Minus the hoarding my mom became like this. She reeked of smoke, mildew, animal waste from her Hoard home. She'd get angry if anyone brought it up.
Self neglect to the degree you describe may be bad enough to require professional intervention by a social worker from Adult Protective Services. You might start by making an anonymous call to a local agency for guidance. Given she's your husband's mother, it would be good to get him on board.
In a similar vein, my T told me, "you have a home not a hospital, and your mother requires professional help that you can't provide."
From:
www.napsa-now.org/get-informed/other-safety-concerns-2/
These are commonly reported signs of self-neglect* reported to Adult Protective Services agencies:
Inadequate heating, plumbing or electrical service disconnected
Pathways unclear due to large amounts of clutter
Animal feces in home
Residence is extremely dirty, filled with garbage, or very poorly maintained
Not cashing monthly checks
Needing medical care, but not seeking or refusing
Lacking fresh food, possessing only spoiled food, or not eating
Refusing to allow visitors into residence
Giving away money inappropriately
Dressing inappropriately for existing weather conditions
* Definitions of self-neglect vary from jurisdiction to jurisdiction. Please contact your local APS office for additional information.
When To Report Other Safety Concerns and Self-Neglect?
If you witness a life-threatening situation involving a senior or adult with disabilities, immediately call 911.
Contact your local Adult Protective Services agency anytime you observe the following:
Appearing disheveled, routinely in soiled and/or rumpled clothing
Appearing with strong odor of feces or urine
Displaying matted or lice-infected hair
Appearing malnourished and/or dehydrated
Appearing inappropriately attired for climate
Living with serious untreated medical conditions and refusing treatment
Living in squalor, dilapidated building or other hazardous situations
Challenging to safely exit or enter residence due to hoarding/cluttering
In reading this, I should have reported my own mother at least two years before. I whimped out thinking my mother would never forgive me. I got a call from a sheriff's deputy who saw the conditions and encouraged him to report. So trust me, I get it if you have any hesitancy to go down this path... .