Composting pet waste
An article in Saturday's Toronto Star discussed composting options for people without organic waste pickup or the ability to have a backyard composter. The article discussed indoor composters that can be used by apartment or condo dwellers who want to satisfy their eco-friendly side.
One of the composters they highlighted states that you an add pet waste, but that's not a good idea. Pet waste can contain a wide range of potentially harmful parasites and bacteria. The composting process can generate enough heat to kill relevant bugs, but it's not guaranteed to do so, and I'd be especially concerned about small indoor composters. Having a few nasty things in the composter itself isn't necessarily a big deal, but what happens down the line? People can be exposed to these microorganisms when removing compost. Also (and maybe more importantly) compost usually ends up in gardens and can contaminate the soil, as well as anything grown in the garden.
One of concerns is the protozoal parasite Toxoplasma gondii. Cats are the natural reservoir of the parasite and can transiently pass it in their feces, yet most people that become infected are likely exposed outside in gardens or from contact with contaminated foods. Composing may not kill toxo, and therefore lead to a risk of exposure, particularly when compost is put into flower gardens that people work in or in vegetable gardens. The risk from an individual animal is admittedly low, since cats are rarely shedding this parasite (even though most have at one point), but it's a preventable risk. There are also various other microorganisms that are potential concerns. While composting is a great way to dispose of most organic wastes, it's best to keep putting dog and cat feces in the garbage or down the toilet (and wash your hands).
If you really feel the need to compost pet waste, the safest alternative is probably to have a separate composter for pet waste that you handle differently....pay careful attention to hand hygiene after handling the compost and make sure the compost doesn't get deposited in gardens or other areas that people might frequent.
International Pooper Scooper Week
I guess there's now a week for absolutely everything. aPaws, the Association of Professional Animal Waste Specialists (no, I'm not making this up) has declared April 1-7 to be International Pooper Scooper Week. The overlap with April Fool's Day is apparently just a coincidence. This group was formed in 2002 in recognition of "the growing problem in our communities, environment and water tables" associated with, yes, dog poop.
The American Pet Association estimates that over 4.4 billion pounds of poop are produced by the some-71-million dogs in the US each year. That's enough to cover 900 football fields with 12 inches of dog waste. (That is some deep do-do!) Dog feces can contain a wide variety of bacteria and parasites, some of which can infect other dogs, and some of which can also infect people. The risk to people and other animals is greatly reduced by prompt removal of feces and proper disposal (i.e. stoop and scoop). It's a pretty simple concept: if your pet poops outside, pick it up. Use a plastic bag, seal it, deposit it in the garbage, then wash your hands (or use an alcohol-based hand sanitizer if you're out for a long walk and there's no sink handy). Most people are conscientious about this, but one look around most parks will show you that not everyone is (and unfortunately that can give those of us who do stoop and scoop a bad name!).
Photo source: http://www.freewebs.com/pooridder/
Updated: Speaking of Baylisascaris...
This post has been updated with new information as of October 2, 2008.
An article was published on Sunday in a local Guelph newspaper about a 14-month-old child who has been battling infection with Baylisascaris larvae in a Hamilton (Ontario) hospital for the last two weeks. This comes on the heals of a very recent Worms & Germs post about Baylisascaris procyonis - the raccoon roundworm.
The disease caused by migration of Baylisascaris larvae through the body - visceral larval migrans - is uncommonly diagnosed in North America, although it may be more common than we think because it is difficult to diagnose with certainty, and the signs in mild cases may be very non-specific. The most severe form of the disease is called neural larval migrans, which occurs when the larvae migrate through the brain or spinal cord, as in this most recent case.
The parents of the toddler in the article, a toddler who is still blind and cannot sit up on his own as a result of his infection, have a message for parents: keep raccoons out of your yard and away from your house. The disease may be rare, but the effects can be devastating, and the risk can be significantly reduced by a few simple steps:
- Keep garbage in tightly-sealed containers.
- Clear brush and seal openings in buildings where raccoons may nest or form latrines.
- If you find raccoon stool or what appears to be a raccoon latrine on your property, clean it up very carefully. Follow this link for more information on identifying and cleaning up raccoon latrines.
- Always wash your hands well after you've been working outside in soil, dirt or water which could be contaminated with raccoon feces.
For more information, see the last Worms & Germs post about Baylisascaris.
Updated: Raccoon Roundworms - Baylisascaris procyonis
This post has been updated with new information as of October 2, 2008.
Raccoons, just like dogs and cats, can have roundworms in their intestine. Dogs are typically infected by the species Toxocara canis, and cats are infected by Toxocara cati. Raccoons are infected by a type of roundworm from a different genus, called Baylisascaris procyonis. There is one thing that all three of the parasites have in common – the larvae of these worms can infect humans, causing a condition called visceral larval migrans.
