Epidemiology of feline hemoparasites in Texas

August 27, 2024

Between 2019 and 2023, TVMDL has assisted Texas veterinarians in diagnosing 32 cases of hemotropic Mycoplasma infection and 9 cases of cytauxzoonosis in cats. These cases have been identified by microscopic examination of peripheral blood smears, targeted PCR testing, or necropsy/histological examination. Using TVMDL testing data gathered since March 2019, this article provides a brief overview of available epidemiological data from Texas cats infected with Cytauxzoon felis or Mycoplasma haemofelis.

Cytauxzoon felis

Since March 2019, TVMDL has helped diagnose 9 cases of cytauxzoonosis in Texas cats. A breakdown of infected animal demographics is as follows:

  • Infected cats ranged in age from 1 to 5 years (average 2.6 years) and were comprised of 6 males and 3 females.
  • Five cases were identified by examining peripheral blood smears at TVMDL; 4 cases were identified via histopathological findings on cats presented for necropsy.
  • Clinical history was provided for 8 of 9 cats; of these, 4 were noted as “outdoor” or “indoor/outdoor” cats.
  • Two cats were noted to have lived with other cats who had recently died and exhibited similar symptoms.

All 9 cats infected with Cytauxzoon felis were located within areas of Texas where tick vectors are confirmed or estimated to occur according to the Centers for Disease Control and Prevention surveillance programs. The map above shows the counties in which positive cats resided.

Mycoplasma haemofelis

TVMDL has identified Mycoplasma haemofelis infection in 32 Texas cats since March 2019. Information on infected cats is below:

  • Positive cats ranged in age from 5 months to 11 years old (average 4.5 years) and were comprised of 25 males and 7 females.
  • Clinical history was provided for 26 cats:
    • 23 cats were noted as anemic, of which 11 were also noted as thrombocytopenic.
    • 5 cats were documented as either not eating/drinking or having lost weight.
    • 4 cats were noted as being “indoor/outdoor”; 1 was noted as being an indoor cat only.
    • 1 cat was documented as having 2 other “adult littermates” with similar symptoms.
  • 17 cats were diagnosed by observing haemofelis in peripheral blood smears. One of these cats was also PCR positive.
  • 15 cases were identified by PCR; 2 cats were still PCR positive 1 month after the initial diagnosis.

To learn more about TVMDL’s feline hemoparasite testing, and other offerings, visit tvmdl.tamu.edu or call 1.888.646.5623.

Carlos Rodriguez

Epidemiology and Informatics Manager