Managing kidney disease in dogs involves careful attention to their diet, with two key components proven to slow progression and extend life: reducing dietary phosphorus and increasing omega-3 fatty acids. These dietary adjustments become crucial once kidney disease advances, typically when creatinine levels exceed 2.0 mg/dL or fasted blood phosphorus is above 4.5 mg/dL. Supplementing with fish oil to provide up to 50 mg of combined EPA and DHA per pound of body weight daily can also offer significant benefits.
For dogs in the early stages of kidney disease (creatinine < 2.6 mg/dL and fasted blood phosphorus ≤ 4.5 mg/dL), certain commercial dog foods, particularly senior and light formulas, may contain sufficiently low phosphorus levels. However, it is essential to always verify the phosphorus content directly with the manufacturer, as formulations can change. The phosphorus content is best compared on a “dry matter” basis, which accounts for the moisture content, making it easier to compare wet and dry foods. While a low protein diet is generally not recommended unless the dog is uremic, moderate protein reduction may be necessary for dogs experiencing proteinuria (excess protein in the urine). Feeding wet food or adding water to dry food can also help maintain hydration, which is vital for dogs with kidney disease.
For comparison, most standard commercial dog foods contain 1-2% phosphorus on a dry matter basis. Dogs with early-stage kidney disease should ideally be limited to no more than 0.6% phosphorus on a dry matter basis. Alternatively, this translates to feeding no more than 30 mg of phosphorus per pound of body weight daily. These limits become even stricter as the disease progresses.
Incorporating Fresh Foods
When prescription kidney diets are not well-tolerated, a strategy involving a lower-phosphorus commercial food supplemented with low-phosphorus fresh foods can be considered. This approach aims to reduce the overall dietary phosphorus percentage. For instance, high-protein commercial diets can be enhanced with low-phosphorus carbohydrates like white rice, pasta, or potatoes. If a lower or average protein commercial diet is used, incorporating fatty meats with low phosphorus content is beneficial. A combination of both lean meats and carbohydrates can be added to any diet.
For dogs in early stages of kidney disease, fresh foods containing less than 100 mg of phosphorus per 100 kcals are recommended. The goal is to achieve an overall dietary phosphorus level of approximately 100 mg per 100 kcals. Dogs with moderate to late-stage kidney disease require even lower phosphorus levels, making non-prescription diets unsuitable. Crucially, calcium should be added at a rate of 1,000 mg per pound of added fresh food. This can be achieved using ground eggshell or other plain calcium sources. Calcium not only aids in binding phosphorus but also meets the dog’s dietary needs. Ideally, dogs with kidney disease should consume two to three times more calcium than phosphorus.
When a significant portion of the diet consists of fresh foods, long-term nutritional balance is essential, especially for younger dogs. Adding a multi-vitamin and mineral supplement that is free of phosphorus can help compensate for any nutritional gaps.
Utilizing Commercial Mixes and Supplements
A convenient method for creating a balanced diet involves using supplements like Balance IT Canine K Plus, which is formulated without added phosphorus. Vets must approve the generation of recipes and the purchase of such supplements. While these recipes might be lower in protein than ideal for some dogs with kidney disease, adjustments can be made. It’s also important to monitor omega-6 fatty acid levels, especially if poultry is used, and consider using coconut oil or olive oil as alternatives.
Recipes generated using these supplements can be customized for protein and fat content. For example, a Beef & White Rice recipe for early-stage kidney disease might initially have 17% of calories from protein. This can often be increased to around 22% while maintaining a 25% fat content, resulting in a phosphorus level suitable for later stages of kidney disease.
Currently, there are limited commercially available base mixes that can be reliably used for early-stage kidney disease without significant modification. When using such mixes, incorporating higher-fat meats, tripe, ricotta cheese, and a combination of whole eggs and egg whites can help manage phosphorus levels. A variety of fresh foods should be used, and small amounts of higher-phosphorus foods like liver can be offered for variety and nutritional completeness. Adding calcium at approximately 500 mg per pound of added fresh food is also recommended to help bind phosphorus.
Interpreting Nutritional Tables
When evaluating commercial dog foods, the “Phosphorus mg per 100 kcals” column is the most critical for dogs with early-stage kidney disease, aiming for 150 mg or less per 100 kcals. The “Phosphorus (dry matter)” percentage is also important, with a target of 0.60% or less for early-stage disease. Combining different foods can help achieve the desired phosphorus balance.
For dogs with significant proteinuria, a moderately reduced protein diet may be necessary, monitored through urine protein:creatinine (UPC) ratios. A UPC of 0.5-0.9 is considered questionable, while 1.0 is abnormal, and glomerulonephritis is typically diagnosed at UPC levels of 3.0 or higher.
If a dog is uremic (BUN > 80, creatinine > 4.0, with symptoms like vomiting, nausea, and lethargy), protein intake should be reduced. However, protein does not directly harm the kidneys unless it’s being lost in the urine (proteinuria).
It’s important to note that phosphorus levels in non-prescription foods can be less reliable than in prescription diets. Always request a detailed nutritional analysis from the manufacturer. If a company cannot provide this information, their products should not be relied upon for specialized dietary needs.
Brands that are consistently too high in phosphorus for dogs with creatinine > 2.0 or fasted blood phosphorus > 4.5 include Acana, California Natural, EVO, First Mate, Grandma Lucy’s (except Valor), Orijen, The Honest Kitchen, Sojo’s, Tiki Dog, Wellness (all dry foods), and Wysong.
Several commercial diets offer lower phosphorus options. For dry foods, options like SquarePet VFS Low Phosphorus Formula Dry Dog Food, Royal Canin Mini Aging +12, and certain Lotus Senior recipes provide relatively low phosphorus levels. Canned food options such as Weruva (various flavors), Royal Canin Mature Consult Canned, and Castor & Pollux Organix can also be suitable choices. Dehydrated and frozen food options like JustFoodForDogs daily meals, My Perfect Pet Kidney Support Blend, and Grandma Lucy’s Valor Chicken are also viable. Cooked food options like Caru Daily Dish stews can also be incorporated.
For specific guidance on food choices and brands, always consult the detailed comparison tables provided in veterinary resources, paying close attention to the phosphorus content per 100 kcal and on a dry matter basis.
