The dog has crusts on the tips of the ears: what could be the reason? Pathology associated with a malfunction of the immune system or vasculitis in a dog: how to recognize and how to treat inflammation of the inner layer of blood vessels

Focal cutaneous vasculitis and alopecia at the rabies vaccination site.
- predisposition: Yorkshire Terrier, silky terrier.
- develops within 1-5 m after vaccination, characterized by a zone of baldness at the injection site.
Proliferative thrombovascular necrosis auricle
- predisposition in dogs of small and toy breeds.
- characterized by wedge-shaped devitalization and necrosis of the distal parts of the auricle.
– early lesions: Diascopy reveals erythema with no pressure blanching (skin hemorrhage).
– initial signs: swelling, erythema and discoloration of the center of the apex of the ventral medial surface of the auricle.
- with the progress of the disease: erosions and ulcers spreading from the tip in a wedge-shaped direction towards the base of the ear.
- Probable necrosis with tissue loss.
- Bilateral lesion is typical, but probably unilateral.
- there are no systemic symptoms.
– Chronic syndrome with slow progress

Cutaneous vasculitis, diseases of the ears and skin in animals.

Clinic for Allergology, Skin and Ear Diseases of Pets, Livonia, USA
School of Small Animal Clinical Veterinary Medicine, Department of Dermatology, Michigan State University, USA

The presented classification of vasculitis does not correspond to that adopted in domestic medicine. In our practice, vasculitis is divided into primary and secondary and classified depending on clinical signs, the size of the affected vessels and the type of cellular infiltrates. Vasculitis and vasopathy are generally considered synonymous.

Review
Ischemic skin lesions can be divided into two groups: forms with abundant cellular infiltrate (vasculitis) and poor cells (vasopathy). Regardless of the form, they are all associated with inadequate microcirculation in the skin.

Vasculitis is characterized by an aberrant immune response directed to blood vessels. Histologically observed inflammatory response, involving and destroying blood vessels, resulting in ischemic changes (see histology). Vasopathy (small cell vasculitis) is also pathological process, in which ischemic tissue changes occur, but a small number of histologically observed inflammatory cells. Differentiation between vasculitis and vasopathy for the treatment of patients suffering from this condition does not matter.

Clinically, vasculitis can be presented as exclusively cutaneous or systemic form(eg, uveitis, glomerulonephritis) or both (mixed form). Vasculitis can be caused by drugs (including vaccines), bacterial, viral, fungal or rickettsial infection (both direct exposure to the pathogen and as a result of the formation of immune complexes (type III hypersensitivity reaction)), idiopathic / genetic causes (jack- Russell Terriers), neoplasms, skin reactions for food or autoimmune disease(systemic lupus erythematosus, SLE).
Cutaneous small vessel vasculitis (SCV) affects small vessels dermis, especially postcapillary venules. CVMS is the most common form cutaneous vasculitis dogs. The most commonly used method for classifying vasculitis in dogs is to assess the skin infiltrate. There are neutrophilic leukocytoclastic, neutrophilic non-leukocytoclastic, lymphocytic, eosinophilic and granulomatous forms. It is important to realize that the result of a biopsy depends on the time of sampling. The predominant cell type in the biopsy may be merely a reflection of the specific stage of the disease, rather than its type. In leukocytoclastic CVMS, if the biopsy was taken early (<24 часов от начала заболевания), можно увидеть гранулоцитарный инфильтрат, а при биопсии спустя 48 часов или позже он будет в основном лимфоцитарным. Встречаются и формы КВМС с изначально лимфоцитарной картиной (напр., вакциноассоциированный).

Clinical manifestations of CVMS
Clinical signs of CVMS include desquamation, hair loss, purpura (palpable papules and nodules with a hemorrhagic component), ulcers, blisters, nodules, congestive edema, acrocyanosis, and panniculitis (if deeper vessels are involved). The elements are located on the distal parts of the limbs (including the tips of the ears and tail) and places of pressure. Systemic lesions may occur as sequelae of vasculitis (hepatic injury, glomerulonephritis, synovitis/arthritis, gastroenteritis, pleurisy/pericarditis) and/or underlying disease (eg, anemia and/or thrombocytopenia in SLE).
A number of vasculitis have been described. The etiology of some is known, while others are unclear. These include:

Urticarial vasculitis, which is a subspecies of CVMS. The clinical picture is represented by wheals or serpentine papules, sometimes with nearby or distant angioedema. Unlike other forms of urticaria, urticarial vasculitis resolves slowly, often over several days, and may be accompanied by purpura. This form is often associated with food intolerance.

Proliferative thrombovascular necrosis of the auricle has an unclear etiology. There is no connection with sex/breed/age in this disease. The elements appear at the tip of the ear and extend proximally to the inner surface. The elements are wedge-shaped, with the tip of the wedge proximal. Ulcers, crusts and peeling are observed.

Familial (autosomal recessive) cutaneous vasopathy in German Shepherds has been described in Canada. This genodermatosis is often caused by vaccination: elements appear 7-10 days after vaccination. The puppy shows signs of a systemic lesion (drowsiness, lameness, swelling in the joints, fever +/ lymphadenopathy). Skin manifestations include tight swelling of the bridge of the nose, ulcers and crusts on the auricle, nose and tail tip. The paw pads are edematous, depigmented and may ulcerate. General and biochemical blood tests, titers of ANA, RF, Coombs reaction and immunoglobulin levels were within normal limits.

