In the 1950s, an attempt was made to improve structure, color and markings of the breed by crossing some Swissys with Berners. These crossbreedings brought the anticipated betterment of coat color and markings. However, this experiment did not improve the structure; in general the crossbred pups had poor gaits and often bad bites. It also had a detrimental effect on the temperament, nervous behavior and shyness replaced the steady and calm disposition of the GSMD. Most well known Swiss breeders discontinued using the crossbred lines and concentrated on purebred stock.

By the late sixties, the breeding population had decreased to the point that in 1967 only 43 Swissy pups were registered with the Swiss Kennel Club. The national Swiss Swissy club, the "Klub fuer Grosse Schweizer Sennenhunde", attributed this decline primarily to the fact that the GSMD was always much less popular with the dog fanciers than the Berner, quite possibly because the Swissy is less flashy and eye catching than the Berner with its much more uniform color, markings and long coat. The Swiss club began to work on spreading the image of the Swissy as a reliable, low maintenance family companion with excellent watchdog qualities.

By 1985, an average of about 20 litters were again registered annually. However, this increase in numbers had come at the expense of the overall health of the breed. Decades of inbreeding and close line breeding, coupled with the overuse of and dependency on a very small number of stud dogs, had led to increasing incidences of hereditary diseases such as Ostechondrosis in the shoulder joints and epilepsy. Many breeding animals showed clear signs of inbreeding depression such as low conception rates, whelping difficulties and small litter sizes in bitches and fertility and breeding performance problems in dogs. Alarmed by these developments, the Swiss club established a comprehensive breeding management program. This agenda includes a follow-up of every Swissy born in Switzerland from birth on during its entire life, a data bank of available stud dogs to assist breeders, mandatory screening for OCD in the shoulder, strict control of all line breeding and limiting the number of common ancestors in the first 3 generations of breeding pairs.

Note: Like with many Swiss pure breed clubs, Swissys can only be bred if they pass the mandatory breeding certification exam (Ankoerung), which consists of health, structure and temperament tests. Only the offspring of animals that have obtained their respective breed club's breeding certification will be registered by the Swiss Kennel Club.

Today in Switzerland, the Swissy is still among the relatively rare breeds. However, the numbers of litters have remained quite steady with about 18 to 25 litters registered every year. And most importantly, thanks to the efforts of those concerned club members who recognized the dangerous situation the breed was facing in the mid-eighties, the overall health situation has improved considerably. The number of OCD and epilepsy cases and other hereditary diseases are decreasing steadily, the performance of stud dogs and brood bitches has and is constantly improving, and very rarely does a stud dog sire more than a couple of litters per year.