With his not being keen to open his mouth, initial reluctance, and unwillingness to play with the cat when you offered the hose, we’d be suspicious that he is sore but trying to put on a brave face. As well, I would say that he does look a bit puffy on the first photo Though the gurgling, drooling, vomiting, and loose stool also raise concerns of nausea and GI upset. Considering both of these, I’d be wary whether he ate something odd when he was digging (where the swelling is soft tissue inflammation) or that he may have been stung by a bee/wasp/spider. The latter can actually cause swelling, discomfort as well as gut upset.
With this all in mind, we’d want to start some supportive care for Peter. Since we have nausea here, we can consider treating with an OTC pet safe antacid like Pepcid (More Info/Dose @http://www.petplace.com/article/drug-library/library/over-the-counter/famotidine-pepcid), Zantac (More Info/Dose @ http://www.petplace.com/article/drug-library/library/over-the-counter/ranitidine-hcl-zantac), or Tagamet (More Info/Dose Here @ http://www.petplace.com/article/drug-library/library/over-the-counter/cimetidine-hcl-tagamet). Whichever you choose, we’d give this 20 minutes before offering food to allow absorption. Of course, do double check with your vet if he has a known health issues or is on any medications you haven't mentioned. Also if you give this and he cannot keep it down due to nausea that is usually a red flag that we need to bypass his mouth with injectable anti-vomiting medication from his vet.
Once he is more settled, you can plan to try small meals of a light/easily digestible diet. Examples you can use are cooked white rice with boiled chicken, boiled white fish, or scrambled eggs, or meat baby food (garlic/onion free only). The aim of these diets is that they will be better tolerated/absorbed by the compromised gut. Therefore, it should get more nutrients in and result in less GI upset and less diarrhea. You can also add fiber (ie canned pumpkin, all bran) to his food to bulk up his stools. As long as improvement is being seen, I usually advise continuing this until the signs are settled, and then weaning slowly back to what you normally feed.
Finally, if we can get his stomach settled and if you think an insect sting is likely, you can also consider starting an OTC antihistamine. Most commonly we use Benadryl/Diphenhydramine (More Info/Dose @ http://www.petplace.com/article/drug-library/library/over-the-counter/diphenhydramine-benadryl). A low dose (ie. 0.5-2 mg per pound of their body weight twice daily) can just be enough to reduce that allergic irritation. We like to keep the dose low, as it can cause drowsiness (just like people). And of course, this medication shouldn't be used if your wee one has any pre-existing conditions or is on any other medication without speaking to your vet first.
Overall, Peter’s signs do raise a few concerns. So, we’d want to settle his stomach, then counter an allergic reaction if suspect. You can also gently cool compress this area for him. If all settles, we are happy. But if his signs linger or you think he has eaten something harmful, then we’d want a check with his vet to get that checked +/- have them start anti-nausea mediation by injection to settle this for him. And at the same time they can check his face and start steroids to counter an allergy or at least dog safe pain relief to get reduce any soft tissue trauma for him.
Please take care,
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