Hello & welcome, I am Dr. B, a licensed veterinarian and I would like to help you with your wee one today.
First, I do want to say that it isn't uncharacteristic to see a poorly cat want to stay in and sleep more then usual. The reason he is likely doing so is (1) since it has been quite chilly here and (2) if he is feeling very poorly then he may not feel up to pretending all is well outside (since letting the world know you are feeling unwell will make you a target for predation or bullying).
Now as I am sure you can appreciate, just like people, cats can have diarrhea that is caused by a range of agents. These include bacterial viral, parasitic (worms but also protozoa like Giardia, Coccidia, Tritrichomonas), toxic, cancerous (ie GI lymphoma) nutrition, and general dietary indiscretions causes. (Though in Kip's case, toxins and dietary indiscretions are potentially less likely). It can be daunting to get to the bottom of which differential is to blame, but since it sounds like he is otherwise normal and the diarrhea is not profuse, there are a few things you can try at home try and get it to settle.(And I am glad to see you have wormed him already, since that does remove one differentials for us).
The first thing you can do is offer a light/easily digestible diet. This will be easier on his compromised gut.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 in cases of gastroenteritis (ie Hill’s I/D or Royal Canin’s sensitivity). These diets aim for provide nutrition to the stressed gut without making it work hard to digest the food. I would advise frequent small meals to minimize strain on the already stressed gut, and to help lower the volume of diarrhea.
Further to this, we do also keep a close eye on his water intake and his hydration. To check his hydration status to make sure your cat is not becoming dehydrated there are a few things we can test at home. One is whether the eyes appear sunken, if the gums are tacky instead of wet/moist, and whether he has a "skin tent" when you lift the skin. To see how to check these parameters for dehydration, you can find a wee video on this HERE. ( 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 already, then you do want to have your kitty seen by his vet before this gets out of control for him.
If you are concerned that he is becoming dehydrated from the fluid loss via diarrhea, you can try and encourage him to drink but offering fresh water or even low-sodium chicken broth. If he isn’t amenable to these, you can syringe feed pedialyte. Pedialyte is good here (though aim for a flavourless one since cats don’t love fruit) because it will get both fluids and lost electrolytes back into your kitty. A typical maintenance rate for hydration in an animal is 48mls per kilogram of 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 the feline daily requirement. (we aren’t calculating losses, so you can add an equivalent volume to match how much diarrhea is being producing). If he vomits when you have given pedialyte, then therapy should be discontinued (since we don’t want vomiting because of our intervention).
Finally. if a cat has diarrhea just due to benign GI upset, the above is usually enough to settle it for them. But sometimes we need to use feline safe anti-diarrheals to slow things down for their gut. As I am sure you appreciate, these would not be a cure (since cures would depend on the culprit and might include antibiotics or anti-parasitics, etc.) but would slow the diarrhea to aid the body potentially absorb more water/nutrients then it would have if the diarrhea were unchecked. In regards XXXXX XXXXX options for Inara, the one we most commonly use in cats is Kaolin (More Info/Dose) available from your local pharmacy (do avoid using any PeptoBismol or similar products with aspirin in them) or Protexin Pro-Fiber (which is available OTC at vet practices; example). Both will slow diarrhea safely for a cat and the Pro-Fiber has the bonus of providing support to the delicate good bacteria of the GI.
Overall, diarrhea can be caused by a wide range of agents. If he is otherwise well in himself, properly hydrated, eating/drinking, and only having mild intermittent diarrhea; then you can try supportive care to see if you can settle his signs. If you try the above and the diarrhea isn’t settling in 24- 48 hours, then do consider following up with his vet, ideally with a fecal sample. They will also be able to examine him to make sure this diarrhea isn't due to something sinister and cover him with broad spectrum antibiotics to clear any GI bacterial gastroenteritis that may be causing this diarrhea and get him back on track as soon as possible.
I hope this information is helpful.
If you need any additional information, do not hesitate to ask!
All the best,
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