He has vomited 3 times in total
I'm sorry to hear that your dog is experiencing these issues. Vomiting, especially when accompanied by lethargy, loss of appetite, and changes in behavior, can indeed be concerning. The clear and slimy vomit suggests it might be related to stomach irritation or an empty stomach.
Given that the vomiting is episodic and triggered by certain factors, it could be due to various reasons such as dietary indiscretion, gastrointestinal upset, or even stress. The lethargy and loss of appetite are also worrying and could indicate that your dog is not feeling well overall.
Firstly, consider dietary management. Offering a bland diet, such as boiled chicken and rice in small, frequent meals, can help soothe your dog's stomach and reduce vomiting.
Secondly, ensure your dog stays hydrated. Offer small amounts of water frequently, and if your dog is reluctant to drink, you can try offering ice cubes to lick.
However, since your dog is showing multiple symptoms—vomiting, lethargy, and loss of appetite—and the vomiting has been ongoing for a day, it is important to consult with a veterinarian. These symptoms could indicate a more serious underlying condition, such as pancreatitis, gastrointestinal obstruction, or an infection, which would require professional medical attention.
If you have any further questions, please feel free to ask. Thank you.