Proliferative arteritis of the nose has been described in St. Bernards and Giant Schnauzers. The author also established such a diagnosis for Great Dane. The etiology is unknown. There are non-itchy linear ulcers on the nose, sometimes with severe bleeding. In the treatment of this disease, success is unpredictable. Prednisolone, topical hormones, tetracycline, niacinamide, and fatty acids (omega-3/omega-6 combination) are used.

Idiopathic cutaneous and glomerular vasopathy in racing Greyhounds ("Alabama Rot"). There is no connection with gender or age. There may be a genetic predisposition to this disease. Clinically, it begins with multifocal erythematous edema of the skin, which later ulcerates. Elements are marked on the extremities +/- stomach and torso. Serous-hemorrhagic discharge may flow from the elements. Pastosity may be observed. Systemic lesions (fever, drowsiness, gastrointestinal involvement) have been described, including symptoms of acute renal failure. As an etiological factor, consider verotoxin produced by E. coli found in undercooked beef products.

Scottish terrier vasculitis has been described as a probable genodermatosis. At 3-4 weeks of life in dogs, nasal discharge begins to depart, followed by ulceration and destruction of the nose and nostrils. There is no effective treatment.

Jack Russell Terrier vasculitis has been described. In one description, the age of the dogs (5) ranged from 3 months to 11 years. The cause of the illness is unknown, but 3 out of 5 dogs developed symptoms 2-3 weeks after vaccination. The author believes that these dogs may have had a late onset of dermatomyositis. There is a high probability that they had vasculitis.

Canine familial dermatomyositis is an ischemic skin and/or muscle disease with a genetic basis (Collies and Shelties). This is the only ischemic skin lesion that is accompanied by muscle involvement. The age of debut is from 6 weeks to 1 year, usually up to 6 months. Elements can decrease and disappear as they grow older, or they can progress. Usually the elements disappear by 1 year of age. Skin lesions that are usually the most prominent clinical sign include alopecia, desquamation, crusting, erosions, ulcers, depigmentation, hyperpigmentation, and scarring. Elements appear on the muzzle, mucocutaneous junctions, pasterns and metatarsus, on the tips of the tail and ears. Onychodystrophy may also be observed. Secondary bacterial pyoderma may occur. Muscle involvement in the process is proportional to the severity of skin lesions and is usually detected after the development of skin lesions. These dogs may develop megaesophagus, or muscle atrophy, involving the masticatory and extensor muscles. The differential series includes demodicosis, dermatophytosis, superficial bacterial folliculitis, discoid lupus erythematosus, and epidermolysis bullosa. In the author's experience, most puppies have a limited muzzle lesion, which the owner takes for wounds / scars received from other puppies or a cat in the house. Diagnosis is based on the dog's characteristics, physical examination, and histological changes consistent with vasopathy.

Idiopathic CVMS can occur in dogs of any breed or age. This diagnosis is made after the exclusion of a genetic predisposition and all other possible causes.

Post-vaccination alopecia after rabies vaccination is an ischemic skin lesion that occurs 2-12 months after the introduction of the rabies vaccine. The risk group includes dogs of small breeds with white hair. The method of administration of the vaccine does not affect the frequency of such a reaction. Skin lesions include scaling, hair loss, plaques, hyperpigmentation, nodules, erosions, crusting, and skin atrophy (scarring). Elements can also be found far from the injection site. Histologically, in addition to changes characteristic of vasculitis, septal panniculitis and focal lymphoid nodules can be observed.

Pathophysiology of CVMS
Regardless of the causative / triggering factor that provokes the development of vasculitis, an immunological hypersensitivity reaction is triggered. This reaction leads to vascular damage and ischemic changes that are observed clinically. Hypersensitivity reactions include the following.

Type I occurs when 2 IgE molecules on the surface of mast cells bind an antigen, resulting in mast cell degranulation and the release of both deposited and newly synthesized mediators, which include histamine, leukotrienes, chemokines, and cytokines. Chemokines and cytokines mobilize leukocytes, including eosinophils, NK cells, and T lymphocytes. This type of hypersensitivity is most often associated with insect bites, but can also occur in response to food components. Histological examination revealed a pronounced eosinophilic infiltrate.

In type II, antibodies of the IgM and IgG classes are involved, landing on circulating cells or directly on tissue antigens - in this case, on endothelial ones. Attachment of these antibodies to the surface of these cells (opsonization) allows phagocytes to attach. Once bound, phagocytes release the contents of their lysosomes, resulting in endothelial cell death. Antigen-antibody binding can also activate the complement system. Being activated, the complement system leads to lysis and death of endotheliocytes. Finally, antibodies can bind to NK cells (cytotoxic lymphocytes). Once bound to the endotheliocyte-antibody complex, these cells activate enzymes leading to apoptosis (cell death).

Type III occurs when there is a supply of soluble antigen-antibody complexes (IgG or IgM) that are normally cleared by macrophages in the spleen or liver. These complexes can be deposited on or between endotheliocytes. When this happens, the complement system is reactivated, leading to cell death.

