What are Hot Spots?
Canine acute moist dermatitis is a form of canine pyoderma also known as “hot spots.” Hot spots are red, moist, irritated patches of skin often caused by an initial irritation and then exacerbated by bacterial infection. The irritated patch can double in size within hours and can become very painful. Common sites of lesions are the head, neck, hips and limbs. Matting of fur, hair loss, scabbing and oozing are often seen. Hot spots seem to be common in long-haired dog breeds and are more prevalent during summer months in times of high temperature and humidity. Hot spots are the result of a bacterial infection. Your dog’s skin becomes irritated and the dog starts itching, licking, or both, eventually causing a red, ugly, oozing sore. Technically hot spots are referred to as acute moist dermatitis or superficial canine pyoderma, usually localized to a specific area. The sore can only be treated by focusing on the underlying infection.
Symptoms of Hot Spots in Dogs
Symptoms of a hot spot may include one or more of the following:
- Itchy, painful patch of skin
- Continual chewing or licking at site
- Abnormal aggression (associated with painfulness of site)
- Possible depression (associated with painfulness of site)
- Inflammation, redness, and swelling in a localized patch of skin
- Crusted scabs or oozing sores
- Dry scaly skin Hair loss
- Moist, matted fur
- Foul odor from lesion
Causes of Hot Spots in Dogs
Possible causes of initial irritation can be any one of the following:
- Flea allergies
- Cuts or abrasions
- Ear infection/anal gland infection
- Foreign objects (splinters/thorns)
- Food allergies
- Matted fur
- Insect bites
- Chewing or licking due to stress or boredom
- Hot spots on dogs are the result of an imbalance in the normal bacteria (Staphylococcus intermedius) on the skin.
- The bacterial imbalance is most often brought about by some initial irritation that the pet bites or scratches at repeatedly.
- Biting and chewing can introduce bacteria from the mouth and nose to disrupted hair follicles at the site of irritation.
- Moisture and heat from matted hair, summer warmth and humidity or open scrapes or cuts can further exacerbate bacterial growth.
- Bacterial growth cause the body immune response to react, resulting in more itching, heat, redness, inflammation and pain.
Diagnosis of Hot Spots in Dogs
If you notice your pet is showing symptoms of a hot spot, you may try an over the counter medication to clean and treat at home. Since hot spots are painful and can worsen within a matter of hours, it is advisable to schedule a visit to a clinic to receive proper treatment.
The veterinarian will take a thorough history and conduct a physical exam to determine the initial irritant. It is important to let your veterinarian know when the onset of symptoms began and any unusual circumstances that may have led to the irritation so the doctor can identify possible allergens or stressors and address them in treatment.
The area will likely be shaved and cleaned to determine severity and size. Shaving and cleaning is also necessary to properly clean and air the lesion. In cases where other forms of pyoderma are suspected, the veterinarian may examine bacterial samples under the microscope or culture a sample for diagnosis.
Treatment of Hot Spots in Dogs
The lesion must be cleaned thoroughly. Matted fur should be shaved off and away from the affected area. Because this can be quite painful, it is a good idea to bring the pet to the veterinarian where nurses can clean and shave the area. Some level of sedation may be necessary. A topical antiseptic such as chlorhexidine can then be used to clean the lesion.
Treating Bacterial Infection
Topical and/or oral antibiotics will often be administered. Antibiotic treatment may last 4 weeks or longer.
Treating Initial Irritation
Some cases of hot spots are idiopathic (the cause is unidentifiable). More commonly, allergies to fleas, pollen or food are identified with a history and examination. Monthly flea treatments or hypoallergenic diets can address allergies. Regular grooming or keeping fur cut short can prevent matting, a common cause of skin irritation. Anxiety-induced chewing and licking can be lessened by introducing toys or chews and exercise and play.
Medications for Pain and Inflammation
Antihistamines may be prescribed to reduce itchiness and irritation. NSAIDS can be prescribed to reduce inflammation. A short acting corticosteroid may be administered one time to make the patient more comfortable and promote healing. Gentamicin/Betamethasone sprays are often prescribed to spray on the lesion daily.
Essential fatty acids may be suggested for pets prone to skin conditions.