Rabbits can suffer from renal (kidney) failure just as humans can. Kidney failure may be either acute or chronic. Acute renal failure occurs suddenly and can be quite severe, while chronic kidney disease usually occurs and progresses slowly, and the signs may be somewhat non-specific (the rabbit just ‘isn’t herself’).
The kidneys are the abdominal organs which filter toxins out of the blood and produce a hormone (erythropoietin) which stimulates red blood cell production in the bone marrow. Toxins filtered out by the kidneys are excreted during urination, along with any excess water.
The causes of kidney failure are varied. With aging pets, kidneys may be the first major organs to slow down and lose enough functionality for symptoms of illness to develop.
Acute renal failure may result from shock, trauma, extreme stress, stroke, heart failure or infections, including pyelonephritis, wherein the kidneys become inflamed, usually due to a bacterial infection. Kidneys may also fail due to ingestion of toxins (certain medication overdoses or medications toxic to bunnies such as gentamicin, poisonous plants, antifreeze) or infectious diseases. A urinary tract obstruction (such as a kidney stone) or a urinary tract infection which has spread to the kidneys can bring on either the chronic or acute form of renal failure, as can any illness or injury which causes a lack of blood flow to the kidneys. High blood calcium levels (usually from a poor diet), fatty degeneration of the liver in obese rabbits, calcification of the kidneys due to excess vitamin D levels, and certain cancers can also result in kidney failure in the rabbit.
Rabbits with urinary (kidney or bladder) stones will have the usual signs of kidney disease but may also demonstrate difficulty and straining with urination, blood in the urine and signs of pain such as a bunched-up posture and grinding of the teeth. A urinary obstruction is a medical emergency and the rabbit must be seen by a veterinarian immediately.
Encephalitozoon cuniculi is a parasite that can also be responsible for renal failure in the house rabbit. E.C. can be transmitted through the urine or it can be ingested, and it moves from the intestines to the kidneys, brain, and other organs. Most commonly it causes neurological issues such as head tilt or paralysis, but it can also cause chronic kidney disease. You rabbit-savvy veterinarian can best advise you as to the best course of action/appropriate medications should E. C. be suspected as the cause of the problems.
Early signs of kidney disease may include increased thirst and urination as the compromised kidney function does not allow for adequate water to be retained by the body (pulled out of the urine). When this happens and more water is lost through urination, the body tries to prevent dehydration by increased water consumption. Litter box habits may decline at this point because of the illness. Other symptoms may include
- Loss of appetite (or bunny may continue to eat well)
- Weight loss, muscle atrophy
- Lethargy and weakness
- Constipation (from dehydration)
- Diarrhea (as toxins continue to build up)
- Difficult or painful urination if an obstruction is present (e.g., a kidney stone)
- Tenderness to touch over the area of the kidneys
- Urine scald
Obviously, the rabbit is not going to feel well. Toxins build up in the blood because the kidneys cannot filter them out. The bunny begins to feel nauseous and of course has no appetite. The compromised kidneys are not producing enough erythropoietin to stimulate the production of red blood cells, and rabbits with chronic kidney disease usually become anemic. Red blood cells carry oxygen to the body, so the lack of red blood cells makes the bunny feel weak and tired.
It is very important to get a proper diagnosis and begin to manage the kidney disease is before the bunny becomes very ill. The goal, of course, is to increase the quality of the pet’s life for as long as possible.
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