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7. RESULTS

7.1. ATTITUDES AND COMPLIANCE OF THE KEY GROUPS (I-III)

Breeders and dog owners find inherited skeletal and ocular diseases to be the most important ones affecting canine well-being. The veterinarians had a different opinion, ranking skin diseases and allergies highest. They even ranked inherited ocular diseases as the least important disease type (Figure 1). This difference is probably due to the veterinarians' broader clinical experience.

Figure 1. Ranking (in Friedman two-way analysis of variance) of importance of different disease types to canine well-being according to Finnish veterinarians, dog breeders and dog owners.

Of all the key groups studied, breeders estimated their own level of knowledge to be the best. Other groups believed their own knowledge to be more limited. For all the key groups important sources of information at present and in the future were judged to be very similar. The Kennel Club's and breed clubs' role as source of information, even for experts (veterinarians and breeders), was considered essential, but expert groups' educational role for non-experts (especially owners, but also in some extent for breeders) was also thought to be very important. For veterinarians, professional education and literature were also supposed to be very effective sources that could have more importance in the future (Figures 2 and 3).

Figure 2. Ranking (in Friedman two-way analysis of variance) of importance of different sources of information about canine health programmes for different key groups at present according to Finnish veterinarians, dog breeders and dog owners.

Figure 3. Ranking (in Friedman two-way analysis of variance) of possible future importance of different sources of information about canine health programmes for different key groups according to Finnish veterinarians, dog breeders and dog owners.

All key groups shared very positive attitudes towards the present health programme. According to veterinarians and breeders, obligatory and voluntary health screenings and registration limitations were considered to be amongst the most effective of the current programme's actions for canine health. In the future, however, all groups believed that educational actions directed to key groups could have a very positive effect (Figure 4). However, veterinarians believed more on registration limitations' and obligatory health screenings' effectiveness also in the future than the other groups.

Figure 4. Ranking (in Friedman two-way analysis of variance) of estimated effectiveness of possible future health actions to canine health according to Finnish veterinarians, dog breeders and dog owners.

7.2. EFFECTIVENESS OF THE PRESENT CONTROL PROGRAMME

7.2.1. Inherited ocular diseases (IV)

7.2.1.1. Disease frequency

For most breeds included in the study, frequencies of inherited ocular diseases are very low and cases tend to be detected by accident. Consequently, no conclusions regarding trends and changes in disease frequencies can be drawn. Only the frequencies of CEA in Rough Collies (30.9%) and Smooth Collies (12.1%) as well as PHTVL in Dobermanns (21.4%) exceeded 10%. In Rough Collies as well as in Dobermanns, a significant increase in disease frequencies during the study period was also noticed. In both breeds, however, the trend was towards milder grades of diseases, and the detected increase is probably due to improved screening routines and methods (biomicroscopy), which enable the milder forms to be detected more reliably than before.

7.2.1.2. Economic effectiveness

Because overall disease frequencies were low, the costs of finding affected animals were very high. In those breeds with high frequencies an increase in disease frequency was noticed. Thus, the present control programme has not been economically beneficial.

7.2.2. Hip dysplasia (V)

7.2.2.1. Disease frequency

A clear between-breed variation of dysplasia frequency was observed: from 2% (Smooth Collie) to 80% (Long-haired Saint Bernhard). In every breed, annual variations of frequency were noticed. Only in nine of the 22 breeds included in this study, were significant changes in hip dysplasia frequency detected. However in four breeds the disease frequency increased, and only in five breeds was a decrease noted. In other breeds the observed changes were so slight that they were thought to be caused by random variation. The frequency of severe HD in each breed followed very closely each breed's overall changes in HD frequency (Figure 5).

Figure 5. Overall hip dysplasia prevalence (straight line) and prevalence of severe hip dysplasia (broken line) according to the year of birth in smooth collie, German Shepherd and long-haired Saint Bernard in Finland. Year 1987 represents the prevalence of all animals in each breed screened before January 1, 1988.

7.2.2.2. Economic effectiveness

As already discussed in Chapter 7.4 numerous calculation models can be created for economic estimation. However, no benefit/cost -ratio over 1 could be shown for any breed or calculation model that were used. In some breeds dysplasia frequency had also increased during the study period, so in these breeds the benefit/cost -ratio was found to be negative. The best benefit/cost ratio (0.82) was achieved in the Nova Scotia Duck Tolling Retriever when calculation Model no 1 was used. This calculation model was the one which assumed the cost of hip dysplasia to be the highest. All calculation models have numerous sources of bias: especially the cost of treating hip dysplasia is very difficult to estimate.

7.3. HIP DYSPLASIA IN GERMAN SHEPHERD DOGS

7.3.1. Heritability (VI)

When the hip dysplasia scores from A to E were coded as numbers from 1 to 5, respectively, the mean value of the subjectively recorded hip dysplasia score was 2.42 with a standard deviation of 1.20. This corresponds average hip scorings between B (normal hips with slight changes) to C (mild dysplasia). The coefficient of the variation was 49.9%. The heritability estimates for hip dysplasia were moderate, varying from 0.31 to 0.35.

7.3.2. Environmental factors affecting hip dysplasia (VII)

Environmental effects: birth year and month, panelist, screening age of the dog as well as the effect of the genetic group of offspring from imported versus non-imported sires had significant effects on hip dysplasia. The litter and the breeder had only very small effects.

7.3.3. Phenotypic and genetic change and breeding values (V, VII)

No phenotypic progress could be shown, the disease prevalence had, instead, increased. As expected, also no clear genetic improvement could be shown in either males or females according to breeding value averages per year of births. Also, breeding values of parent animals were very similar to those of the whole population, which gives reason to suspect the effectiveness of selection.


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