Life with Milo my diabetic rat by Nina Jensen

Milo came to me with his brother as a rescue at only 4 weeks old. They were big boys for their age and I would have guessed at them being 6 weeks not 4. They were lovely friendly boys who would snuggle up in my dressing gown and brux and boggle happily. They were very healthy boys who quickly grew into big cuddly lads.

The first sign that there was a problem was the water bottles going down very quickly and the cage being wetter than normal. I tested a urine sample from a puddle on the shelf and it was very high in glucose and I quickly saw that Milo was at the water bottle a lot. He lived with his friends in a Savic Royal Suite which is a very large cage and I was finding I had to do almost a full cage clean out every day including hammocks. We went to our vets and she did a blood test to see if it was a problem with his kidneys or diabetes and the diabetes was confirmed.

At first we tried to control it by changing his diet following a diabetic diet from the Scuttling Gourmet and the Fancy Rat forum but this was unsuccessful. He was losing weight rapidly despite eating loads, becoming more lethargic and generally looking unwell. He also had a couple of infections with one making us very worried about him as he looked so poorly.

As the diet alone didn’t work we started him on insulin, gradually increasing it each week and doing weekly blood tests at the vets to monitor his progress. At first I was terrified of hurting him but he was so good and after every injection he snuggled up for a cuddle and bruxed away until he went back to rejoin his friends. To inject I just had to pinch the skin up around the back of his neck, push the needle in, pull the plunger back to check there was no blood in the syringe and push the insulin in. Once I got used to it this was very easy to do. He had a bit of baby food after his injection as a reward and if he was on meds at the time they would be hidden in that too. We decided to do the injections in the morning as my vet wanted his blood tested 4 – 6 hours after the injection (so they were open for the blood test) and they all got their dried mix for breakfast. He was so good and always raced to the door in the morning for his insulin, cuddle and I guess for him more importantly his tasty baby food.

A few weeks later I noticed his eyes seemed paler and the vet confirmed the diabetes had caused glaucoma in both of his eyes and he was going blind. Being a pew his eyesight had never been good so apart from not making too many changes that would confuse him it didn’t really seem to affect him at all.

We were going to the vets every week to have his blood tested so I bought a human blood glucose monitor and after testing it against my vets for a couple of weeks I started doing them at home as it was less stressful for him and I could be more accurate with the timing. There was a bit of a difference in the readings so we adjusted the results I got from my monitor so it would correspond with the vets. Eventually we had our first normal blood and we were over the moon. He still drank a lot and I had to do a lot of cage cleaning but he was much more active and looked healthier.

After failing to get a blood reading for him I decided to take him to the vets to do it rather than stress him out by continuing to try at home. I’m glad I did as his result had shot right up again. Of course this was a lot later than the test would have been but it showed that we needed to increase his insulin injections to twice a day.

After that we finally got his diabetes under control and he only had issues when he got a infection as the diabetes made him susceptible. I just had to keep a eye out for any sign of illness and I tried to always change the water bottles at the same time each day so I could keep a eye on the amount of water that had been drunk. Changing the water at the same time each day is useful for all animals and has alerted me when other rats have developed kidney issues so they could get prompt treatment. I had stopped the blood tests by this point as he was stable and any sign of illness I would do a urine test. Later his drinking peaked again and after a test and conferring with my vet we agreed Milos kidneys had started to struggle a bit so we added ipakitine to his baby food and all was fine again. He had a few uti’s, an abscess and a few eye infections but all responded quickly to treatment.

As he got older he slowed down a bit but still seemed well and happy. In September this year he seemed fine in the morning but very ill in the evening. I did a blood test which showed his glucose was very high and raced to the vet. She did an ultrasound which showed a large internal mass and the decision was made that it was kinder to let him go. He went to sleep in one of his cubes and then passed away in my arms.

Milo was amazingly good natured and I am so proud of him. We don’t know why he became diabetic and his brother never developed it. It was hard work to start with but he was one of the most amazing rats who has ever owned me.
RIP Milo, you will always be missed.

Anyone who is facing this at the moment, try not to panic. I found the thought of having to inject him terrifying but once you get into a routine it’s not that bad. My life did revolve a bit around his meds time and there were a lot of vets visits initially but that all settled down. I also became extremely protective much to horror of a cover vet who thankfully forgave my snappiness when I apologised with a tasty box of choccies. Treats for his cage were mainly weetabix and some dog biscuits (packaging checked for no added sugar) and we stayed on the diabetic diet from the Fancy Rats forum. To save some money I bought his needles and later the ipakitine online from reputable stores but the insulin always came from the vets as it doesn’t travel well. I am not a vet so cannot tell you what is for the best but am just sharing my experience of a very special boy.

Pet dog insurance vets bills and more

If you ask some dog owners why they have pet dog insurance, the most common response may be ‘to provide financial cover’ in the event that the dog falls ill or is in an accident and needs medical treatment.

Vets fees can be extremely expensive and if your pet has to have surgery for example or needs ongoing treatment, then looking at costs, which could run into three or four figures, may cause financial worry.

So, even though it may not provide cover for things such as regular vaccinations, neutering and the like, pet dog insurance may provide an invaluable financial support.

While vets fees may obviously be an important consideration for your pet insurance, they are really only a part of the whole story.

There are quite a few other ways where having pet cover may help you avoid significant expenditure or loss.

To consider just a few situations:

  • with just a couple of days to go before your holiday, you pet is taken ill and needs emergency and life-saving treatment. In this situation, in addition to the cost of the treatment, you may also be facing the prospect of cancelling your holiday at short notice;
  • your pet dog disappears, so you advertise and offer a reward for its safe recovery;
  • you or a close family member, have to go into hospital and there is no one around to care for your pet;
  • your dog causes injury to a third party or damage to their property.

You may find that there is pet insurance that can provide financial assistance in any of the above situations (and others).

Cheapest pet insurance

If you have more that one pet, you may understandably be on the lookout for the cheapest pet insurance.

You may find that the price may be linked to the level of cover offered, so while one policy may be cheaper than another it may not offer the cover that you are looking for to provide complete peace of mind (in other words, what is cheap pet insurance for one person may not be for another).