A type IV hypersensitivity reaction is associated with an abnormal response of T-lymphocytes to an antigen. Being sensitized by antigens, these T-lymphocytes infect tissues. Cytotoxic CD8+ T lymphocytes cause direct damage, while T helper-1 (CD4) secrete cytokines that activate cytotoxic T lymphocytes and mobilize and activate macrophages. Activated macrophages produce inflammatory cytokines, which are the main cause of cell damage.

It is important to understand that the immune system reacts abnormally to an antigen through various mechanisms. If we can detect this antigen, the treatment is more likely to be successful.

Differential Diagnosis
Vasculitis is differentiated from coagulopathy, cold agglutinin disease, frostbite, DIC, demodicosis, dermatophytosis, superficial bacterial folliculitis, and discoid lupus erythematosus.

Diagnostics
Diagnosis of any skin disease is based on a thorough history taking, clinical manifestations (primary localization, nature and distribution of elements), laboratory tests and response to treatment. The most valuable laboratory technique for vasculitis is histological examination. Evaluation of patients with confirmed vasculitis should include a detailed history of medications (including vaccinations), a thorough physical examination (including retinal examination), and basic laboratory testing - complete and biochemical blood tests and urinalysis. To detect protein-losing nephropathy, the total protein/creatinine ratio or microalbuminuria should be tested. Other diagnostic procedures depend on the characteristics of the dog and the clinical picture. These include detection of ticks, culture of blood, tissue or urine samples, Coombs test, determination of ANA (antinuclear antibodies), x-rays of the chest and abdomen, ultrasound of the abdominal organs.

Histology
Since the number of histological manifestations of vasculitis is limited, it makes sense to think of vasculitis as a response pattern to a number of different etiological factors. Regardless of the cause, vasculitis is a pathological process characterized histologically by inflammation and destruction of blood vessels, as well as ischemic changes, manifested by blurring and pallor of skin collagen, superficial squamous cell dermatitis, keratinocyte dyskeratosis, necrosis of the entire thickness of the epidermis, atrophy of follicles and skin appendages, and folliculitis .

Treatment
The first step is to identify and treat the causative condition (if possible) and/or avoid it (eg, drug reactions). Once a treatment plan has been determined, it must be ensured that the treatment will not cause more harm than the disease itself. Depending on the severity of symptoms, treatment may include: pentoxifylline, glucocorticosteroids (GCS), other immunosuppressants, cyclosporine, and immunomodulators.

In any case, if systemic treatment is necessary, the author starts with pentoxifylline (trental), either alone or in combination with other drugs. Pentoxifylline is a methylxanthine derivative that increases the elasticity of red blood cells and reduces blood viscosity, improving blood flow through constricted/edematous vessels. It also inhibits the synthesis of pro-inflammatory cytokines such as IL-1, IL-4, IL-12 and TNF-. Pentoxifylline is prescribed at a dose of 15 mg/kg 3 times a day. A complete clinical response can be achieved with a delay of 30-90 days.

Vitamin E (400-800 IU 2 times a day) and essential fatty acids (omega-3) are prescribed for their anti-inflammatory and antioxidant properties.

If systemic treatment is required, a combination of tetracycline and niacinamide may be added to therapy. This combination has many anti-inflammatory and immunomodulatory properties. The dosage of tetracycline and niacinamide for cats and dogs less than 10 kg - 250 mg of both every 8 hours, for dogs heavier than 10 kg - 500 mg of both every 8 hours. With a clinical response (which usually takes several months), the drugs are slowly withdrawn - first up to 2, and then up to 1 r / day. Side effects are rare, but when they occur, they are usually caused by niacinamide. These include vomiting, anorexia, drowsiness, diarrhea, and elevated liver enzymes.

Glucocorticosteroids (GCS) are the mainstay of treatment for many forms of vasculitis. The most powerful veterinary topical drug is synotic containing fluocinolone acetonide. If the disease is localized (eg, at the tip of the ear), but does not respond to treatment with a synotic, the author uses an even stronger remedy - deoxymethasone at a concentration of 0.25%. These external preparations are applied 2 times a day. until clinical remission is achieved (but not more than 21 days), and then slowly canceled over several months. Make sure the owner wears gloves when applying this medication. Be aware that topical hormonal preparations can cause polyuria/polydipsia/polyphagia. This reaction to corticosteroids is highly variable and can occur in unexpected situations. If side effects occur or if there is no response to treatment, topical tacrolimus (0.1%) may be tried.

If more aggressive therapy is needed, tetracycline/niacinamide is substituted with prednisolone, which is given at a dose of 1 mg/kg b.i.d. for 4 days, and then by mg / kg 2 r. / d. for the next 10 days. Re-examinations are carried out every 14 days. If remission is achieved, the dose is reduced by 25% every 14 days. The author defines remission as the absence of active (fresh) elements. You can not reduce the dose too quickly! The goal is to keep the dog on 0.25 mg/kg or less every other day. If this is not achievable, azathioprine is added to therapy (see below).

If the animal does not respond to prednisolone, then not only must other immunosuppressive agents be added (see below), but it must also be replaced with dexamethasone or triamcinolone. For both drugs, the initial dose is 0.05-0.1 mg/kg 2 times a day. Cancellation occurs as gradually as with prednisone.

Animals receiving GCS for a long time, regardless of the dose, require monitoring of general and biochemical blood tests, general urinalysis and urine culture (to exclude asymptomatic bacteriuria) every 6 months.

