Marissa, pets' digestive systems are sensitive, and feeding them any novel food substance, even one that is nontoxic, can cause digestive upset. Therefore, it is important when adding new foods to your pet’s diet, to watch carefully and take away any substance that might be causing digestive upset. Also, people food and pet treats should make up no more than five to 10% of your pets' daily caloric intake. The rest of their calories should come from a high-quality, nutritionally complete pet food intended for your pet's phase of life and lifestyle.
Ham can be high in fat and sodium, so feeding large amounts to your pet can cause health problems and large amounts of liver can cause vitamin A toxicity, which can affect your pet’s bones and muscles.
For information on avocados, cheese and canned tuna, please read our Ask the APCC Archive─People Food.
More helpful information on foods potentially toxic to pets can be found at: Top 10 People Foods to Avoid Feeding your Pets.