However, if you opt for cover where you receive a discount for insuring your other pets as well, you may find that this might reduce your pet dog insurance premium costs.

Mum rats refusing to feed their babies

Question: I have a litter of ten baby rats, born on Thursday or Friday. Their mother is avoiding them. I’ve been trying to hand feed them all night, but they just won’t feed from me. I’m terrified that they’re going to die. If you can offer any advice, I’d be really grateful.

Answer: Feed lactol which is a small animal / kitten milk, from a pipette; cotton bud; or rubber glove finger pierced at the end. When taking milk, if they open their mouths really wide, this means they are enjoying it. If milk comes out of nose, then stop – you could choke or drown their lungs.

After the baby has eaten / drunk, stimulate their genitals in order to make them pee and poo. Use a warm cotton bud and rub it over their bits (this is what their mum would do to make them go to the loo).

Once that the rat’s eyes are open, start feeding mushy foods plus the milk, Weetabix, baby food etc

If you are a member of a Rat Club or, see if anyone has a foster mum that can feed the babies. Try rescues in your area as they may have new mums in too.

Baby orphaned wild rats

We do get a lot of people contacting us re: caring for wild baby rats that they have found.

Babies are born hairless with their eyes shut and will open their eyes at around 14 days.

Keep them warm and safe in a cage with narrow bars or a well ventilated tank, away from any other household pets.

In the early days, feed lactol which is a small animal / kitten milk, from a pipette; cotton bud; or rubber glove finger pierced at the end. When taking milk, if they open their mouths really wide, this means they are enjoying it. If milk comes out of nose, then stop – you could choke or drown their lungs.

After the baby has eaten / drunk, stimulate their genitals in order to make them pee and poo. Use a warm cotton bud and rub it over their bits (this is what their mum would do to make them go to the loo).

Once that the rat’s eyes are open, start feeding mushy foods plus the milk. Weetabix, baby food etc

Then introduce traditional rat food with cereals thrown in as well as seeds to accustom them to a wild rat diet. Put mealy worms in some spoil to encourage them to dig for wild food.

Some people do go on to keep their wild rat and tame them. Others will release them somewhere safe at around 6 weeks.

If you need further help, please email ENSURING you state whereabouts you are in the Country.

Dental disease in Exotic Small Mammals

At our Practice we see a large number of small mammals with symptoms of dental disease both as first opinion cases and as referrals from other practices. This article deals specifically with dental disease in Chinchillas (Chinchilla Langier). Degus (Octodon degus) and Guinea Pigs (Cavia porcellus).

The most common presentations include weight loss, anorexia, cachexia (chronic wasting), excess salivation (slobbers), small faeces or absence of faeces. An ocular (eye) discharge or a discharge from the nose may also be evident. The incisions (front teeth) are commonly overgrown and there may be a history of repeated burring or clipping of these teeth as an attempted treatment for the anorexia. On careful palpation the jaw of these presenting animals may be irregular and painful. Sometimes the animal will grind its teeth, a sign of pain in these species. There is often a poor dietary history which will be addressed later.

One of the most important points to stress is that a detailed oral examination of a conscious small mammal is nigh on impossible. This is especially true of the species dealt with in this article. Guinea pigs often have food in their mouths at the time of examination (in fact if they don’t it is a worrying sign), chins and degus resent oral examination vigorously. Anaesthesia is often required to thoroughly examine the oral cavity and this allows the clinician to perform skull radiography, arguably the most informative diagnostic tool in small mammal dentistry. This is because most dental disease processes in exotic small mammals are concerned with the tooth “roots” which are encased in bone and therefore not visible on a dental examination. In fact, many animals with severe dental disease have mouths that look essentially normal on casual examination of the anaesthetised patient.
Dental Anatomy

Guinea pigs, chinchillas and degus have the dental formula of 2 x I 1/1 C 0/0
P 1/1 M 3/3 (where I = incisors, C = canines, P = premolars and M = molars). The premolars and molars act as a functional unit to grind food and the incisors are used for prehension and cutting of fibrous foodstuffs. All teeth grow continuously. There is no true anatomical root. The lower (mandibular) cheek teeth are arched toward the tongue and overgrowth can lead to tongue entrapment. The upper (maxillary) cheek teeth are angled outward (laterally). Angulation of the teeth provides an effective surface for grinding thin fibrous food material and when eating this high silicate foodstuff, rapid tooth wear occurs and new growing tooth replaces the wear caused by grinding. In the wild these animals spend a long time eating low quality grasses which are high in silicates (the precursors of glass). This continual grinding prevents overgrowth of the teeth.

Diet and dental disease

Captive bred specimens are larger than their wild counterparts and it is established that a proportion of cases of dental disease can be attributed to genetic causes. However, by far the most cases of dental disease in Guinea pigs, chinchillas and degus results wholly or in large part from inappropriate diets. Specifically a lack of dietary fibre is implicated. Most modern “complete” diets are complete in that they contain adequate protein, carbohydrates, fats and trace elements. However, their sole use leads not only to problems with obesity but also does not allow these animals to spend the large amount of time chewing and wearing their molar teeth that they require to grind down their continually growing back teeth. This can lead to spur formation and entrapment of the tongue by the diagonally growing lower molars. This can be picked up and treated by a detailed examination of the mouth. All the time however, a more sinister development is occurring which is all together more difficult to treat.

If less time is spent chewing, the exposed parts of the teeth elongate. This puts pressure on the teeth which slows eruption, but tooth growth continues at a slow rate. Essentially what happens next is that the cheek teeth grow backwards, invading the structures of the skull. The teeth can grow into the nasal sinuses causing respiratory infections or towards the eyes causing weepiness. The lower teeth invade the jawbone causing bony changes and sometimes abscess formation (common in rabbits). The net result of this growth is that the mouth is progressively forced open. The front teeth elongate as they do not meet any more and becomes progressively more difficult for these animals to eat (try swallowing with your mouth open!). This leads to the condition known as slobbers where saliva spills onto the skin often causing a fetid smell. Clients often notice this and the fact that the incisors are growing and present these animals for incisor trimming. In fact the incisors are growing because they are not meeting as a result of the mouth being forced open by the overgrown back teeth. Skull radiography is the only way to accurately quantify if this has occurred and to what extent. All too often, animals are referred to this practice with histories of repeated anaesthetics with no radiography performed.


