T . serialis was found in 7 dogs on 6, properties. E . granulosus was found in only 2 dogs on 2 properties and both infections were with a small number of worms. Overall 134 of the 304 dogs had a tapeworm infection and 59 (44% of infections) were with two or more species. The most common mixture was of D. caninum and T . hydatigena or T . pisiformis. Discussion
As this survey appears to be the first in Western Australia no comments can be made on trends of infection. Some comparisons can be made however with the results of recent surveys elsewhere in Australia in which markedly differing infection rates were found. Such comparisons must be made with caution because in this survey properties were selected with apparently high infection rates in sheep with C. ovis, as determined by meat inspection procedures. The most striking features of this report are the prevalence in dogs of I". ovis and the common practice of feeding untreated sheep-meat, The high T . ovis incidence, which at 8.9% is 2% higher than that reported by Jackson and Arundel (1971) for mid-western Victoria, is possibly a direct result of this practice. Obviously Australian Veterinary Journal, V d . 52, February, 1976
the method of selecting properties, and hence dogs, for inclusion in the survey may have augmented the infection rates found, but the magnitude of this effect cannot be determined. The common practice of feeding untreated sheep-meat is to be expected. Extension in the past has been primarily aimed at controlling hydatidosis, and raw offal-feeding has been discouraged, but few warnings have been given against feeding raw sheep-meat. Recent detailed dissections of sheep at Albany abattoirs indicate that 20-25% of sheep show evidence of infection with C . ovis and that about 98% of properties have some infected sheep (J. B. White unpublished data). This figure is similar to the 25% found by McNab and Robertson (1972) in New Zealand. This high figure contrasts with the figure of 3-5% of sheep found infected by usual meat inspection procedures (Arundel 1972, Broadbent 1972, Whiting 1972; J. B. White unpublished data). Obviously the feeding of such infected meat in an untreated form will result in a high incidence of T . ovis in dogs. The infection rate for T . pisiformis at 15.1% is much lower than that of 35.4% found by Jackson and Arundel (1971) in Victoria. This may be because there is a smaller population of rabbits in the Albany area than in Victoria, as suggested by Arundel (1972), or because the farmers do not feed rabbit to the dogs. The 73.6% of dogs that are restrained would have little opportunity of catching rabbits to eat and so becoming infected with T . pisiformis or T . serialis. The infection rate of E. granulosus at 0.7% is lower than the infection rate for this tapeworm found in recent surveys elsewhere in Australia (Jackson and Arundel 1971; Arundel 1972; Clegg and Bawden 1972; Broadbent 1972). Western Australia generally experiences a relatively low rate of hydatidosis in humans (Gemmell 1961; Stein and McCully 1970) and sheep and cattle (Gemmell 1959; 1960; Austen 1967). Gemmell (1958) states that low rainfall or high temperatures for 5 or more months of the year prevent the completion of the hydatid cycle. In much of the area surveyed these limiting conditions occur. The feeding of dogs cannot be limiting on E . granulosus because T . hydatigena, which also occurs in its larval form in the visceral organs of sheep, was found in 15.1% of dogs. This latter figure is a higher infection rate than found in Victoria (Jackson and Arundel 1971). The higher infection rate with T . hydatigena (15.1%) than with T . ovis (8.9%) seems anomalous when the numbers of farmers feeding raw offal (24.8%) and raw meat (73.6%) is
