Small Pets

We've raised and, in some cases, trained a number of small pets: everything from Bushy Tailed Jirds to button quail, and in their own way, each one is just a wonderful creation.

(And yes, you can train small animals - there's more to doing it than I have the time to delve into here but I would highly recommend visiting the following sites for more info: Rabbit Agility, Rat Agility, Gerbil Agility and More at )

Eventually we'd like to devote this page to articles on pet care - if you have a pet in mind, email us and we'll hopefully have the incentive we need to complete this page! Smile

Pet Tip for the month:

When introducing small pets (and in many cases, large pets too!) it is best to do it slowly over many days or even weeks.

With rodents, a mixture of citrus and apple vinegar can be applied to the scent glands of the animals. This will mask the animal's personal scent and hopefully let them concentrate on getting to know each other with out the territory match.

Speaking of which - If they are small, they can be introduced in a neutral territory - like the bathtub - where they can't jump escape, and it is pretty easy cleanup.


Rabbit Care
Rat Care
Chinchilla Care

DumansArk Rabbit Care tips

The #1 ultimate rule to remember - no rule is perfect for everyone. This is not a 'one size fits all'. Time and experience will show you, the rabbit raiser, what methods, products, and ideals work best for YOU and YOUR animals.


Water: IS A MUST. Rabbits overheat quickly, so in the summer, fresh water is an absolute necessity. In the winter, you'll still need to go out and give fresh water too if your pet does not live indoors. Everyday, several times a day, rabbits will need water bottles and bowls refilled.
Pellets: A good quality mix will have the nutritional value that your rabbits need to grow strong and healthy. For instance, if you are raising meat rabbits, you may want a higher protein percentage to ensure faster growth.
Hay: Young rabbits are often fed alfalfa hay, however, rabbits that are 6 months and older are given Timothy hay. Roughage is an important componant to the rabbit diet - remember that undomesticated rabbits don't have an extruder just popping out perfectly balanced pellets, and our domesticated pets still need more than what those pellets offer.
Fresh Fruits and Veggies: Not only are they good treats in moderation, they are healthy for your rabbits to eat. For a good list of vegetables safe for rabbits, visit:


A female rabbit is referred to as a 'doe'.
A male rabbit is referred to as a 'buck'.
When a doe gives birth, it is called 'kindling'.
Her group of young are referred to as her 'litter' and the babies are called 'kits'.
Once she has had a litter, she is a mother rabbit, or more properly known as a 'dam'. The father of the litter is known as the 'sire'.
A buck can be sexually active at 6 weeks of age. The litter is generally sexed and seperated by gender at this time to prevent the bucks from impregnanting their dam.
When does reach approximately 6 months old, they can be bred. The gestation period for rabbits is 28 to 32 days.
The size of the litter will vary - five kits being fairly common although you will want to research your breed as some are known to have more or less on average in their litters.
Kits are generally born hairless and blind. Does that do not go into labor until after the 32nd day may give birth to large babies that are more fully developed - this is not necessarily a good thing, as it is more taxing on the doe and may result in litter loss and/or the loss of the doe herself. Litters kindled too early due to pregnancy complications will also have a significantly lower survivablity rate.
The kits' eyes will begin to open shortly after the first week of life.
A doe does not have a 'heat cycle' like a dog would. Instead, ovulation is spurred into action when the doe is mounted by a buck. This means that a female can become pregnant ANY TIME she is mounted by a buck - even if she just had a litter! So it's important to seperate the doe once she's been bred to ensure that in 28 to 32 days, she can kindle and raise her kits in peace without having to fight off the attentions of an arduous buck.


This varies depending on the breed of rabbit you keep. If you have a mixed breed and it is not easily determined what breeds made up your pet, you'll have to guess and may need to upgrade to a larger enclosure as your pet grows.
Essentially, you want to determine if this is an indoor or an outdoor enclosure.
Indoor enclosures don't have to be weatherproof, obvisouly.
That determined, both types of cages will need to be big enough to allow the animal to move freely in all directions, to stretch out fully lying down, and to be able to excersise lightly.
An outdoor enclosure also needs to have a nestbox area where the rabbit can go to stay warm and dry - the rest of the cage can be made of wire.
If you will be using the cage for a breeding doe, you will want a nestbox that is big enough for her to kindle in - she must be able to stretch out fully, and turn around comfortably.
Colony enclosures and set ups are once again becoming popular. Some farmers never stopped using them - we've had the pleasure of meeting a third generation farming family that, for as long as they can remember, their father and his father, and his grandfather have had rabbits living in the chicken coop and chicken run. There are certainly pros to such an option.
But there's good and bad in everything right? Be sure to research which housing option is right for *your* situation.
For information on colony set up, we recommend visiting and


