Tube feeding is an alternative way of providing nutrition to a cat that is suffering from anorexia or has some anatomical or surgical condition that prevents it from eating normally.
An esophagostomy tube is a small rubber tube that enters the esophagus through a surgical incision on the side of the neck. This allows food you to place food directly into the esophagus so that it can flow down into the stomach. The feeding tube is not placed directly into the stomach.
Too much vitamin A or hypervitaminosis A can lead to serious toxicity. While somewhat uncommon in North America, vitamin A toxicity is sometimes diagnosed in cats that are fed primarily table scraps. There seems to be considerable variability in how susceptible individual cats are to this problem. It takes a long time for the clinical signs associated with vitamin A toxicity to develop; symptoms do not usually appear until the dog is at least middle-aged.