First of all, How old is your cat? Is he a kitten or an older cat?
What food are you feeding? I HIGHLY recommend Iams Hairball or Iams Original for underweight cats. It has a high nutritive value and is much better than other store-bought foods. Stay away from foods such as Meow Mix, Deli Cat, Alley Cat, Cat Chow, etc. These foods have low nutritive value and are full of preservatives and fillers. They can also increase the likely-hood of crystal formation in the bladder which can be a life-threatening problem in male cats.
Stay away from canned foods except as treats. Canned food is 70 to 80% water and has low nutritive value as well.
Stick to one brand of cat food (Iams, preferably). Buying and feeding a different brand of cat food every time can cause intestinal upset, diarreah, vomiting, gas, etc. all of which can put your cat off his food.
Milk is a No-No for cats. They can't break down the large protein molecules and it can cause upset stomach and diarreah.
Eukanuba has a Maximum Calorie dry food available for safe weight gain available through veterinarians.
I strongly suggest you have the cat tested for Feline Leukemia (FeLV) and maybe have a CBC/Profile or at the very least a Profile run on your cat. If cat's don't eat well or at all, the liver can get fatty deposits. This causes the skin to turn yellow or orange and can be deadly if not treated.
In summary, get your cat tested for FeLV (which is a deadly virus and highly transmittable), have the vet do a lab Profile (chem 12), and get a high quality food like Iams and stick with it.
You can email me at
[email protected] if you have more questions.
Regards,
Michelle :)