Thank you again,
Now I am glad that Vicious's eyes aren't actually sunken since that would be a sign of severe dehydration as opposed to weight loss from his self-starvation. As well, its good that his gum color isn't excessively pale (you can compare this to his brother if you did have any doubt on the color) and his belly is comfortable since issues with those parameters would raise concerns of possible foreign body or toxin ingestion (which of course would be urgent issues).
Now those aside, when a cat goes off their food with lethargy, these are vague clinical signs that can occur with a range of issues. If we are able to remove oral differentials (since he's had no drooling or previous struggles with eating) then we can turn our attentions to the conditions that induce nausea (a common reason for them to stop eating even without vomiting). And I would note that when considering these, we need to consider issues that would target his GI but also those that would affect the body on the whole. This includes grumbling bacterial infection, viral disease, pancreatitis, metabolic conditions, organ disease (ie liver or kidney
troubles), cancer (ie lymphoma), and those aforementioned toxin and/or foreign material concerns.
Now to complicate matters for us, we get very concerned for cats who go off their food (and this is getting worrying with the level of weight loss you are seeing already) because cats were not well designed for the anorexic lifestyle. When they are off their food, body fat is broken down and released into the blood stream, causing their liver distress (ie. hepatic lipidosis) that can make getting them better even more difficult for us.
Now if Vicious is turning away from food, then his signs could include nausea despite not showing any vomiting. Therefore, we need to rule out nausea here. To do so, you can try him on antacid therapy. There are a number of antacids that are available over the counter and pet friendly. I would advise only treating with one, but the ones I tend to recommend are:
* Pepcid (More Info/Dose @ http://www.petplace.com/drug-library/famotidine-pepcid/page1.aspx#.VGJLgsn9XPg) or
* Zantac (More Info/Dose @ http://www.petplace.com/drug-library/ranitidine-hcl-zantac/page1.aspx)
* Tagamet (More Info/Dose @ http://www.petplace.com/article/drug-library/library/over-the-counter/cimetidine-hcl-tagamet)
This medication of course shouldn’t be given without consulting your vet if he does have any pre-existing conditions or is on any other medications. Ideally, it should be given about 30 minutes before food to ease his upset stomach.
As well, you will want to try and see if you can get him eating (as I am sure you have been). Favourite foods are allowed or you can tempt Vicious with a light/easily digestible diet. Examples of this would be boiled chicken, boiled white fish, scrambled eggs (made with water and not milk), meat baby food (do avoid the ones with garlic powder in the ingredients) or there are also veterinary prescription diets that can be used here (ie Hill’s I/D or Royal Canin’s sensitivity.)
Further to this, if tempting doesn’t work, then we do have to consider initiating syringe feeds to get food in. In that case, you may want to try Hill's A/D from your local vet. This is a critical care diet that is comes as a soft, palatable pate. It is calorically dense, so a little goes a long way nutrition-wise and this could just help get some more calories into him even if we can’t get a huge volume of food in. As well, for syringing food, you can use the animal version of Ensure (balanced for animals dietary requirements) called Clinicare Canine/Feline Liquid Diet. It is actually by the same people who make Ensure, but is formulated to meet out pet's dietary needs. Your vet should be able to order it for you but it is available without a prescription. They also make one specifically for older cats with kidney troubles, and this could be an alternative for an older cat. And finally, in a pinch I would note that you could also consider offering or syringing wet kitten food as this too will have more nutrition per bite compared to his normal food. This way it would a means of getting food, staving off hepatic lipidosis, and buying you time to uncover the reason for his anorexia and lethargy.
On top off all of this, you do need to keep an eye on his water intake and hydration as we have been discussing. Just to make sure we are on the same page with checking those parameters, I do want to note a wee video on checking these HERE. (http://www.ehow.com/video_12232503_dog-dehydrated.html). They use a big dog but it makes it easier to see and the principles are exactly the same. If you are seeing any signs of dehydration at any stage, then you do want to have Vicious seen by his vet before this gets out of control.
In regards ***** ***** you can do to help stave off dehydration at home (though do note that if he is already then he will likely need more the oral rehydration), encourage him to drink by offering fresh water or even low-sodium chicken broth. As well, wet foods (as mentioned above) are 35% water, so getting him to eat will help us deal with water intake as well. If he isn't amenable to drinking, you may wish to offer unflavored pedialyte via syringe feeding. While we cannot do this if they are vomiting, it would be an option for this situation. A typical maintenance rate for hydration in an animal 48mls per kilogram of body weight a day. If you do give syringe pedialyte, this should obviously be divided up into multiple offerings through the day rather then all at once. This value will give you the total he needs for the day and is a good starting point to give you an idea of his daily requirement. If he does vomits if you give pedialyte, I would discontinue this as a therapy. (since we don’t want vomiting because of our intervention).
Overall, when a cat is anorexic and lethargic, it can mean a wide range of underlying issues. And in Vicious's situation, it does sound like this is taking quite a toll on him already. Therefore, we can try the above for him but if he isn't showing positive improvement in 12-24 hours or he worsens (vomits, etc), then you do want to get your vet involved at that stage. They can assess hydration, check for signs of any sinister lumps/bumps or internal issues. As well, you may consider having them check a blood sample to assess the state of his organs. They can also cover him with antibiotics, anti-nausea/vomiting medication by injection and even appetite stimulating drugs if necessary. Depending on the findings, the vet will be able advise you on what is likely our culprit and what can be done to help your wee one before he just fades away on us.
Please take care,