Toy poodle not eating

Question
    My 16 month old toy poodle has not been eating well for about a week and a half.  She sometimes goes through stages where she does this (eats about half her normal amount of food or less).  Her energy level seems okay.  I feed her Eukanuba small breed adult food with a small amount of Iams sauce on it (she gets easily constipated and this seems to work well because it adds extra fiber).  She is also having normal bowell movements (although smaller because she is eating less food).  
    My niece and nephew were over right before this happened and they really wore her out.  She is also overdue for a grooming so her hair is very long and the weather has gotten very warm (in the 80s or 90s most of this time).  Is this just a normal thing?  (She seems to do this more right before she gets groomed.)  Or is this something that I should be concerned about?  

                               Kat

Answer
It could be that she is worn out from their visit but it shouldnt be going on this long. Yes It could be the heat. I personally would take her to the vet and some bloodwork done.  Have the heart and thyroid checked and the blood sugar levels.  I wouldnt wait or leave it up to chance.  Its not worth the risk of loosing your pet.