Azathioprine is an antimetabolite that is converted to its active form, 6-mercaptopurine, in the liver. 6-MP disrupts the normal synthesis of DNA and RNA, preventing cell division leading to cell death. It is metabolized in the liver by 3 different enzyme systems, one of which is xanthine oxidase (XO). KO metabolizes azathioprine to an inactive metabolite. It should be remembered that allopurinol, which is a KO inhibitor, is used to treat urolithiasis in dogs. Do not administer azathioprine to dogs receiving allopurinol.

The action of azathioprine reaches full potency with a delay of 4-6 weeks. The drug is prescribed simultaneously with GCS. Initial dose of azathioprine 1.0 mg/kg 1 r./d. After achieving remission and canceling or reducing GCS to minimal doses, azathioprine intake is reduced every 2-3 months. The author usually reduces not the dose, but the frequency of administration, first appointing every other day, and then 1 time in 72 hours. Complete (with platelet count) and biochemical blood tests are monitored every 14 days for 2 months, then every 30 days for 2 months, then every 3 months as long as the dog is on azathioprine. Possible side effects include anemia, leukopenia, thrombocytopenia, hypersensitivity reactions (especially in the liver), and pancreatitis. Azathioprine should not be given to cats as it can cause irreversible bone marrow depression.

Dogs that do not respond to or cannot tolerate azathioprine should be treated with chlorambucil. The treatment regimen/precautions/monitoring for chlorambucil is the same as for azathioprine. Initial
dose 0.1-0.2 mg/kg/day.

In the case of neutrophilic vasculitis that does not respond to the treatment described above, the administration of sulfasalazine at a dose of 25 mg/kg 3 times a day may be effective. (maximum 3 g per day). Side effects include anemia, keratoconjunctivitis sicca, and hepatotoxicity, so CBC, CBC, and Schirmer tear test should be monitored every 14 days for 2 months, then every 30 days for 2 months, then every 3 months for as long as the dog is sulfasalazine. If neutrophilic vasculitis does not respond to sulfasalazine, dapsone may be tried, although it is more toxic than sulfasalazine.

In the case of eosinophilic or urticarial vasculitis, or any vasculitis that does not respond well to treatment, the dog should be placed on a homemade elimination diet.

Bibliography
Scott DW, Miller WH, Griffin CE. Muller & Kirk's Small Animal Dermatology. 6th ed. Philadelphia: WB Saunders; 2001:742-56.
Nichols PR, Morris DO, Beale KM. A Retrospective Study of Canine and Feline Cutaneous Vasculitis. Vet Dermatol 2001: 12:255-264
Affolter VK. Cutaneous Vasculitis and Vasculopathy. In: World Small Animal Veterinary Association World Congress Proceedings, 2004
Torres SM, Brien TO, Scott DW. Dermal arteritis of the nasal philtrum in a Giant Schnauzer and three Saint Bernard dogs. : Vet Dermatol. 2002:13:275-81.
Hargis AM, Mundell A. Familial canine dermatomyositis. Comp Cont Ed Pract Vet 1992; 14:855-65.
Rees CA, Boothe DM. Therapeutic Response to Pentoxifylline and Its Active Metabolites in Dogs with Familial Canine DermatomyositisVet Ther 2003:4:234-241
Vitale CB et al. Vaccine induced ischemic dermatopathy in the dog. Vet Dermatol. 1999; 10:131.
White SD, Rosychuk RAW, Reinke SI, et al. Tetracycline and niacinamide for treatment of autoimmune skin disease in 31 dogs. J Am Vet Med Assoc 1992:200:14971500.

Skin diseases in dogs are almost always quickly detected even by inattentive owners, since it is necessary to try hard not to suspect a patient in a bald, scabbed and ulcerated pet. So the owners notice vasculitis in dogs almost immediately, but few people know how dangerous redness and baldness of small areas of the skin can be ...

Vasculitis is an inflammation of the blood vessels, leading to severe damage to their wall. Inflammation is caused by an autoimmune reaction, when the body's defense mechanisms begin to destroy its own tissues and cells. There are many causes of vasculitis: infections (bacterial, viral, fungal), reactions to drugs and certain vaccines, neoplasia, and certain primary autoimmune diseases.

In dogs, this disease is not very common, but the pathology can affect animals of all ages, breeds, it does not depend on gender and physiological state. Other causes for systemic vasculitis include:

"Wrong", unpredictable interaction between drugs. This often happens when owners decide to “treat” their pet on their own, stuffing it with medicines without regard to their compatibility. Nobody reads the instructions.

Neoplasia is an abnormal growth of tissue, a tumor.

Surprisingly, .

. The more predisposed a dog is to them, the higher the risk of developing vasculitis or other autoimmune disease.

Chronic joint diseases such as rheumatoid.

Read also: Ear Diseases in Dogs: List of Diseases, Symptoms and Treatment

Clinical signs and diagnosis

Since the disease can affect almost all organs and tissues (which is not surprising, since there are vessels everywhere), the symptoms in different cases are strikingly different. For example, in vasculitis due to an inadequate response to a vaccine, there is a strong inflammatory reaction and hair loss at the injection site.

It is very easy to distinguish this phenomenon from the usual side effects or infection caused by non-compliance with the rules of asepsis and antisepsis: it develops two to three months after vaccination.