Super Brief Notes about Rabbit Care

**The following is not intended as an inclusive guide to rabbit care. It is the responsibility of the individual to research the needs and husbandry of their animal. is not accountable for whatever happens to you or your pet before or after reading the following.
IT’S HOT. IT’S COLD. --- Perhaps the Number One Reason reported for rabbit deaths is extreme temperature fluctuations. For example; it is 80 degrees or 90 degrees (or more) outside, and you take your rabbit from the air conditioned house and set them in a cage outdoors. THIS OFTEN RESULTS IN DEATH DUE TO HEAT STROKE. Conversely, if they are living in the warmth of the house and you suddenly cage them outside when it is a chilly 18 degrees, they can also die. If they get rained on, if they are in direct sun, if they do not have an area that protects them from inclement weather; if this all sounds like Common Sense info then you’d be surprised at how many people are shocked when their pet suddenly ‘expires’ due to one of these scenarios.

H2O --- Water: Rabbits drink a lot of water. Some more than others. Water should be provided at all times; a water bottle, a bowl, a spout attached to a Rabbit Auto-Watering System; something.
CHOW TIME --- Food: Most breeds of rabbits need to have food constantly available. The easiest way to ensure this can be the case is to place food in a large enough bowl or auto feeder that the rabbit can easily eat out of and yet still has some food in it by the next feeding time. If this doesn’t sound like exact science, it is because IT ISN’T. You will need to watch and learn how much your rabbit eats. This will change throughout the course of their life.

RABBITS BREED LIKE RABBITS. If you place a buck rabbit with a doe rabbit, eventually your doe rabbit will give birth. If the buck is still housed with her at the time she goes into labor, she may or may not bother to pull hair to make a nest. The buck is generally so interested in re-breeding the female that the kits will be trampled as they are birthed.

VET CARE --- Rabbits are pretty much as Low or High Maintenance as you want to make them. Some people like to take their pet for yearly checkups and that is their prerogative.
Overall, rabbits are amazingly healthy and robust creatures. There are no approved vaccines in the USA for rabbits at this time, so no need to go to the animal doctors for inoculations once a year. Barring injury or illness, they do just fine without ever setting foot on a Vet’s table.


Frequently asked questions about RABBITS:

Q: What is the adult weight of a lionhead rabbit?
A:*****Ideally, they'll weigh around 2 to 4lbs.
Q: Do they come in a mini or is it just lionhead?
A:*****They do not have a specific 'mini' category - yet. At this time, they are not even accepted as a breed by the American Rabbit Breeder's Association. Perhaps because of this, those that do breed them are kind of going for their own personal standard of perfection - so maybe in the future there will be different sizes like Mini Lionhead and Standard lionhead and so on.
Q: Now what is a dutch harlequin?
A: ******Oh, so gorgeous! We love the harlequin's color patterns - and we like the striking white bands and blazes of the dutch. So when we stumbled across this mixing of the two breeds we had to have one!
You can see some good pictures and info of this breed at this site:

Q: Females of most animals are more gentle than males, does that hold true for rabbits?
A: This is a tough question. First, I have to say, that the answer will totally and completely depend on who you ask.
Second, I truly believe that this is determined by the individual who OWNS the rabbit.
I'm not kidding!
Me, for example. For whatever reason, my favorite rabbits have been males - for the most part. (I LOVED Aussie, my Flemish Giant, and Speed, a complete 'mutt' - not 'worth' anything to anyone but our family.
I would have chosen her over the nicest pedigreed papered champions - no joke. She had a lot of heart.) Not based on breed, or color - but over time I've noticed that pattern.
But that's just me.

