Never use garlic as a "home treatment" for fleas. It is not effective and can be toxic to your pets! Onions, garlic, chives, and leeks are in the Allium family, and are poisonous to both dogs and cats. Garlic is about five times as potent as onions. Japanese breeds of dogs such as the Akita and Shiba Inu, and cats are particularly susceptible.
Onion and garlic ingestion not only upsets your pets' GI tracts, but also can result in oxidative damage to the red blood cells which makes the red blood cells more likely to rupture. Garlic and onions can cause nausea, oral irritation, drooling, abdominal pain, vomiting and diarrhea.
Other clinical signs of garlic and onion toxicity include:
- pale gums
- elevated heart rate
- increased respiratory rate
- exercise intolerance
Onion and garlic poisoning may have a delayed onset, and clinical signs may not be apparent for several days. While minute amounts of these foods will be tolerated in some pets, especially dogs, larger quantities can be very toxic.