Tuttle Animal Medical Center in Florida has reported six dogs with severe bloody diarrhea, vomiting and fever, over the past month. The affected dogs were from the same general area in Sarasota County, and all but one died within 24 hours. However, care must be taken when interpreting information such as this. Apparently, most dogs were owned by people with limited finances, so it's hard to say whether they would have died if aggressive (and expensive) treatment could have been provided. A disease like parvovirus is highly fatal without treatment, but survival rates are excellent if proper treatment is provided.
Initial testing of these dogs to identify the causative agent has been unsuccessful, including a rapid in-clinic test for parvovirus. Because of limited finances, complete diagnostic testing has not been performed, and it's likely that only a very limited range of possible causes have been investigated. That's a problem with a user-pay system such as this. There's no incentive for owners of dead pets to pay for further testing that could help understand the problem and/or help other peoples' pets.
Various experts have been consulted, but it sounds like there is minimal material (e.g. saved fecal samples) to use for further testing. Trying to make a diagnosis based on clinical signs and basic laboratory data collected by the clinic during standard work-up and treatment is essentially impossible. Veterinary infectious disease expert Dr. Cynda Crawford told VIN News Service by e-mail last Wednesday "There is very little case material to work with, so am struggling with meaningful diagnostic approaches,...Everything is basically speculation at this point."
Florida's Division of Animal Industry is apparently "monitoring the situation." At this point, there's nothing that can really be done, but hopefully assistance with testing will be provided should further cases be identified. One official from this agency speculated that E. coli O157 could be the cause. That seems pretty unlikely. This bacterium can cause disease in dogs but it's quite rare. Six apparently unrelated cases due to such a rare cause seems pretty unlikely, although it shouldn't be dismissed.
A general tenet of medicine is "common things occur commonly." Situations like this are most often unusual presentations of a common disease (e.g. parvovirus) rather than a new disease. More aggressive diagnostic testing for known causes of disease, along with additional testing to try to identify new pathogens is needed if further cases are identified. Sometimes apparent outbreaks like this go away on their own without any intervention or diagnosis. Only time will tell whether this is a small local event or the "tip of the iceberg."