A study was undertaken to determine the possible interaction between aggressive behavior and Feline immunodeficiency virus (FIV) disease progression based on semi‑quantitative viral load levels and health status in naturally FIV‑infected cats. FIV status was determined in ninety‑six owned and stray cats, using nested polymerase chain reaction (PCR). Aggressive tendencies were assessed based on observation and the cats' demeanor as determined by the owners and shelter caretakers. Results showed that forty‑seven cats (49%) were PCR‑positive for FIV infection and all aggressive cats were FIV‑positive (100%). FIV infection was significantly linked to extreme aggressive tendencies and the extremely aggressive FIV‑infected cats were more likely to have an unhealthy status compared to the non‑aggressive individuals (p = 0.022). There was also a significant difference (p = 0.012) in the mean Cycle threshold (Ct) values between the aggressive and non‑aggressive FIV‑infected cats and also between the unhealthy FIV‑infected cats with extreme aggressive tendencies and the healthy FIV‑infected individuals without aggression (p = 0.001). Accordingly, results indicated that parameters associated with FIV disease progression are directly linked to aggression. The possible impact of FIV on the behavioral pattern of naturally infected cats should not be underestimated. However, there is an urgent need to conduct more experiments to support the assumptions about the possible exacerbation of aggression tendencies in naturally FIV‑infected cats following the direct effect of FIV through the course of the infection.
Keywords: Feline immunodeficiency virus; Cat; Aggression; DNA; PCR.