Age-related cognitive impairments in domestic cats naturally infected with feline immunodeficiency virus.

BACKGROUND: Age-related dementia has been documented in domestic cats; however, its interaction with naturally occurring feline immunodeficiency virus (FIV) infection has been investigated minimally. METHODS: Visuospatial working memory (VSWM) and problem-solving (PS) ability were evaluated in FIV-infected (n = 37) and control cats (n = 39) using two cognitive tasks tested serially, which assessed the ability of cats to remember the location of a baited container after a set delay, then evaluated the capability of the cats to manipulate the container to obtain the food within a time limit. Cats were categorized using 7 years of age as a cut-off to determine age-related differences. The relationship between cognitive performance and FIV viral load was investigated using real-time PCR cycle threshold (Ct ) values. RESULTS: Age significantly affected VSWM and PS ability. Younger cats had better VSWM performance and PS ability compared to older cats with the same FIV status. There was no difference between younger FIV-positive and negative cats in either part of the task. While older FIV-positive cats had significantly worse VSWM than older FIV-negative cats, no differences were found in PS ability. Additionally, Ct values predicted VSWM but not PS ability. CONCLUSION: Age-related cognitive impairments and FIV infection appear synergetic, causing greater cognitive deficits in older FIV-infected cats.

The incidence of aggressive behavior in cats naturally infected with Feline Immunodeficiency Virus (FIV) and its interaction with FIV disease progression.

A study was undertaken to determine the possible interaction between aggressive behavior and Feline immunodeficiency virus (FIV) disease progression based on semi­quantitative viral load levels and health status in naturally FIV­infected cats. FIV status was determined in ninety­six 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 forty­seven cats (49%) were PCR­positive for FIV infection and all aggressive cats were FIV­positive (100%). FIV infection was significantly linked to extreme aggressive tendencies and the extremely aggressive FIV­infected cats were more likely to have an unhealthy status compared to the non­aggressive individuals (p = 0.022). There was also a significant difference (p = 0.012) in the mean Cycle threshold (Ct) values between the aggressive and non­aggressive FIV­infected cats and also between the unhealthy FIV­infected cats with extreme aggressive tendencies and the healthy FIV­infected 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 FIV­infected cats following the direct effect of FIV through the course of the infection.