considered. This may be due to the fact that while the infection rate in sheep for C. ovis is high, most cysts are not viable, whereas a high proportion of C. tenuicollis cysts is viable (Broadbent 1972). The techniques for disposing of offal may also have an affect on the T . hydatigena figures. Many farmers were observed to leave it in the immediate environs of the killing area. Such offal is readily accessible to scavenging dogs. The answers provided in the questionnaires suggest certain management changes which should be extended to farmers in this area in order to reduce the incidence of adult tapeworms in dogs, and, ultimately, larval tapeworms in sheep. T . ovis incidence should drop if farmers thoroughly cook or freeze all sheep-meat fed to dogs. Boiling viscera for 4 0 minutes is recommended to kill E. granulosus cysts (Fastier 1949) and this should raise the temperature within meat being boiled to 56°C which will kill C. bovis (Allen 1945) and presumably C . ovis. Thoroughly cooking then means boiling for at least 40 minutes. If freezing is to be used to kill C. ovis, Whitten ( 1971) recommends that the meat be maintained at -10°C for 7 days. Feeding alternative whole foods could perhaps provide a safer means of control, but these foods, though used by 51.1% of farmers as supplements, do not appear to have been accepted as entire rations. Some farmers suggested that if dogs were fed wholly on such rations, the dogs’ scavenging activities would increase. E. grunulosus incidence could be reduced if the 24.8% of farmers feeding raw offal stopped this practice and fed cooked offal, meat or manufactured whole foods. Because offal is not always cooked adequately even by farmers with the best intentions, the feeding of offal in any form should be actively discouraged. Control of dogs does not appear to be as significant a factor as does the method of feeding. There were only 2.4 dogs per farm and 74.6% of farmers claimed that their dogs did not roam at will. Obviously unless control is very strict, a dog which does not roam may occasionally have access to infected meat or offal and so complete control of all dogs is desirable in order to reduce the chances of dogs becoming infected by scavenging meat scraps when farmers are killing sheep for rations, and to stop infected dogs spreading eggs. Stray or ownerless dogs as such were not a problem. The 33.1 % of farmers who considered that stray dogs were prevalent were referring to straying, but nevertheless, owned dogs. Proper disposal of meat scraps, offal and other waste from home killing will further reduce the chance of a dog becoming infected if it does manage to stray. Carcases in
Australian Veterinary Journal, Vol. 5 2 , February, 1976
71
paddocks, though possibly of minor importance (White and de Chaneet 1975) should be removed. The treatment of dogs with cestocides was not widely practised. Regular treatment of all dogs with a cestocide at 60 day intervals on all properties should further reduce the incidence of T . ovis by eliminating worms acquired during mistakes in the feeding control before the worms mature. The high prevalence of C. ovis in sheep in the Albany area would appear to be due to a high incidence of T. ovis in farm dogs because of uncontrolled feeding of raw sheep-meat, coupled with lack of regular treatment of dogs with cestocides. This situation shows that there has been a poor understanding of the importance and biology of C. ovis by farmers in the Albany area. This is being remedied, and a control program based on the findings of this survey will be reported in a later communication.
and stray dogs were considered prevalent on 23.3% of properties. Suggestions for control of Cysticevcus ovis are made based on an interpretation of the significance of these findings.
were allowed to roam on 21.8% of the properties
(Received for publication 17 October 1972j
Acknowledgments
This work was supported in part by an Australian Meat Research Council Grant. The survey could not have been conducted without the assistance of the owners of the 134 properties. Messrs R. MacDonald, R. Oates and G. McAuliffe provided willing assistance at the laboratory bench.
