I study as a veterinarian and I have the answer to your question. Despite the fact that I'm only a student, my experience is on a high level! I even write my college essay about pet's feeding. So... Although garlic is also useful, regular feeding of garlic to a dog can lead to disastrous consequences. Feeding the animal with garlic will give rise to the development of gastritis, accompanied by inflammatory processes in the stomach and intestines, abdominal pain, spasms. Complications of gastritis can be an ulcer. If the pet has worms, consult a doctor! The plant can cause poisoning, the symptoms of which appear on the 2-4 day after eating the plant. Characteristic signs of poisoning are shortness of breath, vomiting, palpitation, weakness, increased breathing, drooling, loss of appetite. Onion is even more dangerous for a dog. Even a small amount can cause problems with the health of the dog. Its main danger lies in the fact that substances contained in onions destroy red blood cells, thereby anemia develops. Common symptoms of hemolytic anemia are rapid heartbeat, weakness, depressed condition, decreased endurance, loss of appetite, vomiting, and diarrhea. In addition to these symptoms, signs of anemia are dark or reddish urine, pale or bluish gums. Changes can occur when using only 5 grams of onions on a regular basis.