STRUCTURE AND FUNCTIONS OF THE SKIN AND HAIR COVER:

 

SKIN

The skin is a very large, extensive and extremely important organ. In humans, it is 15% of body weight, in the animals up to 24% (12-24%). Performs a number of important functions including protection, regulatory and secretory functions. Constitutes a barrier separating both the body from the environment, and it communicates with it.

FUNCTIONS OF SKIN:

  • It is a mechanical protective barrier against environmental factors, physical stimuli, chemical and biological.
  • Regulates the balance of water and electrolyte.
  • Adjusts the internal temperature of the body, among others, ensured by features of the vascular bed and hair coat.
  • Receives sensory stimuli, has touch receptors, temperature, pain and itching receptors.
  • Has secretory function – sebaceous glands, sweat and perfumes.
  • Participates in the synthesis of vitamin D.
  • Produces keratin structure, i.e. hairs / fur and nails / claws.
  • Performs the function of mechanical and chemical barrier against microorganisms, bacteria and fungi.
  • Performs immune function, providing local immunity (Langerhans cells – dendritic cells presenting the antigen).
  • Contains dye cells (melanocytes) – determines the color of skin and hair.

STRUCTURE OF SKIN:

Skin is composed of three basic layers – from the outside:

 

Epidermis – five layers of epidermis (from the outside: cornified layer, clear/translucent layer, granular layer, spinous layer, basal/germinal layer).

Dermis

Hypoderm – subcutaneous tissue.

useful information: Structure of skin

 

Each of these layers has a fixed functionality, although some of them contained in them structures (e.g. the sweat glands, hair follicles or sebaceous) penetrates the layers. The skin of the ears, lips, eyelids or the pads differs from the structure of the skin covering other parts of the body, eg. Merkel cells are located only in the skin of tips of paws.

 

useful information: Epidermis

 

 

The epidermis undergoes constant manufacturing processes and exfoliates any dead cells. Performs a number of important functions, ensures the continuity and integrity of the skin, produces keratin structures, i.e. hairs / fur and nails / claws. In the epidermis are located, among others, pigmentary cells (melanocytes), dendritic cells (Langerhans cells – immune processes) receptors of pressure and pain (Merkel cells) and openings of sebaceous glands, sweat glands, hair follicles and odoriferous glands. The epidermis is covered with a coat of fat and lipid (epidermal emulsion), which is responsible, among others, for the maintenance of an adequate level of acid-base balance of the skin (pH). This layer is also responsible for the hydration of the skin.

 

Dermis. In this layer, there is a series of functionally specific structures: the sebaceous glands, the sweat glands, scent glands, hair follicles and blood vessels, lymphatic vessels and nerves penetrating the layers of the epidermis and the so-called arrector pili muscle, responsible for “ruffling” of fur. In the dermis are embedded hair and nails. In this layer of the skin are cells of the immune system: macrophages, dendritic cells, basophils, and other cells like fibroblasts affecting, inter alia, proliferation of cells of the stratum corneum or mast cells involved in allergic reactions.

useful information: Dermis

 

useful information: Hypoderm

Subcutaneous tissue acts as a support, protects the body against low temperatures and a reserve of energy (mainly fats). It is composed of loose connective tissue (collagen fibers forming a loose network) and adipose tissue (fat droplets filled with the network of collagen fibers).


Skin’s pH:

pH of the skin is acid-base equilibrium (or acidity) at the surface of the stratum corneum which is outermost skin layer. The acidity of the skin is regulated, among others, secretion of skin glands mostly sweat glands. In dogs, sweat secreted by the sweat glands do not participate in the process of thermoregulation as it has a place for humans. Suitable pH of the skin determines the skin’s resistance to bacterial infections, and is a prerequisite for maintaining homeostasis (equilibrium physiological). pH of the skin of dogs and cats is significantly different from the pH of human skin, as it is markedly higher, i.e. more alkaline. While the average pH of the surface of human skin is 5.2 – 5.6, canine pH of the skin ranges from 6.65 to 7.70. The alkaline nature of the animal skin gives much better than in the case of human skin, conditions for pathogenic microorganisms, bacteria and fungi. This is a frequent cause of complications in the form of bacterial and / or fungal infections in the course of some dermatoses. Similarly caused wounds (cuts, bites, etc.) are more susceptible to opportunistic infections complicating them and for this reason, among others, it is necessary to implement special procedures for dealing with wounds.


