Immune-Mediated Hemolytic Anemia in Cats with Feline Infectious Peritonitis

Area of Science:

• Veterinary Medicine
• Immunology
• Infectious Diseases

Background:

• Feline infectious peritonitis (FIP) is a serious disease caused by mutated feline coronaviruses.
• Immune-mediated hemolytic anemia (IMHA) is characterized by immune-mediated destruction of red blood cells.
• IMHA can occur independently or be associated with other diseases, including FIP.

Purpose of the Study:

• To investigate the occurrence and outcomes of immune-mediated hemolytic anemia (IMHA) in cats diagnosed with feline infectious peritonitis (FIP).
• To evaluate the efficacy of antiviral and glucocorticoid treatments in cats with concurrent FIP and IMHA.

Main Methods:

• Retrospective review of medical records for cats diagnosed with FIP and associative IMHA.
• Inclusion criteria included exclusion of other anemia causes, positive saline agglutination test, and/or Coombs test.
• Treatment involved nucleoside analogs and glucocorticoids; outcomes were assessed at follow-up.

Main Results:

• 45 cats with FIP and IMHA were identified (26 effusive, 19 non-effusive).
• Median hematocrit was 18%; anemia was predominantly non-regenerative (80%).
• Survival rate was 73% (33/45 cats), with 17 cats achieving remission of both FIP and IMHA.

Conclusions:

• FIP is an uncommon but important cause of associative IMHA in cats.
• Concurrent IMHA should be considered in cats with anemia and FIP.
• Antiviral and glucocorticoid therapies show promise for managing cats with FIP and IMHA, improving survival and remission rates.