Rickettsial Infection in Cats: Causes, Symptoms & Prevention

Rickettsial infection in cats primarily involves bacteria of the genus Rickettsia, especially Rickettsia felis, which is mainly transmitted by cat fleas (Ctenocephalides felis). These infections usually occur during warmer months when flea and tick activity increases, particularly in spring and summer.

The Causes of Rickettsial Infection in Cats

The main causative agents are Rickettsia felis and related species such as Candidatus Rickettsia senegalensis. They are transmitted primarily through bites from infected cat fleas, which feed on the blood of cats. Ticks can also carry other rickettsial bacteria but are less commonly involved in cat infections in the UK. Cats may also be infected by ingesting prey animals that harbour rickettsial organisms.

Although Rickettsia typhi, which causes typhus in humans, is a flea-borne rickettsial pathogen, it is rarely found in cats or their fleas in many regions. The main focus remains on flea-borne rickettsial pathogens.

Recognising Symptoms: What to Watch Out For

In most cases, cats carrying rickettsial infection show no obvious clinical signs. However, rare cases of illness have been documented involving systemic and blood-related symptoms. Watch out for signs such as:

• Fever and lethargy
• Low blood platelet count (immune-mediated thrombocytopenia), which can cause bruising or capillary bleeding
• Increased white blood cells leading to immunodeficiency
• Increased thirst and kidney-related signs such as azotemia (high urea and creatinine levels)
• Nausea associated with liver enzyme changes
• Muscle spasms from low calcium levels
• Dizziness or hypersensitivity to stimuli

How Vets Diagnose Rickettsial Infection in Cats

Diagnosis can be challenging as symptoms are often non-specific and infections may be subclinical. Your vet will take a detailed medical history, including checking for flea or tick exposure, and perform a thorough physical examination.

Diagnostic tests your vet may use include:

• Full blood count to assess platelets and white cell levels
• Urinalysis to check kidney function
• Serological tests to detect antibodies
• Molecular detection assays (PCR) to identify bacterial DNA from blood or fleas
• Tissue biopsies and microscopy as needed

Treatment Options and Supportive Care

If rickettsial infection is confirmed or strongly suspected, antibiotic therapy—typically doxycycline—is prescribed. It is crucial to complete the entire course to ensure the infection clears fully, even if your cat improves quickly.

Severe cases may require hospitalisation for intravenous fluids, supportive care, and possibly blood transfusions to stabilise platelet levels and organ function.

Prognosis and Recovery

Cats diagnosed early and treated appropriately usually have a good prognosis. With supportive care and monitoring, most recover fully. However, failure to treat can lead to complications and more serious illness.

Prevention: Keep Your Cat Safe

Preventing rickettsial infection centres on protecting cats from fleas and ticks year-round. Effective flea and tick control products are widely available through veterinary clinics and reputable pet suppliers. Regular use of these products significantly reduces the risk of infection transmission to cats and also minimises the potential zoonotic risk to humans.

Routine flea control also reduces the risk of your cat scratching or ingesting flea faeces contaminated with rickettsial bacteria.

Why Flea Control Matters for Your Cat and Your Family

While rickettsial infections in cats tend to be mild or asymptomatic, some rickettsial species can infect humans, causing febrile illness with potential complications. Cats and their fleas can serve as reservoirs posing a zoonotic risk, particularly to immunocompromised people.

Therefore, maintaining good flea and tick hygiene not only safeguards your cat's health but is also a responsible step to protect your household's wellbeing.

By staying vigilant, practising routine parasite prevention, and promptly seeking vet care for ill cats, you help ensure a happy, healthy life for your feline friend.