References Allen, R. W. (1945)-J. Purasifol. 31: Suppl. 21. Arundel, J. H. ( 1 9 7 2 h A u s t . vet. J . 4 8 140. Austen, K. J. (1967)-J. Agric. W . A . 8 (series 4): 253. Broadbent, D. W. (1972&Aust. vet. J . 48: 452. Clegg, J. L. and Bawden, R. J. (1972)-Aust. vet. I . 4 8 216. Coman, B. J. ( 1 9 7 2 b A u s t . vet. I . 48: 456. Summary Coman, B. J. (1973)-Aust. vet. J . 49: 378. A survey of the cestode infections of 304 dogs de Chaneet, G. (1972)-Aust. vet. J . 48: 40. from 134 properties in the Albany area of Western Fastier, L. B. (1949)-Purusifology 39: 157. M. A. (1958)-N.Z. vet. J . 6: 106. Australia was performed. Purgation was induced Gemmell, Gemmell, M. A. (1959)-Aust. vet. J. 35: 505. by oral administration of arecoline and the purge Gemmell, M. A. (1960)-IfeIrn. Abstr. 29: 355. examined for cestodes. The cestodes found and Gemrnell, M. A. (1961)---BuZZ. Off. int. epizoot. 56: 1009. their infection rates were: Dipylidium caninum P. J. and Arundel, 3. H. (197l)-Aust. vet. J . 16.4%; Taenia spp 36.5%; T . ovis 8.9%; Jackson, 47: 46. T . hydatigena 15.1%; T . pisiformis 15.1%; T . McNab, J. D. and Robertson, T. G. (1972)-N.Z. vet. 1. serialis 2.3 % ; Echinmoccus granulosus 0.7% ; 20: 67. Questionnaires completed on 133 of the 134 Pullar, E. M. (1946a)-Aust. vet. J. 22: 12. E. M. (1946b)-Ausf. vet. J . 22: 40 properties at the time the dogs were purged Pullar, Stein, G. R. and McCully, D. J. (1970)--Med. I . Aust. 1: showed that:- 73.6% of farmers were feeding 848. raw sheep-meat and 24.8% were feeding raw offal White, J. B. and de Chaneet, G. C. Ausr. vet. J . in press. to their dogs; dogs were treated on a regular basis Whiting, R. H. (1972)-Aust. vet. I . 48: 449. with a cestocide on 23.3% of properties; dogs Whitten, L. K. (1971)-N.Z. vet. J . 19: 223.
BOOK REVIEW HANDBOOK FOR THE HOME This bookzk is well presented comprising sections on families, furnishings, and communities. In each section there are articles by different authors. It is well illustrated with both black and white photographs and drawings. The object of the book is t o provide a basis for families t o use their income wisely. It is of course based on ~ ~ and ~ customsf and sections i on~ *Handbook For The Home. United States Department of Agriculture. 1973. U S . Government Printing Office. 382 p. $5.70 US.
living costs and management of money are of limited value for the Australian scene; nevertheless the principles are often similar. Other sections however, have more application in Australia when they deal with more general topics, e.g. aesthetics of colour. texture and design Unlike ~ earlier~ Year Books it has little application for veterinarians professionally but it will have appeal for their wives and B. C . Duff
72
Australian Veterinary Journal, Vol. 52, February, 1976
C H ANEET, "
B.V.Sc., and J. B. WHITE,** F.R.C.V.S., F.A.C.V.Sc.
htroduction
Ovine cysticercosis has been causing concern to the meat industry in recent years because of the limitations it has placed on the export of sheep meat to the USA and Canada. Arundel (1972) has reviewed the literature on cysticercosis and in this review discusses its economic importance. Because little is known of the epizootiology of the causative parasite, Taenics ovis (Arundel 1972) it was decided to examine the problem in Western Australia. The Albany region was chosen as the centre of work because there is good tracehack from the local abattoirs to farms submitting affected sheep. The first step in the program was to survey the rural dogs in the region for tapeworms. Surveys have been carried out in Victoria of dogs (Pullar 1946a, b; Jackson and Arundel 1972), foxes (Pullar 1946a, b; Coman 1973), and dingoes (Coman 1972), but there has been no survey in Western Australia. The results of a survey of the rural dogs of the Albany region are reported here. Materials and Methods The survey commenced in October 1969, and ended in December 1971. Properties originally included in the survey were those that submitted to the Albany abattoir, lines of sheep or lambs that showed a 3% or greater incidence of Cysticercus ovis when examined by normal meat inspection procedures, and which were within 70 miles of Albany. Towards the end of the survey it was decided t o organise a pilot control program on 32 contiguous properties at Mt Manypeaks. As a prelude to this, all the dogs on these farms were tested, and the results are included in this report. The owners of properlies to be included in the survey were contacted, and were requested not to feed their dogs for 24 hours prior to the agreed time of testing. On the day of testing, all dogs on the property were purged unless they were aged, debilitated, pregnant or lactating, or less than three months of age. Purge samples were collected in the manner described by Jackson and Arundel (1972), with the exception that if a dog had failed to purge within an hour of arecoline administration, it was redosed with half the original dose of arecoline. During the visit a questionnaire was completed that recorded the size of the farm, the type of stock kept, the numbers of dogs kept, the feeding of the dogs, any anthelmintic therapy of the dogs, whether or not the
* Animal Health Laboratories, Department Jarrah Road, South Perth. ** Department of Agriculture, Albany.
