Chronic kidney disease (CKD): CKD is the most common kidney disease in dogs and cats. Regardless of the cause, CKD is characterised by progressive damage to kidney. It destroys small functional units of the kidney called ‘nephrons’ and reduces the filtration rate from 30 percent to 50 percent of normal.
Basically this is auto-maintained process. As there is damage to some of the nephrons and they become non-functional, other nephrons have to take burden to purify the blood. At some point of time, a stage comes when these nephrons exhaust with their capacity to purify the blood and again they become non-functional and process continues. It’s progression to end stage i.e. renal failure proceeds at relatively constant rate. If measures are not taken in due time, improvement in the kidney function is quite difficult because compensatory and adaptive changes to sustain the kidney have already occurred.
Kidney failure: Kidney failure occurs when 75 percent or more of the nephron population becomes non-functional. Kidney failure is a condition that can have many causes, but the final outcome is more or less same. Whatever may be the underlying disease, the main damage is always done to nephrons. Kidney itself has a great reserve capacity and continues to function normally until more than two thirds of its functional units i.e. nephrons are destroyed. This is a major reason why dogs and cats are often presented to veterinary surgeon quite late in disease process. That’s why external signs simply do not exist in early stages!
Kidney failure can affect dogs and cats at any age, but it is more common in middle aged or older animals. The incidence of chronic kidney failure increases with age. It is thought that cats and dogs aged seven or older are more at risk of developing the condition. According to research, around 10 percent of cats and dogs suffer from kidney failure at this age. Numbers are probably greater for animals who are still in the pre-clinical phase of disease, not showing any external signs of a problem. As the problem can progress quite slowly, signs are often ignored as they occur gradually and are easy to miss in early stages.
Tips for pet parents
Observe your pet carefully; it may go a long way in ensuring his healthy life.
- Urination: You should track changes in volume and frequency to urination. Many a time your dog is incontinent because he is urinating in the house when in reality he is urinating more frequently (polyuria) and not allowed outdoors frequent enough.
- Water intake: Water intake is more easily detected than urination. Water intake should not exceed 80-90 ml/kg per day and 40-45 ml/kg per day in cats, though it may vary depending on season, physical condition and diet.
- Other signs: Some signs like weight loss, dehydration, oral ulceration, vomiting, diarrhoea and loose teeth may be observed.
- Regular tests: If your cat or dog is aged seven or older, even if none of the external signs are present, ask your vet about specific testing for kidney problems.
- Treatments: There are a range of possible options your vet might consider. Changing to a prescription renal diet, adding in dietary supplements and sometimes, in the later stages, using some prescription medication (with prior consultation of your vet).
(Dr Ajay Pore is product executive–Companion Animals, Vetoquinol India Animal Health Private Limited, Mumbai).