Dogs and cats are usually dewormed as puppies and kittens, and often as adults as well, which dramatically decreases the number of pets that are infected with roundworms. Raccoons are not so lucky – in the northern and northeastern parts of North America, over 70% of raccoons may be infected with Baylisascaris. In Ontario, it has been estimated that only about 20-30% of raccoons are infected, but usually with high numbers of worms. In either case, younger raccoons are even more likely to be infected. Infected animals may shed millions of parasite eggs in their stool, and the eggs can survive in the soil for months or even years.
After a few weeks, the eggs in the raccoon stool become infective. If a person swallows the eggs, they hatch in the small intestine and release larvae. These larvae can then burrow through the wall of the intestine and migrate through tissues all over the body, causing tissue damage and inflammation. The signs of illness are often not very specific, and may include things like fever, fatigue and nausea. If the larvae migrate through the brain or spinal cord, a person may develop neurological signs like loss of coordination and muscle control. This is called neural larval migrans, which is the most serious type of disease caused by these larvae. If the larvae migrate through the eye, they can cause blindness. This condition is known as ocular larval migrans.
There have been less than 25 cases of confirmed visceral larval migrans due to Baylisascaris in the USA as of 2003, but the condition is very hard to diagnose with certainty, and it is possible that many cases are mistaken for other illnesses. The disease is also very difficult to treat, and neurological damage from neural larval migrans is usually permanent, so the best thing to do is prevent infection in the first place. Here are some tips on avoiding Baylisascaris:
- Avoid contact with raccoons. Many people think raccoons are cute, but they are wild animals. Raccoons are also a risk for transmission of rabies if a person is scratched or bitten. NEVER keep a raccoon as a pet.
- Discourage raccoons from hanging around your house. Clear brush and seal access to basements and attics where raccoons may try to nest or form latrines. Keep garbage in tightly-closed garbage cans. Eliminate outdoor water sources.
- Always wash your hands well with soap and water after working with soil (e.g. in the garden).
- Clean up raccoon latrines. This must be done very carefully - avoid getting any raccoon stool on your hands or clothes. The stool should be burned, buried or sent to a landfill. Clean the area where the stool was found with boiling water. Wash your hands very carefully when you’re done. Follow this link for more detailed information on how to identify and clean up raccoon latrines.
Baylisascaris procyonis less commonly infects animal species other than raccoons, including skunks, and it has even been found in dogs. It's important to have your dog's stool examined for parasite eggs on a regular basis (typically once or twice a year) and to follow your veterinarian's recommendations for deworming your dog.
More information about Baylisascaris is available on the CDC’s Baylisascaris Infection website.
Dog stool and garbage
For approximately 20 years I have been involved in waste collection for the Parks Division. A considerable amount of the waste which I collect on a daily basis is dog excrement. This is usually, but not always contained in a plastic bag and thrown into a large garbage barrel which I man-handle and dump in a waste truck. Years ago I contacted the local Health Unit and asked if there was any special health risks associated with this job. They advised me at that time the main danger to health would be with E.coli contamination. I use neoprene gloves while carrying out my duties and of course try to ensure that I do not come in contact with any debris. This is not always possible.
There are 3 main risks with handling dog stool: exposure to bacteria that cause diarrhea, exposure to intestinal parasites and infection of wounds.
Various bacteria that can cause diarrhea can be present in dog stool. These include Salmonella and Campylobacter. E. coli is not a major concern because strains found in dogs are not typically those that cause disease in people. A few intestinal parasites are also of concern, including Giardia and roundworms. The risk of exposure to these is hard to say because you don't know anything about the health status of the dogs, but it's wise to treat all stool as infectious. However, for these to cause disease, they must go from the garbage and into your mouth. The risk of this should be minimal with basic common-sense precautions.
A large number of bacteria present in stool can cause infections of wounds like cuts and scratches, or other skin lesions such as eczema. Direct contact of these lesions with stool would be required to cause infection. The risks of this can also be greatly reduced with basic preventative measures.
Some basic precautions (many of which you are doing) include:
- Wear gloves when handling bags containing stool.
- Change your gloves if they become contaminated with stool.
- Have your gloves cleaned periodically, and whenever they become contaminated. Otherwise, use disposable gloves.
- Promptly wash or disinfect your hands if they become contaminated. Carrying an alcohol-based hand sanitizer in your truck would be useful.
- Wear coveralls or some other sort of outerwear that can be removed easily if contaminated. If your clothing becomes contaminated, change it (and wash your hands after).
- Wash your hands after removing your gloves (and especially before eating).
Overall, the risks to you should be very low.
