E. Coli infection in Dogs

PetMD Editorial
By PetMD Editorial on Jan. 19, 2010
E. Coli infection in Dogs

Colibacillosis in Dogs

Colibacillosis is a disease caused by the bacterium Escherichia coli, commonly known as E. coli, which normally resides in the lower intestines of most warm blooded mammals, including dogs. Normally, the presence of E. coli is benign, and even beneficial, but in some cases it can cause a diseased condition, especially in newborn puppies.

E. coli infection is most commonly seen in puppies in the first weeks of life. In the first day after giving birth, bitches produce a watery milk that is rich in antibodies. This milk, called colostrum, plays a pivotal role in protecting a newborn puppy's undeveloped immune system against various infections, as it coats the intestinal tract, protecting the puppy from most infections. In the absence of these antibodies, puppies are more vulnerable to a number of infections, including E. coli infection.

If the pregnant bitch is infected with E. coli, the bacteria can also invade a puppy’s blood supply while it is still in uterus, during birth, or the puppy can acquire the infection from feeding from its mother's inflamed mammary glands.

Colibacillosis often leads to a condition called septicemia, or blood poisoning, meaning there is an dangerously high presence of bacteria in the blood. Though primarily a disease of young dogs, it can also affect older dogs. E. coli infection, when combined with other infectious agents, also increases the severity of parvovirus infection in dogs. 

Symptoms and Types

Colibacillosis is sudden (acute) in nature and may cause the following symptoms in an affected puppy:

  • Depression
  • Dehydration
  • Lack of appetite
  • Vomiting
  • Rapid heart rate
  • Weakness
  • Lethargy
  • Watery diarrhea
  • Cold skin (due to low body temperature)
  • Bluish colored mucous membranes (i.e., gums, nostrils, lips, ears, anus) due to inadequate oxygen in red blood cells


Colibacillosis is ultimately due to an E. coli infection. However, risk factors for this type of infection include poor health and nutritional status of the pregnant bitch, lack of colostrum (first milk) to the puppy, unclean birthing environment, difficult or prolonged birth, crowded facilities, concurrent infection/disease, inflammation of the mammary glands in the nursing bitch, and placement of intravenous catheter.


Due to the acute onset of this disease, few abnormalities may be noted in blood testing. In order to see if E. coli, or any other infectious agents are present in the dog's blood, your veterinarian will take blood, urine, and if possible, fecal samples for culture.


As colibacillosis is an acute condition, most affected puppies need to be hospitalized for emergency treatment. Good nursing care is required, with balanced fluids administrated by injection to restore body fluids. To treat diarrhea, a glucose solution will be administrated by mouth. Antibiotics can be prescribed initially based on the observed symptoms, and may be changed, if necessary, according to the results of the bacterial culture and sensitivity testing of E. coli.

Unfortunately, because of a newborn puppy's undeveloped immune system, treatment is often not successful and the newborn may succumb to death rapidly. Therefore, prompt treatment and supportive care is essential for saving the puppy's life.

Living and Management

Restricted activity, cage rest, monitoring, and warmth should be provided during the recovery period. To maintain an adequate nutritional level, bottle feeding or intravenous nutrients may be advised. This is necessary if the mother's mammary glands or blood are infected. Otherwise, it is preferable to have the puppies drinking their own mother's milk in order to benefit from the antibody rich milk.

During the recovery period, your veterinarian will take blood samples to run bacterial blood culture testing to determine the status of the infection. Home care will involve monitoring your puppy's body temperature and watching for any changes in health so that you can contact your veterinarian immediately for guidance. Once your puppy has stabilized and is out of danger, further treatment will depend on how the puppy progresses.


To prevent E. coli infection, make sure that your breeding, pregnant, or nursing bitch is in good health and nutritional status. The birthing environment should be kept clean and sanitized, and bedding should be replaced frequently after the birthing (the linens that were used for the birthing should be discarded in a sanitary manner, as in most states they are considered hazardous waste material).

The most important safeguard for preventing E. coli infection in puppies is to allow them full access to their mother's colostrum (the first milk after birth). In addition, you must always wash your hands and change your outer clothing and shoes before dealing with newborn puppies in deference to their developing immune system. This is a general rule, but is especially important after handling other dogs or animals.

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