However, some factors that may contribute to its development include obesity, genetic deformities of the chest region, slippery flooring in whelping boxes and excessive heat. (petpremium.com)
It must be remembered, that puppies, in whelping boxes, are not monitored every minute of every day by humans. (meritpuppy.com)
Norwich Terrier breeder Magda Chiarella has suggested that the shape and surface of whelping box may be important. (servicedogtraininginstitute.ca)