Understanding Sebum

The Natural Oil That Supports Skin and Coat Function

Category: Skin Science
Suitable For: Professional Groomers • Veterinary Professionals • Breeders • Exhibitors • Pet Owners

“Sebum is not simply grease to be removed. In normal amounts, it is part of the skin and coat’s protective surface environment.”

Sebum is an oily secretion produced by sebaceous glands associated with hair follicles. It spreads across the skin and hair, contributing to lubrication, flexibility, water resistance and the surface environment of the skin.

Too little surface oil may leave the skin and coat feeling dry, while excessive or altered sebum can contribute to a greasy, heavy or odorous coat. Professional grooming aims to remove accumulated dirt and excess oil without unnecessarily stripping the skin and coat of all surface lipids.

Key Takeaways

• Sebum is produced by sebaceous glands, usually associated with hair follicles.

• It helps lubricate the skin and hair and contributes to water resistance.

• Sebum production and distribution vary between individuals, body regions and coat types.

• Oiliness is not always caused by poor hygiene.

• Effective grooming removes excess oil and debris without treating all natural oil as undesirable.

• Persistent grease, odour, scaling, inflammation or hair loss may require veterinary assessment.

What Is Sebum?

Sebum is a lipid-rich substance produced by sebaceous glands within the skin.

In dogs and cats, these glands are connected to hair follicles. Together, the hair follicle, hair shaft, sebaceous gland and associated structures form the pilosebaceous unit.

Sebaceous cells produce sebum through a process known as holocrine secretion. As these cells mature, they accumulate lipids and eventually break down, releasing their contents into the follicular canal.

From there, sebum moves onto the skin surface and along the hair shafts.

Skin-gland secretions help to lubricate and waterproof the skin and coat. It also notes that canine and feline follicles are compound structures, meaning several hairs may share associated glandular structures.

The Pilosebaceous Unit

A typical pilosebaceous unit may include:

• A primary hair

• Multiple secondary hairs

• A sebaceous gland

• An apocrine gland

• An arrector pili muscle

• The surrounding hair follicle

Unlike a human follicle, which usually produces one hair, canine and feline compound follicles may produce several hairs from one follicular opening. Secondary hairs within the same unit may share sebaceous secretions.

This arrangement helps distribute oil through a coat containing hairs of different diameters, functions and growth cycles.

What Does Sebum Do?

Sebum contributes to several normal functions of the skin and coat

Lubrication: Sebum coats the surface of the hair fibre and skin, helping reduce dryness and friction.

This does not mean that sebum acts as a complete conditioner in the cosmetic sense. However, it contributes to the natural flexibility and handling characteristics of the coat.

Water resistance: Lipids on the skin and hair reduce how readily water penetrates the coat.

This function is particularly relevant in dense and double-coated animals, where guard hairs, undercoat and surface oils work together to influence how water moves through the coat.

Support of the skin-surface environment: Sebum becomes part of the complex mixture on the skin surface alongside epidermal lipids, sweat-gland secretions, shed cells and microorganisms.

This surface environment is not sterile. It normally supports populations of bacteria, fungi and other microorganisms collectively described as the skin microbiome.

Sebum Is Not the Same as Skin-Barrier Lipids

Sebum and the lipids of the epidermal barrier are related to skin-surface condition, but they are not identical.

Sebum is produced by sebaceous glands and released through follicles.

By contrast, important barrier lipids such as ceramides, cholesterol and free fatty acids are organised between cells within the stratum corneum.

Both contribute to skin function, but sebum should not be described as the entire skin barrier.

This distinction matters because removing surface oil does not automatically mean the barrier has been destroyed, just as replacing oil on the coat does not rebuild all components of the epidermal barrier.

How Sebum Reaches the Coat

Sebum does not spread evenly by itself.

Its distribution is influenced by:

• Hair movement

• Contact between individual fibres

• Grooming and brushing

• Coat density

• Hair angle

• Natural movement of the animal

• The structure of the follicle

Regular brushing can help distribute surface oils along the coat while removing shed hair and accumulated debris.

This is particularly important in dense coats, where trapped undercoat may interfere with airflow, drying and the even distribution of natural oils.

Different areas of the body contain different concentrations and types of skin glands.

The base of the tail contains a specialised glandular region commonly called the supracaudal gland or violet gland. In some dogs, excessive secretion or glandular changes in this area can contribute to greasy hair, comedones, altered coat texture or localised hair loss. These signs should not be treated as ordinary coat oiliness and may require veterinary investigation.

Why Some Coats Become Greasy

A greasy coat may result from more than one factor.

Possible contributors include:

• Normal individual variation

• Coat density

• Infrequent or ineffective bathing

• Incomplete rinsing

• Product residue

• Accumulation of shed cells and hair

• Increased sebaceous activity

• Environmental contamination

• Changes in skin turnover

• Underlying dermatological or hormonal disease

For this reason, oiliness should be assessed rather than automatically treated with the strongest available degreasing product.

