Potassium: important in maintaining normal heart rhythm.

Calcium: regulated with the aide of a hormone called calcitrol. Abnormal values in the bloodstream due to  high phosphorous levels leads to calcium deposits in kidneys and other organs.

Phosphorous: regulated with the aide of parathyroid hormone. High concentrations in the blood can cause a pet nausea.


Red blood cell production


The hormone erythropoietin is secreted into the blood stream by the kidneys, it travels to the bone marrow and stimulates it to create red blood cells. If a kidneys ability to secrete this hormone is impaired it can lead to anemia.


Chronic renal failure pathology


A pet will rarely be diagnosed with the actual cause of its renal disease, be it genetic predisposition, auto immune, infectious or as in most older pets, degenerative. No matter what the cause most pets will only start to show some symptoms of crf when their kidneys have lost the permanent or temporary function of approximately 75% of their nephrons. The loss of a nephron is permanent when it is replaced with scare tissue and can be temporary when its function is impaired due to inflammation. 


When the remaining nephrons can not keep up with the demand placed on them, a build up of nitrogen waste products in the bloodstream results. The brain registers the waste build up and tries to compensate by increasing thirst. More water taken in means more water excreted which flushes out the built up waste along with, unfortunately, important proteins and electrolytes. The result is muscle weakness, weight loss and paradoxically, dehydration due to excess urination.


The build up of waste products in the blood stream affects the digestive system as well. Ulcers can occur in the mouth, stomach and intestines. This causes the pet to vomit, lose its appetite and shed weight, sometimes at an alarming rate. The gums can also be affected so that any pre-existing periodontal disease (receding gums due to bacterial infection) will be aggravated.


High levels of phosphorous in the bloodstream causes the bones to release calcium into the bloodstream which can then inflame and mineralize parts of the kidney, further damaging them. High blood pressure due to impaired sodium ion regulation can lead to blindness.


Anemia eventually results from inadequate production by the kidneys of the hormone erythropoietin. This causes weakness as well as cold and exercise intolerance. 


Toxic build up  will affect the nervous system in a number of ways. It can cause the pet to become lethargic, agitated, confused and act strangely. Cats when suffering from central nervous system toxicity will bury their heads and cover their eyes with their front paws while lying on their stomachs'. Very high toxin levels will cause seizures.