Rats are particularly prone to urinary tract infections because their bodies are carried close to the ground and bacteria are present in large numbers on their underside and can often invade the urethra. Mostly, the rat can shrug off such an invasion, but if it is suffering from another condition, for example diabetes or is immune-suppressed it may not be able to and a urinary tract infection is the result. Some animals are born with a congenital problem in the urinary tract that leaves them predisposed to infections, in that there might be a blind loop or something similar which allows urine to pool and the bacteria to multiply. Also, the rat may be prone to kidney or bladder stones, which will give it an increased tendency to develop urinary tract infections.
What to watch out for
Rats are champion urinaters and it may be difficult to tell if there is any change in their output for that reason. They are also quite vocal creatures and often chunter away to themselves as they move about the habitat, so sounds when they are urinating, or trying to urinate may get lost in the background chatter. If the rat is behaving oddly, squatting frequently as if to urinate and squeaking or squealing as it does so, this may be a sign that it has an infection. When picked up, the rat may be damp around the perineum and also the bladder may feel distended, even when the rat has just squatted to void urine.
All rats smell a bit and their cages have a distinctive smell which some people find unpleasant. A cage belonging to a rat with a urinary tract infection will smell horrible to even the most devoted rat fan and this is something that is sometimes the clincher. If all of these signs are noticed, it is a good idea before taking the animal to the vet to check for any signs of bloody or cloudy urine. This can be done by examining the bedding or alternatively putting the rat on a clean tray; it will be urinating frequently and only a few drops are necessary to check the state of the urine. If some can be collected to take to the vet, that will save problems at the surgery.
Diagnosis of urinary tract problems
One thing the vet will do is check the urine for bacteria; this takes 24-48 hours to culture the urine and to identify the causative organism. Another cause of urinary problems is the bladder threadworm and the vet will need to check for that as antibiotics will have no effect and a vermicide will need to be administered instead. The vet will probably prescribe an antibiotic to be started straight away, to be adjusted when the cultures and sensitivities come back from the lab; with luck, the rat will already have been given the right one and can continue with the course. Sometimes more than one course is needed to completely clear the infection up.
Treatment and nursing care afterwards
Rodents suffer particularly badly if the antibiotic knocks out their normal gut flora and it will save problems later if the rat is given something to replenish the flora, such as yogurt or lactobacillus granules. Many rats like yogurt anyway, so this will be a welcome treat, particularly as it may be that the animal has a poor appetite. The owner should push fluids as the more that can be moved through the kidneys, bladder and urethra, the better the bacteria will be flushed out. The rat may try to ‘hold on’ to the urine as passing it will be painful; large quantities of liquid will prevent this and will stop the bladder silting up, particularly if the infection has been partially caused by a tendency to kidney and bladder stones and gravel.
Many people swear by cranberry juice to fight the symptoms and recurrence of cystitis and it works for rats also. It should not be given instead of water, but in addition. Its reason for being so helpful is not completely known but it is believed that it stops the bladder and urinary tract from being so ‘sticky’ and so bacterial and fungal spores cannot hold on to the walls and so are more easily flushed away. Whether or not this is the reason, it seems to work and if the rat will take it, it is a useful aid to a faster recovery. The rat will probably be in quite a lot of pain at first and the vet may also prescribe a painkiller. The rat will certainly feel a lot more comfortable if the bedding is kept clean and dry; the foul smell of the urine would probably mean that it is something the owner would want to do anyway. This must only be done if it does not stress the rat; stress can make urinary tract problems worse.
Prevention of urinary problems in rats
Prevention is always best done by making sure that the habitat is kept very clean and if a rat has an infection it should be kept away from others. Rats as they grow older often become less able to clean themselves and so elderly male rats should be inspected often to make sure that their penises have not developed a waxy plug which will make passing urine more difficult and bladder distension and possible reflux of urine into the kidney more likely. This can be cleaned away with a dampened cotton bud. Due to other conditions, rats occasionally suffer from diarrhoea and if they do, it is important to keep the whole back end clean; if the rat is feeling under the weather with any other condition, the opportunistic bacteria could easily infect the urinary tract and the animal would have few resources with which to fight it off successfully.