The veterinarian will begin with a standard diagnostic test, which includes a complete blood count, biochemistry, and urinalysis. The more methods used, the more accurate the diagnosis. X-rays and ultrasound are also used: with their help, lesions of internal organs are detected. The "gold standard" for diagnosing vasculitis is a skin biopsy.

Read also: Malassezia dermatitis is a fungal disease in dogs.

If an allergic reaction to food, medicines, care products is suspected, then it is advisable to exclude them for a while. In the case when they were the cause of the animal's poor health, it will be possible to do without potent drugs. The prognosis for this disease depends on many factors: the root cause, the localization of the main morphological and functional disorders (on the skin or in the internal organs - the difference is large), and the neglect of the case.

Therapeutic methods

The main goal of therapy is to eliminate the root cause that led to the development of an autoimmune reaction. Of course, this is true only for those cases where it was possible to install it at all.

Common treatments for vasculitis in dogs involve the use of the following medications:

Corticosteroids, including prednisolone.
Pentoxifylline.
A combination of tetracycline antibiotics and niacin (nicotinic acid).
Dapsone.
Sulfasalazine.
Cyclosporins.
Imuran.

As a rule, combined treatment is required. In some cases, the dog will have to be on medication for life, while other dogs heal relatively quickly. Relapses are possible, and their appearance does not depend on the time of cessation of active treatment.

The "non-standard" methods of therapy include massage. It is known to reduce inflammation and increase blood circulation. Since vasculitis is an inflammation of the blood vessels, and in many cases implies "side effects" arising from this, manual therapy will be useful in many situations.

Massage is also helpful for dogs with vasculitis who are prescribed prednisone. The fact is that one of the side effects of this drug is overweight, and manual therapy helps maintain muscle tone.

But! If the dog has pronounced symptoms of vasculitis, including inflammation and even tissue necrosis, massage is strictly contraindicated, as it can worsen the condition of the animal, and one should not forget about severe pain. This technique should be used only (!) as an addition to medical treatment, and only after the attenuation of pronounced symptoms. In addition, massage can be useful as a measure to prevent recurrence of the disease (with the exception of the periods of relapse themselves).

Various diseases that occur in dogs should not be ignored by the owner. Vasculitis in dogs is one of the most common diseases that occurs in dogs as a result of malfunctions of the immune system. The development of the disease is accompanied by inflammatory processes in the blood vessels, leading to serious violations of their walls. As a result of the fact that the immune system begins to attack its own healthy cells, various parts of the dog's body begin to suffer.

Reasons for the development of vasculitis

The inflammatory process affecting the inner layer of blood vessels (endothelium) occurs for several reasons. So, in the vast majority of cases, vasculitis occurs in diseases of a viral nature, when pathological microorganisms begin to destroy the cellular structures of blood vessels. Destroying diseased and affected cells, the immune system begins to kill its own, healthy cells. Other causes of vasculitis in dogs on the ears are:

the result of exposure to the animal body of strong medications (incorrect selection of drugs and self-medication can provoke the development of autoimmune reactions);
complete incompatibility of the active substances of various medicines;
neoplasia (the occurrence of tumor neoplasms and pathological growths of ear tissues);
kidney failure and other pathologies that have a negative impact on the entire body of the animal as a whole;
allergic type reactions;
chronic diseases that destroy joint tissues in dogs;
violations of metabolic processes in the body;
diabetes;
systemic lupus erythematosus.

Symptoms of vasculitis

The characteristic signs of an autoimmune disease depend on the individual characteristics of the animal's body, as well as on the causes that led to the development of the pathology. The symptomatology of vasculitis is clearly different from the signs of violations of the rules of hygiene of the auricle. Every dog owner should be aware of the signs of vasculitis in order to promptly contact a veterinarian for help and prescribing an adequate treatment regimen. The main symptoms of vasculitis are:

ulcerative lesions of the inner side of the auricle in dogs;
subcutaneous hemorrhages, similar to small bruises;
particles of necrotic tissue;
the appearance of bleeding, swelling in the ear;
febrile conditions in an animal;
general disturbances in the health of the dog (loss of appetite, weight loss);
inflammatory processes in the joints and articular bags.

In dogs with rabies vaccination-associated baldness, the lesions appear as partial alopecia, crusting, and pigmentation changes at the site of the lesion. A pet with ear vasculitis may suffer from anorexia, depressive and febrile conditions, arthropathy and myopathy in parallel.

Idiopathic ear vasculitis in dogs, especially in animals with a genetic predisposition, manifests itself as alopecia at the edges of the ears. After that, the skin begins to acquire a dark color at the site of the lesion, thicken and become pronouncedly necrotic.

The presence of several obvious signs of pathology should alert the owner and seek help from a veterinary clinic. Vasculitis therapy is prescribed only after all the necessary laboratory and clinical studies have been completed. The diagnosis is made on the basis of differentiation of the disease from other pathologies. It is necessary to separate the vasculitis of the auricles from such diseases as:

systemic erythematous pemphigus (an autoimmune disease);
disseminated intravascular coagulation (violation of the process of blood clotting);
cold agglutinin syndrome (chronic disorder of intravascular hemolysis);
cryogluglobulinemia (the presence in the blood of specific precipitated protein components that precipitate at temperatures below 37 degrees);
ischemic necrosis (necrosis of a part of an organ in case of impaired blood supply).

