Question:

What recommendations can you provide for stainless steel dish sanitation in shelters? How effective is a dishwasher at disinfecting feed bowls?

Answer:

Thank you for your inquiry about dish sanitation. When cleaning stainless steel dishes, as with other hard surfaces, a three-step process should be performed;

1. Removing of all organic material/debris, such as feces,
2. Applying a detergent product, and
3. Applying a disinfectant.

We recommend using Rescue^TM (Accelerated Hydrogen Peroxide) as it can act as both a detergent and a disinfectant, and it maintains efficacy in the presence of organic material. Therefore it allows you to combine steps 2 and 3 noted above. We recommend using a concentration of 1:16 (8oz/gal) with at least 5 minutes of wet contact time, or 1:32 (4oz/gal) with at least 10 minutes of wet contact time. Bleach can be used, but we do not prefer it as it requires use of a detergent beforehand and will get deactivated by any organic material.

Your shelter's current guidelines utilize this process with bleach and are appropriate for proper dish disinfection, if all organic material is properly removed. The use of a dishwasher can improve efficiency based on the model. Within a healthy population, a standard dishwasher or thorough mechanical cleaning are likely sufficient in removing pathogens without needing an additional disinfectant step, as long as all organic debris is completely removed.

In cases of where infectious diseases are of more concern (active outbreak, high prevalence, etc.) some dishwashers have a sanitation cycle which allows for the addition of a disinfectant (Rescue or bleach) or has a steam sanitation cycle that may replace both step 2 and 3 listed above. It is important to note the temperature which is reached during the sanitation cycle, as temperatures greater than 180 degrees Fahrenheit are needed to inactivate resistant pathogens such as parvovirus. Each dishwasher is different. Discussion with a manufacturer prior to purchase or use will allow for discovery of information regarding sanitation cycles and maximum temperatures reached.

Please let me know if you have any further questions,

Emmy Ferrell, DVM MS
Shelter Medicine Resident
Oregon Humane Society
On behalf of UW Shelter Medicine Program
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