Cat hoarding has been in the news in the Toronto area a few times lately. Multiple incidents of serious cat hoarding have been identified in the past month, involving large numbers of cats being kept in horrible conditions. It’s not hard to see how cat hoarding can create infectious disease challenges. I can’t see how anyone could keep a large number of cats in a house without problems, even if they worked very hard to keep things under control. Add together the  issues of keeping massive numbers of cats in a confined space, no veterinary care, poor nutrition and limited hygiene, and you can see how the cats and the building would quickly become biohazardous. Add in mental health issues and hoarding of other objects (both or which are also common in such situations), and you get a house that’s a cesspool, fire hazard and no place for humane housing of any animal or person.

When cat hoarders are investigated, there are often dead cats found in or around the house. There are also often cats that end up being euthanized promptly because of severe disease. A wide range of diseases can be encountered in such cat-dense and hygiene-deficient situations. Mostly, the typical feline diseases are found, including vaccine-preventable illness and a whole range of opportunistic bacterial infections. However, these cats can be very compromised and therefore prone to rare infections as well. A recent report describes one of these unusual infections. The report (Brooks et al, Veterinary Microbiology 2013) describes extraintestinal pathogenic E. coli (ExPEC) infection in one of about 60 cats from a hoarding situation. The cat died and the bacterium was found to be the cause of pneumonia and kidney abscesses.

Is this a major concern for feline health? Not really. This is presumably a rare infection that occurred in a highly compromised cat, and not the crux of a new problem. However, it shows the wide range of diseases that can occur and, probably most importantly, that some of these infections are zoonotic: ExPEC is actually a significant human health concern, since it can cause similarly severe disease in people. It’s been previously shown that people and pets can share the same strains of ExPEC within households, and pets have been suggested as being a potential source of some human E. coli urinary tract infections (another form of ExPEC infection).

In the hoarding situation with the ExPEC-infected cat, there was concern not only for people who had contact with the cat, but a wide range of emergency responders, public health personnel and probably many other people who entered the house (since one cat with disease probably means many cats shedding the bacterium in their feces, which means lots of contamination in the hoarder’s house).

Dealing with hoarding is a complex problem because of typically weak laws, reluctance to enforce laws, mental health issues and a range of other challenges. Early identification of hoarders with proactive intervention – before the place becomes a disaster – is important, but easier said than done.