Monday, July 16, 2018

Everyone Uses Bleach Wrong: A PSA with BONUS! Super Hero Analogy

I worked in an animal shelter once upon a time, and as you can imagine it was both rewarding and stressful; there were high highs, and low lows of all kinds, but there was one area that never failed to suck me into a twilight zone of misery: catching a volunteer or co-worker in the act of -- and then correcting on -- the improper use of chlorine bleach.

Bleach is our friend. It is the most effective, cheapest, most environmentally-friendly option for killing most of the terrible germs out there. And everyone seems to use it incorrectly. Too many people treat bleach more like a magic talisman than a disinfectant, filling a spray bottle and spritzing it on everything in the style of Windex Mom in My Big Fat Greek Wedding.

Bleach is like a comic book hero who has super strength only under the right circumstances. If the "bad guys" are hanging out somewhere wide open and clean, bleach is unstoppable. Other disinfectants like QAC's are more like stealthy assassins, sneaking in through the air ducts to get to the center of the bad guys' hideouts. The bad guys can learn to stop the assassins by simply blocking the air ducts, but they have no defense against the brute-force of bleach. (This is also why germs are not likely to develop resistance to chlorine bleach the way they can to the QAC's).

Except... like all good super heroes, bleach has a major weakness: dirt (all organic material, actually). The moment bleach touches dirt, it loses all its power. The bad guys can hide inside a microscopic ball of organic matter all day long. It's like a giant, multi-room mansion to them, and all bleach can do is peek in the windows.

Chlorine bleach does not work on:

Plush toys 
Most furniture
Fabric* (gray area, see below)
Dirty dishes
Dirty concrete
Dirty anything

Let me repeat this, because I've talked to a lot of people about this, from all walks of life, and it's always a hard sell: I swear to you, no matter what you've heard (or who you've heard it from): Bleach will not work on porous or dirty things. I'm sorry, you can't disinfect that cutting board you bought from the thrift store. Or the second-hand drift wood for your lizard's terrarium. We've all done it at one time or another. You're not the first one to dump bleach onto the slobbery dog toys, or litter-encrusted cat box, or into your parvo-contaminated lawn, or spritz it on your ringworm-covered clothes, and think that you killed a few germs. It really doesn't do anything except sometimes change the object's color.

And I have more bad news: the same is true for all the other disinfectants out there; there is no such thing as a magic disinfectant that will solve all your organic material problems, no matter what certain brands' marketing implies. (With the possible exception of accelerated hydrogen peroxide and potassium peroxymonosulfate, but even those are only slightly better in the presence of organic matter. Plus they're much more expensive, and have higher health risks to users, than bleach).

But do not despair! Microorganisms don't always need to be killed, they can be PHYSICALLY removed from their hideouts. Washing with detergent, tons of rinsing, hot dry cycles. Don't forget about that overlooked hero, Heat. The most important disinfection process of all, autoclaving surgical instruments, doesn't use any special chemicals at all, just heat.

And sometimes you have to just bite the bullet and throw contaminated things away. If that thing is your yard, digging out the contaminated soil and throwing it away, or burying it in a thick layer of mulch may be a better answer than trying to clean it. Speaking of...

Soiled soil
Yes, it's tough when an outdoor area is contaminated by something nasty and contagious. The most porous and dirt-laden place of all is the same place most likely to be contaminated when you have a sick pet. Most of our worst enemies like parvo, panleukopenia, crypto, and ringworm can live for a long time in the soil. Many pet websites (and a lot of veterinarians) recommend, in addition to other protocols, at least giving a chemical disinfectant a try on your yard if you've had for example, parvo dogs pooping there. I could probably get on board with the idea of giving it a try, just in case it kills a few baddies, except for one problem: if it doesn't work, (and the science tells us it probably doesn't) you won't be able to tell, and you risk getting complacent.

Dealing with contaminated clothing is almost as fraught as a contaminated yard. Yes, some bleach products are labeled to disinfect clothing - but in a very limited way: Adding the correct amount to a load of laundry in a washing machine run with cold water that doesn't contain very much organic material. In which case, the action of the detergent and water alone may physically remove more germs than the bleach will kill.