A dog that feels oily because shampoo residue remains in the coat requires a different response from a dog with recurrent greasy scaling, odour, inflammation or hair loss.

Sebum and Odour

Fresh sebum is not necessarily responsible for strong coat odour. Odour may develop when surface oils mix with:

• Environmental debris

• Shed keratin

• Moisture

• Saliva

• Microbial by-products

A greasy, odorous coat may therefore indicate an accumulation of material on the skin surface, altered microbial activity or an underlying skin condition.

Groomers should document persistent or worsening odour, especially when accompanied by redness, itching, scaling or discomfort.

Can Sebum Build Up Around Follicles?

Yes. Sebum, keratin and cellular debris can accumulate within the follicular opening.

When this material forms a visible plug, it may appear as a comedone. Comedones can occur for several reasons and should not automatically be interpreted as dirt. Recurrent or widespread comedones, pustules, hair loss or inflamed follicles warrant veterinary assessment.

Cleansing Without Over-Stripping

The objective of professional cleansing is not to leave the skin completely free of oil. A suitable bath should remove:

• Dirt

• Environmental contaminants

• Excess surface oil

• Odour-producing residues

• Loose skin cells

• Shed hair

• Previous product build-up

All without excessively stripping sebum.

However, the term over-stripping should be used carefully.

A cleanser does not remove sebum permanently. Sebaceous glands continue to produce new secretions. The practical concern is whether the cleansing process leaves the skin and coat excessively dry, irritated or difficult to manage. That outcome depends on more than shampoo strength alone.

It may also be influenced by:

• Product concentration

• Water temperature

• Frequency of bathing

• Repeated degreasing

• Contact time

• Rinsing

• Individual skin condition

• The conditioning stage

There is no single ideal level of sebum for every dog.

Breed, body region, follicle type, hormones and individual physiology all affect sebaceous activity. This variation is one reason broad claims such as “oily coats need no conditioner” or “all natural oil must be removed” are scientifically unreliable.

 

Coat Type and Sebum Distribution

Coat architecture influences how oil is seen and felt.

Short coats: Sebum may be more noticeable because there is less hair length over which it can spread. The coat may develop a slick or greasy feel relatively quickly.

Long coats: Surface oil may move along the hair shafts and influence shine, separation and weight. Heavy product application can combine with sebum and make the coat appear limp.

Medium, Dense & double coats: Oil, shed cells and loose undercoat may accumulate beneath the guard coat. Thorough wetting, rinsing and drying become especially important.

Hairless breeds: Without a substantial coat to absorb and distribute sebum, oil remains more visible on the skin surface. Hairless animals may therefore appear oily more quickly, but their skin should not automatically be subjected to aggressive degreasing.

A Professional Approach to an Oily Coat

When presented with an oily coat, begin with assessment.

Consider:

1. Is the oil generalised or localised?

2. Is there scaling, odour, redness or itching?

3. Is the coat oily at the roots, through the lengths or only in selected areas?

4. Is there evidence of product build-up?

5. Has the coat been thoroughly dried?

6. Is this normal for the individual animal?

7. Has the condition changed since the previous visit?

A grooming routine can improve cleanliness and cosmetic appearance, but recurrent or abnormal oiliness may be a clinical sign rather than a simple grooming problem.

When degreasing is required, use the least aggressive routine that achieves a clean result.

More shampoo is not always more effective. Close - Open - Close method is highly recommended.

How Iv San Bernard Applies This Science

Iv San Bernard professional routines distinguish between cleansing excess surface oil and removing every trace of natural lipid from the skin and coat.

Product selection should consider:

• The amount and location of oil

• Skin comfort and visible condition

• Coat density and texture

• The presence of scale or residue

• The desired grooming finish

A lighter conditioner may suit a coat that requires control without added weight, while a more nourishing mask may be selected where the coat is dry or difficult to manage.

The most appropriate routine is determined by assessment rather than by the assumption that all oily coats require the same degreasing protocol.

Frequently Asked Questions

Is sebum unhealthy?

No. Sebum is a normal skin secretion. Problems arise when there is excessive accumulation, altered composition, uneven distribution or an underlying condition affecting the skin.

Should groomers remove all sebum?

No. The goal is to remove excess oil, debris and residue while leaving the skin and coat clean and comfortable.

Does an oily coat need conditioner?

Yes Conditioner should be selected according to the coat’s structure and desired finish. A light, well-diluted formula may provide manageability without excessive weight.

Is a greasy coat always caused by poor bathing?

No. Greasiness may reflect individual physiology, product residue, coat density or a dermatological or hormonal condition.

When should a groomer recommend veterinary advice?

Referral is appropriate when oiliness is persistent or accompanied by marked odour, inflammation, itching, pain, pustules, widespread comedones, altered skin colour or hair loss.