To sum up, difficult at best. Most presented cases have advanced disease. Aggressive burring of the cheek teeth may be attempted. If abscesses have formed, these need specific treatment. Eye infections require antibiotics. Otherwise force-feeding and anti-inflammatory drugs are required. Quality of life needs to be assessed on a regular basis and weight monitoring with faecal output are useful indicators of appetite. The liquid anti-inflammatory drug meloxicam (Metacam: Boehringer Ingleheim) is well tolerated in these species. It has the advantage of being very palatable (it tastes like honey) so is well accepted also. Often patients require life long treatment. Secondary problems associated with anorexia (e.g. intestinal stasis where the guts shut down and stops moving) also need to be addressed. Often euthanasia is required in patients that fail to respond.


As always, better than cure. The diet of these animals needs to resemble their diet in the wild. They are not like dogs and cats that get a bowl of food twice daily and that’s it. Their anatomy and physiology is specifically set up to deal with ingestion of large quantities of lower quality foodstuffs in order to meet their nutritional requirements. This means lots of good quality hay. Timothy hay is usually the beat. The fibre requires lots of chewing and keeps the intestines moving which is essential for health. 1 to 2 tablespoonfuls maximum of concentrate mix is the recommended daily allowance; the rest should be good quality hay with occasional treats. Offer the hay in a hayrack to prevent contamination with faeces. This also provides environmental enrichment, as the animals have to work a little harder for their food. Twice yearly veterinary checkups allow careful palpation of the cheek teeth. Also monitor weight and faecal output on a regular basis so that any symptoms can be managed early in the course of disease.

Pictures courtesy of Mark Rowland

Normal Chinchilla and Degu showing roots of molar (back) teeth
in normal anatomical position :



Degu and Chinchilla with elongation of roots of molar teeth forcing mouth open causing the front teeth (incisors) to overgrow as they no longer meet :



Slobbers (excess salivation) in a Guinea pig:


BSAVA Manual of Exotic Pets 4th edition
Hillyer, Quesenberry: Diseases of Ferrets, Rabbits and Rodents 2nd edition
O Malley: Clinical Anatomy and Physiology of Exotic Species
Carpenter: Exotic Animal Formulary 3rd edition

About the Author

Mark Rowland BVSc cert Zoomed MRCVS is in practice at: Trinity Vet Centre, Hermitage Walk, Hermitage Lane, Maidstone, Kent, ME16 9NZ. He is an Exotics specialist with a soft spot for chinchillas.

Vet Rat Respiratory Guide

Written by a vet and for vets, the Guide discusses various causes of the disease as well as suggests proven treatments.

Over the last ten years’ one of the most common questions we, as a high profile pet rat rescue, get asked about is the treatment of respiratory disease in rats. This Guide is a combination of our experience and our vet’s expertise.

To date there has been very little information available about respiratory disease, so we felt the need to share our vet’s knowledge in order to help reduce the amount of unnecessary deaths and suffering caused by this sadly very common illness.

You can download a free copy of the guide to print off and give to your vet to give them some other ideas in the treatment of respiratory guide.

You can download a PDF version of this report to either email or print off for your vet here

For a laymans version of this guide please visit Rat Respiratory Guide

Safe And Healthy Bedding For Rodents

Since we humans have domesticated animals, we owe them a debt of responsibility. Through domestication, we have made them utterly dependent upon us for their health, care, feeding and general living and life-style conditions. It is thus of paramount importance that we afford them the same respect, and care that we would our own kind.

Rodents, by virtue of their size are especially vulnerable. Unlike cats and dogs, who can roam around the house and yard at will, most rodents (pet or laboratory) are kept in confined spaces in cages. Their natural range is thus very restricted. As such, the bedding that they are kept on is the only substrate that they will know for the duration of their short lives. Not only should this bedding be kept clean and changed at very regular and frequent intervals, it should be appropriate for the species concerned.

Most bedding materials are derived from wood shavings. This was acceptable until recent times when it was established that the phenols and resins contained in pine and cedar are especially deleterious to a rodent’s health. These two woods are the most widely used in pet bedding since they are relatively inexpensive and easy to come by.

This discussion intends to give an overview of the most appropriate bedding to use for rodents. It will also give the reasons why the use of pine and cedar woods (except under exceptional circumstances) should be discouraged. It is also intended that this discussion will give recommendations for rodent bedding.

Disadvantages of Softwoods as Bedding

Pine and cedar woods are generally known as softwoods. They are most often used because they give off a nice smell and have a clean look. However, they contain relatively large amounts of phenols and resins which are volatile (evaporate easily), aromatic (with a pleasant aroma) hydrocarbons (large, ring-like chemical structures with a lot of carbon in them)4,6. They are caustic, poisonous, acidic compounds present in these softwoods and can cause liver and kidney damage in rodents, rabbits, cats, dogs, and humans. They are what make disinfectants cover smells and cedar and pine shavings cover the smell of animal urine12. These phenols interact with the liver and respiratory system in the body, potentially producing unwanted and harmful side-effects9.

The effects of cedar and pine on the respiratory system is clear, and well documented through several years of scientific research: the natural chemicals present in softwoods can damage the respiratory tract, leading to chronic respiratory disease and asthma. Although most of this research describes the effects of wood products in humans, it should be noted that the effects are likely to be more pronounced in small animals, who have a much greater sense of smell, and are therefore more sensitive to respiratory irritants9. They will also be spending all or most of their lives on this bedding, unlike humans whose exposure to these irritants is mostly transitory.

The primary irritant in cedar is plicatic acid, present in highest concentrations in western red cedar. Although the mechanism is not fully understood, plicatic acid has been shown to cause asthma, and inflammatory and allergic reactions after long-term exposures. The natural irritant in pine, called abietic acid, also exhibits allergic responses, though these are much weaker than those induced by plicatic acid. However, the oxidation of abietic acid does form compounds that are rather potent allergens9.

