GLIMMIX for joint modeling of two different negative binomial

[Tonyaa]

I'm trying to joint modeling two responses through GLIMMIX, which is similar to the following linked example:

https://support.sas.com/documentation/cdl/en/statug/63033/HTML/default/viewer.htm#statug_glimmix_sec...

The problem is that the two responses I have are both negative binomial, instead of one binary and one count. I'm wondering if there is a trick to implement the joint model of two different negative binomial distributions using GLIMMIX. 

Thanks in advance!

[sld]

I would not think that the two distributions are required to be different, but I don't know for sure. Have you tried it to see whether it works?