A deficit of total body water. Dehydration can be caused by excessive fluid loss, for instance via the kidneys in CKD, or by insufficient fluid intake.

Imbalance of organisms of the the microbiome (all microbes on or within an animal’s tissues), for instance the imbalance of the intestinal flora as part of the microbiome.

Electrolytes are substances that produce an electrically conducting solution when dissolved in water, releasing mineral ions such as sodium, potassium, chloride and calcium. These ions can either be the positively or negatively charged or, combined as a salt, neutral.

Erythrocytes are red blood cells and contain the blood pigment haemoglobin. Red blood cells are responsible for transporting oxygen from the lungs into the cells of the tissues. They are predominantly produced in the bone marrow of larger bones.

Erythropoietin, abbreviated to EPO, is a growth factor that stimulates red blood cell production. EPO can be produced biotechnologically and administered for kidney failure or after chemotherapy.

= Feline Odontoclastic Resorptive Lesion = degradation of the tooth by the body’s own cells which destroy the tooth.

The glomerular filtration rate (GFR) is defined as the volume of fluid that is filtered by the glomeruli of the nephrons of both kidneys per unit of time to produce primary urine. It is, therefore, the chief measure of kidney function. The rate corresponds to a mathematical value.

Abnormal increase in blood calcium due to a disturbance of calcium-phosphate balance. It can occur in chronic kidney disease as a consequence of excessive parathyroid hormone synthesis and subsequent release of calcium from bones (in bone resorption). Elevated calcium levels are also associated with bone tumours.

Increased phosphate in the blood.

Increased salivary flow, for instance due to inflammation and ulcers in the mucosa of the mouth.