A dog’s skin is made up of three main layers: the epidermis, dermis and hypodermis. Each layer contains different cells and structures that have important roles in protecting and supporting the dog.
Epidermis – The Outermost Layer
The epidermis is the top layer of a dog’s skin. It acts as a strong protective shield against bacteria and environmental damage, such as the sun and water. It also helps protect the dog from substances that may cause an allergic reaction.
Cells and structures found in the epidermis:
- Keratinocytes – These cells produce waxy keratin, which helps prevent water loss through the skin.
- Melanocytes – These cells produce melanin, which gives the skin and hair its colour.
- Langerhans cells – These are part of the immune system and respond to irritating substances.
Dermis – The Middle Layer.
The dermis is the middle layer of the skin structure. It contains a number of important structures that help with healing, sensory awareness and temperature regulation.
Structures found in the dermis include:
- Blood vessels
- Hair follicles
- Nervous system
- Immune cells
- Sebaceous glands
The sebaceous glands secrete sebum onto the dog’s skin and hair. This helps keep the skin soft and pliable, as well as making the dog’s coat shiny.
Hypodermis – The Deepest Layer
The hypodermis is the deepest layer of the dog’s skin and has a number of important functions.
It mainly provides:
- Insulation from heat and cold
- Cushioning for the dog
- Overall structural support for the body
Structures found in the hypodermis include:
- Fat cells
- Blood vessels
- Lymph vessels
- Muscle
The Three Layers of the Hair
As well as the three layers of skin, the dog’s hair itself also has three main layers: the medulla, cortex and cuticle.
Medulla – The Innermost Layer
The medulla is the innermost layer of the hair. This layer can be mostly absent in light or fine-coloured hair.
It consists of soft keratin and loosely packed cells, which affects the hair’s texture and flexibility.
Cortex – The Middle Layer
The cortex is the core strength of the hair. It makes up most of the hair’s weight and volume.
It contains keratin, which gives the hair its:
- Strength
- Elasticity
- Resilience
The cortex is also where melanin determines the hair colour.
Cuticle – The Outermost Layer
The cuticle is the outermost layer of the hair. It consists of overlapping cells that resemble fish scales.
Its main job is to protect the hair from things such as:
- UV rays
- Pollutants
- Environmental damage
A healthy cuticle gives the hair a healthy, radiant shine and smoothness.
When the cuticle becomes damaged, it can lead to the hair looking dull and frizzy, and in some situations, it can cause the hair to break.
Serums or conditioners containing silicone are best to use to seal and smooth out the cuticle.
