Look at what sea otters & dogs eat
From ANIMAL PEOPLE, September 2002:
SAN FRANCISCO, LONDON– Cats were accused of spreading
toxoplasmosis to California sea otters and dogs were accused of
spreading campylobacter bacteria throughout Britain in new studies
released in early July 2002–but while the allegations were quickly
amplified by mainstream news media and picked up by anti-feral cat
and anti-street dog activists, the research behind each study
overlooked key dietary factors in the transmission of the diseases.
Marine biologist Melissa Miller and colleagues with the
Wildlife Health Center at the Davis campus of the University of
California claimed in the July edition of the International Journal
for Parasitology to have traced an ongoing seven-year decline in the
population of endangered California sea otters to the fecal parasite
Toxoplasma gondi. They found the microscopic parasite in 66 of the
107 sea otter carcasses they examined.
As domestic housecats are the only animal known to transmit
Toxoplasma gondi in oocyst form, the form in which it could infect
sea otters via water pollution, Miller et al concluded that the sea
otters are in effect being killed by surface runoff contaminated by
outdoor cats and/or untreated sewage containing feces from
However, Toxoplasma gondi is most often transmitted by
ingesting raw meat from another infected animal. Cats typically
acquire Toxoplasma gondi from eating mice and birds. Gulls may be
the most voracious major mouse predator along the California coast,
and California sea otters routinely kill and eat gulls they stalk
from underwater, as well as scavenging fresh gull carcasses.
Miller et al did not even mention the possibility that the
sea otters, like cats, may be infecting themselves through their
own predatory habits.
Aberdeen University professor of microbiology Hugh Pennington
meanwhile told a committee of the British House of Lords that about
half of the estimated six million dogs in Britain appear to be at
least seasonal carriers of campylobacter, and can transmit it to
humans just by being petted.
Confirmed human cases of campylobacter infection in England
and Wales have surged from 25,000 in 1986 to 56,000 in 2001,
overtaking salmonella and listeria as the most common forms of food
poisoning in Britain, Pennington said. He estimated that only 10%
of all cases are detected.
Untreated severe cases can occasionally trigger Guillan-Barre
syndrome, a form of creeping paralysis that starts in the hands and
feet, moving slowly toward the neck.
Campylobacter poisoning was previously most closely
associated with consumption of contaminated poultry. As dogs’ saliva
has potent antiseptic qualities, the association of campylobacter
with dogs is a surprise, Pennington acknowledged–but he apparently
did not consider that the dramatic global rise in human poultry
consumption over the past 20 years has coincided with a steep rise in
the use of poultry byproducts in dogfood.