of Agriculture,
Australian Veterinary Journal, Vol. 5 2 , February, 1976
dogs roamed the property and whether stray dogs were prevalent. A modification of the process described by Jackson and Arundel (1972) was used to examine purge material in the laboratory and identify any tapeworms presznt. The modifications were the use of the technique described by de Chaneet (1972) to relax tapeworms that were hard and contracted because of prolonged fixation, and the examination of the uterine morphology of all taeniid tapeworms found which had scoleces. When a scolex was not present, no attempt was made to identify the tapeworm, except in one case where, because of the morphology of gravid segments, a worm was identified as a T . ovis.
RWUltS
Questionnaire Questionnaires were completed on 138 of the 145 properties that were visited. Five of the 138 did not keep dogs. Dogs were purged on 134 of the 145 properties. Thirty-seven (26.8% ) of the 138 properties ran sheep only and 14 (10.1%) ran cattle only at the time of the visit. The majority of properties, 71 (51.5% ) ran both cattle and sheep. The sizes of the properties varied from 20 to 4,200 hectares, the average being 597 hectares. Annual rainfall on the properties varied from 102-119 cm for those on the coast to 51-64 cm for those further inland. The rainfall is predominantly seasonal, with approximately 70% falling in the winter, The numerical distribution of dogs on properties is shown in Table 1. It can be seen that the majority of properties have two dogs, the overall average being 2.4 dogs per farm. Data derived from the questionnaires on the feeding of dogs, anthelmintic therapy, whether dogs were free to roam or restrained, and prevalence of stray dogs, are shown in Table 2. One hundred and twenty-nine farmers fed some sheep meat to their dogs, though in some cases it was a small proportion of the diet, and only 31 were careful to cook all meat used as dog food. Where raw meat was being fed it was often as heads, shanks or flanks from home killed sheep, and many of the 98 farmers listed as feeding raw meat made some attempt to cook any carcase meat they fed. Offal was fed on only 44 properties, but was fed uncooked on 33 of these. Manufactured dry foods such as kibbles, pellets or meals 69
TABLE 1 Distribution of Dogs on Properties Completing Questionnaire
TABLE 3 Prevalence of Tapeworms in Dogs and on Properties ~
Number of
Number of Dogs
Properties*
Total Dogs
1 2 3 4 5 6 7
8 9 10 0
31 57 18 17 4 3 1 1 0 1 5
31 114 54 68 20 18 7 8 0 10 0
Total
138
330
*
T . serialis E . granulosus Total dogs purged successfully
Tapeworm Species Found and Zncidence The species found were Dipylidium caninum, T . ovis, T . hydatigena, T . pisiformis, T . serialis and Echinococcus granulosis. Three hundred and four dogs on 134 properties were purged successTABLE 2 Answers to Ouestionnaire Obtained on 133 Properties
Is the meat cooked?
Are dogs fed offal?
Is the offal cooked? Are dogs fed meal, kibbles, etc? Are dogs treated for tapeworms? Do dogs roam farm? Are stray dogs mevalent? * Percentages are
129 97.0%* 31 23.3% 44 33.1% 10 7.5% 68 51.1% 44 23.3% 29 21.8% 44 23.3%
No 2 1.5% 98 73.6% 77 57.9% 33 24.8% 55 41.3% 83 62.4% 98 73.6% 81 60.9%
No Answer 2
12
1 10
6 6 8
related to total pronerties with dogs (133) on which a questionnaire was completed.
