There is a recent review on treatment of Feline Immunodeficiency Virus (FIV) including use of zidovudine here http://www.mdpi.com/2306-7381/2/4/456/pdf 

The conclusions of the article suggested by dr Mellora Sharman  are obvious

Unfortunately, the efficacy of antiviral compounds for the treatment of FIV in cats has been generally poor. The duration of treatment in many clinical trials was relatively short and might have been inadequate for infections with a long clinical course. In addition, it is difficult to compare treatment results of cats infected experimentally and kept under laboratory conditions and pet cats infected with field strains of FIV. Therefore, further well-designed double-blinded, placebo-controlled trials using antiviral drugs in naturally FIV-infected cats are needed to determine the efficacy and side effects of different antiviral compounds

Thanks a lot for your contributions. I hope that the cientific comunity can find a better treatment to fithg this disease.

Please have a look at this useful PDF attachment.