In addition, it is necessary to exclude:

drug-induced dermatitis;
normal frostbite;
ordinary vesicle.

To make a diagnosis, ultrasound methods, a biochemical blood test, and radiography are used. The method of studying particles of biological material (biopsy) has a high efficiency.

Treatment for vasculitis

Therapy of vasculitis of the auricle in dogs should be comprehensive, including a number of activities. Treatment of diagnosed vasculitis begins with a course of antibiotics to prevent the development of pyoderma. Antibiotic therapy lasts up to 30 days. Experts note that dogs treated with antibiotics are more likely to survive than relatives receiving exclusively immunosuppressive therapy.

Local treatment involves the use of special drugs containing steroid components, reducing the inflammatory processes of a focal nature. The success of therapy depends only on the correct approach to the problem and the correct combination of drugs with each other. Depending on the individual characteristics of the body, dogs cope with the disease in different ways.

Pets diagnosed with systemic vasculitis should be under the constant supervision of a veterinarian to adjust the treatment regimen. It is important to constantly monitor changes in the blood picture. The drugs used for treatment greatly weaken and suppress the immune system, so the owner of the animal must monitor the health of the dog. When the first signs of infection appear, it is necessary to inform the attending physician. When treated with the anti-inflammatory drug Prednisolone, the immune system almost completely stops its activity, so any pathogenic microorganism can threaten the dog's life.

Vasculitis in Dogs: Signs, Diagnosis, and Treatment

What it is?

In dogs, this disease is not very common, but the pathology can affect animals of all ages, breeds, it does not depend on gender and physiological state. Other causes for systemic vasculitis include:

"Wrong", unpredictable interaction between drugs. This often happens when owners decide to “treat” their pet on their own, stuffing it with medicines without regard to their compatibility. Nobody reads the instructions.

Neoplasia is an abnormal growth of tissue, a tumor.

Oddly enough, kidney disease.

Allergic reactions. The more predisposed a dog is to them, the higher the risk of developing vasculitis or other autoimmune disease.

Chronic joint diseases such as rheumatoid arthritis.

Clinical signs and diagnosis

The veterinarian will begin with a standard diagnostic test, which includes a complete blood count, blood chemistry, and urinalysis. The more methods used, the more accurate the diagnosis. X-rays and ultrasound are also used: with their help, lesions of internal organs are detected. The "gold standard" for diagnosing vasculitis is a skin biopsy.

Therapeutic methods

The main goal of therapy is to eliminate the root cause that led to the development of an autoimmune reaction. Of course, this is true only for those cases where it was possible to install it at all.

Common treatments for vasculitis in dogs involve the use of the following medications:

Corticosteroids, including prednisolone.
Pentoxifylline.
A combination of tetracycline antibiotics and niacin (nicotinic acid).
Dapsone.
Sulfasalazine.
Cyclosporins.
Imuran.

Massage is also helpful for dogs with vasculitis who are prescribed prednisone. The fact is that one of the side effects of this drug is overweight, and manual therapy helps maintain muscle tone.

But! If the dog has pronounced symptoms of vasculitis, including inflammation and even tissue necrosis, massage is strictly contraindicated, as it can worsen the condition of the animal, and one should not forget about severe pain. This technique should be used only (!) as an addition to medical treatment, and only after the attenuation of pronounced symptoms. In addition, massage can be useful as a measure to prevent recurrence of the disease (with the exception of the periods of relapse themselves).

Prevention

Remember - the more often you show a dog with vasculitis to your veterinarian, the more carefully the latter will be able to control the treatment process and, if necessary, make adjustments to it. It is very important (especially at the beginning of therapy) to constantly check blood counts. It is critical to follow your veterinarian's instructions exactly.

Since the drugs used in the treatment suppress the immune system, you will need to constantly monitor the condition of your pet, identifying the slightest deviations from the norm. If there are any signs of infection, notify your veterinarian immediately. Many dogs have little to no immune system function when treated with prednisolone, so any pathogen can be deadly.

Do not treat vasculitis in a dog yourself, as you can only make the animal worse! Many of the drugs that are used for this are very dangerous in themselves, and only a specialist should deal with their appointment and administration.

Vasculitis in dogs

Symptoms
Diagnostics
Treating Vasculitis in Dogs

Vasculitis in dogs is an inflammation of the walls of blood vessels as a result of the deposition of immune complexes in them.

This pathology can have only a skin form of manifestation, be systemic or mixed.

There are also primary and secondary vasculitis.

In the cutaneous form of vasculitis, small vessels of the dermis are more often affected.

In the systemic form, the kidneys (glomerulonephritis), eyes (uveitis), liver, joints, gastrointestinal tract, etc. are affected.

Causes of Vasculitis in Dogs

The causes of primary vasculitis are hereditary factors. German Shepherds, Greyhounds, Dachshunds, Jack Russell Terriers are predisposed to them.

Infections, chronic injuries, neoplasms, allergic reactions, vaccination, etc. can lead to the development of secondary vasculitis.

The reasons that gave impetus to the development of vasculitis cause the activation of immunity.

The resulting immune complexes damage the walls of blood vessels and inflammation develops. Chronic inflammation contributes to the formation of blood clots that clog the lumen of small vessels, which leads to impaired blood supply and the development of necrosis and ulcers.