The problem is, I've seen way more people using bleach incorrectly with clothing than any other application. I've observed multiple professionals (veterinarians, certified vet techs, nurses) recommend spraying contaminated clothing with a bleach solution (or other disinfectant, like a quat, usually). This isn't doing jack sh*t. I totally understand you want to feel like you're doing something, but using it this way isn't just useless, it may make things worse by encouraging less caution with the (still contaminated) clothing.

Proper use of bleach: an original mnemomic, just for you!

If you have a non-porous thingy to disinfect, remember to S.W.A.P.

Stay cool! Heat kills bleach (aka, it accelerates the loss of the chlorine ions before they can do their work). Mix with cold water only; if you're going to use in a washing machine, set it to cold; don't use bleach on something hot, like recently washed dishes.

Wash First! -- always pre-clean before disinfecting.

Alone! -- Bleach works best alone. Don't mix it with anything besides water. Unless you're experimenting with re-creating mustard gas, and want to burn your lungs out, then by all means.

Yes, I know they make "cleaner and disinfectant in one" products that had to have passed some efficacy tests before being sold. Buy them if you can afford it, but please, please, don't try to mix your own. Don't try to mix in an essential oil because you don't like the smell of bleach (yes, I once had to stop a volunteer from doing this at the shelter).

Proper dilution! more is not always better. Believe it or not, for some germs, more concentrated bleach doesn't work as well as properly diluted bleach - I suppose it would be as if Super Bleach were all hopped up on Angry Acid and screamed the whole time he ran down the street before attacking the bad guys' hideout - announcing his presence so forcefully would give the bad guys a chance to run away (non-enveloped bacteria link). The perfect dilution of Bleach allows it to punch through the bad guy's defenses with exactly the right amount of force and speed to complete demolish them it before they know what's happening.

OK, that's one of the worst mnemonics I've ever heard, but you get it.

Now, go forth and kill some parvo!

Bleach factsheet from the NIH
Bleach factsheet from the CDC
Cleaning and disinfecting in shelters
UW FAQ on killing parvo
UC Davis FAQ on killing parvo in yards
Resistance mechanisms of bacteria to antimicrobial compounds (PDF)
Antiseptics and Disinfectants: Activity, Action, and Resistance
Bacterial resistance to disinfectants containing quaternary ammonium compounds
How long can different germs survive on surfaces?
Air temperature greatly affects how long crypto can live on the ground: one day vs. 73 days

Image description: a crude cartoon drawing of a anthropomorphized bottle of bleach, labeled "super bleach" and wearing a mask and cape, as it faces off against a blob of brown substance containing anthropomorphized microorganisms, who are frowning at the hero.

Wednesday, February 7, 2018

Who to blame for shelter dog euthanasias?

So, you saw a sad advertisement on social media about shelter pets dying from "lack of homes". You got sad, then you got mad. Time to blame someone! Odds are good, whoever made the ad already has a target handpicked: Is it... breeders? "irresponsible" pet owners? Maybe the solution is to punish people more, to enact more laws, give the maker of the ad money?

It feels good to blame "the other" for bad things. It's human nature. But let's all take a breath and consider what's really going on. Since the odds are good that the ad you just saw fudged or outright lied about some statistics, let's start with...

Real Numbers* 

About 670,000 dogs are euthanized in US shelters per year. Of those, about 10% are euthanized for a good reason** (ie, the same reasons that a compassionate pet owner would). So, the number of deaths-from-lack-of-home is actually about 570k.

Good news: There are about 78 million pet dogs in the US, so 570k dogs represents less than 1% of the dog population as a whole. Overall, we as a society are doing pretty good by our dogs. Let's not lose sight of that.

More good news: this number has been dropping steadily and significantly for the last couple decades. Also, the numbers of dogs entering shelters has been declining, the percentage being adopted has been increasing, and the number of strays returned to owner has been increasing. Something to celebrate!

Even more good news: even though it's still a large, sad number, there are actually more than enough homes available for these dogs***. It is a complete myth that there is an "overpopulation" of dogs in this country. It might have been true in the 1960's or '70's, but now it is not. There are 17 million potential homes, and only 570,000 dogs killed for "lack of a home". The only real question is, how to get them into the hands of people who are looking for them?

