Ten years ago, after 3 y of investigations, attempts to determine the cause(s) of reproductive and developmental problems at a dog kennel in Allegan County, MI were suspended. This kennel had lost more than 120 litters of Shetland Sheepdogs (Shelties) over the preceding 12 y; many of the puppies that died were deformed as were several that survived. Similar effects occurred in Persian cats, although on a smaller scale, and later in German Shepherds and Golden Retrievers. Such problems began after drilling a deeper water well and the building of a new kennel of concrete and metal fencing in 1969. Prior to that time the kennel owner had successfully bred and raised at least 15 litters/y of mostly Shelties in an old wooden chicken coop. Health problems in the kennel owner prevented her from breeding dogs in the late 1980's. She gradually resumed a more regular breeding schedule in 1989, initially with some success. However, in 1992 reproductive problems returned. Female dogs ceased cycling or had abnormal "unbreedable" seasons. Sperm checks revealed a lack of sperm in four males. Concurrently, neither the Persian nor mongrel female cats in the kennel showed signs of cycling. Two dairy farmers in Allegan County, who reportedly had similar health, reproductive and management concerns in cows, were contacted. Tests performed at these dairy farms had revealed the presence of what has commonly been called stray voltage. Equipment brought by the farmers to the kennel revealed the presence of AC and DC currents on the premises, which was later confirmed by a Staff Engineer of the Michigan Public Service Commission (PSC). Such current was detected even when the electrical power to the premises was shut off. For example, 2.45 volts AC and -0.150 volts DC were detected at the well head, with variable amounts detected at various locations in the kennel. The current was not constant, with transients (spikes) frequently detected. Similar problems were evident in Van Buren County at a recently constructed kennel about 15 miles south of the kennel in Allegan County. Shortly after moving to the property, health problems not previously experienced by the breeder began cropping up in the dogs. Experts from the power company, the PSC, and 2 independent consultants have taken a variety of measurements on the property. The tests confirmed the presence of stray voltage (AC and DC) with periodic voltage spikes, as well as electromagnetic fields and electric fields. None of the extensive tests have proven the property owner to be at fault.(ABSTRACT TRUNCATED AT 400 WORDS)