The acids given off by pine and cedar shavings are very damaging to the respiratory tract. These acids can actually destroy cells that line the lungs and trachea1. This has significant implications for rats since the most common diseases in pet rats are respiratory infections. Many owners of pet rats have reported the improvement of respiratory problems when they have switched their pets to a sort of bedding other than pine or cedar shavings4.

Since phenols are caustic, their direct connection to respiratory problems and pneumonia in rats, mice, and guinea pigs is clear. The constant irritation to the nasal passages, throat, and lungs gives harmful bacteria an easy opening. Phenols also affect organs such as the liver and kidneys because these organs are responsible for filtering blood and urine and eliminating toxins from them. While the kidneys and liver can handle a small amount of toxins, when they are presented with a large amount over time, they are unable to filter it all out and begin to fail. In addition, a rat or mouse with a damaged liver will have a depressed immune system, which can lead to more common “old age” symptoms such as respiratory and pulmonary infections11.

Pine and cedar toxins affect more than the respiratory tract4. Several studies5,8,14,15 have shown that rodents kept on softwood beddings have elevated levels of liver enzymes. The liver is the body’s detoxification system, and elevated liver enzymes indicate that the body is working harder to eliminate toxins. In mice these enzymes started rising after only 24 hours exposure to cedar shavings and only returned to normal when the mice were away from the shavings for 12 days14. If pine or cedar shavings are heat-treated or soaked in a solvent, so that some of the phenols are removed, the effects are not as great, but still occur14,15.

One of the early medical studies of softwood beddings and hepatotoxicity found a connection between the use of red cedar, white pine, and ponderosa pine and changes in both barbiturate sleep time and the activity of liver enzymes14. The researchers proved that the length of barbiturate sleep time (the amount of time a mouse or rat stays “out” when under a controlled dose of anaesthesia) was inversely proportional to the level of enzyme activity in the liver (i.e., that sleep time decreased as enzyme activity increased). This inverse ratio occurs because the hepatic enzymes control the metabolism of the barbiturates. In an attempt to deal with the toxin (phenols, in this case), the liver produces more enzymes and hence, wakes the mouse up sooner. This study determined that softwood beddings alter the liver’s activity in response to drugs significantly enough to suggest that such beddings not be used for animals in pharmacological experiments for fear of skewing the results.

Another study goes even further. It concludes that rats and mice kept on four bedding types were affected most by red cedar, but that white pine was the next most hepatotoxic bedding. In fact, “sleep times of C57BL/6J male mice on each bedding were significantly different in the following order: mixed hardwood > white spruce > white pine > red cedar. In both strains, liver:body ratios of mice on red cedar bedding were significantly increased compared to mice on white pine, white spruce, or mixed hardwood beddings”2. Mice kept on mixed hardwood bedding slept an average of 135 minutes, while those on cedar slept an average of 56 minutes. Mice housed on white pine slept an average of 85 minutes—between the other two sleep times, but closer to the sleep time of cedar than that of hardwood. Enzyme activity was significantly increased in cedar and pine mice and their livers were heavier (i.e., more greatly damaged) than those mice kept on hardwood. It is important to realize that the level of hepatotoxicity noted here was induced by only 24 hours to 5 days of exposure to the beddings in question.

Several people have claimed that their pet rodents have always been kept on pine or cedar with no adverse effects. However, animals with elevated liver enzymes do not show any symptoms, and unless these animals received full autopsies at death with no sign of enlarged livers or liver dysfunction, respiratory infection, or altered immune system, how can they claim that the pine or cedar did not affect them?4

Recommendations for Alternative Beddings

In the light of the above, it is recommended that rodents are housed on alternative bedding materials. However, this is not always possible due to availability. At the University of Cape Town Medical School Animal Unit in South Africa, South African pine wood shavings were used. The Pinus spp. used were either of the P. elliottii, P. patula and P. taeda species. These were untreated with pesticides and obtained directly from a factory. Upon arrival at the university, these shavings were autoclaved at 121°C for 15 to 20 minutes. After this, the wood was thoroughly dried in a hot air oven at about 100є C for up to an hour. This was said to both sterilise the bedding as well as to remove any phenols and resins it might contain.

Some claim that pine shavings which are heat-treated are safe because the heat drives off the toxins. There are currently products being sold, notably All-Pet Pine, Feline Pine, and Pine Fresh, in the United States that claim to be free of toxins. However, the studies in references 14 and 15 found that heat treatment did not remove all the toxins from the wood. Heat-treated shavings still caused a rise in liver enzymes in rats and mice4.

The Humane Society of the United States (HSUS) specifically states in their Foster Volunteer Handbook7, that cedar wood should never be used. They further recommend that bedding should be clean, dry, non allergenic and absorbent, non-abrasive, non-allergenic, dust-free, non-toxic and at least three inches deep. Bedding should also be inedible, free of pathogenic organisms, and be able to control odour3,6.

As far as woods are concerned, it appears to be unanimous that the most appropriate wood is Aspen. Aspen is one of the most widely distributed tree species in the British Isles13. It is present over most of the mainland and on the main offshore island groups such as the Hebrides, Orkneys and Shetlands. Aspen is also well distributed in Ireland. In England, aspen is generally a tree which is associated with heavy clay soils, often in conditions where water-logging occurs. In places it forms dense stands up to about 60m in diameter but generally it is present in smaller isolated thickets12. There is thus no reason why Aspen woods should not be used in the UK.

Failing that, spruce may be used. This is a relative of pine but with lower phenol content.

Shredded cardboard seems to be one of the cleanest and easiest to use beddings and is also the most environmentally friendly as it breaks down nicely in the compost. Shredded cardboard is dust free, absorbent and cheap to use. It can be bought from a number of companies. EcoPetbed® may be bought by the pallet load or Finacard.
Paper-based cat litters may also be used. The main ones are Yesterdays News® and Biocatolet® paper based cat litter. All are recycled paper and are dust extracted and state on the packaging that they are suitable for small animal bedding. If rats are kept in a “living room” environment, they are cleaner and less aromatic than shavings. These are apparently the only safe paper-based beddings that should be used for rodents.
Other alternatives are Megazorb®, which is made from virgin wood pulp and is deemed to be safe for rats and Hemcore® which is hemp bedding10.


