Are cats really so bad for our health?

IS Your cat affecting your mental health?

I don’t mean their incessant yowling or the way their claws damage your furniture. What I’m talking about is how cats can carry a parasite called toxoplasma gondii that may affect how you behave and could even trigger depression.

A study has found an association between the infection and the extreme premenstrual tension experienced by some women.

The idea that infections can alter our mind may sound like something out of science fiction, but there are instances where we know this happens.

The bacteria Treponema pallidum — which is responsible for the sexually transmitted disease syphilis — can, if left untreated, cause neurosyphilis, symptoms of which include depression and psychosis. It can also affect memory.

I once saw a patient who had been wrongly diagnosed with Alzheimer’s when his memory problems and confusion were down to a syphilis infection that he probably contracted while in the Navy many decades previously.

There’s another condition known as PANDAS (paediatric autoimmune neuropsychiatric disorders associated with streptococcal infections) which affects children. It is caused by a bacteria which can trigger a reaction that results in either Obsessive Compulsive Disorder or Tourette’s syndrome — a psychiatric condition where the sufferer has uncontrollable tics or swears inappropriately.

While it’s perfectly possible that parasites in cats can affect human behaviour, I fear the dangers are exaggerated. It might be easy to blame some microscopic bug — indeed, some researchers claim toxoplasma gondii can cause road rage — but the truth is that we humans have the power to moderate our behaviour.

So don’t blame the cat when you feel moody. That’s just a cop-out.