alopecia dog alopecia dog
Dr. Chiara Noli, Dipl CDSC
Introduction alopecia, which is the total or partial lack of hair, a symptom is present in the course of many diseases and is one of the most common skin disorders in domestic carnivores. The causes of the lack of hair are:
- Mechanical grubbing, induced with the animal scratching or licking, owing to the itching;
- loss of hair for inflammatory diseases of the hair follicle;
- the lack of growth hair due to illness noninflammatory hair follicle or due to systemic diseases (whole body).
There are different clinical pictures of alopecia? The alopecia can be divided in their clinical appearance in focal / multifocal (patchy) and diffuse / symmetrical. The first, especially if the skin lesions and exudate appears, are more frequent in cases of inflammatory diseases of the hair follicle. These diseases are parasitic in nature (or demodicosis Red mange), fungal (fungus or ringworm) or bacteria. The diffuse alopecia
/ symmetrical are more indicative of non-inflammatory diseases of the hair follicle (often congenital and / or hereditary) or systemic diseases (metabolic and hormonal).
What are the causes of alopecia in patches? The main causes of patchy alopecia (alopecia focal and multifocal) were bacterial, fungal and parasitic diseases of the hair follicle.
bacterial infection called pyoderma, occurs more frequently in animals suffering from allergies or diseases that weaken the immune system, but also short haired dogs in good health. On the skin can also be observed blistering, crusting and red patches or black. The therapy is based on antibiotics, but should also include research and treatment of any allergic disease or immunosuppressive therapy that prepared bacterial infection of hair follicles.
fungal infection called fungal infection, ringworm or dermatophytosis, is rare in dogs, and occurs more frequently in puppies, animals in contact with cats and animals suffering from immunosuppressive diseases. Fungal infections are cured easily with antifungal drugs, but require careful disinfection of the environment since the spores can be infectious for humans and other animals living with them.
parasitic infection of the hair follicle, called red mange or demodicosis, typically occurs with a few patchy alopecia (localized form) a few months of life, and can heal spontaneously. However, in some cases it may involve large districts skin (form generalized) and occur in adulthood or old age. In these cases the infection is sometimes associated with an immunosuppressive disease. As it is an established genetic transmission of predisposition to this infection, you should not play with animals, especially if suffering from generalized form and more than a year old. The therapy is based on the application of pesticides or sponging on the medication by mouth, and not always able to definitively heal the animal, which can then reach out to relapse in moments of stress (heat, pregnancy, lactation, illness).
What are the common causes of alopecia and symmetrical? diffuse and symmetrical alopecia may occur at birth or during the first few months of life, in adulthood or when the dog is elderly. Depending on the age things might be different.
alopecia present at birth or occurring in the first few months of life
The congenital alopecia (ie, occurring at birth) are normal in some breeds nude (Chinese crested dog, mexican hairless) while they are very rare in normal-haired breeds . This alopecia is sometimes accompanied by other defects, such as teething problems or abnormal production of tears.
dystrophy hair blacks is a form in which dogs are born with a normal coat, but the black hairs grow more slowly than white and marked alopecia develops in the black areas from the first weeks of life. Areas with a white mantle are completely normal.
alopecia occurring in adulthood or late adulthood
In the absence of hair can be seen as a result of systemic disease, usually a hormonal problem or a major stress, or due to a defect acquired in the development of hair.
hormonal problems, such as Cushing's disease, hypothyroidism or testicular tumors, are among the most often symmetrical and diffuse alopecia. They usually occur in dogs mature or advanced, and is accompanied other symptoms.
In the course of Cushing's disease, more common in older dogs of small size, we observed increased thirst (polydipsia), increased urination (polyuria), increased appetite (polyphagia) and distended abdomen. Alopecia is common on the hips and trunk, the skin appears thin, and are very visible blood vessels underneath.
In the course of hypothyroidism in general more frequent in dogs of medium and large size, the animals are less active, at times lethargic and feel the cold more than normal. The alopecia is usually located on the back of the nose, tail, trunk, and on pressure points (such as under the collar).
In the course of cancer testicolare nel maschio, o di disturbi ovarici nella femmina, si possono osservare anomalie degli organi sessuali (prepuzio pendulo, vulva ingrossata, mammelle grosse) o del comportamento (urinazione “da femmina” nel maschio). L’alopecia è diffusa al tronco e nei punti di frizione (sotto al collare), il pelo sembra secco e opaco e a volte è sbiadito (rossiccio nei cani normalmente neri).
I difetti del follicolo pilifero che causano diradamento del mantello sono l’alopecia da diluizione del colore, l’alopecia ricorrente dei fianchi, l’alopecia pattern baldness e l’alopecia X. Per queste malattie dei follicoli piliferi la causa è ancora in parte o completamente sconosciuta.
How is it diagnosed the cause of alopecia? In all cases of alopecia is important that the vet run some tests originally designed to identify possible parasitic infection, bacterial or fungal infections of the follicle. These tests include skin scrapings, cytologic examination of pus (if any) microscopic examination of the hair. The veterinarian also may consider appropriate to remove hair for a fungal culture from the center and periphery of the lesions.
If you are not certain the infection of the hair follicle, or if the alopecia is diffuse and non-inflammatory, it is necessary to perform further tests to identify hormonal diseases. These are typically blood tests for Cushing's syndrome and hypothyroidism, an abdominal ultrasound, the testes or ovaries, or a urine test.
If the tests above have not led to a diagnosis, you may perform a skin biopsy. The levy is largely limited to one or more small pieces of skin of 6mm diameter, usually performed under local anesthesia. Histological examination of biopsies can be clearly diagnostic, as in the case of follicular infection, or your veterinarian can give an indication of excluding certain diseases, or suggest others.
How they treat the alopecia? for curative therapy of alopecia you must know its cause. For this reason, we can usually resolve the infection caused by alopecia and follicular hormonal diseases, giving the animal a targeted therapy.
For congenital and hereditary is not therapy, and you should not use animals to play with. For
acquired defects of the hair follicle, because you do not know the real cause is not known therapy termination. You can improve the appearance of the coat with good nutrition, balanced and rich in essential fatty acids, or with the administration of supplements specifically designed for skin and coat. Recently we have seen moderate results with the administration of melatonin in some animals suffering from alopecia cyclical pattern baldness and alopecia of the flanks. Generally, as the alopecia caused by acquired defects of the hair follicle are essentially problems of an aesthetic nature, we do not recommend the administration of any therapy.