My mother tends to fall in love with great mother rabbits & persnickity bucks. Is it because my mom just appreciates good mothers & bucks that have a great sense of their own style? I don't know. I love great moms - I couldn't raise rabbits without girls that nurture and love their litters and who can't use a guy that knows just knows how gorgeous he is?
So why are the rabbits that stand out the most in my mind as 'favorites', majority speaking, "boys"?
Beats me.
So I think that you will find that no matter what anyone tells you - you will find yourself falling in love with the gender that speaks to you. Or maybe you won't! Maybe you'll love either gender equally.
I will warn you that some sources (rabbit books, some websites, etc) will say that females are more likely to scratch, kick, and bite.
We have come across this from time to time - in BOTH genders. Some rabbits just DO NOT like to be picked up or held. Or they'll tolerate it - but only for a while.
And if a person is happy in a relationship with an animal that they can pet, feed it treats, and clean up after it and water it and feed it but they can't pick it up without getting scratched - then that's their perogative.
But as a personal choice, we prefer to have rabbits, to raise rabbits, that even a child (a mature, gentle, animal -friendly child of course!) can pick up and carry without getting kicked.
I truly do wonder if the bad rap doe rabbits get is more due to the fact that people are told they are nasty tempered so they expect them to be nasty tempered and they then breed the nasty tempered animals who raise nasty tempered offspring - it's simply a viscious circle.


Care and Housing for Rats

This is in no way a complete guide - think of this more like helpful tips.

And really, these are all merely opinions.

The first rule is - there ARE no set rules.

It's true. What works for them might not work for you.

You'll have to research, make decisions to the best of your ability based on what you've learned, and go with whatever works best for YOU and YOUR pets.

Good luck!

Above: DumansArk Raleigh, a beautiful little dwarf Dalmation doe


What you'll need to get started... Well, a cage, right?

Boy, not as easy as it sounds.... which one?

Wire, glass, or plastic?

=generally, going with a cage that offers bars is best - better ventilation. Less for the rats to chew, too. Plastic = chewable surface to a rat. Some will never chew it, others can't seem to stop.


Glass is easy to sterilize but is also easily breakable.
Plastic bottles are easy to chew (see above note about chewers). But also easy to replace.
Water bottle protectors can be purchased for most plastic bottles and some work fairly well.


Food bowl.

Ceramic ones are now made with dishwasher safe glaze so they are colorful, attractive, and easy to clean. They are also heavy enough that your rat probably wont go to the effort of moving it around much.

Plastic dishes can be chewed... you get the idea =)


Hide box.

Pay for something pretty - or use a Poptart box - it's chewable and FREE - after you eat all the Poptarts, of course ;)


Where to find a rat? Pet Store, 'Feeder' Rats, Breeder, Animal Shelters, - check the advertisement board at your local feed mill, co op, pet store, humane society, newspaper, college, etc.


Now some will turn up their nose at Feeder rats. The side that feels Feeder Rats have merit often cite some form of the following Pros of purchasing one from a feeder tank: They are low cost (a penny saved they say). They save a life. Generally, they can be found young - (although large ones for larger reptiles are certainly available too) and therefore easier to tame. Feeder rats can come in a multitude of colors - and as to derail the topic, many color variations were not created in a pedigreed, breeder rattery - but were in fact found in a pet store.

Don't believe me? Case in point: Harley rats. They are rats with long straight hair. Found in a feeder tank! And Merle Rats - first documented rat with merling was found in a pet store feeder tank in Michigan.

Which brings us to the cons. Wouldn't it be nice to know who that Harley rat's parent's were? Or the Merle's? The health, longevity, etc of the line?

Oh! Back to the cons: So no pedigree. Sometimes, due to cramped, dirty, conditions, feeder rats come a little roughed up and maybe not as healthy as they should be. That said, we have also seen some GREAT pet stores with wonderfully cared for animals. So really, go for the animal that is healthy, handled or handle-able, and make it a happy pet.

WHERE it came from does NOT make the rat. How YOU treat it does.

Choosing a Rat from the Pile

Mini Checklist:
Bright eyes
Clean fur
Fur rests close to body
Animal is alert (not listless)

More on this soon...

Coming soon

Training = tricks!
Coming soon

Do's and Don'ts.

#1. This cannot be stressed enough. DO NOT SCARE PEOPLE WITH YOUR RAT. It isn't fun for the rat, and it isn't fun for the person being terrified. Plus, you may have mentally and emotionally scarred a potential rat-lover - and you could get in trouble, and worse, the ANIMAL could suffer for your actions.

So. DON'T. DO. IT.


Chinchilla Care


Chinchilla Care Sheet:

Chinchillas are ADORABLE animals - and their fur is so soft - there is nothing quite like it! Never had a chance to pet one before? The next time you bake cookies, grab a handful of powdered sugar. Feel that powdery, smooth softness? A chinchilla's coat is softer - and plushy!


