Cat breeding is becoming increasingly popular in Sweden,
with at present 33 different cat breeds registered, and
overall morbidity and mortality has recently been reported
based on breed [12–14]. Many of these breeds are numerically
small, but even breeds that are numerically larger
often have low numbers of breeding animals [12–14]. This
may be due to a large number of neutered cats, a wish by
the owners to avoid contact with other cats or a restrictive
selection of suitable breeding animals. Consequently, the
genetic pool may become narrow in several cat breeds,
which can cause problems due to inbreeding. However, the
effect of inbreeding within breeds and the genetically
different cat breeds may also present research opportunities.
Because cats and humans often are affected by
similar diseases, genetic studies of disease-causing mutations
in cats may greatly facilitate subsequent studies also
in humans, as has previously been described for dogs
[15–21]. Thus, studies in cats are likely to be valuable for
future disease prevention, health, and welfare, not only for
their own species. A prerequisite for such genetic studies is
identification of the disease incidence