70
37 27.6% 23 17.2% 36 26.8% 35 26.1% 6 4.5% 2 1.5%
T . pisiforinis
Dogs were treated for tapeworms on a regular basis (but possibly only 6-monthly) on 44 properties. Most dogs were kept under control and only 29 farmers allowed their dogs to roam at will. Stray dogs were considered prevalent on 44 properties.
Are dogs fed meat?
Properties +ve
50 16.4% 27 8.9% 46 15.1% 46 15.1% 7 2.3% 2 0.7%
T . hydatigena
were fed as part of the dug's ration on 68 properties. On none of these was the manufactured feed the sole component of the dogs' ration.
Yes
Dogs +ve
D . caninum T . ovis
Average number of dogs per property 2.4.
Question
Tapeworm
304
Total properties 134
fully, and the incidence of the various taDeworm species in the dogs and on the properties i's shown in Table 3. D. caninum was the most common species with 50 of the 304 dogs being infected. Taeniids of one species or another were found in 111 of the dogs. The most common Taeniids were T . hydatigena and T . pisiformis (46 dogs for each species). T . ovis was found in 27 dogs on 23 properties. T . serialis was found in 7 dogs on 6, properties. E . granulosus was found in only 2 dogs on 2 properties and both infections were with a small number of worms. Overall 134 of the 304 dogs had a tapeworm infection and 59 (44% of infections) were with two or more species. The most common mixture was of D. caninum and T . hydatigena or T . pisiformis. Discussion
As this survey appears to be the first in Western Australia no comments can be made on trends of infection. Some comparisons can be made however with the results of recent surveys elsewhere in Australia in which markedly differing infection rates were found. Such comparisons must be made with caution because in this survey properties were selected with apparently high infection rates in sheep with C. ovis, as determined by meat inspection procedures. The most striking features of this report are the prevalence in dogs of I". ovis and the common practice of feeding untreated sheep-meat, The high T . ovis incidence, which at 8.9% is 2% higher than that reported by Jackson and Arundel (1971) for mid-western Victoria, is possibly a direct result of this practice. Obviously Australian Veterinary Journal, V d . 52, February, 1976
the method of selecting properties, and hence dogs, for inclusion in the survey may have augmented the infection rates found, but the magnitude of this effect cannot be determined. The common practice of feeding untreated sheep-meat is to be expected. Extension in the past has been primarily aimed at controlling hydatidosis, and raw offal-feeding has been discouraged, but few warnings have been given against feeding raw sheep-meat. Recent detailed dissections of sheep at Albany abattoirs indicate that 20-25% of sheep show evidence of infection with C . ovis and that about 98% of properties have some infected sheep (J. B. White unpublished data). This figure is similar to the 25% found by McNab and Robertson (1972) in New Zealand. This high figure contrasts with the figure of 3-5% of sheep found infected by usual meat inspection procedures (Arundel 1972, Broadbent 1972, Whiting 1972; J. B. White unpublished data). Obviously the feeding of such infected meat in an untreated form will result in a high incidence of T . ovis in dogs. The infection rate for T . pisiformis at 15.1% is much lower than that of 35.4% found by Jackson and Arundel (1971) in Victoria. This may be because there is a smaller population of rabbits in the Albany area than in Victoria, as suggested by Arundel (1972), or because the farmers do not feed rabbit to the dogs. The 73.6% of dogs that are restrained would have little opportunity of catching rabbits to eat and so becoming infected with T . pisiformis or T . serialis. The infection rate of E. granulosus at 0.7% is lower than the infection rate for this tapeworm found in recent surveys elsewhere in Australia (Jackson and Arundel 1971; Arundel 1972; Clegg and Bawden 1972; Broadbent 1972). Western Australia generally experiences a relatively low rate of hydatidosis in humans (Gemmell 1961; Stein and McCully 1970) and sheep and cattle (Gemmell 1959; 1960; Austen 1967). Gemmell (1958) states that low rainfall or high temperatures for 5 or more months of the year prevent the completion of the hydatid cycle. In much of the area surveyed these limiting conditions occur. The feeding of dogs cannot be limiting on E . granulosus because T . hydatigena, which also occurs in its larval form in the visceral organs of sheep, was found in 15.1% of dogs. This latter figure is a higher infection rate than found in Victoria (Jackson and Arundel 1971). The higher infection rate with T . hydatigena (15.1%) than with T . ovis (8.9%) seems anomalous when the numbers of farmers feeding raw offal (24.8%) and raw meat (73.6%) is
