Wednesday, July 8, 2015

What disinfectants should be used when cleaning up after animals?

dog dishwasher rinse cycle
Dishwashers need to operate at 60 degrees C to kill most pathogens - especially if they incorporate an extra "rinse" cycle.

What disinfectant do you use to clean up after animals? What is the best disinfectant for vet practices to use? It seems like a simple question, but disinfectants have a LOT of work to do. We rely on them to control infectious diseases. 

According to a panel of feline experts, “the cornerstone of good hygiene is effective disinfection” (Addie et al, 2015). 

Appropriate disinfection, as part of a good cleaning regime, will save lives. 

They’ve just published guidelines on disinfectant choices for feline environments – but the guidelines can be applied to dogs also.

In nature animals are more spread out so there is usually less density of bugs. In households, shelters and vet hospitals, animals are closer together, exposing them to unnaturally high levels of pathogens.

The hardest bugs to kill include parvoviruses (that includes feline parvovirus or panleukopenia virus), protozoal oocysts, mycobacteria, bacterial spores and prions. The best way to kill these is heat, under pressure, which is fine for autoclaving surgical equipment but not appropriate for human hands or animals.

A very important consideration when it comes to choosing an appropriate feline disinfectant is that they are susceptible to toxic effects not necessarily seen in other species. For those who want the detail, cats lack the enzyme UDP-glucuonosyl transferase, which is used by other species to detoxify agents like phenols. It is believed that because cats are true carnivores they’ve not been historically exposed to plant toxins and thus have lost the ability to metabolise these via glucuronidation (the use-it-or-lose-it approach to evolution). This is one reason why essential oils should not be used in cats.

Another quirk of cats is that they spend 5-25 per cent of their time grooming so tend to orally ingest just about anything in the environment if they walk, sit or lie on it. 

cat grooming
Hero grooms his little paws.
So while it is important to choose a detergent that blows bugs out of existence, it needs to be safe to animals and humans.

Other key points are:
  • Dishwashers and washing machines should operate at a temperature of 60 degrees Celsius to eliminate spores and viruses;
  • Alcohol, especially ethanol, is very good at killing enveloped viruses and is not easily contaminated – but it’s not so good at killing the non-enveloped viruses;
  • Bleach is very effective and very safe IF it is not inactivated by organic material, heavy metal ions, biofilms, low temperature, low pH or UV radiation. In other words bleach needs to be applied to a clean surface (this applies to most disinfectants really);
  • Chlorhexidine which is commonly used as a skin scrub is easily contaminated and not as effective as alcohols;
  • Quaternary ammonium compounds such as benzalkonium chloride are not recommended. While they are effective against some pathogens there is increasing documentation of resistance, and not just to these products but a cross-resistance can develop to antibiotics including drugs like chloramphenicol;
  • No single disinfectant will kill everything we want it to, so it’s important to do an inventory of the cleaning products in your hospital, shelter or home. As antibiotic resistance is an increasing issue, we will be relying more on disinfectants.

According to the authors, we may be seeing an increased use in UV radiation and products containing silver being used for disinfection in the future. They recommend cardboard litter trays in outbreak situations and this seems like a very good idea in a veterinary hospital context, bearing in mind the waste that may be created. Of course there are other important things we can do to reduce the risk of infectious diseases - isolating unwell animals, avoiding over-stocking or over-crowding (which is not just bad for the physical but also the emotional and mental health of animals, as it is for people) and appropriate vaccination.

You can download and read the guidelines hereYou can also subscribe to the guidelines at the website.

Reference


Addie DD, Boucraut-Baralon C, Egberink H, Frymus T, Gruffyd-Jones T, Hartmann K, Horzinek MC, Hosie MJ, Lloret A, Lutz H, Marsilio F, Grazia Pennisi M, Radford AD, Thiry E, Truyen U, Mostl K (2015) Disinfectant choices in veterinary practices, shelters and households: ABCD guidelines on safe and effective disinfection for feline environments. Journal of Feline Medicine and Surgery 17:594-605.