Symptoms of Vasculitis in Dogs

Affected dogs may experience: skin peeling, alopecia, edema, ulcers, papules and nodules, necrosis (usually the edges of the auricles, tail tips), hemorrhages on the skin, lesions of the paw pads (loss of pigmentation, ulcers), nasal mirror or skin next to him.

In the generalized form, multiple skin lesions (alopecia, crusts, ulcerations) appear. Vasculitis usually develops in dogs on the ears, tail tip, and skin protrusions.

Diagnosis of Vasculitis in Dogs

The diagnosis is made on the basis of histological analysis.

It is important to differentiate vasculitis from discoid lupus erythematosus, DIC, bacterial folliculitis, dermatophytosis, frostbite (cold agglutinin disease), demodicosis.

Treating Vasculitis in Dogs

In the treatment of vasculitis, the main role is played by immunosuppressive agents (corticosteroids, cyclosporine), as well as angioprotectors.

Treatment of vasculitis in dogs should be carried out under the supervision of a veterinary dermatologist a.

Definitions

Cutaneous vasculitis is an inflammatory disease of the blood vessels that is usually secondary to the deposition of immune complexes in the vascular wall. Cutaneous vasculitis is just a term to describe a skin reaction pattern that can be associated with a variety of causes.

Etiopathogenesis

Cutaneous vasculitis includes many diseases, the final link of which is an immunological reaction with damage to the vascular component of the skin or subcutaneous tissue. More often postcapillary venules are affected, thrombosis and blockage of which cause tissue hypoxia with subsequent necrosis.

Cutaneous vasculitis can be caused by:

Diseases: food hypersensitivity, insect bites, neoplasms, connective tissue lesions, metabolic disorders (eg diabetes, uremia), SLE, cold agglutinin disease;

Medications: vaccines, itraconazole, and even corticosteroids (prednisone and dexamtetasone);

Infections: bacteria, viruses, protozoa.

In most cases of canine and feline vasculitis, underlying causes are not identified and the disease is idiopathic.

Clinical signs

The disease most often affects dogs, but rarely occurs in cats. The disease is represented by various syndromes, the main ones are listed below.

Proliferative thrombovascular necrosis of the auricle.

Wedge-shaped necrosis of the tips of the ears is characteristic. Dogs of small and that breeds are predisposed. Initially, edema, erythema, and discoloration of the center of the apex of the ventral medial surface of the auricle. With the progress of the disease, erosions and ulcers are formed, which spread wedge-shaped from the tip of the ear towards the base. Probable necrosis with complete loss of ear tissue. Bilateral symmetrical lesions are more common, but unilateral lesions are also likely. There are no signs of systemic diseases. This syndrome is characterized by a chronic and progressive course.

Hereditary cutaneous vasculopathy in German shepherds.

The onset of the disease is 4-7 weeks of age, characterized by loss of pigment and swelling of the pads, followed by the development of erosions, ulcers and crusts. Depigmentation is likely before ulceration begins. Similar lesions are likely on the ears, tip of the tail, and nasal speculum (rare). Probably signs of a systemic lesion - lymphadenopathy, fever, depression.

Similar lesions have been described in Fox Terriers and Miniature Schnauzers.

Greyhound vasculopathy (skin and renal glomerular vasculopathy).

Age predisposition - 1-5 years. Localization of lesions - in most cases on the limbs, sometimes spread to the trunk and groin, the head and mucocutaneous junctions remain intact. At the beginning of the lesion, erythema is noted, which quickly progresses to ulcers. Ulcers are deep, with well-circumscribed edges, about 1-5 cm in diameter, merge into groups of seven or more. With a significant lesion, swelling of the distal parts of the limbs is often noted. Once healing has begun, new lesions do not develop.

The disease also affects the vessels of the kidneys with the development of nephropathy of varying severity. Probable systemic manifestations are depression, hyperthermia, polyuria / polydipsia, vomiting and diarrhea, acute renal failure.

In addition to Greyhounds, the disease has been described in Great Danes.

Focal cutaneous vasculitis and alopecia at the rabies vaccination site.

Breed predisposition - poodle, Yorkshire terrier, silky terrier. The lesion develops 2-6 m after the subcutaneous injection of the vaccine, persists for months or years. The lesion itself is characterized by alopecia and hyperpigmentation, with occasional erythema or scaling.

Generalized ischemic dermatopathy.

Characterized by multiple skin lesions due to generalized ischemic dermatopathy. There are several syndromes that can manifest as alopecia, crusts, hyperpigmentation. Localization - edges of the ears, periocular, skin over bony prominences, tip of the tail, pads. Possibly a tongue lesion.

Urticarial vasculitis(urticaria) - an acute lesion, characterized by the development of intense erythroderma, and consolidating blisters. Common in dogs with underlying food allergies.

Diagnosis

A presumptive diagnosis is a characteristic clinical picture and the exclusion of other diseases. The final diagnosis is histopathological examination.

It is important to try to identify and correct probable underlying causes.

Differential Diagnosis

Bullous pemphigoid (pemphigus)

Pemphigus vulgaris

Vasculitis in dogs

Vasculitis is an inflammatory lesion of blood vessels associated with impaired functioning of the immune system. With vasculitis, immune complexes are deposited in the vascular wall. This disease is manifested by various skin symptoms. We are talking about ulcers, necrosis, etc. Dachshunds and Rottweilers most often face this disease.

