Feline immunodeficiency virus (FIV) is thought to affect over 11% of the cat population worldwide. It is closely related to the Human Immunodeficiency virus (HIV).
Whilst the virus is not typically lethal, it can result in a higher occurrence of infections and degenerative conditions that can be stressful and uncomfortable for the infected cat.
Many cats afflicted with FIV suffer from intestinal disorders such as colitis, chronic diarrhoea or inflammatory bowel disease. A recent study investigated the effects of probiotics on the feline intestinal tract and found that they have the potential to reduce the severity of intestinal problems by restoring normal conditions in the gut.
Feline Immunodeficiency Virus
FIV is a type of lentivirus that is believed to infect 11% of cats worldwide. 1 The infection is not curable, so infected cats will live with the virus for the rest of their life. How the virus affects an infected cat varies between individuals, some cats succumb to the direct effects of the virus, whilst other may suffer from secondary infections due to the virus’ effect on the immune system. Some cats may even go their whole life without ever displaying symptoms, but continue to spread the virus.
The transmission of FIV from one to cat to another requires saliva from an infected cat to enter the bloodstream. This means deep bites or scratches are required for the virus to spread. Infected females can spread the virus to their offspring during pregnancy as the virus can be transferred in the uterus.
FIV attacks the immune system of the infected cat, it targets the white blood cells responsible for dealing with infections. The weakened immune system increases the chance of infected cats developing secondary infections.
A vaccine is available, but it is difficult to test how effect the vaccine actually is. Due to the high number of possible variations of the virus, it is also difficult to protect against all strains with a single vaccine. One study did show the vaccine was able to protect an entire sample group from infection with one sub-type of the virus. 2 Vaccination is the choice of the owner.
A treatment for FIV is available in the USA. It is known as Lymphocyte T-Cell Immunomodulator (LTCI) and it works by increasing the production of certain white blood cells (CD-4+ T-cells). Increasing the production of these cells can help reduce the immunosuppressive effects of FIV.
Chronic Diarrhoea in FIV Positive Cats
FIV positive cats have been observed to suffer more frequently from chronic diarrhoea than FIV negative cats. Whilst there are a number of theories that could explain this increase, a definitive explanation is yet to be found.
FIV is associated with intestinal mucosal dysfunction. The intestinal mucosa is what lines the wall of the intestines. so if there are problems with the way that it functions, absorption of nutrients and water can be disrupted. It is this disruption that can lead to chronic diarrhoea.
It is also thought that intestinal mucosal dysfunction associated with FIV positive cats disposes them to bacterial or viral infection. If pathogenic bacteria establish themselves in the instestine this too can cause chronic diarrhoea. Some pathogenic bacteria release toxins that contribute to poor gastrointestinal health and diarrhoea.
When the cause of the gastrointestinal stress is unknown, the diagnosis is often inflammatory bowel disease (IBD). IBD is a chonic inflammation of the intestinal lining that occurs as a result of the body’s own inflammatory cells reacting continually and excessively.
See this extensive guide on the relationship between FIV and chronic diarrhoea: FIVTherapy
Probiotic Treatment for FIV Positive Cats
The chronic diarrhoea associated with FIV can be stressful for both the owner and the cat, so any beneficial treatment is warmly welcomed. A recent study showed how administration of probiotics (‘good bacteria’) to FIV positive cats is a beneficial therapeutic treatment. 3
Treatment with probiotics (in the case of the study, Lactobacillus acidophilus) helped to restore intestinal homeostasis i.e. returning the intestine to a stable system.
Probiotic treatment altered the release of inflammatory mediators responsible for inflammation of the intestines (that can lead to chronic diarrhoea). Probiotics are also beneficial, as they can prevent ‘bad bacteria’ establishing themselves in the gut.
Image Credit: akk_rus
- Feline immunodeficiency virus vaccine: Implications for diagnostic testing and disease management ↩
- Dual-subtype vaccine (Fel-O-Vax FIV) protects cats against contact challenge with heterologous subtype B FIV infected cats. ↩
- Infection with feline immunodeficiency virus alters intestinal epithelial transport and mucosal immune responses to probiotics ↩