Now, to care for that coat, chinchillas DO NOT bathe. Most in fact, despise water and will drink it, but that's about it. Water is not good for their coat. Instead, they need to 'dust bathe'. Volcanic ash, often sold as Fullers Earth and similar brands, is a finely ground bag of well? Dust! You can sprinkle it in their cage, rub it on the chinchilla, or best yet, put it in a clean litterbox or specialized commercial Chin Bathing Box and let the chinchilla go wild!

Some believe chinchillas should be offered the bath once a day, others think no more than once a week or so - you'll have to find what works best for your chinchilla. Dust Baths prevent bugs from irritating them, from oils building up on their coat, and it keeps them happy.

(A female that's given birth should not be offered her bath for two weeks though to prevent infections)


Chinchillas love to try new treats - and fresh fruits and veggies are great for everything, right? Maybe. Research which treats can be given and ONLY give them in moderation. Just because your chinchilla has had a bit of bannana once doesn't mean you can give them a whole chunk two months later - bad idea! A tiny piece, the size of a small raisin, given once in a while would be fine though.


The bigger the better - it's true! Now sure, you can keep a chinchilla in a small cage. Most pet stores sell them as 18"x18"x18 or so. But chinchillas are very mobile, active creatures, and they love to jump, climb, run, and play. Hard to do in such a tiny enclosure. Give them levels, give them ramps, give them slides and be creative! But be safe too - bars that are large enough for a foot to slip through can eventually cause your Chinchilla to break a leg - it's sadly far too common. Cover up bars with plexiglass sheets cut to fit, wood, thin granite sheets (which double as cooling blocks in the summer) or PVC sheeting.

Keeping Cool:

Chinchillas are not tropical animals. They like it cool - need it, actually. Those thick, plush coats insulate them to an extent, but in the heat - well, imagine yourself wearing three or four thick knit layers on an 80 degree day. You'd have heatstroke pretty quick. It's best to keep your pet's enclosure out of direct sunlight. Keep them in an air conditioned part of the house. And remember - they don't care for the humidity and can't tolerate it well - so near a dehumidifier if necessary.’s CAVY CARE SHEET

Cavy make wonderful pets. They are personable, gentle, and very intelligent animals. Here's some quick tips on how to care for them.

Food and Water:

Should be provided at all times. Cavies tend to be very hard on their water bottles so it is best to purchase a back-up bottle to have on hand when the primary one suddenly starts to leak.

Food bowls need heavy bottoms or a way to attach them to the cage as some pigs make a game of flipping their dishes. When the animal is young, it is a concern that they will flip the dish on themselves; although uncommon, we have been told babies can suffocate under a dish so be sure to choose sturdy ceramic or No Tip bowls to be safe.

The food itself should be a mixture of a pellet diet, *small amounts* of fresh fruits and vegetables at first (if your pet is not used to them, or is very young, you don't want them to get diarrhea from too much, too fast), and orchard grass or timothy hay.

It has been debated widely on Pet forums and groups, but most agree that rabbit pellets are suitable for cavy to eat. Don't believe this? Compare the ingredients and nutrition labels the next time you are at the store. Some, not all, are identical. Added dried veggies and such are nice, but why pay more for cavy food when you can give them the cheaper rabbit pellet AND provide the fruit/veggies FRESH anyway? Just a thought.

Cage: Cage space is a largely debated issue. But the ideal cage will allow for your cavy a space for a hide-away box of some sort, for a feed/water area, and some space to run and play with the toys you provide.

Taking your pig out to be handled on a regular basis also makes a difference – if the cage is modest, yet your pig is out and spends hours exploring your bedroom floor every day, then there isn’t a need for a gargantuan enclosure.

As for the type of cage to use, cavy are kept in everything from Rubbermaid tubs to homemade wire and zip ties, to empty ‘stock water tanks’ --- they are adaptable creatures and your imagination is the limit.

They will need a Hide area – this can be as elaborate as a wooden Cavy House, to as simple as an empty 12pk soda can box.

Chewing: guinea pigs’ teeth grow continually, and they need to be kept worn down. To do that, offer cardboard and apple-wood branches for your pet to gnaw on. If you offer the apple-wood, do not be alarmed if your pet actually eats some of the bark and fiber; this is normal, and actually beneficial.

Feet: If you keep your pig on wire, be sure to offer solid surfaces in the Hide box area, and by the food and water areas. Cavy have tender feet and being on wire can cause a condition called “bumble foot” – their feet develop sores and can become infected.