considered. This may be due to the fact that while the infection rate in sheep for C. ovis is high, most cysts are not viable, whereas a high proportion of C. tenuicollis cysts is viable (Broadbent 1972). The techniques for disposing of offal may also have an affect on the T . hydatigena figures. Many farmers were observed to leave it in the immediate environs of the killing area. Such offal is readily accessible to scavenging dogs. The answers provided in the questionnaires suggest certain management changes which should be extended to farmers in this area in order to reduce the incidence of adult tapeworms in dogs, and, ultimately, larval tapeworms in sheep. T . ovis incidence should drop if farmers thoroughly cook or freeze all sheep-meat fed to dogs. Boiling viscera for 4 0 minutes is recommended to kill E. granulosus cysts (Fastier 1949) and this should raise the temperature within meat being boiled to 56°C which will kill C. bovis (Allen 1945) and presumably C . ovis. Thoroughly cooking then means boiling for at least 40 minutes. If freezing is to be used to kill C. ovis, Whitten ( 1971) recommends that the meat be maintained at -10°C for 7 days. Feeding alternative whole foods could perhaps provide a safer means of control, but these foods, though used by 51.1% of farmers as supplements, do not appear to have been accepted as entire rations. Some farmers suggested that if dogs were fed wholly on such rations, the dogs’ scavenging activities would increase. E. grunulosus incidence could be reduced if the 24.8% of farmers feeding raw offal stopped this practice and fed cooked offal, meat or manufactured whole foods. Because offal is not always cooked adequately even by farmers with the best intentions, the feeding of offal in any form should be actively discouraged. Control of dogs does not appear to be as significant a factor as does the method of feeding. There were only 2.4 dogs per farm and 74.6% of farmers claimed that their dogs did not roam at will. Obviously unless control is very strict, a dog which does not roam may occasionally have access to infected meat or offal and so complete control of all dogs is desirable in order to reduce the chances of dogs becoming infected by scavenging meat scraps when farmers are killing sheep for rations, and to stop infected dogs spreading eggs. Stray or ownerless dogs as such were not a problem. The 33.1 % of farmers who considered that stray dogs were prevalent were referring to straying, but nevertheless, owned dogs. Proper disposal of meat scraps, offal and other waste from home killing will further reduce the chance of a dog becoming infected if it does manage to stray. Carcases in
Australian Veterinary Journal, Vol. 5 2 , February, 1976
71
paddocks, though possibly of minor importance (White and de Chaneet 1975) should be removed. The treatment of dogs with cestocides was not widely practised. Regular treatment of all dogs with a cestocide at 60 day intervals on all properties should further reduce the incidence of T . ovis by eliminating worms acquired during mistakes in the feeding control before the worms mature. The high prevalence of C. ovis in sheep in the Albany area would appear to be due to a high incidence of T. ovis in farm dogs because of uncontrolled feeding of raw sheep-meat, coupled with lack of regular treatment of dogs with cestocides. This situation shows that there has been a poor understanding of the importance and biology of C. ovis by farmers in the Albany area. This is being remedied, and a control program based on the findings of this survey will be reported in a later communication.
