Damage (trauma) to tissues. Perthes disease in dogs Malignant smooth muscle tumors

Necrotic necrosis is a severe form of infection of organs and tissues that come into contact with the environment. The skin, respiratory organs and genitourinary system. The process of tissue death is accompanied by severe intoxication of the body and poses a threat to the health and life of the pet.

Treatment is not only conservative in nature, but also includes surgical methods excision of affected tissue.

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Causes of gangrene

Veterinary specialists distinguish between exogenous and endogenous causes of the development of the necrotic process in animals. External factors include:

• Mechanical injuries. Soft tissue bruises of the 3rd and 4th degrees, as a rule, are accompanied by crushing and muscle damage, ligamentous apparatus, blood vessels, nerve endings. Violation of the tissue structure provokes the development of inflammation, and the ingress of pyogenic microflora leads to the development of necrosis.
• Compression factors during prolonged tissue compression. Tightly applied bandage or a hemostatic tourniquet, bedsores as a result of the immobility of the animal lead to impaired circulation and contribute to tissue necrosis.
• Thermal factors. or frostbite of degrees 3 and 4 are characterized by deep structural damage, as a result of which necrotic processes develop in the deep layers of the epidermis.

• Impact chemical substances . Contact with the skin and mucous membranes of acids, alkalis, and organic solvents destroys not only the outer layers of the dermis, but also leads to the destructuring of nerve and blood vessels.
• The intestines often undergo necrosis due to torsion or entrapment section of intestine in the hernial ring.

TO endogenous reasons Veterinary experts include the following:

• Pathology of the vascular system. Thromboembolism (blockage), partial or complete break vessels provoke disruption of tissue trophism and lead to infection.
• Hormonal diseases. Pathology thyroid gland, diabetes provoke degenerative processes in tissues and impair their nutrition.
• Disturbance of tissue innervation(supplying them with nerves, which ensures communication with the central nervous system) due to concomitant diseases.

According to veterinarians, gangrene in animals can be caused by excessive blood loss, exhaustion, and chronic inflammatory processes of internal organs.

Why does it most often occur on the paws?

In veterinary practice, there are often cases of owners asking about the development of a gangrenous process in the extremities. The delicate tissues of a dog's paws are susceptible to mechanical damage on a walk. Danger to the animal sharp objects, thorns and thorns of plants, glass fragments, etc. Microtraumas and cuts are not always noticed by the owner and lead to tissue suppuration.

The cause of paw gangrene is often hypothermia. Walking your pet for a long time in the cold leads to reflex contraction capillaries, trophic disturbances, cell death.

Does the animal have an allergic or fungal infection? interdigital dermatitis – common reason development of gangrenous melting of paw tissue.

Dry, wet and gas gangrene

IN veterinary medicine It is customary to distinguish the following forms of gangrene in animals:

• Dry. The pathological process is caused by the development of coagulation necrosis. In this form of the disease, tissues that disintegrate under the influence of autolysis processes release moisture into environment. Necrotic tissues dry out, their structure remains without significant changes. The damaged area has a dark brown or even black color, becomes dense and brittle.

Normally, this process occurs in newborns with an umbilical cord stump. At pathological development Dry gangrene usually affects the external areas skin on articular protrusions, tail, limbs, as well as cartilage tissue auricle.

• Wet. The colliquation form of the disease is accompanied by tissue decomposition as a result of the action of pyogenic microflora. The pathology is aggravated by the phenomena of autolysis (dissolution of tissue under the influence of its own enzymes). Destroyed tissues are characterized big amount transudate.

The development of the process is facilitated by the introduction of anaerobic and putrefactive infection into the tissue. The danger of this form of gangrene lies in the fact that the putrefactive decay of protein structures affects living tissues and prevents the development of the demarcation barrier. A complication of the wet form of the disease is severe intoxication of the body with tissue decay products and the development of sepsis in the animal.

• Gas. It is a type of wet form. Necrosis is characterized by a large accumulation of gases in tissues due to infection of extensive wounds anaerobic bacteria from the genus Clostridium.

Classification of the disease is important for determining the treatment tactics for necrotic phenomena in tissues.