Generally speaking, your pet will not be at risk for bumble foot if kept on shavings or pelleted bedding. However, if you notice your pet’s feet getting sores, you can switch to old towels as bedding.

Handling: Cavy are very smart. They can learn many tricks. We highly recommend as they have videos and information on training your pig to do everything from coming to their name to playing Tic Tac Toe.

Provided that the handler is gentle, and responsible enough to be left alone with a pet, then you have a wonderful companion in a cavy. The best way to pick up your cavy from a cage is to reach your hand in and place it in front of your pet’s face so that it sees you – just looming over and grabbing it will frighten your pig (at first – we have seen/met a few cavies that were raised this way so they got used to this method of being picked up)

Cavies are very social, and once they learn to trust you, they will want to be with you more than they will want to be alone. Cavies, male and female, learn not to eliminate outside their cage (just be sure to take them back to their cage every once in a while so they can use the bathroom – for babies, this could be every 10 or 15 minutes, for adults this could be an hour of play before they have to relieve themselves). Because of this, you can keep your cavy on your desk while you do work (just be sure your pig stays away from the edges – sometimes they don’t realize they are so far from the floor!), or let them play on your bedroom floor.

To get them comfortable with this, lie belly-down on the floor. Place your pig in front of you, in the circle of your arms. If your pig is calm, you can open your arms so your pig can see around them. Soon, they will leave you to go check out the apple slice you left them, a few inches out of the circle. They will run for it, and as they chew their treat, say a word like “Treat”. Repeat the word until they are done eating. Once they are finished, they will scurry back to you. Praise your pig for coming back.

Every time you hand your pet a treat, use the command word you decided on. This will help later when you want them to do tricks. Also use your pet’s name frequently – as you talk to them, as you pet them – they will learn to associate their name with comfort. This will help your pet learn to come when called – either with their name, or with the treat command word.

Grooming: guinea pigs’ nails need clipping. Not too far – light colored nails are easiest to do, as you will see a white area at the tip and inside the white area, you will notice a pink band that runs back into the toe. That’s know as the “quick”. You only want to snip the part that curves, and only the white part that does not contain the quick.

Your pet will shed hair – you can use a soft bristle brush to brush the coat, from head-to-rump motion, or use a baby wipe. Baby wipes will catch most of the loose fur – you just pull it over them, from the neck to rump.

Vitamin C: It is VITAL to cavy. Provide plenty of fresh veggies and of course, oranges. Grapefruit is also readily eaten. When your pig is young, you won’t want to give them much, but you will want to give some every day. A slice is good. As they age, you can give them more and more – until you are giving a whole carrot at a time, an entire Roman lettuce leaf, two slices of grapefruit or orange and so on.

Breeding: If you decide to raise a litter of cavy, it must be said that sows should not be bred after 7 months of age. Their hip bones fuse together, and so when the sow delivers, the babies will not be able to pass through the canal.

If your pet is between 5 and 7 months of age, you can place her in with a boar. When she is receptive, she will allow him to mate with her.

Gestation for cavy is quite long; 64 days. The young are fully furred, have their eyes and ears open, and can walk and eat solid foods just after birth. They do still need their mother though as they need to nurse.


When introducing cavy to each other, or to the family dog, etc, it is best to do it slowly over many days or even weeks and with 100% supervision.

The Bathtub is a great place to set cavy so they can better get to know each other; it's a perfect nuetral area.

Showing: to show cavies in 4H, you will need to join a 4H chapter and follow their rules in order to participate in show classes and demonstrations. 4H Youth are paid for every prize they win, as well as given ribbons for their achievements.


Heatstroke: Cavy can get heat stress very easily. Unlike dogs or cats, they do not ‘pant’ when they get overheated, so it can be difficult to see the signs of imminent heat stroke. Direct sunlight or over 70 degrees is dangerous to cavy. It is most likely one of the top reasons we hear of for cavy deaths; we’ve heard people explain that they only had their cavy out to play for an hour or so while they took pictures on the grass – but if you think of an animal that is used to air conditioning, then is placed in the sun on a sweltering 80 degree day; this is extremely hard on a body, most especially such a small animal.

New guinea pigs are especially prone to this. Car rides, strange sounds, new people, new smells, new surroundings, and possibly new cagemates is sure a lot for anyone to take in, let alone a small pet. It is tempting to want to hold your cavy right away, but it is instead best to give them a day or two to settle into their new home and routine. Then start slow, taking them out for a few minutes of play each time before giving them cage rest again. As mentioned before, once they trust you, they'll want to be with you rather than in their cage. Smile


Most importantly: have fun with your cavy! May you have many good, fun filled years together.

