I apologize if this question/ concern had been asked.... I have a 6 day old chick who has developed a swollen vent which smells awful as well and a loss of feathers around the vent. The chick has been chirping like crazy and has been active. We have been washing its butt in warm water but are very concerned. The chick is with 3 others and the hen who hatched them. They have fresh shavings and water and food daily. Thanks in advance.
Would a photo be possible? It may be a prolapsed vent which is not always successfully treated in chicks. Are you sure it is the vent, and not the umbilicus or navel? If it is a prolapsed vent, try putting honey or Preparation H ointment on it, and push it back inside, then hold it for 15 minutes. If you can't get it back in, take a QTip with vegetable oil or vaseline, and lubricate the vent to make sure that the chick can pass stool. This is much more common in hens of laying age or in roosters who are constipated. Make sure the chick is drinking well or dip it's beak into water often. Also make sure the brooder temperature is 90 degrees with a thermometer on the floor, and a cooler place to escape to.
Here are some similar threads about prolapse in chicks, and the last is a good one for treatment: https://www.backyardchickens.com/t/857614/help-prolapsed-vent-chick https://www.backyardchickens.com/t/917068/week-old-chick-prolapsed-vent https://www.backyardchickens.com/t/351494/please-help-with-my-chicks-prolapsed-vent http://www.the-chicken-chick.com/2012/04/prolapse-vent-causes-treatment-graphic.html