This author would not recommend that newspaper ever be used for rodent bedding under any circumstances. First and foremost, the inks used in the printing are toxic to rodents. Secondly, the colours will stain the coat which will be licked, thus internalising the poisons. It is suggested that their bedding should comply with the recommendations set out above. It is further recommended that the rodent housing is not left bare, but that additional nesting materials are provided. Materials such as hay, alfalfa, Safebed Paper Wool® should be included in the housing in order to supply the rodent with a semblance of environmental enrichment as well as a means whereby to follow the natural instincts of nest-building. Whatever the bedding used, it must follow the guidelines in this report, so as to ensure longevity, health and a sense of well-being in the rodents that will be housed on it.


The author wishes to thank Debbie Ducommun of the Rat Fan Club and R.A.T.S, Chico, California, United States of America for her permission to use her materials and for the work she has done in promoting the welfare of domesticated rats.

01. Ayars, G.H., Altman, L.C., Frazier, C.E., and Chi, EY.;1989; The toxicity of constituents of cedar and pine woods to pulmonary epithelium; Journal of Allergy and Clinical Immunology; 83: 610-18
02. Cunliffe-Beamer, T., Freeman, L.C. and Myers, D.D.;1981; Barbituate sleeptime in mice exposed to autoclaved or unautoclaved wood beddings; Laboratory Animal Science; 31 (6): 672-675.
03. Daly, C.H. (DVM); 2002; Rats A Complete Pet Owner’s Manual; Barrons; New York.
04. Ducommun, D.; ©1999-2002; The Toxicity of Pine and Cedar Shavings; The Rat Report;; Retrieved on 28 Apr 2007
05. Ferguson, H.C. (1966) Effect of red cedar chip bedding on hexobarbital and pentobarbital sleep time. Journal of Pharm. Science, 55 p.1142-8
06. Harkness, J.F. and Wagner, J.; 1995; The Biology and Medicine of Rabbits and Rodents, fourth edition; Lea and Febiger; Philadelphia.
07. The Humane Society of the United States (HSUS); Foster Volunteer Handbook, A Reference Guide for Rabbit/Small Mammal Foster Care Volunteers;; Retrieved on 4 May 2007
08. Jori, A. et al.;1969; Effect of essential oils on drug metabolism; Biochemical Pharmacology; 18: 2081-5
09. Safe Pet Bedding (FAQ); Originally created and posted by Emily Rocke;; Retrieved on 4 May 2007
11. TeSelle, E.R.; 1993; The Problem with pine: a discussion of softwood beddings;
AFRMA Rat & Mouse Tales News-Magazine, July–October 1993; American Fancy Rat and Mouse Association;; Retrieved 8 September 2007
12. Trees for Life;; Retrieved 9 September
13. Perring, F.H. and WALTERS, S.M.; 1976; Atlas of the British Flora. Botanical
Society of the British Isles. Second Edition; Wakefield
14. Vesell, Elliot S. (1967) Induction of Drug-Metabolizing Enzymes in Liver
Microsomes of Mice and Rats by Softwood Bedding. Science, 157:1057-8
15. Weichbrod, Robert H. et al, (1988) Effects of cage beddings on microsomal oxidative enzymes in rat liver; Laboratory Animal Science; 38 (3): 296-8

Author : Colleen McDuling, B.Sc(Med.Hons), MSc(Med.Sc.), Animal Behaviourist

Scientific Representative of the South African Rat Fan Club.

Signs of illness in rats

Most people are aware that red staining around a rat’s eyes or nose (which, although it looks like blood, isn’t) are a sign of stress and / or illness.

However, just because a rat doesn’t have these tell-tale signs that all is not well, it doesn’t mean that he is 100% fit and healthy.

You may be surprised to learn that rats can be quite stressy creatures and, like humans, stress can lower their resistance to disease and make them more susceptible to infections. Baby rats, in particular, can get stressed as they go from the warm confines of Mum in to a strange tank with their siblings. As you can imagine, it can be quite frightening for them!

This means that some can develop respiratory infections as the stress takes hols. Left untreated, these infections can cause permanent damage to the rat’s respiratory system, especially their lungs, meaning that they will more than likely become very ill as time goes on and eventually die from a painful death.

An infection caught early and treated appropriately – a rat normally responds well to medication – means that he should go on to live a long life.

So what other signs do you need to look out for?

First of all, the red staining (which is called porphyrin):a little bit first thing in the morning is okay – it’s a bit like us when we get up and have sleep in our eyes. However, a lot of staining and ongoing is a cause for concern.

Secondly, look at the rat’s fur. His fur should be smooth and soft. If it is “staring” (which is the posh word for fur that is sticking up), then this means that he really isn’t well.

Look at their breathing. When he breathes, just his sides should go in and out (rats do breathe quite rapidly by the way). If his whole body moves – you may see his head move as he breathes – this means that he is struggling to breathe, a bit like when you or I have a heavy cold.

When holding him, listen to him. Rats shouldn’t make any noise that is audible to a human unless he is playing / fighting with another rat when you’ll hear a succession of loud squeaks! If you can hear a slight noise, a gurgle or a little squeak as he breathes, then he needs veterinary treatment as this is indicative of respiratory problems.

As another point, rats don’t ‘hiccup’. So if you see a rat ‘hicupping’, he isn’t. This is also a sign of a respiratory infection.

Finally, do check that any rat in your care is playful. Rats that sit hunched in a corner or don’t socialise with their friends and are very ‘quiet’ aren’t right. As example, four years ago we got Kolin from a local branch. He was listless and didn’t seem as boisterous as his cage mates. However, to someone who hasn’t seen thousands of rats over the years like we have, he would have looked well.

An x-ray revealed that Kolin had a tumour in his immune system. Of course, no-one would have known this as he looked so well, but by watching young rats’ behaviour and learning what is normal and what isn’t can go a long way to seeing when a rat is suffering.