NOTE: offers personal thoughts only and is not responsible for any damage to property, person, or animal. We always recommend that you contact your pet's vet and breeder if you have any questions.

An interesting study about Pine Bedding:
Specifically, Pine shavings. From horses to hamsters, pine shavings have been used as bedding for decades. Sawdust has surely been used as animal bedding for centuries.
If domesticated animals haven't all died out from the evils of pine by now, are shavings really that bad?

It is a topic that has been hotly debated among the pet circles in the last fifteen years or so.
In most countries (example: Australia) a number of respected breeders use sawdust. Some even use sand. I have met breeders that use Pine exclusively, and one in particular had been raising rats since the 80s. (Keep in mind that it is widely believed that rats are extremely susceptible to the "side effects" of pine - everything from respiratory ills to organ failure is rumored.) When I asked her about it, she said starting out, she just selected for the rats that didn't show respiratory issues on it. I found that fascinating. Over the years I have seen some of the pet rat forums push paper toweling, I have seen them fiercely push fleece covers or shredded paper etc. Do rats still have problems & URIs on these "safe" beddings? You bet. Clean environments *and* selecting for health & hardiness in a line are key. And as always, the golden rule is there is no one right way ;)

Come to think of it, the wonderful breeder we bought our Chinchillas from had a 19-year old pair of Chinchillas that were and had always been kept with kiln dried pine.

Wow, on a Pet list I am on, quite a few chimed in with stories like the two above, with healthy animals raised on pine. After years of the mini drama witch hunts on some groups, this is a nice change seeing the topic openly discussed.

But don't take my word for it. Here is an in-depth article for your review, be it rabbits or cavy or gerbils that you keep - this is worth a look:

There is a lot of debate in the pet world about the suitability of Kiln Dried, Triple Dust Extracted Pine Shavings. This article is an in depth explanation about pine shavings, what they contain and how this may affect your pet.

This article was written by Corinne Fayo and has been used with permission of the author.

This article has been published in the following newsletters:
Mt. Ears (12/97)
Valley Voice (9/97)
PGNDRC Newsletter (1/98 )
The News Disrict II NDRC (3/98 )

This article was written by Corinne Fayo

This article has been reviewed by Carol Green a rabbit breeder with a Ph.D. in Pharmacology and Toxicology, her area of research is drug metabolizing enzymes and she has more than 80 publications in the field. She said the article is accurate.

And by a medical doctor & research writer who had studied the HME system for six months. Her comments to me were; “If all the phenols do is to induce some of the microsomal enzymes, that’s nothing to be concerned about.”

This article started out as an internet post on the list because I wanted to find out the truth about pine shavings. I have used pine shavings for as long as I’ve had rabbits and have never had respiratory problems, cancer, or liver disease in my animals. I have not heard stories or rumors of problems, just posts or articles on the internet which often didn’t cite studies or articles but made outlandish claims of health problems. I did e-mail Harriman and Flentke regarding their articles, and the “Rat “Lady e-mailed me once and asked if I had read certain studies which I had, I let her know she mis-quoted a study never heard back. To date no one has challenged the information in the article, rather they say since I’m not a Ph.D or a vet I can’t be believed, or the new one that since it wasn’t published in a major scientific journal that it is to be discounted. It was never intended to be published in a scientific journal, rather to explain what the studies found about pine and cedar. However the other articles on the ‘net which claim a danger in using shavings also have not been published in any major scientific journal, why the double standard?

