An infrequent, puzzling phenomenon is the litter in which many, if not all, of the whelps become
strangely deformed sometime in the first two weeks of life. A flattening of the thorax and abdomen, top to bottom, becomes evident about a week after birth from some unknown cause. It happens most often in the dwarf (chondrodystrophic) breeds but has been seen in the German Shepherd Dog and other breeds.
Instead of the thorax developing normally into a progressively deeper tube from the prosternum/neck area to the diaphragm, it forms more of a flattened cylinder with the height from floor to spine about the same all the way back to the loins, and perhaps even lower midway down the back. The forechest, instead of dropping from the prosternum to the last sternal vertebra, may even be concave, and as time goes on the puppy becomes even more pancake-shaped.
 

     As the ribs bow out, the heart and other organs may be pushed into the pleural cavity and displace or decrease the air volume of the lungs; as a result, pups become lethargic, lacking in energy and strength. By the third to fourth week, when normal pups would be running around, affected pups have not yet learned to push themselves up into a standing position. If the extended limbs, especially front legs, are moved at all, it is with a paddling motion to the sides, hence the disorder is called "Swimming-Puppy Syndrome." "Swimmers" have very poor circulation, respiration, and ability to swallow food or keep milk in their stomachs, and as they are old enough to wean, are very slow when eating from pans. Stifles may be rotated underneath the belly, patellas are often luxated, and other orthopaedic or osteochondral defects may be noted. Many die from
inhalation pneumonia (from inspiring regurgitated milk) or other forms of respiratory failure.

         If swimmers are not given some sort of therapy, there is a less than even chance they will survive to eight weeks. Those that do manage to live, only begin to walk at or after this age. A 1981 Veterinary Medicine/Small Animal Clinician report on a litter of Shepherd pups, five out of six of whom were swimmers, mentions one pup that started walking by nine weeks old, but by six months was still unsteady and slightly undersized (female, 40 pounds). Because she tired rapidly, even after only moderate exercise, she was euthanized. Autopsy showed that her vertebra/rib joints were enlarged, but internal organs seemed normal in appearance. Based on this sort of evidence it's possible to conclude that there might be another cause for the weakness other than ventro-dorsal compression. Many factors have been accused of contributing to the syndrome, both environmental and some of unknown genetic origin. For awhile, most people blamed slippery floors, but I've raised all my litters on smooth, impervious flooring covered with newspaper and have never had a swimmer in my own operation. The VM/SAC report mentioned above involved excellent footing in the whelping/nursing box: clean, dry, rough-surfaced indoor/outdoor carpeting.
Until this report, it was generally believed that such a floor would prevent swimmers from developing.

         Some Dachshund breeders told me they were fairly successful in correcting the syndrome by putting each of the pups in a sling for at least part of each day. This practice encouraged them to make contact with the floor with their pads. Some tied hobbles to the front legs to keep them under the body and the elbows close together. This, they felt, prevented the front legs from becoming spread-eagled. Dish-shaped nests of straw have also been suggested, but not only does that present the danger of filthy conditions, it isn't practical. A modification of the idea has also been proposed: put the whole whelping/nursing area into a sling thus making the "floor" more like a hammock with the canvas or vinyl suspended at the corners and edges and lower in the center. I doubt the efficacy of any of these, but, as sailors used to say, "Any port in a storm."

     Other therapy which may be beneficial, although tiresome and time-demanding of the breeder,
includes massage (passive exercise), administration of vitamin E (with selenium added if they're not getting solid food yet; let your vet advise, as it's easy to overdose selenium, which is then toxic), taping hobbles to prevent splaying, and suspension in warm water. The last-named is probably the most promising if either active or passive movement can be induced. Thus, swimming (the real kind, in water) may help correct the swimming syndrome. Whirlpool baths are beneficial for partially-paralyzed or weak adults such as those suffering from coonhound paralysis, but of course the waves in such a tub would overwhelm a 3- to 6-week-old puppy. Therefore, hold him in your hand or a sling, with support to keep his head up out of the water, and let him paddle for a while in warm water (probably around 75 to 80 degrees F to prevent chilling), but take him out and dry him thoroughly if he tires. As many of these sessions as you can manage should help the pup to develop coordination, muscle development, and better circulation while putting much less weight on his body. Your hand or makeshift sling plus the buoyancy of the water will take the weight off the chest. Finger manipulation of his limbs would be a good idea, too, while he's in the water, but also when he's out.

      What to do with "Swimmers"? Everyone has to make up his own mind, but there is always the
somewhat eugenic approach: if there are pups born and reared in the same conditions and who never develop the disorder, then there must be a genetic component. How "large" that is, is a guess, but some would say that such pups should never be bred, nor their parents bred again. Further, that it might be economically wise to put such dogs down and spend one's money and time on dogs that could be of more benefit to society or the breeder or owner. It's your decision.