using System;
using System.Collections.Generic;
using System.Linq;
 
public class Test
{
	public static void Main()
	{
		string text = "енот, енот, гваделупский енот, косумельский енот, енот, енот-полоскун, енот-ракоед, косумельский енот";
		var result = text.Split(',').Select(x => x.Trim()).Distinct().Aggregate((r, word) => r + ", " + word);
		Console.WriteLine(result);
	}
}

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