The Truth About Pine Shavings The great pine/cedar debate has been raging on the internet for quite awhile and many people have been mislead about the use of softwood (pine and cedar) bedding for small animals. Many people have been spreading incorrect, inaccurate information and have misinterpreted several scientific studies. Actually reading the studies and correctly interpreting them reveal there isn’t a danger in using softwood bedding for animals. After reading this article you will learn that treated shavings are safe and even recommended by veterinarians, the effects untreated softwood beddings cause is not harmful to the animals, and the claims they cause problems such as liver disease, damage, or cancer are not correct.Hepatic Microsomal Enzymes (HME) The real “debate” is over whether or not untreated pine and cedar shavings are a danger. It has been proven that untreated pine and cedar contain an inducing agent of HME activity. HMEs are by-products of the liver after processing drugs. “It is simply the way the body-or more specifically, the liver-handles many of the elements it comes into contact with each day.”(20). I was also lucky enough to run into a medical doctor/research writer who had studied the HME system for six months. Her comments to me were; “If all the phenols do is to induce some of the microsomal enzymes, that’s nothing to be concerned about.” She continued with “I know that there are lots of things that both induce and suppress microsomal enzymes in humans, and it’s no big deal except when it causes a concomitantly administered drug to be metabolized differently. When that occurs, all you have to do is to adjust the dose of the drug appropriately.” After reading the studies which are most often quoted as providing evidence untreated shavings are harmful I must state I don’t see where any demonstrate a danger. What I have learned from the studies about HME is that there are many factors which can affect this sensitive system and cause an increase or decrease in activity (2,3,4). This is a partial list from one study (4): Table 1 list of factors affecting drug disposition: air exchange and composition, barometric pressure, cage design, cedar and other softwood bedding, cleanliness, coprophagia, diet, gravity, handling, humidity, light cycle, noise level, temperature, age, cardiovascular function, castration and hormone replacement, circadian and seasonal variations, dehydration, disease, fever, gastrointestinal function, genetic constitution, hepatic blood flow, malnutrition, starvation, pregnancy, sex, shock, stress…” “Dirty environments should now be added to the growing list of factors that affect the extremely sensitive hepatic microsomal system for metabolizing drugs. Among others, these factors include, age; sex; strain; litter of origin; painful stimuli; ambient temperature; degree of crowding; time of day or season of drug administration; hormonal; nutritional; and physiological status; and type of bedding.” (2)

As you can see by the factors listed many things can set off a change in HME activity. Dr Hawley’s article also mentioned grapefruit juice can induce HME, as did the medical doctor I spoke to (20). So why are the scientists so concerned by HME and the inducing effects of pine and cedar? Several studies mentioned the problem of getting standardized test results in pharmacological studies (1,2,3,4). “Differences in the capacity of various beddings to induce may partially explain divergent results of studies on drug- metabolizing enzymes.” (1) “These experiments offer an explanation for differences in the results of studies on drug-metabolizing enzymes in mice and rats.” (1) “These numerous factors contribute to large day-to-day variations that have become a major problem impeding investigation of drug disposition and response in laboratory animals.” (4) “These data suggest that commercial bedding materials differ in their ability to affect microsomal enzymes. Thus, interlaboratory variability in basal enzyme activities reported in the literature may be partly due to bedding materials used in animal cages.” (19) “Pharmacological and biochemical investigations of hepatic microsomal enzymes (HME) in rodents have been plagued by large day-today variations in control values for these enzyme activities” (4). It seems HME activity to the scientists is actually a sort of “background noise” in their experiments, but important to note so test results can be accurately interpreted.

Do the scientists feel untreated pine and cedar should not be used in any laboratory? Not from what I have read in the studies. “Rejection of all softwood beddings because they are potent inducers of hepatic microsomal enzymes does not appear justified.” (3). However in an effort to standardize certain test results it is suggested untreated softwood not be used (6). “Softwood beddings have been used, but the use of untreated softwood shavings and chips is contraindicated for some protocols because they can affect animals’ metabolism (Vesell 1967, Vesell and others 1973, 1976).” (6). “White spruce may provide a relatively inexpensive alternative to hardwood for studies that require bedding that does not alter barbiturate sleeptime” (3). I think the above quotes illustrate that the inducing effect of untreated softwood shavings is important only to the scientific community in the process of studying drugs and their effects. In addition Dr Hawley writes that “Nearly every commercial laboratory today uses pine, cedar, or other hardwood beddings, except when conducting specific drug metabolism studies.” (20).

I did come across an interesting result shown in several studies, accumulation of urine and feces which increase ammonia levels cause a decrease in HME activity (2,3,4). Now we all know increasing ammonia levels can cause damage in our animals. It has been associated with causing increased susceptibility to Pasturella infections and respiratory damage. “The present experiments reveal that drug metabolism in hepatic microsomes was inhibited when urine and feces of rodents were not removed twice daily but permitted to accumulate for 1 week. Inhibition of drug metabolism in rats kept under these conditions may arise from hepatic toxicity due to increased concentrations of ammonia (5) in such environments.” (2). May I also point out that I have yet to find in a study a reference to pine or cedar causing hepatic toxicity. Dr Hawley also points out that the presence of these enzymes do not suggest there is damage to the liver (20).

