Minus 20C weather is supposed to have some benefits – at least that’s what we try to tell ourselves. (Maybe we’re just trying to justify why we haven’t migrated south.)

I’ve written about leptospirosis a few times recently, given the horrible lepto season we’ve been having. This bacterial disease isn’t new, but there have been two big differences this year: one was the number of cases, which was well beyond what we’ve ever seen here in Ontario; the other was the timing of cases. I’ve been saying, for weeks, that the lepto season has to be over soon. The bacterium is shed in urine of certain wildlife hosts and likes wet – but not frigid – environments. Yet, we’re still seeing new cases.

• We’re currently trying to figure out why this is, but I guess the key message I have for people at this point is “vaccinate,” since avoiding exposure is tough when we really don’t understand the main exposure risks.
• The other thing is to consider lepto in sick dogs, even this time of year. Rapid treatment is important for management of this potentially serious disease, and it’s easy to understand how it would be overlooked in late December, since it’s considered a fairly seasonal disease.

Another area we’re working on a lot is tickborne diseases. The general dogma regarding ticks is that the will begin to quest (search for a host) when the temperature hits at least 4C. That’s a distant memory around here, as it hasn’t been above -10C in a while. Yet, I got a report from a reader about a feral cat carrying engorged ticks, from an area north of here that’s snow covered and even colder than here (currently sitting at -27C). It’s been well below freezing there for a long time, and well beyond typical adult tick attachment times. So, where did this cat pick up a tick? Maybe in a warm area such as a barn? Or, is 4C not really the right threshold.  It’s probably a matter of some ticks finding warmer microenvironments and cats seeking out those same warmer (or less cold) spots.

• Regardless, this reinforces the message we’ve been saying: even in many cold climates, tick exposure is a 12-month-a-year risk. Even using the 4C threshold, it’s not unusual to get a few few days of 4C weather in the middle or winter around here. If the exposure threshold is even lower (or irrelevant if ticks can be questing in some isolated, warmer locations during cold periods) then even that gets tossed out the window.
• For lepto, the main message is “vaccinate and be aware.” For ticks, it’s “use tick prevention and don’t stop tick-checks.” The risk is presumably quite low in winter, but low doesn’t mean zero, and tick avoidance practices aren’t particularly hard or expensive.

I guess I need to come up with a different “on the bright side…” excuse for this weather.