Treatment and surgery as a last chance

Any type of gangrene requires emergency treatment. First of all, it is necessary to stop the necrotic process. In the case of a dry form, it is strictly forbidden to use compresses with a warming effect, as well as bandages soaked in ointments and solutions. The affected area is regularly treated with 3% iodine solution, Septonex, alcohol solution brilliant green, gentian violet.

The use of novocaine blockades with an antibiotic in the first stages of gangrene is highly effective. This procedure eliminates vascular spasm and allows tissue nutrition to be restored. Depending on location pathological process chest, epipleural or perirenal blockades are used.

It is useful for dry gangrene to treat the affected area with Sollux and InfraRug lamps. After the formation of the demoralization line veterinarian conducts surgical excision dead tissue.

Enzyme preparations are widely used in the treatment of gangrene in animals. In veterinary practice the following are used: Trypsin, Fibrinolysin, Lidaza. Bismuth and aluminum preparations are used as astringents for treating dead tissue. In some cases good effect gives the use of aluminum-potassium alum, iodoform.

Treatment tactics wet gangrene comes down to converting it into dry form. For this purpose, the surgeon makes special incisions in the damaged tissue and partially drains them. This manipulation helps remove moisture from dead tissue and form a demortal line. At this stage, dry heat is applied to the damaged areas - Sollux lamps, sources with an infrared spectrum.

IN mandatory a sick animal is given a powerful antibacterial therapy. Antimicrobial agent applied on the basis of microflora sensitivity analysis. A feature of antimicrobial treatment for gangrene is high doses of drugs.

The most effective are modern drugs from a number of sulfonamides and cephalosporins. With necrosis bone tissue intraosseous injections of an antibiotic with novocaine are used.

In order to reduce intoxication of the body, a sick dog is injected intravenously with a 40% glucose solution and a 10% calcium chloride solution. IN complex therapy include drugs to support cardiac activity - Caffeine, Cordiamine. Melting of tissues is accompanied by a pronounced pain syndrome, which justifies the use of painkillers. In some cases, blood transfusion is used.

Often a veterinarian has to deal with severe course gangrene, when the only way to save an animal’s life is amputation of a limb.

For information on treating burns in dogs and providing first aid to a pet, watch this video:

Prevention of development

Prevent this dangerous pathology like gangrene, owner four-legged friend Maybe, observing the following preventive measures:

• Prevent mechanical, thermal and chemical damage to living tissues.
• Avoid hypothermia and prolonged exposure of the animal to the cold.
• Any, even minor, injury to the skin should be carefully treated with antiseptic agents.
• Prevention of bedsores in bedridden patients.
• Increasing immunity, the body's resistance to pathogenic microorganisms.

Gangrene in dogs is a dangerous process accompanied by tissue melting. The disease leads to severe intoxication of the body and is dangerous for the development of sepsis in the animal. Treatment is aimed at stopping the necrotic process. In some cases, surgical excision of damaged tissue is used, followed by powerful antibacterial therapy.

/ Hepatocutaneous syndrome in dogs and cats (superficial necrolytic dermatitis)

Hepatocutaneous syndrome in dogs and cats (superficial necrolytic dermatitis)

Text of the article and photos 1-10 from the SMALL ANIMAL DERMATOLOGY A COLOR ATLAS AND THERAPEUTIC GUIDE 2017

Translation from English: veterinarian Vasiliev AB

Peculiarities

Hepatocutaneous syndrome/superficial necrolytic dermatitis is a unique skin disorder in animals with chronic liver disease or glucagon-secreting pancreatic tumors. The exact pathogenesis of hepatocutaneous syndrome is unknown, but increased gluconeogenesis triggered by hyperglucagonemia (pancreatic tumor) or increased amino acid catabolism in the liver (chronic liver disease) is thought to cause low plasma amino acid concentrations and epidermal protein depletion, which causes superficial necrolytic dermatitis.

It is uncommon in dogs and rare in cats, with most high frequency occurrence in older animals. Dogs that may be predisposed are Sheltie, West Highland White Terrier, Cocker Spaniel and Scottish Terrier. Skin lesions are characterized by minimal to intense itching, bilateral symmetrical erythema; scales, crusts; erosions; and ulcers on the distal parts of the extremities and around the mouth and eyes. Lesions may also involve the ears, elbows, hocks, external genitalia, ventral trunk and oral cavity. The finger pads usually have weak to strong degree severity of hyperkeratosis, fissures and ulcers.

