Mental illness can be acquired from cats.
We just had a very bad case of cat hoarding discovered this year in this area. There were over 50 cats in a very nice-looking suburban home. The cats had taken over the house, and destroyed the interior of it. There were some dead cats found there, and the people had moved out eventually, just coming there to feed the cats! The entire place had to be condemned until it could be completely emptied and fumigated. I consider this a form of mental illness. I think that the mental illness might have existed before the cats -- they might have had OCD, hoarding, or ADD or some other problem first -- but they also could have gotten mental effects from exposure to cats first.
There is research that shows that the toxoplasmosis bug actually has figured out a way to enter the brains of rats and eliminate their natural fear of cats. The infected rats are then easier to catch, because they actually are attracted to the cats' urine (pheremones) instead of repelled by them. The reason this seems to be necessary for the bug, is that this bug can only reproduce inside of cats, not rats, so the bug has to somehow get itself from inside the rat to inside the cat in order to procreate.
This same bug can infect humans. However, does the bug know where to go inside a human's brain, since the human brain is so much larger than a rat's? (In most people.)
I think it gets to the human brain and gets lost there, possibly affecting other areas of the brain than intended. Perhaps this means that infected humans get a chemically enhanced love of cats from this infection, also causing other kinds of mental abnormalities. This mental illness then causes the infected person to harbor more cats than they would have otherwise (if not infected by toxoplasmosis), but with less mental organizational capability to care for them in a sanitary way, causing even more infection and disease for both the cats and the people. If the bug causes rats to be attracted to cat urine, this could explain why the people who own lots of cats don't seem bothered at all by their urine and litter, and stop cleaning up after them.
Other illnesses acquired from cats:
Bartonella (Rochalimaea) henselae (cat scratch fever)
Bergeyella (Weeksella) zoohelcum
Chlamydia psittici (feline strain)
Cutaneous larva migrans
Plague (Yersinia pestis)
Visceral larva migrans
NIMH Neuroscience Center, St. Elizabeths Hospital, Washington, DC 20032, USA.
Studies have suggested that some cases of schizophrenia may be caused by viruses. We hypothesize that such cases may be cases of viral zoonosis transmitted primarily from house cats. Epidemiological aspects of schizophrenia and a case-control questionnaire support this hypothesis.
Recent epidemiologic studies indicate that infectious agents may contribute to some cases of schizophrenia. In animals, infections with Toxoplasma gondii can alter behavior and neurotransmitter function. In humans, acute infection with the cat virus "T. gondii" can produce psychotic symptoms similar to those displayed by persons with schizophrenia. Two other studies found that exposure to cats in childhood was a risk factor for the development of schizophrenia.
Whether any geographic association exists between the prevalence of toxoplasmosis and the prevalence of schizophrenia is unknown. France, which has a high prevalence of Toxoplasma-infected persons, was reported to have first-admission rates for schizophrenia approximately 50% higher than those in England (41). Ireland also has a high rate of Toxoplasma-infected persons in rural areas (42)
Dr. Robert H. Yolken, the director of the Stanley Laboratory at Johns Hopkins University, and his colleagues reviewed military medical records. They found that soldiers who developed schizophrenia were twice as likely as other soldiers to show signs of Toxoplasma infection in blood samples."
People with cats should all be tested for cat transmitted diseases, particularly if they show any signs of mental instability. Children should also be kept away from cats and cat litter boxes. And where cats are allowed to roam outside should always have shoes on. Outdoor children's sandboxes should be kept covered.