In my experience it is not unusual for a cats fur to change color to some extent during the course of its life. The sun may well bleach darker colors lighter and this even can occur indoors if your cat spends time in the sun at the window or glass door. It is interesting that the color change is mostly the back and sides, which would be exposed to the sun most.
Certainly diseases may cause coat changes including color, however, there would likely also be other indications. If your cat is 6 or 7, it would be wise to have some basic laboratory work done to rule out underlying systemic disease (blood, urine) and if these are normal, I would do as you have suggested, and not worry about it.
On the other hand, if abnormalities are found, pursue them. I would also have laboratory work done at least yearly from now on, to allow the earliest detection of the problems that develop with advancing age and to enable you to treat them early.
It has been said that the eyes are windows to the soul; I think the skin is a similar window, but to the bodies' overall health. Many times with systemic illnesses, the skin and coat will be abnormal as well, as the body becomes less able to sustain a normal appearing skin. Remember the skin is always protecting against the hostile environment and requires bodily maintenance. Only a fully healthy body can accomplish that maintenance adequately. An abnormal skin or cot may portend another problem.
Please have some lab work done, and if normal, then do it again next year.
Dr Arnold L. Goldman
Thank you for such a thorough response. I have an apt. on Saturday- my instinct is that it is related to the sun- as she does spend a lot of time in the windows on her perch. In addition- she did have that food change so maybe there is some mild deficiency going on there. But I will take her in to see. If it is from the sun, should that get better in the fall when the sun isn't as strong? wondering if I should just wait it out a bit longer and see if it goes back to its darker grey color.
The only other thing I forgot to mention is that Fluffy has a history of yeast infections and severe wax buildup in her ears- about once a year- sometimes twice- they always seem to come back...not sure if that is connected or if that is a common problem in some cats. Otherwise she is acting perfectly fine and her appetite is great. thanks- Jennifer
I think bleached fur will stay bleached, until replaced by new fur. If you were to limit sun exposure you just might see more "normal" color near the roots of still growing fur, as the fur grows out and is replaced, much like a brunette whose bleached blond hair begins to grow out (no offense to anyone!). But most pets fur grows discontinuously and simply falls out as a new hair begins, unlike us where growth is continuous.
"Infections" in the ear canals may be multifactorial but are most often secondary to other problems. For example seasonal allergies with itchiness and self trauma (scratching, shaking, rubbing) may lead to excessive discharge among other things.
I am skeptical that would be connected to overall fur color changes.
Very best to you,
The only thing that I would add to Dr. Goldman's excellent responses is that this color change could be due to a phenomenon called "phorphyrin staining". Basically, when cats or dogs consume a food that includes animal tissues that has hemoglobin (from blood) or myoglobin (from muscle) in it, one of the compounds in these two proteins is called a phorphyrin ring. When the body uses these compounds for energy or to build tissue, a breakdown product of phorphyrin is excreted, partially in saliva and also in tears. When the cat grooms, she deposits this onto her coat. Interestingly, when phorphyrin is exposed to sunlight, it turns a dark brown color! This is completely harmless, but can cause a pet's coat to turn a reddish-brown hue in affected areas and is also responsible for the dark tearing taht you see around the eyes of some coated white dogs.
Since you changed foods about one month ago, it is possible that your new food has a higher level of animal-source protein in it, and thus would be expected to cause more phorphyrin staining on your cat's coat. (One way to check for this is to look at an individual hair. In phorphyrin staining the color will be deposited on the part of the hair shaft that the cat grooms and will not be found at the base or throughout the hair. If color change occurs in bands, this suggests something systemic, rather than topical as in phorphyrin staining.
Thank you Linda- this may sound stupid- but what part of the hair is the shaft and what part is the base? Is the hair shaft like the root for us? The brown I can definately see is the part of her fur that is obvious to the eye- I havn't actually looked at the root to see if it is a different color. And when you say "if it occurs in bands"- what does that mean? sorry for the stupid questions...Im an amenture!
Not stupid at all, Ms. Catgirl. I was typing fast, so may not have explained it well. If a color change is applied topically (licking, from shampoo or conditioner), it will appear only in the part of the hairs that are touched by the treatment. So, if it is licking, if you pull out a hair (carefully!), you will see that the base (near the root) is not colored, but the top of the hair is (the shaft). And, the color should be rather uniform, as it was essentially "painted" onto the hair via licking during self-grooming.
Alternatively, if the color change is occurring as a hair develops within the hair follicle (which is located within the cat's skin), then you will see horizontal bands of color (like stripes). The width or fatness of these bands indicates how long the cat was exposed to whatever it is that is causing the coat color change. An example is zinc deficiency, which can cause a greying or dilution of coat color (don't worry, this is not what your cat has - just an example).
From your description, you are looking at a topically applied color change. So, since you did change food, I am leaning toward porphyrin staining, especially since her skin health is good and you are not seeing any other changes.
I am seeing both a painted on lOok, as well as some areas that look like stripes. What basic bloodwork would you recommend- her apt is sat morning? When I initially called her vet about it she didn't seem too knowledgable about the issue- stating she hasn't heard of cats furr changing color due to food change or sunlight. She said that would be unusual and she would do labs to make sure there is nothing else going on. Wondering if I should make the apt with one of the older more experienced vets.
If this is porphyrin staining, there is nothing really to worry about in terms of your cat's health, as it just reflects the presence of animal-source protein in the food (i.e. not a deficiency). As far as basic blood work goes, I would refer you back to Dr. Goldman for this advise. I believe he recommended basic bloodwork, which usually means a CBC and Blood Chem panel, but he may have had other tests in mind as well.
Your Fluffy is lucky to have such a attuned and caring caretaker - best of luck!
Hi again...one last thing...when I looked closely at her fur today the color change does appear to just be on the surface- when I seperate te fur and look at the fur underneath it is still all gray- so it seems it is just the very top coat that is changing- which could be from sun or that staining you are referring to. If it is from the staining from the food- is that harmful? Does it mean she is deficient in something? or is it perfectly fine. I am thinking of holding off on her vet apt and observing now. What are our thoughts? thank you for the very interesting tips.
I respectfully suggest, and Ms Case agrees, that Fluffy would benefit from basic laboratory work as soon as you are able to arrange it. Even if normal, you have gained a valuable bit of knowledge: an exact, documented moment of known organ function values. At "approx" 6 or 7 years old, it is time to begin annual screening for the inevitable signs of aging. This process is most valuable when it begins while a pet is still normal. Even if the fur color issue is nothing, there is value in documenting a normal set of lab values.
I suggest a complete blood count (CBC), a chemistry panel (typically includes liver, kidney, electrolyte, protein levels), a thyroid level ('T4') and a urinalysis. This "minimum database" will be useful later as a standard with which to compare future lab values. That comparison provides a view of the speed and magnitude of changes in the body that will inevitably occur. Better to it when you need it, than to wish you did.
Very best regards,