Section: Veterinary Care In-depth
Diagnosis In-depth
Your veterinarian will take a thorough medical history and examine all body systems. Other medical tests will be necessary to establish the diagnosis.
Microscopic examination. Your veterinarian may open a pustule and apply the material within the pustule to a microscope slide. The slide is then stained and viewed under a microscope. The presence of pyoderma will reveal bacteria with white blood cells, especially neutrophils.
He may also make an impression of the discharge from a draining sore seen with deep pyoderma by pressing a slide to the lesion. This slide can be stained and examined under the microscope.
Culture and antibiotic sensitivity. In cases of deep pyoderma lesions, this test must be done to identify the bacteria responsible and to select the most appropriate antibiotic. Cultures of superficial pyoderma pustules are rarely done, since they nearly always grow Staphylococcus intermedius.
Visualization. Your veterinarian can usually diagnose surface pyoderma by visualization of the lesion. Hot spots have a characteristic appearance of a moist, red skin lesion with sudden hair loss. Skin fold pyoderma is a red, moist lesion associated with a skin fold. Hot spots are triggered by an itchy skin problem. Thus, diagnostics to determine the itchy underlying cause may be necessary, especially with recurrent hot spots. Often, flea allergy is the culprit.
Superficial pyoderma may cause a cat to be itchy. This can cause confusion in the diagnostic process since itching may lead to pyoderma. The veterinarian may ask if your cat's lesions preceded the itching or if the itching preceded the lesions. If the itching came first, then a pruritic underlying cause is suspected. If the lesions appeared first, then immune suppression may be the cause.
If itching is suspected, the following tests may be done to determine the source of the problem:
Examination of the skin and hair with a flea comb for fleas and lice
A skin scraping to look for mites and other microscopic parasites
Fungal cultures to rule out ringworm fungus (dermatophytes). These skin fungi may cause itching and lead to a secondary pyoderma.
Allergy testing or a food trial to rule out food allergy in chronic cases of pyoderma
In cases where superficial pyoderma is suspected to be caused by immune suppression and in all cases of deep pyoderma, tests are needed to look for the cause of the immune deficiency. Examples include:
Tests for Cushing's disease (hyperadrenocorticism), a disease where the adrenal glands make too much of a hormone called cortisol. One effect of the excessive cortisol can be immune suppression.
Severe, chronic illnesses, such as cancer, can suppress the immune system.
Related Articles
-
1
Miliary Dermatitis
Miliary dermatitis is a papular, crusting skin disease accompanied by varying degrees of pruritis. Cats with miliary dermatitis have multiple, small bumps on their skin that are usually associated with...
» Read More
-
2
Flea Allergy Dermatitis in Cats
Flea allergy dermatitis is the most common allergy in cats and is caused by flea bites, specifically the saliva of the flea. It is a very itchy disease and predisposes to the development of secondary skin...
» Read More
-
3
Pruritus (Itchiness) in Cats
How pruritus affects your dog’s health depends on the degree of the pruritus. Severe pruritus leads to intense scratching, which may result in painful skin lesions that may become infected.
» Read More
-
4
Acute Moist Dermatitis
A hot spot starts because something irritates the skin, and the body either itches or becomes inflamed. The itching then causes the dog to lick or chew the area, which further damages the skin, creating...
» Read More
-
5
Atopy in Cats
Atopy is a pruritic (itchy) skin disease of animals that is caused by an allergy to substances in the environment. It can be difficult to diagnose in cats and, therefore, is probably under-diagnosed.
» Read More
-
6
Skin Lesion or Sore in Cats
There are many different types of skin lesions that can occur in the skin of cats, and each lesion or combination of lesions can be caused by multiple diseases and conditions.
» Read More