and stray dogs were considered prevalent on 23.3% of properties. Suggestions for control of Cysticevcus ovis are made based on an interpretation of the significance of these findings.
were allowed to roam on 21.8% of the properties
(Received for publication 17 October 1972j
Acknowledgments
This work was supported in part by an Australian Meat Research Council Grant. The survey could not have been conducted without the assistance of the owners of the 134 properties. Messrs R. MacDonald, R. Oates and G. McAuliffe provided willing assistance at the laboratory bench.
References Allen, R. W. (1945)-J. Purasifol. 31: Suppl. 21. Arundel, J. H. ( 1 9 7 2 h A u s t . vet. J . 4 8 140. Austen, K. J. (1967)-J. Agric. W . A . 8 (series 4): 253. Broadbent, D. W. (1972&Aust. vet. J . 48: 452. Clegg, J. L. and Bawden, R. J. (1972)-Aust. vet. I . 4 8 216. Coman, B. J. ( 1 9 7 2 b A u s t . vet. I . 48: 456. Summary Coman, B. J. (1973)-Aust. vet. J . 49: 378. A survey of the cestode infections of 304 dogs de Chaneet, G. (1972)-Aust. vet. J . 48: 40. from 134 properties in the Albany area of Western Fastier, L. B. (1949)-Purusifology 39: 157. M. A. (1958)-N.Z. vet. J . 6: 106. Australia was performed. Purgation was induced Gemmell, Gemmell, M. A. (1959)-Aust. vet. J. 35: 505. by oral administration of arecoline and the purge Gemmell, M. A. (1960)-IfeIrn. Abstr. 29: 355. examined for cestodes. The cestodes found and Gemrnell, M. A. (1961)---BuZZ. Off. int. epizoot. 56: 1009. their infection rates were: Dipylidium caninum P. J. and Arundel, 3. H. (197l)-Aust. vet. J . 16.4%; Taenia spp 36.5%; T . ovis 8.9%; Jackson, 47: 46. T . hydatigena 15.1%; T . pisiformis 15.1%; T . McNab, J. D. and Robertson, T. G. (1972)-N.Z. vet. 1. serialis 2.3 % ; Echinmoccus granulosus 0.7% ; 20: 67. Questionnaires completed on 133 of the 134 Pullar, E. M. (1946a)-Aust. vet. J. 22: 12. E. M. (1946b)-Ausf. vet. J . 22: 40 properties at the time the dogs were purged Pullar, Stein, G. R. and McCully, D. J. (1970)--Med. I . Aust. 1: showed that:- 73.6% of farmers were feeding 848. raw sheep-meat and 24.8% were feeding raw offal White, J. B. and de Chaneet, G. C. Ausr. vet. J . in press. to their dogs; dogs were treated on a regular basis Whiting, R. H. (1972)-Aust. vet. I . 48: 449. with a cestocide on 23.3% of properties; dogs Whitten, L. K. (1971)-N.Z. vet. J . 19: 223.
BOOK REVIEW HANDBOOK FOR THE HOME This bookzk is well presented comprising sections on families, furnishings, and communities. In each section there are articles by different authors. It is well illustrated with both black and white photographs and drawings. The object of the book is t o provide a basis for families t o use their income wisely. It is of course based on ~ ~ and ~ customsf and sections i on~ *Handbook For The Home. United States Department of Agriculture. 1973. U S . Government Printing Office. 382 p. $5.70 US.
living costs and management of money are of limited value for the Australian scene; nevertheless the principles are often similar. Other sections however, have more application in Australia when they deal with more general topics, e.g. aesthetics of colour. texture and design Unlike ~ earlier~ Year Books it has little application for veterinarians professionally but it will have appeal for their wives and B. C . Duff
72
Australian Veterinary Journal, Vol. 52, February, 1976