Luckily, an amazing combination of medication kept Kolin well and happy and he lived to the grand old age of 2 and half years old, meaning that caught early enough, illnesses can, in a lot of cases, be successfully treated or controlled.

Rodents and Rabbits in Research

Why focus on these animals? Well, worldwide trends have shown that they are the most abused in the name of science. The general statistics are as follows:
Rodents = 87%!!!

67% = Mice
18% = Rats
2% = Others

Rabbits = extensively used in the past.

The “Others” are represented by hamsters, guinea pigs, gerbils, chinchillas and other rodents who really form a minority.

If we consider that around 3,000,000 animals are used in the UK alone, the rodent fraction translates to a whopping 2.5 million animals used each year. What about the rest of the world?

Some Common Uses of these Animals

  • Mice LD50 for cosmetic Botox
  • Mice Most genetically modified
  • Rats Toxicology studies
  • Rats Academic papers/teaching
  • Gerbils Stroke research, epilepsy
  • Hamsters Dental caries research
  • Hamsters Cancer research
  • Guinea pigs Vaccine testing
  • Rabbits Immunology
  • Rabbits Pyrogens, Draiz

The Common Rationale for using these Animals:

  • Small
  • Easily housed
  • Reproduce fast – a rat can give birth every 28 days! A hamster’s pregnancy lasts for only 16 days!
  • Short lifespan – rats live up to three years. Mice and hamsters live for between 18 months and two years”
  • Vermin!
  • Cost effective
  • Social reasons – less public objection, and less public sympathy.

And yet, they feel pain and suffering no less than the larger animals people always focus on. They are no less important than the cats, dogs and primates that people always seem to find sympathy for.

Animal Behaviour

Let us take a closer look at these animals and look at their behaviour, and get to know them better. Now, by way of explanation, ethology is the scientific study of animal behaviour in the natural environment. So, when one wants do study animal behaviour, one lets the animal roam around in a state of unrestricted freedom, and observes carefully what the animals are getting up to. So, ethology is considered to be a science.

These rabbits and rodents are sentient beings. This means that they have the capacity to feel. They are capable of feeling pain and suffering. In addition, they can feel mourning and loss. When a few of them have formed a close bond, when one of that small group dies or is taken away, there are clear signs of depression amongst those who remain. They don’t eat, lie listlessly, and sniff around for the deceased one. All of these animals, rodents and rabbits, are capable of showing affection to other members of the group, and to human beings as well.

Altruism is the capacity to show compassion, and science has revealed that this is the case. Most stories are anecdotal, however this compassionate behaviour has been seen over and over again.

In Hans Ruesch’s Slaughter of the Innocent, he mentions two incidences where rats have been seen to demonstrate this altruism:

“When rats discover poisoned food morsels, they cover them with their faeces, to warn other less perceptive members of the community.”

“A British miner once saw two large rats proceeding slowly along a roadside, each holding one end of a straw in its mouth. The miner clubbed one of them to death. To his surprise, the other rat didn’t move, so the miner bent down to observe it more closely. It was blind and was being led by the other.”

Father mice, and father Siberian hamsters will go to great lengths to retrieve the young if they have strayed from the nest. Sometimes, they put their own lives in danger.
Astra and Michaela were two very old, frail and unrelated rats in my study group. They formed an extremely close bond, and would look after each other. For instance, they would bring food to each other, and try and rearrange the bedding that they slept in. When Astra died, Michaela lost the will to live herself and died within two weeks.

Rabbits assist other species. It has been well documented that rabbits will try and assist an injured bird.

Most of these animals are highly gregarious and have communal living arrangements. An exception to this rule is the Syrian Hamster who must live alone and does not tolerate company. Those who live communally form peaceful, functional societies, which ensure equal opportunities between the sexes. General law and order is observed where the elders are respected and the young nurtured. This is especially true of rats who where the subjects of a massive study undertaken by Lore and Flannelly, and published in Scientific American in 1977.

Rodents and rabbits are highly intelligent. They have a large capacity for learning, and are capable of complex problem solving. They have a high need for mental stimulation, and do not like to be neglected or left in barren living quarters. They are very active animals. If you have ever kept mice, you will see just how busy they can be. A Syrian hamster will run for about 10 kilometres in one night on his/her search for food.

Communication forms an important part of their social structure. Most of the time, they communicate in ultrasound. These are sounds which our human ears cannot hear. It is said that ultrasonic communication is an evolutionary adaptation to prevent these small and vulnerable animals from being detected by predators. In his behavioural studies on rats, Professor Jaak Panksepp, Distinguished Research Professor of Psychology, and Professor of Psychiatry at the Bowling Green State University of Ohio, USA, discovered that rats emit ultrasound (sounds not heard by human ears) during play that is the equivalent of human laughter. They also emit these sounds whenever they are played with by humans. Professor Panksepp said: “Our work shows that rats are highly emotional creatures, with some basic feelings similar to our own. Few people realise how emotionally sophisticated these little guys are. The scientific world has vastly underestimated their emotional capacities. . . things that you can only see once you have become friendly with them.”

Other studies by Holy and Guo at Washington University in St. Louis, USA have revealed that male mice sing songs to female mice in order to woo them or to attract them. This is very similar to human men singing love songs to their lady friends!
Play and grooming forms an integral part of the daily routine. It is seen to be a method of communication and grooming reinforces the bond between animals.

These animals are fastidiously clean. In the wild, and if kept in captivity, they will have distinctly separate nest and ablution areas, and areas in which food is stored. They spend a large amount of time grooming themselves and each other. This accomplishes two things at the same time – bonding and cleaning. They like to have clean nest materials, and rapidly push out any dirty or soiled nesting. They will avoid excrement.

Their Biology and how it Differs from Ours

Physiological differences are important. It would appear that their immune system is far more sophisticated than ours. Very often rats live in sewers because they cannot find anyplace else to live that is away from predators. Their immune system has to be very good to cope with such an environment.

Rabbits and rodents do not have a menstrual cycle. They have an oestrus cycle. When we humans are not impregnated, our uterine lining comes away in the process of menstruation. This does not occur in these animals. If they are not impregnated, they simply resorb the uterine lining – a very conservative process. And yet, rodents have been used to test human female contraceptive and other drugs. No wonder we get such bad side effects!