Lameness may occur due to damage to the pads of the toes. Polydipsia or polyuria may be present if diabetes mellitus is also present. On the other side, systemic symptoms underlying metabolic disease is rarely obvious when initial examination, but usually become obvious after a few months.

Differential diagnoses

Diagnosis

1 General analysis blood: neutrophilia or normocytic, normochromic, non-regenerative anemia may be present.

2 Biochemical analysis blood ( liver failure): Findings usually include a mild to moderate increase in serum alkaline phosphatase and alanine aminotransferase, total bilirubin and bile acids. Hypoalbuminemia and decreased urea levels are common. Hyperglycemia may be present.

3 Plasma concentrations of amino acids are sharply reduced (hypoaminoacidemia).

4 Serum glucagon concentrations: increased in glucagenoma, may be elevated or normal in hepatopathy.
5 Ultrasonography abdominal cavity: evidence of chronic liver disease (small liver with a hyperechoic, reticular pattern surrounding hypoechoic honeycomb areas), pancreatic tumor, or liver metastases (hyperechoic or hypoechoic foci in the liver parenchyma).

6 Histology (liver biopsy): Chronic liver disease is usually characterized by a distinct vacuolar hepatopathy with parenchymal collapse or extensive liver fibrosis (cirrhosis).
7 Dermatohistopathology: Early lesions show diagnostic findings of pronounced diffuse parakeratotic hyperkeratosis with intercellular and intracellular edema, degeneration of keratinocytes in the upper layers of the epidermis, and hyperplastic basal cells that give rise to the characteristic “red, white, and blue” histological appearance of strionigral degeneration. A mild superficial perivascular dermatitis with evidence of bacterial, dermatophyte, or yeast infection may be present. Chronic changes usually reveal nonspecific changes that are rarely diagnostic.

Treatment and prognosis

1 Any secondary or yeast infection skin lesions should be treated with appropriate antimicrobial therapy.

2 If the underlying cause is resectable glucagenoma, then surgical removal tumors lead to recovery.

3 If the underlying cause is liver disease, this cause should be identified and corrected (eg hepatotoxicity due to anticonvulsant therapy). In order to symptomatically improve liver function, therapy with one of the following antioxidants may be useful:

• S-adenosylmethionine (sAME) denosyl 18–22 mg/kg orally once daily (90 mg for small animals, 225 mg for larger animals)
• Urzodiol (Actigall) 10 mg/kg orally once a day
• Vitamin E 400 IU orally every 12 hours

4 In dogs with liver fibrosis, colchicine 0.03 mg/kg orally given once daily may help slow the progression of fibrosis. Potential side effects long-term use of colchicine include vomiting, increased peristalsis, and diarrhea.

5 Parenteral amino acid support is symptomatic treatment choice for reducing the severity of skin lesions in animals with chronic disease liver and can increase life expectancy by several months. A 10% amino acid solution (Aminosyn; Abbott Laboratories, Abbott Park, IL) 25 mL/kg IV can be given through a jugular catheter over 6-8 hours, or a 3% amino acid and electrolyte solution (ProcalAmine; Braun Medical, Bethlehem, PA) 25 mL/kg IV can be given through a peripheral venous catheter over 8 hours. Treatment can be repeated every 7-10 days or as long as needed. Significant improvement in skin condition should be observed within 1-3 weeks.
6 Oral administration of amino acid solutions works well. Alternatively, oral support of 3-6 raw egg yolks per day, zinc and essential fatty acids may help improve skin conditions in some animals, but these treatments are usually not as effective as intravenous administration amino acids.

7 Treatment with anti-inflammatory doses of prednisone may temporarily improve the skin condition, but some dogs are susceptible to diabetes and additional disease liver after the use of glucocorticoids.

8 Symptomatic topical therapy (keratolytic or moisturizing shampoos) may improve skin condition.

9 The prognosis for animals with chronic liver disease or metastatic pancreatic neoplasia is poor and survival time from the onset of skin lesions may be only a few months.