Causes of Vasculitis in Dogs

Vascular inflammation can be infectious, drug-induced, neoplastic and idiopathic. Vasculitis can develop as a result of infectious pathology, autoimmune processes, tumor lesions, and the use of various drugs. In the case of an unexplained cause of the disease, they speak of idiopathic vasculitis. The development of this disease is based on an allergic process.

Clinical picture of vasculitis in dogs

As a rule, vasculitis is manifested by ulceration and necrosis of the skin. The most common localization of pathology are the ears and limbs. Edema may develop in the affected areas of the body. Vasculitis in dogs may show non-specific signs of the disease. We are talking about the lack of appetite, the oppression of the animal, the rise in body temperature. The appearance of other clinical symptoms is influenced by the underlying or concomitant pathology. Joint damage is manifested by lameness. When the respiratory tract is involved in the pathological process, ulcerations are found in the oral cavity. Symptoms of malignant tumors are toxicosis and damage to various organs.

Diagnosis of Vasculitis in Dogs

Diagnosis of the disease is based on anamnestic data, clinical symptoms and laboratory results. To confirm the diagnosis, the use of biopsy followed by histological examination is indicated. To identify the infectious agent of vasculitis, you can use PCR and other methods. To distinguish pathology from systemic lupus erythematosus and cold agglutinin disease, it is necessary to conduct a blood test for lupus bodies and an agglutination test.

To detect tumor formations, the use of radiography and ultrasound is shown.

Treating Vasculitis in Dogs

First of all, it is planned to identify and eliminate the cause of vascular inflammation. For the treatment of skin problems in this disease, the use of drugs that improve blood circulation (pentoxifylline) is indicated. Corticosteroid drugs (prednisolone) are used to suppress immune inflammation. An associated bacterial infection is an indication for the use of antibiotics.

Prevention of vasculitis in dogs

Prevention of pathologies that can cause vasculitis is provided. To reduce the infectious infection of dogs, it is necessary to carry out timely vaccination. Given the likelihood of developing vasculitis due to the use of certain medications, their use is prohibited without first consulting a veterinarian.

Vasculitis in dogs

Vasculitis in dogs is an inflammatory process that affects the wall of blood vessels. The cause of this pathology is considered to be immune complexes that are detected on the surface of the vessel.

Vasculitis can be primary or secondary. The cause of secondary vascular inflammation is infectious lesions, neoplasms, allergic reactions, rabies vaccination, diabetes mellitus, systemic lupus erythematosus, an adverse reaction to the use of certain drugs, etc.

Pathogenesis

Etiological factors cause the activation of some structures of the immune system. As a result, neutrophils accumulate at the site of damage to the vessel. Subsequently, enzymatic damage to the vascular wall occurs. It is worth noting that inflammation of the vessels often leads to the formation of blood clots. These elements clog the vascular lumen. As a result, necrosis and ulcers develop.

Vasculitis in dogs is an inflammatory process that affects the wall of blood vessels. The cause of this pathology is considered to be immune complexes that are detected on the surface of the vessel.

Pathogenesis

Clinical picture of the disease and pathology syndromes

Necrosis of the auricle as a result of thrombus formation

This disease is more common in small dog breeds. Wedge-shaped necrosis of the final part of the auricle is characteristic. In the early stages, the disease is manifested by redness, which does not fade after pressure. This indicates the presence of skin hemorrhage. With the progression of the pathology, the appearance of ulcers and erosions is noted, spreading towards the base of the ear. In most cases, there is bilateral necrosis of the auricle. Characterized by the absence of systemic lesions. There is a slow progression of the syndrome.

Hereditary cutaneous vasculopathy

The breed tendency is typical for German Shepherds. Pathology is manifested by a decrease in pigmentation and swelling of the paw pads. In addition, the appearance of erosion and ulceration is noted. Also, the localization of lesions can be ears, the tip of the tail, etc. With hereditary cutaneous vasculopathy, systemic symptoms are likely to appear in the form of swollen lymph nodes, lethargy, etc.

Greyhound Vasculitis

Young running dogs face pathology. Characterized by the appearance of dark red redness, which is replaced by an ulcer. The ulcers are well defined and tend to merge. Localization - limbs, trunk and inguinal region. In addition, there is damage to the kidneys. The occurrence of systemic manifestations of pathology (fever, vomiting) is characteristic.

Generalized ischemic dermatopathy

The appearance of multiple skin lesions is characteristic. We are talking about crusts, hyperpigmentation, the appearance of areas of baldness. As a rule, ears, the tip of the tail, skin protrusions, etc. are affected.

Vasculitis in dogs - diagnosis

Histological diagnosis is indicated to confirm the diagnosis. Using this method, an inflammatory lesion of the vascular wall is detected. In addition, the phenomena of fibrosis and thrombus formation are found in the vessel wall. Direct immunofluorescence helps to detect deposits of immunoglobulin.

Vasculitis in dogs must be distinguished from systemic lupus erythematosus, pemphigus vulgaris, frostbite, etc.

Treating Vasculitis in Dogs

To optimize the functioning of the immune system, immunosuppressive therapy is provided. In this case, corticosteroid agents (prednisolone) and cytostatics (azathioprine) are used. To improve blood circulation in damaged vessels, pentoxifylline is used.

The prognosis is affected by the specific disorders and the severity of the dog's condition.