Dogs and fur stains

Updated March 2019

Most people who own a dog, particularly one with white fur, will be familiar with the issue of fur staining. Patches of fur in certain areas of the body turning red or brown and growing darker in colour over time.

Thankfully, this discolouration itself doesn’t cause your dog any harm – it’s merely a cosmetic issue. However, it can be a symptom of an underlying health problem.

The chemistry of it all

At the chemical level, red-brown fur staining is caused by a compound called porphyrin. Porphyrins are iron containing molecules produced when the body breaks down red blood cells. They are removed from the body primarily through faeces. However, porphyrin can also be excreted through tears, saliva, and urine. All dogs produce and excrete porphyrins, but porphyrin staining is of course more noticeable in dogs with white fur.

Causes of fur staining

There are a number of different factors that can contribute to your dog’s fur becoming stained.

Young puppies produce more tears when they are teething. This should decrease once they reach maturity.

In adult dogs, contributing factors can be broken down into three categories – medical issues, allergies and breed.

Medical conditions

Eye staining

Medical issues that can lead to staining around the eyes include eye irritation, blocked tear ducts, eye infections (bacterial, viral or fungal) and trauma to the eye (e.g. a scratch or cut). Poor grooming, resulting in a lot of hair around the eye can also stimulate excess production of tears, and can give yeast infections an environment in which to thrive and grow.

Anatomical or conformational abnormalities that can lead to stained eye fur include overactive tear ducts, narrow tear ducts, narrow eyes, shallow eye sockets, extra skin folds, abnormally placed eyelashes and rolling of the eyelids.

Mouth staining

Medical issues such as periodontal (gum) disease, excess saliva production and dental problems including abscesses can result in dogs producing large amounts of saliva. In a lot of cases, the excess saliva is produced as a way to try and get rid of excess bacteria that is present as a result of dental / periodontal problems.

These issues can also result in your dog having difficultly chewing their food, which in turn can cause excess saliva to produced, be unevenly distributed around the mouth and to trickle down the sides of the mouth.


As with people, dogs have allergies to things like pollen, certain foods, certain plants etc. And as with people, dog’s will do everything they can to relieve the irritation and discomfort caused by these allergies.

By and large, the way dogs do this is to lick the affect area. This means they are depositing a lot of saliva on different areas of fur around their body. Saliva which if not cleaned up and left to accumulate can result in staining.

Licking to relieve allergy symptoms also makes the fur quite damp, and scratching to relieve it can result in damage to the skin. Both of these can lead to areas of fur that act as a rich, fertile breeding ground for yeast infections that can result in brown fur staining.

Allergens can also cause irritation and inflammation to the eyes which results in production of more tears and so can lead to staining around the eye area.


Breeds of dog that are more susceptible to experiencing fur staining tend to be dogs who have poor drainage, short noses and who have shallow eye sockets etc. These include Poodles, Maltese, Boxers, Bichons and Bulldogs.

How to treat fur staining

For the most part, the best thing that can be done for a dog with stained fur – and to stop fur becoming stained in the first place – is to avoid allergens that may cause them irritation, feed a high quality diet and ensure they’re properly groomed.

This includes maintaining their hair to ensure it doesn’t grow too long and cleaning their fur and face twice daily to remove excessive tears/saliva. Using a contact lens cleaner with boric acid can lighten already stained fur.

It’s important to be aware of people trying to pedal remedies and supplements to remove stains on fur. Very often, these people will be selling you products that won’t work and care should be taken before using these – and any other – supplements.


Diet can change things for many dogs but it is important your veterinarian has ruled out medical causes before changing your dogs diet.

If your tap water is high in minerals, consider swapping your dog to filter water.

Always feed from a stainless steel or ceramic food bowl. Plastic is easily scratched and can harbour bacteria which can cause facial irritation.

There are a few veterinary prescription diets (hydrolyzed protein diets), where the protein is broken down into very small particles from which the body (theoretically) shouldn’t react.

You can also prepare you dogs food at home using the same high quality ingredients that you eat. A home-prepared diet can work wonders and sometimes all it takes is a change from commercial to home-prepared.

Here’s a gorgeous little boy I worked on a while back, before and a few weeks after diet change. Big improvement!

If you’d like to try cooking for your dog, the best way to ensure that the diet is meeting all of your dogs nutritional needs is to get your recipe from a qualified nutritionist. A home-prepared diet should not be undertaken lightly and should be done by someone who will work with your dog and balance the diet to NRC recommended allowances.

If you have any questions regarding this blog or need any advice please don’t hesitate to get in contact with us.

If you enjoyed reading this, you may also enjoy these blog:

How your dogs immune system can go wrong – Allergies

Home-prepared dog diets

Beware of dog food recipes found in books or online

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