Severe bacterial and yeast pododermatitis often complicates clinical picture this syndrome.

Type of distribution of lesions in canine and feline hepatocutaneous syndrome

Photo 1. Hepatocutaneous syndrome in dogs and cats. Cortical dermatitis with alopecia on the nasal planum and muzzle.

Photo 2. Hepatocutaneous syndrome in dogs and cats. Close-up view of the dog in Photo 1. Cortical dermatitis with alopecia on the lips and nasal planum is similar to the lesions seen in autoimmune diseases skin.

Necrosis can be direct (direct destruction by a traumatic factor) or indirect (due to disruption of tissue nutrition).

Why does a dog have necrosis?

The reason that a dog has soft tissue necrosis can be an injury, wound, or lesion electric shock, exposure to high or low temperatures, chemical reagents (acids, alkalis). With indirect necrosis, there is a disruption in the supply of oxygen and nutrients to cells and tissues as a result of prolonged pressure, compression, pinching, spasm of blood vessels and nerves, thrombosis.

Necrosis is almost always accompanied by pathogens that cause necrotic infections. Necrosis of soft tissues includes: heart attack, gangrene, bedsores, dry and wet (appearance of pus) necrosis. The speed and extent of spread of dead cells depend on the duration of mechanical action, the infection that has joined, and also anatomical features damaged organ.

Symptoms: swelling, inflammation, pain reaction, discharge of pus, discoloration of the damaged area of ​​skin or limb, blistering, unpleasant odor from the wound. Subsequently, poisoning of the entire body occurs, which is accompanied by an increase in body temperature and weakness of the animal. If proper assistance is not provided, the dog will die.

Treatment

Treatment is carried out comprehensively: necrotic tissues and organs are surgically removed, and immunostimulants and drugs that have regenerative properties are prescribed in parallel. Painkillers and antibiotic therapy are also used. Surgically, necrotomy (dissection of necrosis), necrectomy (removal or amputation) can be performed.

Necrotomy is performed for necrosis that takes up large area, in particular on the limbs and chest. During this manipulation, necrotic tissue is cut into living tissue, due to which oxygen access is restored to it and nutrition is improved. Necrectomy is carried out within viable tissue after the boundaries of dead tissue are clearly defined. After removing the necrotic tissue, sutures are applied. Amputation of a limb or part of it is carried out only if necessary to ensure that the infection does not spread further and the animal does not die.

Since minor injuries - punctures, bruises, bites - can cause such a serious disease as necrosis, you need to carefully monitor your four-fingered friend, especially while walking. IN postoperative period hygiene rules must be observed to prevent secondary infection. When dangerous symptoms, seek advice from a specialist as soon as possible.

Necrosis is the death of tissue. There are several types of necrosis according to localization. The most common lesions in dogs are soft tissue necrosis and bone necrosis.

Necrosis of soft tissues includes: gangrene, heart attack, bedsores, wet (with pus) and dry necrosis. Bone necrosis can be complete (the entire bone dies) or partial (a small area of ​​the bone is affected). If the surface of the bone becomes necrotic, such necrosis is called cortical, and if there is necrosis of the deep layers, it is called central or deep.

Necrosis of soft tissues can be direct or indirect, depending on the reasons that caused it.

1. Direct necrosis caused directly . Indirect necrosis occurs due to disruption of tissue nutrition. Direct necrosis occurs as a result of trauma, electric shock, various wounds, burns or frostbite, and the action of chemicals (acids, alkalis).
2. Reason indirect necrosis is a disruption in the supply of nutrients and oxygen to cells and tissues as a result of prolonged compression, squeezing, pinching, thrombosis or spasm of nerves and blood vessels.

Necrotic infections are caused by pathogens that always accompany necrosis. Bone necrosis occurs when purulent inflammatory processes in certain layers of bone tissue, as well as mechanical injuries(concussions, bruises, broken bones), especially frostbite, chemical exposure. Due to these factors, thrombosis occurs and the nutrition of the bone from the blood vessels is disrupted.

