3. Analysis of the observed data using the dynamic model 3.1. Effect of demographic risk factors. Now we consider the full model, including both males and females, and compare how integrating the different risk factors increases the goodness-offit to our observations using likelihood ratio tests. We performed the data analysis with each of the following values for the proportion of non-captured cats (p NC ): 0.15, 0.30 and 0.45. Since the results obtained from these three values are very similar, we only show those obtained for p NC = 0.30. It is important to note that from now on, likelihoods are calculated with the distributions of FIV prevalence in males and females, without removing the cases of extinction (i.e. we use the distribution d). The probability of observing zero infected individuals is an important characteristic of the models, and removing extinction cases would lead to lose very important information, especially relating to the external virus transmission rate.