Guinea pig anatomy: Urinary tract
This consists of 2 kidneys; the right is normally more forward than the left. Two tubes called ureters connect between the two kidneys and the bladder; from there a single tube, the urethra, connects to the outside.
The kidneys are multifunctional, because they have a number of jobs that they have to do. The kidneys are where the blood is filtered to remove the waste from metabolic processes, such as urea, uric acid and sodium. They have to re-absorb the water from these products to prevent dehydration, and also glucose and some minerals, such as phosphorus. They also ultimately have to deal with the products from any drugs that the guinea pig may have had.
The concentrated urine is collected in the bladder via the two ureters; it is then excreted to the outside via the urethra. This is a very basic description of the functions of the Urinary tract, as you can imagine, there are many complicated reactions and cycles that the kidneys do in order to complete the blood cleaning functions that they do non-stop.
The blood arrives to the kidneys via the renal artery; the kidneys themselves need a rich blood supply to provide the energy needed for these essential processes.
Guinea pig urine is normally creamy-yellow in colour, and is alkaline about pH 9. The urine may contain small crystals of ammonium or calcium compounds. This is what may cause a build up or stain in the guinea pig's run/pen/cage, removal of which can be helped with a solution containing an acid, such as vinegar.
What can go wrong?
(If you suspect your Guinea Pig is ill please have your pet examined by a Vet)
Increased Urine output (Polyuria)
This can be a symptom of a few problems:
- Cystitis - UTI
- Chronic renal failure
- Eating a large amount of fresh foods with diuretic properties causes transient Polyuria, e.g. Dandelions. Even stress incontinence in pregnant sows
Cystitis: or Urinary Tract infection (UTI)
This seems to occur equally between boars and sows. The guinea pig may squeal and strain when passing urine, and there may be blood in the urine (Haematuria).
Here it is maybe worth mentioning that Beetroot can stain the urine red, and carrots can make urine orange.
Treatment is antibiotics from your vet, usually Tribrissen (Trimephoprim and sulphdiazine). Borgal (Trimephoprim and suphadoxine) or a drug called Furadantin (Nitrofuration).
Alternative treatments: (please discuss these with your vet, these are to be used alongside any therapy that your vet may give you.)
Cranberry juice: Dilute 50/50 with water, and put in a small bottle next to the water bottle, so your guinea pig has a choice to drink from either. You can also use cranberry and raspberry juice mix. There is a substance present in cranberry juice that keeps bacteria from adhering to the walls of the bladder. Potassium citrate: (pot’ Cit) mixture from the chemists. A traditional treatment for human UTI’s.
Sludge, gravel and stones (Urilithiasis)
Guinea pig urine may contain tiny crystals of calcium, phosphates and carbonates, these generally cause no problems. But together with other substances and factors, such as compounds of oxalates, along with high calcium intake, incorrect balance of phosphates and calcium; or low water intake, these may form larger crystals.
A guinea pig with a kidney/bladder stone or gravel will adopt a hunched up posture, squeal on passing urine, there maybe blood in his/her urine, and be listless, loose appetite and interest in food. A large stone may be felt in the bladder, just in front of the genitals by running a finger gently over the area. The stones will also show up on x-rays. Along with the stones there may also be an infection, (UTI).
Treatment: Surgical removal of the stone/s and antibiotic therapy for any infection is usually very successful. Small stones or gravel may be dissolved if the urine is acidified e.g. Vitamin C, again Potassium Citrate may help by the citrate binding with the calcium rather than the calcium to oxalates. The citrates are water soluble therefore excreted.
Again, cranberry juice may help to prevent the situation getting worse and also may help prevent the formation of stones in the future. Remember to check this out with your vet and use alongside any treatment he/she prescribes.
It may be worth asking your vet about painkillers if your guinea pig is in a lot of pain. Remember the kidneys have to deal with any products of any drug your guinea pig is given, and this has to be taken into consideration. There is Metacam, a veterinary painkiller that is very good, also Buscopan (Butylscopolamine) which is very good for cramping colic type pain that can occur with Uroliths and UTI's
Acute renal failure
This is usually lethal, symptoms include drooling, tremors and general depressed state, occasionally a distinctive sweet smelling breath. Sometimes this is due to oxalic acid poisoning from over feeding with beetroot or beet leaves, spinach, mature dock stems, sorrel. Also household and garden chemicals, i.e. weed killer, slug pellets. This sort of poisoning is usually accidental, for example when the guinea pig escaping into the garden.
If you suspect any kind of poisoning from ingesting plants or chemicals, you must contact the vet immediately, take a sample of plant, substance and/or its container to the surgery with you. Manufacturers of any chemicals may also be able to advise, if your vet contacts them.
Chronic Renal Failure
This is often an illness in older guinea pigs, often known as the wasting disease. The guinea pig starts to increasingly drink more and more water, also urine output increases (polydipsia) causing a wet bottom and damp bedding which needs changing more regularly. As the disease progresses there will be loss of weight, depression and diarrhea.
This is not really a disease of the kidneys, but affects the kidneys and causes kidney damage. A diagnosis is usually by detecting sugars in the urine. The symptoms are increased water intake and weight loss, despite a good appetite. Sometimes guinea pigs with diabetes develop cataracts.
Treatment is usually by controlling the diet.