Dogs are susceptible to a variety of bacterial and viral infections, some of which can even prove fatal for them. Skin, eye, ear, urinary tract, kidneys, nervous system and even the respiratory system of the dog is vulnerable to such bacterial infections. Even minor infections can lead to severe dog health problems when left untreated, and therefore it is necessary to identify the problem and initiate treatment at the earliest.

Bacterial Skin Infections: Staphylococcal pyoderma is a skin condition in dogs caused by a Staphylococcus sp. infection. This bacteria is in fact a part of the dog's normal skin flora. However, in case of wounded skin, or skin that has aberrations and cuts, the bacterium may enter under the skin and cause skin infections. A staph infection in dogs is characterized by itchiness, crusted skin, pustules and small, raised lesions. As the severity of the infection increases, there is loss of hair, and dried discharge is given out in the affected area. Most of the time, it affects the superficial layer of the dog's skin. However, if there is deep laceration then the inner folds of the skin are also affected. To treat skin infections in dogs, topical medication along with antibiotic doses is prescribed, especially to eliminate recurrence of the disease.

Leptospirosis Infections: Leptospirosis affects both humans and animals throughout the world. Leptospirosis is caused by a group of bacteria called Spirochaetes. This highly contagious disease affects dogs when they come in contact with urine of infected animals or contaminated stagnant water. Transmission is also seen via mating, being bitten by another infected dog, or through the consumption of infected carcasses (seen in case of wild dogs rather than pet dogs). The initial signs of Leptospirosis are fever, redness of the mucous membranes and depression. This is often accompanied by vomiting. The dog seems to ache all over and becomes extremely lethargic. In extreme cases, dogs may develop kidney inflammation, causing permanent damage to the kidney.

Brucellosis Infection: Brucellosis in dogs, is caused by Brucella canis bacteria. The transmission of the bacteria is through the mucous membranes. The bacteria may hence enter the body through nose, mouth, conjunctiva of the eye and the vagina. It is commonly transmitted via mating, and hence usually occurs in the breeding season. While the male dogs may develop prostatitis, the infected pregnant females abort their fetuses; if born, puppies die shortly afterwards. It should be noted, that Brucella canis can also cause disease in humans.

Actinomycosis and Nocardiosis Infection: While Actinomycosis is caused by the Actinomyces sp., the causative agent of Nocardiosis is Nocardia sp., mainly those living in the soil. Both these infections are usually caused by the bacteria entering the skin wounds and other abscesses. Both of these diseases are uncommon and usually result in the swelling of the lymph nodes around the wounded site. If the infection is carried deeper into the body, it may break into the chest or the abdomen, causing pus to accumulate there.

Streptococcal Infections: Streptococcal infections caused by various species of the genus Streptococcus are prevalent among puppies and older dogs due to a weakened immune system.

Staphylococcal Infection: Caused by the Staphylococcus sp., these bacterial infections affect the upper respiratory tract of animals or the skin of the host. It is usually transmitted between animals. The disease also has a zoonotic risk attached to it (i.e. it can be transmitted from an infected dog to a human being).

Plague in Dogs: A bacterial infection caused by the Yersinia pestis, plague is usually transmitted in dogs by rodent fleas. Dogs can become infected through the bite of infected fleas or by eating a rodent, rabbit or other animal carrying infected fleas. However, in contrast to other domestic animals, dogs are pretty resistant to this bacterial infection and may develop only swollen lymph nodes.

Bacterial Ear Infections: Numerous types of bacteria, and a yeast species called Malassezia pachydermatis, cause ear infections in dogs. While a normal, healthy dog has good defense against these organisms, environmental changes, dog allergies, hormone abnormalities or moisture, can make the ear susceptible to a bacterial or yeast infection.

If you find signs of bacterial infection in your dog, it is important that you take them to the veterinarian, to ascertain the cause of the disease. Based on the type of infection, the vet may recommend various treatment options, such as antibiotic and anti-inflammatory medications, allergy shots or certain shampoos. Remember, that by making dietary changes and regular exercising, the dog's immune system can be strengthened in order to help it ward off the infection.