Avacado contains persin, which is a fungicial toxin. In is considered not a serious threat for most dogs, but may cause upset stomach, diarrhea, and / or vomiting, especially in large amounts.
Chocolate contains theobromine, which dogs have a difficult time processing it quickly (unlike humans). Consumption can result in muscle tremors, seizures, internal bleeding or a heart attack. Ultimately it can be fatal.
Some symptoms include:
- Extreme thirst
- Hyperactivity; too much energy
Grapes and Raisins
Both consumption grapes or raisins can lead acute renal failure (kidney failure) with anuria (stoppage of urine production). The exact reason is unknown.
Onions and Garlic
These two items contains thiosulphate, which can cause hemolytic anemia, liver damage, and death for dogs if enough is consumed.
Xylitol is used as a sweetener (sugar substitute) that can be found in low amounts in corn, lettuce, oats, trees, various fruits, and amongst other plants. The problem is humans extract in high quantities and used in foods as an additive. One good application is sugar-free chewing gum. In significant amounts it causes a enough surge of insulin release, causing hypoglycemia, which can develop liver failure and / or lead to fatality.
Here is an article by CBS News on Mar 13 2016 about it.
Symptoms of xylitol poisoning include, but not limited to are:
- Weakness; difficulty walking or standing
- Depression / sadness
- Tremors and shakes