"Rickettsial Infection in Cats

"Rickettsial Infection in Cats

Rickettsial infection is a term that refers to several types of infection that cats can develop when they are bitten by either ticks or fleas. The infections are caused by what is known as proteobacteria which both fleas and ticks transmit to cats when they feed off their blood. There are many types of rickettsial bacteria and as such, they can transmit several types of diseases and the bacteria can even infect a cat's red blood cells which then leads to immune-mediated thrombocytopenia. Rickettsial infections tend to take hold when the weather warms up which is when ticks and fleas tend to be a real problem.

The Causes

One of the most common types of rickettsial infections seen in cats is caused by fleas (Ctenotcephalides felis) and although the infection is rarely serious in itself, studies have shown that some infections can be passed on to other animals and people too which makes them zoonotic in nature, but as previously mentioned this rarely occurs. Cats are infected through flea bites or when a cat scratches at a bite on an area of their skin which has been contaminated by a flea's faeces.

There are a few types of rickettsial organisms that can be transmitted to cat when they eat any prey they catch which have been infected with the bacteria. Studies have also established that ticks carry various sorts of the bacteria (Rickettsia) which can cause several diseases in cats although research has shown this to be quite rare.

Symptoms to Watch Out For

When cats are infected they typically show signs of there being something wrong with them by displaying the following symptoms:

  • Fever
  • Low blood platelet count - a condition known as immune-mediated thrombocytopenia
  • An increase in white blood cells which causes immunodeficiency
  • Increased thirst
  • Lethargy due to low sodium in a cat's blood stream
  • Abdominal pain due to an increase in ureas and creatine in a cat's blood which is a condition known as Azotemia
  • Nausea due to an increase in liver enzymes
  • Muscle spasms due to low calcium levels in a cat's system
  • Kidney failure
  • Dizziness
  • Hypersensitivity to stimuli

Diagnosing the Problem

A vet would need to have a cat's full medical history before thoroughly examine them paying special attention to whether a cat has fleas or ticks in their coats. The vet would also want to rule out any other underlying health issues as to why a cat might be displaying symptoms associated with the disorder. The type of tests a vet would want to carry out could include the following:

  • A full blood count
  • A urinalysis

It can often prove challenging when diagnosing rickettsial infections in cats because it only takes a few of the bacterial organisms to cause the damage. As such, a vet would recommend doing several tests which could include examining tissues under a microscope. Other tests might include the following:

  • Serological tests
  • Molecular detections assays

Treatment Options

Should a vet be able to confirm a diagnosis that a cat is suffering from rickettsial infection, they would typically prescribe a course of antibiotics and for this to be effective, it is essential for the full course to be completed even if a cat shows signs of improvement after a few days. Cats need a lot of supportive care should their condition be deemed severe and as such may need to be hospitalised so they can be given fluids and treatment intravenously. In some cases, cats need to be given blood transfusions to stabilise their condition.


Cats diagnosed and treated early are less at risk of the condition developing into something more serious. It takes time, but with lots of supportive care and careful monitoring, the prognosis tends to be good and cats make a full recovery.


The only real way of preventing rickettsial infection in cats is to make sure they are always well protected against fleas and ticks. Fortunately, today there is a good choice of effective flea and tick products on the market, some are only available through vets, whereas others can be purchased over the counter at reputable pet outlets.

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