Garlic — Food safety facts
Do not feed · Dogs · full breakdown on the linked food page
Toxic. Damages red blood cells (hemolytic anemia), often days later. Powdered garlic is concentrated — worse by weight.
Short answer
Yes, garlic in any form, including powder, is toxic to dogs. It damages their red blood cells, which can lead to weakness, pale gums, and anemia, and these signs may not appear until a few days later. Garlic powder is especially concentrated, making even a small amount by weight potentially harmful. Do not wait to see if symptoms develop. Contact your veterinarian or the ASPCA Animal Poison Control Center at 888-426-4435 right away for advice based on your dog's size and what was ingested.