Following experimental inoculation of kittens with FIV, lymphadenopathy, sometimes accompanied by mild pyrexia, depression and leucopenia, usually develops after about 4 weeks. This lymphadenopathy can be less severe in older cats, however, and is therefore usually missed in naturally infected cats. The lymphadenopathy gradually disappears after a few weeks to months.
Infected cats can then remain healthy for years before clinical FIV-related disease is seen. Indeed many cats probably die of other causes long before AIDS-like disease develops.
- Clinical disease associated with FIV infection is seen mainly in middle-aged to elderly cats.
- Like AIDS in man, clinical signs are often caused not directly by FIV but by secondary infections often with micro-organisms which in an immunocompetent animal would cause only mild, if any, disease.
- The clinical syndromes most often associated with FIV infection are:
- chronic stomatitis and severe gingivitis
- chronic upper respiratory tract disease
- chronic skin disease
- chronic diarrhoea
- neurological signs.
- Neurological disease is thought to be caused directly by FIV infection of CNS. FIV-related neurological disease may present as motor or sensory deficits or as behavioural changes, including abnormalities of sleep pattern, the clinical signs presumably reflecting the area of CNS most affected.
- Ocular disease is not uncommon in FIV-infected cats. Diagnosis of ocular disease associated with FIV infection may require careful ophthalmic examination and is often not associated with obvious loss of vision. Anterior uveitis, glaucoma or pars planitis have all been described in FIV-infected cats, and it has been suggested that the syndrome of idiopathic uveitis seen in cats over six years old might be FIV-related.
- There is some evidence that FIV may be associated with an increased pre valence of neoplasia.
- Clinical signs in FIV infections are often associated with secondary
- Many FIV-infected cats with chronic stomatitis also have persistent feline calicivirus (FCV) infection in the oropharynx, although whether this indicates a causative role for FCV in the disease or merely increased FCV excretion by immunosuppressed cats is not known.
- Cats with chronic upper respiratory tract disease are also often infected with FCV or feline herpesvirus. In both chronic oral and chronic respiratory disease, bacterial infection undoubtedly also plays a role as antibiotic therapy can alleviate, but usually not eradicate, the clinical signs. Severe systemic herpesvirus infection has also been reported in FIV-infected cats.
- Severe systemic cowpox virus infections have been reported in FIV-infected cats.
- Active toxoplasmosis appears to be more common in FIV-infected than non-infected cats, and FIV-induced immunosuppression may be associated with clinical toxoplasmosis in cats.
- Chronic skin disease in FIV-infected cats has been associated with parasites, such as Notoedres, Cheyletiella and Demodex species, and with various fungal and bacterial infections.
- Other opportunist or secondary infections which may be associated with FIV infection include haemobartonellosis, intestinal coccidiosis, candidiasis, aspergillosis, cryptococcosis, and pseudomonad and mycobacterial infections.
- Co-infection of FIV and feline leukaemia virus (FeLV) may be associated with very rapid development of immunodeficiency and clinical disease both in the field and experimentally. Co-infection of FIV and FeLV is, however, uncommon because most cats with FeLV are infected when young, whereas FIV infection is more common in older cats.
- No association has been found between FIV infection and feline corona-infection or clinical feline infectious peritonitis
Back to top
Back to menu