COAT HAIR (FUR)

Coat hair (fur) it has the essential protective functions acting as an insulating barrier and has thermoregulatory function as well as participates in the receiving environmental stimuli (receptor function) as well as in sending messages and information to the other animals (behavioral function).

The coat consists of several types of hair. Their occurrence, distribution, length and density varies between breeds of dogs and cats.

In the cover the hair are long, rigid, centrally located, single basic hair surrounded by several shorter basic hairs forming a covering, which are surrounded by dozens of smaller and more delicate and soft hairs forming the so-called undercoat. For some breeds of dogs (German shepherd) basic hair are surrounded by a very large amount of secondary hair, forming dense undercoat, in other breeds (Terriers) short and rough hair prevail, while in boxer’s basic hair are considerably shortened, and the amount of secondary, soft hair is clearly increased what gives the hair of dogs of these breeds specific “soft” character.

The color of the hair depends on the presence of pigmented cells located in the cortex of the hair.

useful information: Hair coat

THE STRUCTURE OF HAIR COAT

The structure of the unit of coat is hair follicle, which includes a centrally located primary hair, a few (5) surrounding it shorter hairs and a few to a dozen secondary, soft hair. Each hair follicle is supplemented by the sebaceous gland and sweat and arrector pili muscle for tensioning the hair, which is responsible for “ruffling” of hair which has a thermoregulatory and behavioral functions. In dogs, the original hair has its own sebaceous and sweat glands, and arrector pili muscle for tensioning hair. The bellows create clustered follicles (follicle tufts).

FLEAS AND TICKS

useful information: Fleas
useful information: Ticks

 

ON THE SKIN DOGS AND CATS CAN SERIES OF INSECTS, ARTHROPODS
AND MITES CAN PARASITE:

 

  • Fleas (cat flea Ctenocephalides felis and dog flea Ctenocephalides canis).
  • Lice (dog lice Linognathus setosus, chewing lice Felicola subrostrata).
  • Mallophaga (dog mallophaga Trichodectes canis).
  •  

  • The scabies (Sarcoptes scabiei, świerzbowiec uszny Otodectes cynotis, świerzbowiec głowowy kotów Notoedres cati).
  • Demodex folliculorum (Demodex spp.).
  • Ticks (Ixodes spp., Rhipicephalus sanguineus, Dermacentor reticulatus).

 

LIVING ON SKIN
PARASITES MAY CAUSE MANY DESEASES INCLUDING:

 

  • Dermatological, resulting in damage or skin irritation, local or systemic inflammation due to insect bites, skin appendages inflammation, allergy, secondary bacterial infections leading to superficial or sometimes deep pyoderma.
  • Damage to hearing.
  • Loss of hair coat in the form of local changes or generalized.
  • Changes in the behavior of animals that are becoming more restless and excitable.
  • Peripheral nerve paralysis due to a toxin (tick paralysis).

 

Feeding on the blood fleas and ticks can with strong invasion in puppies and kittens lead to significant blood loss leading to anemia.

Some parasites can be transmitted from animals to humans ( eg. Mites Sarcoptes scabiei and Notoedres cati) causing serious skin diseases. Others are vectors carrying the germs (bacteria, viruses, parasites) of many serious human and animal diseases.


 

THE MAIN VECTORS OF DISEASES ARE FLEAS AND TICKS.

 

useful information: Flea

 

FLEAS

In dogs and cats the most commonly encountered is cat flea (Ctenocephalides felis), which also infects humans. Fleas besides that they cause severe irritation of the skin, leading to allergic dermatitis (FAD – flea allergic dermatitis) can be a source of diseases caused by bacteria and parasites:

 

  • Dipylydioza – Taeniasis (Dipylidium caninum) occurs in humans as zoonosis.
  • Yersiniosis (Yersinia enterocolityca, Yersinia pestis). Fleas are the primary vector of the plague bacteria – Yersinia.
  •  

     

     

  • Leishmaniasis (Leishmania spp.). The disease seen in dogs and humans. In animals revealed a change in behavior, muscle atrophy, weight loss – not treated leads to death of the animal.
  • Cat scratch disease (CSD, Bartonella henselae), in clinical form occurs most often in people (children, feline breeders, veterinarians), is characterized by inflammation of the skin at the site of scratching and inflammation of the lymph nodes (local or generalized).