Obesity in these animals is extremely rare. The vivisectionists make them obese by genetically engineering them, or feeding them huge amounts of unnatural foodstuffs, mostly fat and carbohydrate. Or they make them obese by manipulating their metabolisms. If obesity is not natural in these animals and is artificially induced, how can they be ideal models on which to study this condition which is so problematic in humans?
Rats and mice naturally produce protein and ketones in their urine. If this was seen in humans, it would be highly indicative of pathology. Most likely of renal damage and diabetes mellitus type one respectively!

It is also important to understand a bit about the pharmacology and biochemistry of these animals. Pharmacology is the way in which drugs are dealt with by the body. Biochemistry is the natural functioning of all the chemical reactions in the body.
Penicillin was discovered by Fleming and later purified by Florey. Florey had to test this new drug, and so he chose rats and mice. In these animals it proved to be OK. Had he have tested it on hamsters or guinea pigs, it would never have been marketed. It is lethal in hamsters and guinea pigs. Now here we have four rodents. In two it is OK, and yet it kills the other two. Note the vast differences in such a closely related group of animals. Not even the rat and mice studies on penicillin could predict the idiosyncratic reactions in humans where some people can tolerate the drug and yet others are highly allergic to it and it can kill them!

All mammalian livers produce a substance called glutathione. Now, humans use this glutathione in cases of crisis such as when they have taken a huge drug overdose – a drug such as paracetamol. Rodents use this glutathione all the time.

Aspartame is an artificial sweetener that has been used in over 6000 foodstuffs throughout the world. It was passed by the authorities as being safe for human consumption. It has not at all been linked with any form of cancer in humans. However, in rats, it causes lymphomas and lymphoid leukaemias.

Aspirin is safe in humans and does not cause birth defects. However, right across the spectrum of rodents, it causes birth defects.

Cortisone is safe in rodents, yet in humans it causes cleft palate in the baby if used in the first trimester of pregnancy.

Let us go into pathology briefly. This is the study of disease. Humans and animals differ greatly in the diseases they get. Their diseases are not our diseases and vice versa. For instance, humans get Parkinsonism. This does not occur in rodents or rabbits at all. These vivisectionists have to induce it in them. They cut a hole through the skull, and get into the brain of the animal and damage it either chemically or physically. The animal gets a quasi-Parkinsonism that is in no way like the natural Parkinsonism seen in humans. And, these vivisectionists expect to learn something about the human condition. It does not make sense.

Cancer is virtually unheard of in these animals unless they are old or their immune systems have broken down. And, their cancers are not our cancers. But they are very often the animals of choice in whom to study cancer. They have human cancers implanted onto or into their bodies. Once the human cancer is implanted it loses a lot of the characteristics it would normally have if left on a human.

Leading causes of natural death between humans and animals are vastly different. In humans the leading causes of death are heart disease, cancer and stroke. Now, in a hamster, for example, the leading causes of natural death are nephrosis, wet tail and amyloidosis.

These animals have been manipulated to suit science. Nowadays you can get rodent and rabbit strains. So, for instance, you don’t just get rats, you get the Fisher rat, the Sprague-Dawley rat, the Wistar rat, the Long-Evans rat, the obese rat, the diabetic rat, and the list goes on. The pharmaceutical industries are cashing in on this, because just by using a specific strain of animal, they can get any result they want, and thus get their drug onto the market. These animals have been tailor-made to maximize profit.

The mouse is the most genetically modified animal on the planet. These mice may look like mice, may sleep like mice, may eat like mice, may function like mice, but genetically they are no longer mice. They have had human genes spliced into their own DNA so that they can simulate or mimic human disease. But these mice will never be able to give an accurate representation of the human condition. They are mice, and humans are humans, and their innate biology is vastly different from humans!

Science has created “unnatural” animals.

So, finally, where does this leave us?

Well, the answer is very simple:

The similarities – these animals are emotionally and behaviourally so like us that they deserve to be left alone in peace!

The differences – we have seen that biologically they are vastly different form us which leaves us with the conclusion that to use them is research represents extremely unsafe and bad science.

In this 21st Century, we should aim primarily to make this a better world for all concerned by the application of sound science, with compassion.

Primum non nocere…

Author : Colleen McDuling, B.Sc(Med.Hons), MSc(Med.Sc.), Animal Behaviourist

Scientific Representative of the South African Rat Fan Club.

Short Notes on Reproduction in Rattus norvegicus

Rats are known for their prolific breeding. Young rats are normally weaned by their mothers when they are 21 days old. However, they usually remain in the family group for a short while later until they are fully independent and are able to cope socially in the environment on their own. Rats are considered to be pups or juveniles until around 60 days of age (two months or eight weeks old). It appears that the complete dispersion of the young does not occur before 60 days of age (Meaney and Stewart, 1981). This is under normal circumstances in the wild, and such circumstances may be applicable to domesticated rats if they were given the opportunity to behave in the social manner that their wild counterparts do.

Rats start to become sexually mature at between 40 to 65 days old (Rowett, 1957; Weihe, 1989; Harkness and Wagner, 1995; Wolfensohn and Lloyd, 1989; Daly, 2002). This means that they are going through puberty. It is during this pubertal stage that the first oestrus occurs. However sexual attraction occurs long before puberty, at around 36 to 45 days old (Meaney and Stewart, 1981). The vagina of the female opens at 35 to 90 days (n = 72), and the testes descend at 20 to 50 days (n = 40) (Donaldson, 1924; Harkness and Wagner, 1995). There is thus great variability on the reproductive time-line of rats of the species that we are dealing with. However one thing is quite clear cut and that is oestrus (the time that a rat can conceive) occurs every four to five days. Once fertilisation has taken place, gestation is between 21 and 23 days in length.

