Thank you for your patience. There are a few things that could be causing these symptoms in your Boxer mix boy, but yes - an allergy could definitely cause both of these issues potentially. A food allergy can cause skin and GI reactions like this, so we have to keep that in mind. To rule a food allergy in or out, you would need to work alongside your veterinarian to start a food trial on your boy. This uses a special novel protein diet or a hydrolysed protein diet to see if the sypmtoms improve over an 8 - 12 week period with no other treats, food or snacks. The skin issue could potentially be due to an environmental allergy (such as to local grasses or pollens for example) and the GI symptoms could potentially be due to another problem altogether.
For now, make sure your boy is up to date with his deworming treatments and be sure to use a reliable allwormer such as Drontal, Milbemax or Panacur for his intestinal deworming treatments every 3 months. Keep your boy on a high quality adult canine diet from your local pet store or veterinary clinic and try to avoid giving him any other treats or snacks for now. If his symptoms continue, definitely follow up with your local vet. Here they can carry out a full physical exam, basic diagnostic testing and start your boy on a food elimination trial to see if this could indeed be due to a food allergy.
If this has just happened tonight only, then you could try your boy with a little benadryl. The typical dose is 1mg per pound of body weight up to twice daily. You can read more about the use of Benadryl in dogs online here: http://www.petplace.com/article/drug-library/library/over-the-counter/diphenhydramine-benadryl .
Best of luck with your boy. I hope all of the above makes sense? If you have more questions or if I can help in any other way, please do not hesitate to ask! If you would like to accept my answer, please press RATE OUR CONVERSATION (I am not compensated in any other way). Bonuses are always welcome. Thanks! I hope to work with you again soon!
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