 

Fleas can also participate in the transmission of tapeworms in both humans and dogs and cats.


useful information: Tick

 

 

TICKS

Ticks are parasites on the skin of humans and animals. Occur almost in any environment (forests, meadows, in parks, in front gardens) dwelling on the grass or low bushes. In Poland, there are 3 basic types of ticks:

 

Ixodes ricinus, known as forest tick.It is present in countries with cold climates (Europe, Russia, Central Asia, North America, Japan). Infects humans, dogs, cats, cattle and rodents. It is the source of: borreliosis (Lyme disease), cattle babesiosis, ehrlichiosis and bartonellosis.

Dermacentor reticulatus exists in forests, parks, the bushes of household, in the dark and damp places. Exists in the zone of cold and moderate climate, among others, in Europe. Infects humans, dogs and small rodents. Is the source of babesiosis.

Rhipicephalus sanguineus is called the dog tick, which adapted to the dry and hot climate. In its development is distinguished by 3 hosts, but the main hosts are carnivores. It is a source of babesiosis, ehrlichiosis, hepatozoonosis, rickettsiosis, haemobartonella.

Ticks carry diseases caused by bacteria, viruses and parasites.

To infect their host tick must first locate him, stick to his skin and start drinking blood. Drinking the blood takes place in two phases: a slow and rapid. The greatest risk of transmission of pathogenic microorganisms are present in the second, rapid phase of drinking blood (within 24-48 hour feeding). The tick gets rid of the excess fluid collected with the blood introducing them into the wound of a host. The fluid may contain various pathogenic microorganisms. Very often, in the case of parasitic ticks on the skin for over 24-48 hours, the transmission of diseases is provoked by the wrong way of removing them. (Learn more)

DISEASES TRANSMITTED BY TICKS
AND TRIGGERED BY TICKS

 

  • Borreliosis – Lyme disease (Borrelia burgdorferi) – the most common tick-borne disease in humans and animals with multiform course, often with permanent complications.
  • Tick-borne, viral encephalitis and meningitis (Flaviviridae) disease of people (mainly) and animals. Characterized by symptoms resulting from inflammation of the meninges, or brain and meningitis, rarely core and meningitis.
  • Babesioses (Babesia canis) – Extremely dangerous disease of dogs and cats with a very serious and often fatal course.
  • Hepatozoonosis (Hepatozoon canis) disease of dogs with different clinical course, often leads to debilitating (cachexia).
  • Q fever (Coxiella burnetti).
  • Ehrlichiosis (Ehrlihia spp.) disease of dogs, the symptoms are varied, can be observed a high fever, weight loss leading to anorexia.
  • Haemobartonellosis (Haemobartonella felis, canis). The disease of dogs and cats during which there is a breakdown of red blood cells and the development of anemia.
  • Paralysis of the peripheral nerves. The disease of people, dogs and cats. It is caused by toxins introduced into the host organism by parasitic ticks.
  •  

SKIN DISEASES

 

1

There are several skin diseases referred to as dermatitis. Dermatitis can be caused by a number of infectious agents such as fungi, viruses, bacteria (e.g. purulent dermatoses ) may be of allergic (FAD, AD), may also be due to improper nutrition (food allergy dermatoses, metabolic), endocrine disorders (e.g. Cushing’s syndrome), or even the impact of external factors such as sunlight. Skin disorders can also affect the coat lead to local and even generalized alopecia.


 

2

A significant role in the occurrence of skin diseases also play ectoparasites (fleas, lice, lice, mites, grain mites, ticks). Fleas e.g. might be the cause of the occurrence of the Flea Atopic Dermatitis (FAD). Common occurrence is seen in dogs hypersensitive to flea allergen. Instance of ticks may in turn lead to the occurrence of purulent skin inflammation. Ticks are also a source of several serious diseases in dogs and cats. Learn more.