This species of rat, although capable of reproducing at a very young age, very rarely does this in the wild. Domesticated rats are also capable of reproducing at a young age. However it is inadvisable to allow them to do so. First mating should be delayed until the female rat is at least 100 to 120 days old when the females weigh approximately 250 g and the males 300 g (Rowett, 1957, Weihe, 1989; Harkness and Wagner, 1995; Warren, 1995). Young females bred at too early an age give rise to small litters and the babies will be small and weak. Breeding at an early age will also shorten the reproductive life of the female. At 120 days, the mother is strong enough and mature enough to raise a litter successfully (Warren, 1995). Leaving the first mating to this later age of around 110 days also gives rise to strong, healthy, vigorous young (Harkness and Wagner, 1995). No female older than 12 months of age should be mated. After 12 months of age, litter size decreases, the litter interval increases and the young are not strong (Harkness and Wagner, 1995). Menopause occurs at between 450 and 500 days (Weihe, 1989; Harkness and Wagner, 1995).

Like most rodents, these rats display a post-partum oestrus. This means that very shortly (within 48 hours) after having given birth, she is able to be impregnated again. However, the use of the post-partum oestrus to breed rats is not advised. Although one maximises the amount of young born, they are not strong, and mortality is increased. In addition to which, if the post-partum oestrus is not used, the mother provides more milk, and larger young and litters (Harkness and Wagner, 1995; Wolfensohn and Lloyd, 1998). The use of the post-partum oestrus for breeding puts an enormous strain on the mother’s body, since she now must not only support her own tissues and organs, but she must also produce sufficient milk for her pups who have been born while she is gestating another litter at the same time (Daly, 2002). If a female rat has been mated in the post-partum oestrus, and is lactating at the same time, there will be a delayed implantation of the new foetuses leading to an increase in the length of gestation by three to seven days (Wolfensohn and Lloyd, 1998). In addition to this, it was found that female rats who conceived in the post-partum oestrus, and then lost their suckling litter, bias the sex ratio of the new litter towards females. This means that more females will be born. It appears that male embryos are less successful in implanting in a uterus immediately after a previous birth and are lost (Bacon and McClintock, 1999).

This post-partum oestrus occurs only when conditions are favourable (Meehan, 1984). This would mean that there would have to be sufficient food available, that the environmental conditions are at best, and that the mother rat is in peak health. In the wild, females rarely produce more than five litters per year (Corbet and Harris, 1991). As far back as 1950, Farris stated that at the Rowett Research Institute, no stock female was permitted to have more than seven litters during her reproductive life, and that the female was rested for seven days after her litter had been weaned. Rowett (1957) recommended that the mother should be isolated until she has weaned her young and then rested for a further two weeks until the next mating. Many 21st Century animal laboratory breeding systems favour this rest period as well.

Should a mother rat have her first litter with her when the litter from the post-partum oestrus conception is born, both litters will suckle from her (Gilbert et al, 1983). This suggests that even more of a strain is exerted on the body of the mother. It also suggests that each one of the pups will not obtain the necessary volume of milk required for optimal nourishment, growth and development, thus leaving them deprived.

In conclusion, this author is of the opinion that breeding rats at the extremes of their reproductive life is highly deleterious to both mother and the young. Similarly, to use the post-partum oestrus for mating is equally injurious to both mother and young. Not only are such practises cruel through the unnatural imposition of continuous breeding on the mother rat, they are also physiologically demanding to both parties. Such practises serve only to maximise the numbers of young rats born. The mother rats suffer as a continuous strain is put on their bodies. The young are not healthy and strong, and mortality is increased. In addition to which, such rats usually have a shortened life-span, and have a greater susceptibility to developing disease.

It is hoped that constant monitoring is undertaken of any facility where rodents are bred, especially where they are bred for the pet trade. Apropos which, it is hoped that ultimately the breeding and sale of live animals as pets is prohibited. It is further hoped that laws will immediately be put in place to make the sale of live animals illegal, and a prosecutable offence. We have to protect all living creatures, who are utterly dependent upon us as humans for their well-being and welfare.


Bacon, S.J. and McClintock, M.K.; 1999; Sex ratio bias in postpartum-conceived Norway rat litters is produced by embryonic loss in midpregnancy; Journal of Reproduction and Fertility; 117: (2), 403 – 411

Corbet, G.B. and Harris, S. (Eds.); 1991; The Handbook of British Mammals, Third Edition; Blackwell Scientific Publications; Oxford; p253

Daly, C.H. (DVM); 2002; Rats A Complete Pet Owner’s Manual; Barrons; New York

Donaldson, H.H.; 1924; The Rat Date and Reference Tables, 2nd Edition; The Weston Institute; Philadelphia

Farris, E.J.; 1950; The rat as an experimental animal; In: The Care and Breeding of Laboratory Animals; Wiley; New York.

Gilbert, A.N., Burgdoon, D.A., Sullivan, K.A. and Adler, N.T.; 1983; Mother-weanling interactions in Norway rats in the presence of a successive litter produced by postpartum mating; Physiology and Behaviour; 30: 267 – 271

Harkness, J.F. and Wagner, J.; 1995; The Biology and Medicine of Rabbits and Rodents, fourth edition; Lea and Febiger; Philadelphia.

Meaney, M.J. and Stewart, J.; 1981; A descriptive study of social development in the rat (Rattus norvegicus); Animal Behaviour; 29 34 – 45

Meehan, A.P.; 1984; Rats and Mice, Their Biology and Control; Rentokil; Felcourt, East Grinstead

Rowett, H.G.Q.; 1960; The Rat as a Small Mammal, Second Edition; Jarrold and Sons; Norwich.

Warren, D.M.; 1995; Small Animal Care and Management; Delmar Publishers; Albany.

Weihe, W.H.; The laboratory rat; In: Poole, T.B. and Robinson, R. (Eds); 1989; The UFAW Handbook on the Care and Management of Laboratory Animals, Sixth Edition; Longman Scientific and Technical; Burnt Mill, Harlow.

Wolfensohn, S. and Lloyd, M.; 1998; Handbook of Laboratory Animal Management and Welfare, Second Edition; Blackwell Science; Oxford

Author : Colleen McDuling, B.Sc(Med.Hons), MSc(Med.Sc.), Animal Behaviourist

Scientific Representative of the South African Rat Fan Club.