Symptoms of necrosis in dogs

• With necrosis of both soft tissue and bone, inflammation and swelling are noticeable at the site of the lesion.
• The damaged area of ​​the skin changes color, hurts, pus may be released from the tissues, blisters may appear, and an unpleasant odor may appear.
• Over time, poisoning of the entire body occurs, as a result of which the animal weakens and becomes weaker.

Without medical care the dog dies. The rate of development of necrosis depends on how long the mechanical impact on the tissue and further exposure to infection lasted, as well as on the anatomical features of the organ that is affected by necrosis.

Treatment

When treating necrosis, surgery cannot be avoided. Dead tissue and organs must be removed. There are two types of operations:

1. necrotomy (cutting through necrosis to remove dead soft tissue)
2. necrectomy (amputation or removal of a dead organ).

Necrotomy is performed for extensive necrosis, most often on chest and limbs. During this manipulation, necrotic tissue is cut down to living tissue. This improves her nutrition and restores her access to oxygen.

Necrectomy is performed to prevent the infection from spreading further, that is, to save the life of the animal. In addition, treatment is carried out as a whole complex. Except surgical procedures therapy is also used.

As a rule, drugs that have regenerative properties and immunostimulants are prescribed. After surgery and painkillers. In case of bone necrosis after surgery, antibiotics are prescribed, which are administered by intraosseous injection.

Disease prevention

Often the cause of such a serious illness is quite minor injuries: bruises, injections, bites.

Most often in the practice of the average veterinarian we encounter Various types inflammatory processes. These pathologies are very dangerous in themselves, as they cause a strong pain reaction and intoxication of the animal’s body. But they are also fraught with more dangerous and serious pathologies. Take, for example, necrosis: it occurs quite often in dogs, and it may well lead to amputation of limbs or even fatal outcome. Of course, this does not always happen, but still, dog owners should always be on alert in order to recognize the dangerous symptoms of this disease in time.

Necros translates as “dead”, “non-living”. Actually, this is the essence of this pathology: cells (or a whole group of them) begin to die en masse. The overall performance of the body is often preserved, but the animal’s well-being is still far from ideal.

Causes

Firstly, its development is often facilitated by negative factors external environment. Thus, necrosis of the auricle is almost always associated with frostbite. This is especially common in smooth-haired dogs of “compact” sizes, for which, in principle, any hypothermia can end very badly. The same necrosis of the tongue in dogs can be associated with the actions of careless owners who feed their pet excessively hot food. Any grass is also dangerous. Thus, tail necrosis occurs very often in dogs. fighting breeds which this one.

Read also: Streptoderma or skin inflammation in dogs (symptoms and treatment)

Chemicals are also bad for the health of the animal. For example, skin necrosis in a dog is often caused by exposure to some aggressive chemical reagent. The same bleach, for example. In general, in order to better understand the general etiology of the process, it will be useful to look at the basic classification of negative factors.

Since any pathology of this type can be treated only by knowing its cause, they are extremely important:

• Physical impact. This includes high and low temperature, radiation, UV radiation, various wounds, which cause tissue necrosis in a dog.

• Chemical. Various aggressive reagents (acids, alkalis), as well as medications. Thus, necrosis of a dog’s ear may well be due to the actions of the owners, who, having decided to “clean the ears” of their dog, poured a couple of glasses of boric alcohol into it. An exaggeration, of course, but big picture exactly like that.

• Infectious. One of the most common types. For example, necrosis of a dog’s hearing organ is caused by the actions of a horde of numerous ear mites: they cause constant irritation and inflammation of the ear tissues, and later all this is complicated by invasion pathogenic microflora. It’s much worse if microorganisms infect internal organs and fabrics. Thus, asphyxial necrosis of the femoral head (more precisely, aseptic) often occurs in old dogs with reduced immune status. In this case femur literally rots, causing terrible pain. In the photo, such dogs look like “living corpses”, as they literally “shrink” from pain.

• Allergic factor. It is allergens that in some cases cause necrosis of the pancreas. This happens when a dog is fed low-quality food of dubious origin for a long time.

• Vascular damage. If, due to some pathogenic factor (thrombus), a large, important vessel fails ( coronary artery), the dog dies immediately. If the vessel is not too important, the matter ends in local defeat. An ideal example is tail necrosis, which is often also caused by frostbite.