 

3

Diseases of the skin, most often resulting from allergic origin, are often accompanied by itching. In implemented medical treatment it is also recommended to use supporting products (shampoos, emulsions, lotions) with antipruritic and anti-inflammatory properties. Learn more.
In the course of dermatoses, in many cases, there is also the development of bacterial or fungal. This concerns both the skin and/or the skin appendages (e.g. purulent inflammation of the hair follicles). The symptom may be, among others, the appearance of unpleasant smell of the skin, sticking of the hair and often baldness. The procedure are usually antibiotics assisted by use of preparations in the form of a shampoo or lotion with combined antibacterial and anti-fungal properties. Learn more.


TYPES OF WOUNDS
CLASSIFICATION OF WOUNDS

 

Wounds can be classified due to:

  • Manner of their creation
  • The nature and extent of the loss of the skin and / or tissue
  • The degree of contamination by mechanical and bacterial infection
  • Time elapsed since the inception of the wound
  • Incidence of associated with wound injuries within the adjacent tissues

Abrasions – the most common form of the wounds are abrasions of various etiologies associated most often with little loss of the epidermis. Sometimes, however, there is also the loss of the dermis and subcutaneous tissues.

Bitten wounds/lacerations – usually arise as a result of being bitten or mechanical factors, e.g. when incarcerated or jamming a limb in “traps” (e.g. manholes, sewer grates, etc.). When attempting to release, often frantically, limbs comes to break the continuity of the skin, muscles and sometimes to tear tissues. The bitten wounds are regarded as highly polluted both mechanically and bacterially.

Puncture wounds – are usually deep penetrating wounds. Some of the puncture wounds have exit holes and are defined as the piercing wounds.

Torn wounds – usually arise as a result of strong mechanical trauma (e.g. road accidents). They are serious deep tissue damage, often detachment of tissues. In the case of this type of injuries occur often also reveal the skeletal elements (e.g. frequently limb joints). These are the most heavily contaminated wounds.

Cuts – common of different etiology. In cuts, there is a break in the skin (or its individual layers). Often cuts are wounds penetrating the deeper layers of tissue (muscle) and sometimes the skeletal elements. In such wounds, it is often to find injuries of the blood vessels, tendons, nerves.

Gunshot wounds – can sometimes be considered a form of puncture wounds. These types of injuries can most often meet at the hunting dogs.

Burns – these types of injuries can occur as a result of thermal burns, chemical, electrical and occasionally due to conducted radiotherapy. There are three degrees of burn wounds:

 

First degree burns – superficial burns, it is characterized by skin redness and slight swelling. It is characteristic that this degree of burns is accompanied by severe pain.

Second degree burns – penetrates to the dermis layer. On the skin surface forms blisters. This is accompanied by severe pain. Depending on the degree of penetration sometimes are distinguished degrees of burns IIA and IIB.

Third degree burns – penetrates deep into the layers of the subcutaneous tissue including muscles. On the surface of the skin appears black scab or may occur charring of the skin and sometimes muscle. Painfulness is slight but tissue injury is very serious, often irreversible (necrosis).

 

A separate category are the wounds are decubitus ulcers (bedsores). Arises from a continuous and long term mechanical stress on the soft tissues. This leads to impaired circulation and cellular metabolism. In animals, it occurs most frequently in the vicinity of tumors of the hip, ischial, shoulder blades, the lateral surface of the tibia (lateral condyle), sternum, olecranon and the heel spur. There are various classifications of the degree of development of decubitus ulcers, depending on the observed changes, i.e. from the minor, characterized by a slight reddening area, no fading under the yoke (during the examination), up to major characterized by irreversible changes in the tissues in the form of necrosis of the muscle fascia, and even joint, and bones.

 

WOUNDS CAN BE CLASSIFIED ALSO DUE TO:

the degree of mechanical and/or bacterial contamination.

