While it doesn't cover infectious disease, this piece by Scott Weese on Worms & Germs does an excellent job of explaining the (lack of) risk to our pets from radiation due to the nuclear plant mishaps in Japan.
I was thinking this exact thing before reading his post: ".....Compared to humans, pets are probably at much lower risk of adverse effects from radiation exposure, because pets have much shorter lifespans, but the effects of radiation exposure tend to cause disease over very long periods of time....."
Of course, if significant plutonium is released from Fukushima Daiishi Reactor #3 with its MOX fuel, all bets are off. Plutonium radiation is essentially forever due to its half-life of tens or hundreds of thousands of years.