Vector-Borne Diseases in Cats

In the Literature

Lappin MR. Update on flea and tick associated diseases of cats. Vet Parasitol. 2018;254:26-29.

The Research …

Several vector-borne pathogens have been detected in cats. A detailed history should be obtained, and potential pathogen transmission should be considered when the patient has come in contact with vectors such as ticks and fleas, as exposure may lead to clinical disease.

Anaplasma phagocytophilum, the causative agent of feline anaplasmosis, is transmitted by Ixodes spp ticks. Fever, anorexia, and lethargy are the most common clinical signs.¹ Rhipicephalus sanguineus, another tick species, can transmit Ehrlichia canis to cats but is not as well characterized in cats as in dogs.^2,3 Risk for exposure to these pathogens coincides with the geographic range of these tick species.^2-4

Fleas can transmit Bartonella henselae, B clarridgeiae, and B koehlerae to cats.^2,5 Numerous clinical signs (eg, fever, swollen lymph nodes, uveitis, myocarditis, endocarditis, osteomyelitis) have been associated with feline bartonellosis.⁶ Occupational risk for exposure exists for veterinarians and support staff due to potential transmission of Bartonella spp by cat scratches and flea bites.⁶

Hemolytic anemia in cats can result from infection with Mycoplasma haemofelis, Candidatus M haemominutum, and/or Candidatus M turicensis.^7-9 More severe feline hemoplasmosis is associated with M haemofelis or coinfection with other hemoplasmas. Transmission is believed to occur via flea bites and by direct cat-to-cat transmission via saliva (eg, from fighting).¹⁰

Feline rickettsiosis, caused by Rickettsia felis and transmitted by the flea Ctenocephalides felis, may manifest as fever in a subset of cats, but past studies have been inconclusive on the role of R felis in clinical disease.^5,11

The most reliable method for detecting any of these pathogens is PCR testing using blood of acutely ill cats,^4,5,10 which can be combined with serologic assays to detect antibodies, depending on the stage of infection. Clinically ill cats can be treated with doxycycline (5 mg/kg PO q12h or 10 mg/kg PO q24h). Duration of treatment varies from 7 to 10 days for hemoplasmosis and 14 to 28 days for anaplasmosis and bartonellosis.^1,12-14

Prevention is recommended for any cat at risk for exposure to ticks and/or fleas. Effective ectoparasite control should be strongly recommended to reduce this risk.

… The Takeaways

Key pearls to put into practice:

• Ticks and fleas can transmit Anaplasma spp, Ehrlichia spp, Bartonella spp, Mycoplasma spp, and Rickettsia spp to cats. These pathogens may be associated with disease, so it is important to determine potential exposure to these vectors when evaluating clinically ill cats.

• PCR testing using blood of acutely ill cats is the most reliable diagnostic test for any of these pathogens. Doxycycline is the treatment of choice.

• Flea and tick prevention should be considered for any cat that may come in contact with these vectors.