Sudden Aggression in Multi-Cat Home

Question
We have 4 female, spayed indoor (always) cats. Two are 11 yrs and two are 6 yrs old (they are litter mates).  Taffy, the biggest 11-yr-old cat has been "top cat" in the house forever.  When we had only two and after introducing the two kittens 6 years ago, she has maintained dominance.  She tolerates all the other cats, eats, sleeps alongside them -- but definitely made it known she is the boss and to be left alone.

2 months ago, the two 6-year old cats suddenly started stalking and attacking Taffy.  They corner her, follow her, attack her, swat at her and chase her relentlessly around the house (2,500 sq ft).  These episodes are happening several times a day.  All 4 cats are eating fine and using the litter box as always.  Taffy is getting edgier and seems afraid of the 6-year old sister cats.  She seems to be in good health and we can see anything that would communicate a vulnerability to the other cats.  Ideas?!?

Answer
Judie,

At 11 years old, Taffy is considered geriatric.  The biggest problem in geriatric cats is teeth and gums.  Neck lesions (a.k.a. cavities) in molars can lead to pathogens directly invading the body.  Teeth with neck lesions should be pulled! The organs responsible for cleaning the blood, the kidneys and liver can have problems because of this.  You might take Taffy into the vet and have the teeth checked and the kidney and liver numbers checked out.

Kidney disease is one of the biggest killers of domestic cats.  Unfortunately, the cats body can compensate for a number of problems, so when the numbers begin to get elevated, the kidney may only be 25%-30% functional.  Furthermore, cats are very stoic and so may conceal feeling puny from their human owners.  If the litter is getting saturated faster and water consumption is significantly higher, that is an early warning sign of kidney problems.

If you have not had Taffy to a vet, that is the first thing I would check out.

Other than that, it is difficult to find out if anything else happened to unseat Taffy from being the alpha cat.  Even worse, there is nothing you can do to help.  In fact human interference will only make things worse.  Cats must be left to establish and re-establish their inter-relationships on their own.  I already cited one reason.  The other reason is that we plain do not understand how cats do relate to each other.

On the brighter side, the fact that Taffy is eating properly and using the litter pan properly is a bright sign in all this.  If she were really upset, she might not being doing either correctly.  So, if there is something amiss medically, it is not too bad yet!!!!!

Please let me know how it goes.

Best regards... Norm.