 

IN THE CASE OF ANIMALS:

  • wounds that are clean only surgical wound
  • all other to be regarded as polluted with the degree of contamination depending
    on the type of wound and the time elapsed since the creation of the wound
A special role in the contamination of wounds plays bacteria (commensal or pathogenic introduced from outside) colonizing the surface of the wound and leading to the formation of the so-called. bacterial biofilm – which is the main obstacle to proper wound healing.

 

BACTERIAL BIOFILM

 

Biofilm is the combined bacterial microcolony (which may be of various kinds of pathogenic bacteria) forming a multi-layered three-dimensional structure surrounded by extracellular matrix.

 

  • Protects bacteria and other pathogens against “harmful” for them by external factors as disinfectants, antibiotics and immune cells.
  • Creates favorable conditions for the continuous proliferation of already settled bacteria and colonization and the development of new bacteria or other pathogens.
  • It affects the spread of infection to neighboring healthy tissue.
  • It distorts the exchange of gas in the wound and the host cell blocks access to nutrients.
  •  

 

Biofilm jis firmly and strongly bonded to the substrate, removing it from the wound surface with normal rinsing (water, soapy water, physiological saline), is not possible. Therefore, you should use appropriate means allowing the efficient removal and prevention of reproduction or formation.


 

PROCEEDINGS WITH A WOUNDS

Normal wound healing takes place in three interrelated steps/phases:

 

1

PHASE OF INFLAMMATION

(Exudative preceded by a short-term haemostasis)

 

2

PHASE OF SKIN-GRANULATION

(Proliferative)

 

3

PHASE OF MATURING

(Reconstruction)

 


Infectious microorganisms, debris, the extraneous material (e.g. mechanical impurities), or necrotic tissue is removed from a wound in the inflammatory phase. The wound is covered with a scab, which protects it from adverse external factors including bacteria. The main cellular factors involved in this phase are platelets (haemostasis), neutrophils and macrophages. The inflammatory phase lasts from 1 to 5 days.

In the proliferative phase, inflammatory processes in the wound are inhibited and begins the process of granulation of tissue and filling defects and the process of angiogenesis. The proliferative phase takes 5 to 21 days and involves mainly the fibroblasts, lymphocytes, endothelial cells and keratinocytes.

 
 

In the final stage, maturation, reorganization of the structures of scar tissue formed in the second phase takes place, i.e. the reduction of the resulting scar. This process can take anywhere from 3 weeks to up to 2 years. A special role in this process is played by fibroblasts.

Very often, however, the healing process is disturbed by a number of external and internal factors such as deficiencies in the inflammatory response within the wound, delay in angiogenesis or granulation resulting from e.g. cardiovascular disorders, metabolic diseases, neuropathy or malnutrition. An important factor influencing the external wound healing disorder is heavy contamination of the wound by, mechanical or microbiological contaminants. A special role is attributed to the emerging in the wound bacterial biofilm.


 

“T I M E” SCHEME

Given the number of problems associated with normal wound healing, and in the light of experience, specialists from the EWMA (European Wound Management Association) proposed in 2003, unified workflow with wounds described as T I M E.

Abbreviation T I M E is an acronym from the first letters of the English names for the various processes and changes (mainly pathological) occurring in wounds and setting out the procedure for the various stages of wound healing.

 

CHANGES

Specifies the processes and pathological changes occurring in the wounds at different stages

 

 

PROCEEDINGS

Each point acronym TIME and simultaneously it corresponds to EWMA guidelines for proper conduct in the process of wound healing in various stages of:

 

useful information: TIME Scheme

 

T I M E is a dynamic scheme subject to constant modifications resulting from both medical knowledge and lessons learned by doctors. For example: the discovery of a specific role played by bacterial biofilm in significant delay in wound healing forced to supplement the scheme with the methods of effective preventing the formation of biofilm in the wound or to control the already formed biofilm. Therefore, were developed methods of combating bacterial biofilm – BBWC (Biofilm-Based Woun Care/Management). One such efficient method (which is a part of the schema in section “T” of T I M E) is lavasepsis i.e.: an irrigation of wounds with special preparations as effective removers and warring bacterial biofilm, as well as cleansing wounds from any other biological and/or mechanical contaminants.