Question from Andi Jane William:

My dog has dandruff . Could it be his diet, what is best to feed him? He is a 7 year old border collie

Answer by Shanika Winters:

Hi, thanks for your question regarding your border collie and his dandruff.  I will answer your question by discussing what dandruff is, possible causes and then possible treatment options.

What is dandruff?

Most people think of flaky white bits of dry skin usually found on the head and shoulders of a person when they hear the word dandruff.  Dandruff is a word used to describe flaky bits of skin, they can be dry or oily, different sizes and come from any area of skin on the body.

Mostly we are talking about dry white coloured flakes when we use the word dandruff to describe the appearance of a skin condition.  The flakes can however be yellow in colour if oily or even red/brown if they also have some scabs/dried blood in them.

Why does my dog have dandruff?

There are various reasons why your dog may be showing the symptom of dandruff including:

  • Diet
  • Excessive shampooing – dries out the skin
  • Parasites -mites such as cheyletiella or after effect of scratching due to e.g. fleas.
  • Skin conditions- such as underactive thyroid and seborrhoea

How do we work out why my dog has dandruff?

The best way to get to the root of the problem if your dog has dandruff is to take him to your vet, where he can have a thorough examination, detailed history of how long the condition has been going on for including how it has changed and have appropriate test carried out.

Your vet will ask general questions about your dog’s health, diet, grooming regime and parasite control.  This will be followed by a physical examination, concentrating on the area of affected skin.  Depending on their finding your vet might then suggest some tests be carried out e.g.

  • Skin scrapes
  • Hair plucks
  • Sticky tape strips
  • Blood tests
  • See response to parasite treatment
  • Skin biopsies
  • Diet trials

Skin scrapes are when a sterile scalpel blade is used to scrape your dog’s skin usually until the point of light bleeding; this sample is then examined under a microscope to look for parasites and signs of infection.

Hair plucks are when a clump of hair is pulled out and then examined under the microscope or cultured to see if any bacteria/fungi are grown.

Sticky tape strips are literally when a strong clear sticky tape is applied to your dog’s skin and it then removed taking with it surface loose hairs and skin which can then be examined under a microscope.

Blood tests are performed on a sample of blood taken from either a vein on your dog’s front leg (cephalic vein) or the large vein on your dog’s neck (jugular vein).  The blood is analysed at your vet practice or may be sent to a laboratory.  Your vet will be looking for conditions that can affect the skin hormonal imbalances such as hypothyroidism (underactive thyroid) and Cushing’s disease (over production of steroids).

If parasites are suspected as the cause of the dandruff, even if they cannot be seen then a response to a course of antiparasitic treatment can be used to make a diagnosis.

Skin biopsies are when a sample of full thickness of your dog’s skin is cut out and sent to a laboratory for analysis.  Often several sites may be biopsied and sent off.  Skin biopsies will usually be performed with your pet under some form of anaesthesia to provide pain relief and to keep your pet still.

A diet trial is when your dog is fed a specific diet and water to drink but nothing else for a period of time, which could be 8-12 weeks.  This is to ensure that other food substances are out of your dog’s system.  Some animals will show a dramatic improvement in their skin condition as a result of a specific diet; this could be one which has avoided a substance your dog is allergic to or perhaps one with added ingredients to support a healthy skin and coat such as omega oils.

How can we treat my dog’s dandruff?

This will depend on the cause of the dandruff.  A good starting point is to ensure good parasite control for your pet, in contact pets and the home environment followed by a good quality diet which is appropriate to your dog’s age, activity level and general body condition.  We will also sometimes recommend dietary supplements to increase the good oils in your dog’s diet as these can help the skin to stay healthy and move away from the itchy pathways. Certain fish oils and evening primrose oil contain a good balance of oils, please do not use products you get from health food shops or which are designed for people unless this is under the direction of your vet.

Some dogs specifically benefit from a low allergy diet, this is one where an unusual protein and carbohydrate source are used or where the molecules of protein are broken down to a point beyond which they can trigger off allergic reactions.  Low allergy diets need to be stuck to strictly and given for a long period, 8-12 weeks minimum in order to see if there is any improvement before we can say they are not working.  Low allergy diets can be bought or home cooked.

If a an infection is found then the correct antibiotic or antifungal medication will be prescribed, this may be in oral form such as tablets or capsules or could be as a shampoo.  Whatever form the treatment is in, it is very important to follow instructions closely to provide the best chances of successfully treating the condition.

In cases of seborrhoea your pet will have a sensitive easily irritated skin that can have dry or oily flakes.  This can be underlying due to a dietary issue which will need addressing but it can also be massively improved by use of an appropriate shampoo.  It is important that you use the shampoo as directed, allowing adequate contact time with your dog’s skin for the active ingredients to do their job. The shampoo will usually need to be used more frequently at the start of the treatment and this will reduce to less often as the condition starts responding and is being more controlled.

Where hormonal imbalances have been detected via blood tests then appropriate medication will be given, in cases of Hypothyroidism supplements of thyroid hormone are given, the levels of which will be monitored in your pet’s blood.  Other conditions such as Cushing’s disease require treatment to stop the overproduction of steroids in the body, these too need carefully monitoring.

I hope that my answer has helped you to understand how complex dandruff can be to get to the bottom. With the help of your vet then we hope that your dog’s coat soon returns to its former glory and that he is much more comfortable.

Shanika Winters MRCVS (online vet)