Logically, since things are already improving every year, if we want to end unnecessary euthanasia. we should focus on the things that work, and keep doing them but even better. The solution to needless killing has nothing with dog breeders, and actually not even all that much to do with the people who relinquish their pets to a shelter. The problem, and the solution, lies mostly with with the decisions that shelters make.

Bottom line: well-functioning shelters have low euthanasia rates; poorly-functioning shelters have high euthanasia rates. All other factors are drops in the bucket compared to the importance of shelter policies and procedures.

What do "good" animal shelter policies look like? They have pet retention programs, they work actively to promote adoptions, actively work to reunite lost pets with their owners... etc.


What does a "bad" animal shelter look like? They don't do the things listed above. Here's some examples.

Some more examples contrasting good vs. bad policies, and how they affect euthanasia rates.

Here's a story of how a bad shelter became a good one.

You still mad about dogs being killed? Good! Use that anger to personally improve the kill rates in your local shelter. If it's already a good shelter, or is on the right track, you can volunteer or otherwise support them. If it's a bad shelter, you can help them get on the right track, or, if they're stubborn, you can speak out, protest, boycott, attend city council meetings... all that good stuff. Be an actor, not a keyboard warrior. And don't share memes without checking them out first.

Maybe you're already very active in the rescue community, and you're angry because it seems like, where ever you turn, you see irresponsible people dumping their pets at shelters. I'm here to remind you that what you see is never the full story, if you knew what people go through when they surrender pets, you wouldn't be so quick to judge, and, even if they are the worst people in the world, they represent a tiny, tiny fraction of dog life in the US. Don't let your anger blind you to the fact that things are getting better all the time, not the reverse. Don't use your anger to spread lies and fear monger. Don't lash out at potential allies like dog breeders. Look at the numbers above and take a moment to celebrate before turning back to the work.

*There is no national organization that tabulates these stats, they vary from state to state, and even from shelter to shelter. I'm using the best estimates available at this time.

**"Good reason" is extremely subjective, and is open for discussion, most knowledgeable people in the field agree that an appropriate "kill rate" for shelter population is somewhere between 1%-20%. I've taken a middle number here for math purposes.

***This is grossly oversimplified, because clearly not every dog will be right for every family, and the US is just too physically large to move dogs around easily, and we can talk about the issues with these numbers, BUT, the point is clear: you can't say that an "overpopulation" exists.


Pet Statistics for 2016 (ASPCA)

ASPCA Research Articles

An Exploration of the Re-Homing of Cats and Dogs in the U.S. (PDF)

Shelter Reform Toolkits

KC Dog Blog

Association of Shelter Veterinarians Shelter Guidelines (PDF)


Saturday, September 23, 2017

Apple cider without a press


Do you have apples and a wish for fresh cider, but don't have the money/time/space to buy/rent/build a cider press? Then I have the solution for you!

Freeze 'em. Thaw 'em. Core 'em. Squeeze 'em with a lemon juicer. Strain, pasteurize.
It does not take as long as you'd think to hand-squeeze cider; frozen and thawed apples are softer than lemons.

Wednesday, May 10, 2017

Sunday, April 9, 2017


We bought a house in autumn 2016. It's in an old neighborhood with lots of old, established trees and shrubs and things. I'm trying to replace all the invasive ornamental plants with native ones. Here's the progress so far:

Pulled out all the english ivy that's creeping in from the neighbor (some day, I'll see if they'll let me kill all their ivy, too), and pulled out all this viney ornamental weed in the shade garden, whatever it was (it used to cover all the ground between the house and the path below).

Despite some slug damage, the wild ginger I transplanted last autumn is doing well, so I went out to the parents' property and liberated some more, plus some other native plants, mostly for the shade garden. Scored some sword ferns, oxalis, bleeding heart

I also got a couple cuttings of salmon berry, and salal.

We'll see how they root.

This clump of dirt and moss pictured above is actually a very old sword fern that was living next to my parent's house.

Here it is the oldest photo I can find of it, c. 1985, but it might have been growing there for many years before that. The house was originally built in the '30's or '40's. Dad's been thinking of killing it for years because it blocks one of the vents, so I saved it. Let's see how it likes being a suburban fern.

On a related note, it is surprisingly hard to find out how long a sword fern can live. Individual fronds only live a few years, but the rhizomes can obviously live for decades. If anyone knows of a reputable source that has this info, I'd love to know.