Avocados have a chemical called persin in them which can be toxic to dogs. In large quantities it can cause vomiting, diarrhoea, myocardial damage and stomach upset, but many dogs can eat avocados in small amounts.
In small quantities, avocado is okay for dogs, but this should never be a regular food you feed, and you should always consult your vet before feeding avocado to your dog. Avocados contain vitamins A, B6, C and E with good sources of antioxidants, fibre, fatty acids and potassium. All these are great for your dog; however, they should be getting a good helping of these from their normal diet. Avocados have a large amount of fat which can lead to pancreatitis in your dog.
If you are thinking of feeding your dog the odd bit of avocado you should make sure you remove the stem, skin and pit as these are difficult to digest, a potential choking hazard and could cause gastrointestinal blockages.
As stated, avocados are packed full of nutrients, but it isn't the best snack for your dog's daily diet due to their high fat content. Instead, feed a complete and balanced dog food like Pure, packed full of vitamins and nutritious ingredients, with fat content that is much better suited to your pooch.