Hello everyone. I have a question - should I deworm my chickies even if they seem healthy and I have not seen any parasites?
Totally your choice. I don't treat mine for anything unless I see a reason. One of my main goals is to raise them for meat. When I butcher I check their intestines for worms. I've never found a worm so mine have never been wormed. I've never treated them for lice or mites either because I've never found lice or mites.
If you decide to deworm find out the withdrawal periods for the eggs. Different active ingredients require you to not eat the eggs for a certain length of time. Also, the active ingredient in Safeguard, fenbendazole, can cause the feathers to grow back curly if you deworm them with it when they are molting. You may want to avoid fenbendazole when they are molting or at least know if you get those funky curly feathers what caused it.
Are chickens like other pets where they need certain vitamins, shots, deworming, etc.?
You'll find that different people do all kinds of things like this. Different supplements and additives to food and drink. Different preventative medications. They obviously think it's "better" or they would not do it. Some people do the same thing to their own bodies, not just their pets.
I don't. I go by what I see. If I see something wrong I treat it. Otherwise I try to strengthen their immune system by exposing them to the environment they will live in. I feed them a balanced diet and try to avoid feeding them so much of a "treat" that it upsets that balanced diet.
What are the essentials other than fresh water and their feed?
Clean water is an essential if you are supplying it. You don't want it to become dirty since unhealthy microbes can live in there. If it rains you may find that they like muddy water. If they find a pool of clean water they may scratch in it to muddy it up before they take a drink. It is fresh, just muddy. If you have a farm pond that is somewhat "not clean" they'll probably enjoy drinking from that. There is no reason to panic if you see something like that. But if you are supplying water, keep it clean.
If all they eat is the commercial chicken feed they will get a balanced diet. A lot of us like to feed them "treats". You can buy mealworms, BOSS, scratch, or other things. Many of us feed kitchen scraps, garden scraps or excess, orchard or berry plants excess, grass trimmings, all kinds of things. To maintain that balanced diet the general rule of thumb is to limit these treats to 10% of their diet. How do you determine what is 10% of their diet? We use another rule of thumb, if they can clean it up within 15 minutes of so when you feed them you are doing OK.
If you let them forage or free range you have lost all control over how much they eat of any one thing. I do that and just keep feed available when they are awake and let them manage that.
Two other things I consider very important. One is that they need dry space. Try to keep their coop and run as dry as you reasonably can. A wet coop and run is an unhealthy coop or run. When the weather sets in wet it may be hard to keep the run dry, but what they need then is a dry place to go. If they can't dry their feet out they can have problems. They can handle some wet but wet runs are a common problem on here.
The other thing I consider very important is space. Behavior problems are made much worse or more likely if they are squeezed into a tiny space. If you follow the link in my signature below you can see some of my thoughts on that. You'll see a lot of recommendations for square feet per chicken on here. I don't put much faith in those, there are a lot of different factors that determine how much room they actually need. Each flock can be different. Instead of relying on a formula that sometimes works my suggestion is to give them as much room as you reasonably can.