Absolutely do not withhold rent. I worked in a property management company for many years, and was the one who filed for evictions and appeard in court. No judge would justify you withholding rent, and will tell you in no uncertain terms that is not the way to handle grievances. You would end up having a judgement against you for past due rent, and face eviction. In my state, if you are one day late the landlord can begin eviction proceedings, which usually take a couple months from the day filed to the day you are evicted.
Do you have anything in writing stating that you can have the chickens? If so, that covers you for having them now, but all the landlord needs to do when that initial 1 year (or whatever term it is) is up, is give you notice in writing that he is no longer allowing them, usually 30 days notice, and that you need to get rid of them.
Does your lease (if you have one) state that you cannot have pets, and the allowance for chickens was made verbally? If that is the case then, unfortunately, there is not much you can do. If you keep the chickens and he evicts you because of it, and has the lease that shows you aren't to have pets, then you are technically in violation, regardless of any verbal agreements.
However, this does not change he fact that his dog killed your chickens and he should be responsible. Going after him for the replacements will certainly result in you being asked to move, since he seems to be that kind of person. If you are outside of your lease term, unfortunately, the landlord does not have to give a reason. However, if you are still under your initial lease, then he has to have reason to evict you, such as non-payment of rent or some other valid lease violation. Don't give him any reasons. It will be obvious to the judge that he is retaliating. He is bound to that contract just as you are.
However, lease or not, he has to follow the eviction laws of your state. Here in PA we need to give notice of eviction for x number of days (we gave 10), which will state what they are being evicted for and basically say, if it is not taken care of, then we will begin proceedings, on the11th day, if the tenant has not vacated the property or rectified the situation, you can file for a judgement, which usually occurs within a couple weeks to a month. At the hearing the tenant is given another 30 days to take care of the issue (such as pay the judgement) or to vacate the property. If that is not done, then you file with the courts for the actual eviction, which happens approximately 30 days from that date. It's a pretty long process to evict a tenant.
