Hello, my name is***** and I have over 20 years of experience as a veterinarian. I am sorry that you have been waiting for a response, but your requested expert isn't online which delayed your question coming up on the list for all to answer. I would like to help if you are still interested in an opinion.
I'm sorry to hear that your girl isn't feeling well and is shedding excessively, is eating poorly, is lethargic, and not very responsive.
Stressed or sick cats shed more, as stress hormones cause release of dead, not actively growing fur.
Her lethargy and weakness could be simply due to eating and drinking less and having less energy available, but truly I think a big part is related to some sort of disease process that is making her not want to eat in the first place.
Cats that aren't grooming are either too sick to care or have mouth pain, and thus are hesitant to groom themselves. If she will let you look in her mouth check her tongue and gums for painful ulcers or redness, any swellings or sign of badly infected teeth, or a mass under the tongue.
A lack of appetite could caused by a full or partial gastrointestinal obstruction, chronic pancreatitis, a dietary allergy or sensitivity, toxin exposure, a viral or bacterial infection, inflammatory bowel disease, disease, hyperthyroidism
(a tumor of the thyroid gland) and subsequent organ disease, internal organ failure (kidney
or liver disease or diabetes
), or even cancers such as lymphoma.
Being an older girl more serious diseases like organ failure or cancer are more likely so I recommend that she be examined by her veterinarian as soon as possible.
Because she hasn't eaten normally in a couple days and seems so weak I am very concerned about her. As her liver breaks down fats for energy to live her liver may become overwhelmed and unable to perform normal functions, and hse may develop a type of liver disease called hepatic lipidosis, which can be life threatening.
Ideally she would see a veterinarian today. Simple stomach upset should pass within 24 to 48 hours. They could examine her, run blood tests and a urinalysis, possibly check radiographs and/or an ultrasound to evaluate her and know best how to treat her.
In the meantime they can administer injectable anti-nausea drugs and fluids to rehydrate her.
If you cannot have her examined tonight for whatever reason there are some things you can try at home.
At home to try and settle her stomach and improve her appetite you can give either:
1) Pepcid ac (famotidine) at ¼ of a 10mg tablet per 5 to 10 pounds of body weight every 12 hours
2) Prilosec (omeprazole) at ¼ of a 10mg tablet per 5 to 10 pounds of body weight every 24 hours
These are acid reducers and may help her feel less nauseous so that she will eat and hopefully not vomit. They are quite safe and can be used long term if necessary.
You can use a medicine syringe to try and force water or low salt chicken broth into her orally.
A couple of hours after giving the acid reducer I recommend offering meat baby foods
or a bland diet of 2/3 boiled, minced, white skinless chicken and 1/3 boiled, plain, white rice mixed with some low salt chicken broth to make it easy to lap up and swallow, get additional fluids in and make the mix more palatable.
If she continues to not eat she should see her veterinarian for an examination, diagnostics and intravenous fluids and supportive care in the morning.
Please let me know if you have any further questions.