I'm asked frequently to formulate homemade diets for dogs and cats with chronic kidney disease. The main reason is that they won't eat their prescription diets. While I'm all for trying a homemade food and some pets (usually dogs) accept them better, these patients are trying to tell us something. Switching foods is ultimately a failing solution to the anorexia thing, unless we address the reasons they won't eat.
Here are the top reasons these patients don't eat:
1. Dehydration, dehydration, dehydration - this is most common and occurs because the kidney cannot conserve body water. Dehydration is uncomfortable!
2. Gastrointestinal ulcers (this is due to elevated gastrin levels, a hormone that increases acid secretion). This will result in nausea, vomiting and pain.
3. Uremia (elevated levels of urea nitrogen, creatinine, phosphorus, parathyroid hormone, etc).
4. Anemia (due to the kidney's inability to produce erythropoietin, a hormone that stimulates the bone marrow to make blood precursors)
5. Hypertension which, in people, can cause headaches and dizziness, among other problems.
6. Infection, especially urinary tract infections to which these animals are more susceptible than normal animals
7. Acidemia - high levels of organic acid that accumulate from the metabolism (and inadequate elimination) of protein.
8. Side effects of drugs (and don't forget herbs and nutraceuticals here either)
9. Other conditions present at the same time - especially pancreatitis
10. Food aversions - usually from offering more and more foods when the pet is feeling nauseous.
So that's a lot to stack against a new diet! I have taken to giving my clients this list as a 'checklist' when the appetite goes south. To address the checklist, we usually need to get blood and urine for a biochemical profile, cbc, urinalysis, and urine culture at least. Checking blood pressures on a regular basis is a good idea too. I'm also a proponent of calcitriol, an 'activated' form of Vitamin D that is deficient in kidney patients. I'm told that it does help some animals have a better appetite - we use this if the calcium and phosphorus levels are normal, and preferably after checking parathyroid hormone levels.
I make sure everyone knows how to check for dehydration, and teach them how to give fluids to correct it. Since we are not using endoscopy to look for ulcers during office visits, we may start long term pepcid at any of these visits just in case they are a factor.
My best pet owners bring me a current written list of all their drugs and supplements at every visit too - this is so that I don't rely on my medical records and possibly misunderstand changes that have gone on at home - people sometimes add things or change doses on their own, or run out of drugs and forget to refill them. That list is a big help to all of us so we can check the most recent regimen and analyze the doses for the potential for side effects.
Check list complete? NOW we can try a new diet!