Kidney disease is one of the most common causes of morbidity and mortality in older cats. Despite recent advances in early diagnosis and therapy, renal disease is a major cause of poor quality of life and ultimately death in our feline population. As with any disease, prevention of kidney failure is preferable to management. This study attempted to identify factors that affected the risk of chronic kidney disease developing in domestic cats.
Healthy geriatric cats (> 9 yrs) were recruited from two primary care practices in England between 2005 and 2009. Cats were followed until death, loss to follow up, the end of the study, or development of azotemia (kidney disease). Cats were reassessed at a minimum of 6 month intervals.
The association of dental disease with kidney failure was not surprising. Cats with dental disease are in a pro-inflammatory state and generally have persistent, low grade oral infections. It is well known that oral inflammation complicates the management of other systemic diseases, such as diabetes. It is possible that oral inflammation may lead to kidney damage through unknown mechanisms. Owners were asked to complete a questionnaire regarding lifestyle, diet, vaccine history, environment, smoke exposure, and a variety of other factors. A Geospatial information system (GIS) was also used to evaluate cat’s location of origin.
148 cats were included in the analysis, of which 27 developed azotemia. The only variables found to be different between azotemic and non-azotemic cats were lifestyle, vaccine history, and dental disease category. No significant findings were detected on geospatial analysis.
The association of vaccine frequency with kidney disease raises many questions. It is important to note, as this study does, that correlation does not necessarily imply causation (ie. the association of vaccine frequency and renal disease does not mean one causes the other). It may be that cats who are frequently vaccinated are also more likely to receive anesthesia, NSAIDs, antibiotics, or other treatments that are more likely to affect renal function. This study does, however, imply that further research should be done into investigating this association. It also reinforces the idea that vaccinations should be given only as frequently as necessary, based on a cat's individual risk factors. One must also, however, keep in mind the amazing success of many feline vaccine programs (rabies, feline leukemia virus, feline panleukopenia) in dramatically reducing the incidence of disease.
