Yersinia Pestis

Yersinia pestis affects humans and mammals. It is caused by Yersinia pestis. Humans and other mammals usually get this plague after being bitten by a rodent flea that is carrying the plague bacteria or by handling an animal infected with the plague.

The plague is famous for killing millions of people and animals. Today, antibiotics are effective in treating any type of plague. However, this disease can cause serious illness or death without proper treatment. 

Human plague infections usually occur in rural areas. The bacteria that causes Yersinia pestis to maintain their existence in a cycle involving rodents and their fleas. Plague occurs in rural and semi-rural areas, usually in upland forests and grasslands where many types of rodent species are. 

Many types of animals, such as:

  • Rock squirrels
  • Cats
  • Woodrats
  • Ground squirrels
  • Prairie dogs
  • Chipmunks
  • Mice
  • Voles
  • Rabbits can be affected by the plague.

Infected animals and their fleas may serve as long-term carriers for the bacteria. 

Other species then become infected, causing an outbreak among animals. Humans at a greate risk after a plague epidemic. These outbreaks occur more likely during cooler summers that follow wet winters. A plague can sometimes occur in urban areas with rat infestations in parts of this world. 

Veterinarians and their assistants have a very high risk of coming into contact with dogs and cats that may be infected with the plague. People who work outdoors in areas where infected animals walk all the time are at a higher risk of getting the plague as well.

People who enjoy camping and going hiking in areas where animals live can increase their risk of getting bitten by an infected flea or animal.

Yersinia pestis can be transmitted to humans in the following ways:

  • Flea bites.
  • Contact with contaminated fluid or tissue.
  • Infectious droplets.

The plague bacteria can enter your body if a cut or open wound comes into contact with an infected animal’s body. Dogs and cats can get the plague as well if a flea that is from another infected animal bites them or they digest it. They can also fall ill if they eat a dead rodent that has had the plague.

Symptoms of plague in animals

  • Lethargy 
  • Fever 
  • Inflammation of the lymph nodes typically below the lower jaw
  • Pus-like lesions along the jaw
  • Lesions in the mouth
  • Cough.

Some of the symptoms are nonspecific. The veterinarian may not think it is a plague immediately. Tell your vet everything during the examination, especially the signs you observe. The vet will then do a full-body exam and then draw some blood to send into the lab for testing to find out what is the cause of your dog’s symptoms.

When the veterinarian gets your pet’s lab results back, and the diagnosis is made, they will then give your pet some antibiotics depending on how bad the illness is.

There is a risk that the plague can be transferred from your pet to you. Your pet will be hospitalized during its infectious period if your vet says it has the plague. If your pet does have the plague, it will be incubated for one full week and receive its antibiotics.

Symptoms Of Plague in humans

  • High Fever
  • Muscle aches
  • Vomiting
  • Headache 
  • Chills and weakness 
  • One or more swollen, painful lymph nodes.
  • Stomach pain 
  • Shortness of breath 
  • Chest pain 
  • Cough Bloody or watery mucous

You need to see a doctor when you feel extremely ill, and you know you have been in an area where a plague has occurred in the past, or there is currently a plague happening. You then need to be examined and tell your doctor all your symptoms so that you can get all the medical help you need so it can prevent really bad complications or death.

The most common sign of plague is the rapid development of a swollen and painful lymph gland. Flea bites or the knowledge of a lymph gland may help a doctor consider plague as a cause of the illness.

There may be no obvious signs that indicate plague. Diagnosis is made by taking blood samples or a swollen lymph gland from the patient and submitting them for laboratory testing. Once Yersinia pestis has been identified as a possible cause of the illness, the treatment should begin immediately.

If your doctor suspects Yersinia pestis, they may look for the Yersinia pestis bacteria in samples taken from your:

  • Swollen lymph nodes.
  • Blood. 
  • Lungs.

If you have respiratory Yersinia pestis symptoms, you may need to wear a surgical mask to prevent spread!

Treatment Options

As soon as your doctor suspects that you have Yersinia pestis, you’ll need to be admitted to a hospital. And then the hospital will treat you and send you home with your needed medication!


  • There is no vaccine available, but scientists are working hard every day to develop a vaccine. For now, all you can do is take antibiotics that can prevent infections if you are at risk or have been exposed to the plague.
  • For now, you can rodent-proof your home, remove any time of clutter outside and inside your home where rats can make a nest, and don’t leave trash bags and old food for them to eat. If you have rodent infestations, you can call pest control, and they will help you get rid of them.
  • If you have pets, ask your vet for a pill to keep fleas from coming in and out of your house and to stay off your pets, so they don’t get sick and give you the disease.
  • Keep your pets clean.
  • Always wear gloves if you know an animal is infected and you have to handle it and wash your hands after taking off your gloves.
  • Use insect repellent as soon as you go outside so that no fleas can jump on you, and you don’t carry them back inside of your home.
  • Do not allow your pets to lay on your couches or bed when you know they have been walking around.

A plague is a serious illness. If you are experiencing symptoms of Yersinia pestis, seek immediate medical attention. Prompt treatment of Yersinia pestis with the correct medications is critical to prevent complications or death.

If your pet is experiencing Yersinia pestis symptoms, take it to the vet immediately.