Despite the common findings of antibodies reactive to B. burgdorferi in cats in endemic areas, clinical disease is rarely reported and poorly understood. Consequently, little is known about the prevalence of infection, disease manifestations, and treatment recommendations for feline infections. It is probable that most cats are able to resist the illness but clinical disease occurs when the animal becomes immune-compromised.
Clinical Signs & Symptoms
Observed symptoms in the few reported cases include:
- Lethargy (weakness / loss of energy)
- Anorexia (loss of appetite which leads to weight loss)
- Pyrexia (fever)
- Inflammatory arthritis – may be mono- or polyarthritis (single or multiple joint involvement)
- Glomerulonephritis (inflammation and accompanying dysfunction of the kidney’s glomeruli)
Sudden collapse and a “zombie-like” trance have been described. In cases of heavy infestation, severe anaemia has been reported. In most cases, diagnosis was successful because tick attachment was observed or reported. Without a tick-bite history, misdiagnosis may occur, because symptoms tend to be ambiguous.
Diagnosis should be based on history, clinical signs, elimination of other diagnoses, laboratory data, epidemiologic considerations, and response to antibiotic therapy. Studies of dog owners have demonstrated that many owners were unaware that their dogs had tick infestations. It is therefore likely that a similar lack of awareness exists amongst cat owners.
Tests can be divided into two categories:
1. Tests which detect the Borrelia organism directly
These include the indirect fluorescent antibody (IFA) assay, enzyme-linked immunosorbent assay (ELISA), or characteristic serum proteins analysis (Western blot technique).
Serology is the mainstay for confirming a clinical impression of Lyme disease. However, asymptomatic cats in endemic areas may be seropositive. Another limitation is that animals can take some time to seroconvert following infection. Therefore, an early case may return a negative result on serology. Animals may also remain seropositive for a long time following treatment, making it difficult to determine whether a successful resolution has been achieved.
Many veterinarians consider the specific C6-based assay to be the initial screening method of choice.
The general treatments of choice are amoxicillin, tetracycline and doxycycline for 30 days. Rapid response is seen in limb and joint disease in most cases, although incomplete or transient resolution of signs may occur.
Due to the persistence of B. burgdorferi sensu lato, relapses can occur. In such cases, antibiotics mentioned above can be used again, as persistent infection is not the result of acquired antibiotic resistance. Prolonged antibiotic therapy (over 30 days) may be beneficial in certain cases with continuing disease signs.
Symptomatic therapy directed toward the affected organ system and clinicopathologic abnormalities is also important, especially in renal disease. In limb and joint disease, the use of NSAID (non-steroid anti-inflammatory drugs) concurrent with antibiotic therapy can lead to confusion over the source of clinical improvement and make diagnosis based on therapeutic response difficult.
There is currently to vaccine against Borreliosis for cats in the UK.