I also found another study which reported that oral administration of praziquantel at a dosage of 1600 mg/kg and 2000 mg/kg caused a significant decrease in 3 drug-metabolizing hepatic enzymes (16). The rabbits who received the dosage of 2000 mg/kg all died within 10-20 hours. In another study rabbits were given aflatoxin to see the effects it would have on liver enzymes (17). None died but body weight gain was altered and again a decrease was noted in some HME, “Biochemical exploration of plasma components revealed a dose-dependent hepatotoxicity characterized by cytolysis and cholestasis.” (17). And finally in a study comparing the activity of HME in rats given single or repetitive fluke infections HME decreases were noted (18 ). Given this evidence I can’t come to the conclusion that increased HME activity is a sign of harm being done to a small animal.

Pet owners also argue that untreated cedar and pine cause shortened barbiturate sleeptimes and that would be harmful for an animal undergoing surgery. The increased HME activity does shorten barbiturate sleeptimes in the studies (1,2,3,4) but note that the scientists were testing for this, not performing surgery. The studies have found that sleeptimes were shortest for cedar shavings compared to the softwoods (3,19). There were also differences among different types of pine bedding with white spruce not significantly different than hardwoods but longer than white pine (3). “In other studies, mice kept on pine beddings exhibited hexobarbital sleeptimes intermediate between those of mice kept on red cedar or Douglas Fir (9), and intermediate between mice kept on red cedar or ground corn cobs (10).” (3). Heat treated pine shavings have been shown not to alter sleeptime in comparison to control animals (19).

But does any of the above really affect us and our pets? I don’t believe so, there are many factors which affect HME and therefore barbiturate sleeptime (2,3,4,). A study also found increased ammonia levels alter sleeptime and that lowering the room temperature lengthens sleeptime (3). The same study also showed that two different strains of mice studied had significantly different sleeptimes. Also consider this quote “No alteration in the hexobarbital concentration in the brain at the time of restoration of the righting response occurred on any of the softwood beddings tested.” (1). “While sleeptimes are decreasing and the microsomal enzyme activity is increasing, the amounts of hexobarbital in the brain on awakening remain unaltered in mice put on softwood bedding; thus, the responsiveness of the receptor sites seems unaffected by softwood bedding.” (1). I have not been able to find any scientific references or entries in veterinary books warning of a danger in regard to surgery when animals are exposed to softwood shavings. If altered barbiturate sleeptimes due to softwood exposure were critical during surgery I would think there would be a warning about it.

I also found an interesting section in the Harkness and Wagner book relating to injectable anesthetics in rats. It is stated that sodium pentobarbitol used in rats “poses considerable risk” (7) pg.109. “Pentobaribitol also has poor analgesic properties in rats and produces profound hypothermia and causes excitement on induction (Wixson et al., 1987a,c,d). The young, the females, cooled animals, and possibly the albinos are more susceptible to the drug, whereas males, animals receiving low caloric diets, and animals on cedar bedding are more resistant.” (7) Pg 109. The same book also states pentobarbital is not recommend for rabbits.

Heat Treated Shavings Heat treated pine shavings are fine for use as bedding and litter for small animals including rabbits. The first piece of evidence is the fact that many people have been using pine shavings for years without any ill effect to their rabbit(s). The next pieces are what the veterinary books and others have to say about the use of shavings for litter. Harkness and Wagner Pg 61: “Bedding, which may be paper, sawdust, or soft pine, aspen, or cedar shavings should be nonallergenic, dust free, inedible, absorbent, nontoxic, and free of pathogenic organisms. Soft pine and cedar wood shavings are used for pet rodent bedding because of their pleasant aroma. However, because volatile hydrocarbons from these shavings may stimulate microsomal enzymes, they are avoided as bedding material for research animals. Softwood shavings and tissue paper make excellent rodent nesting material” (7) TBLR Pg 29 “Bedding must be used in nest boxes. It may be straw, hay, excelsior, wood shavings, or other such material.” (8 ). Hillyer and Quesenberry pg 292 small rodent section: “Pine shavings remain the most commonly used bedding for small pet rodents in many parts of North America. Corncob products and recycled paper products are excellent for certain rodents such as gerbils and dwarf hamsters. Cedar shavings also are popular but their use is controversial. Cedar has been shown to affect microsomal oxidative liver enzymes. Although these changes affect factors such as drug metabolism, no clinical signs associated with them have been documented.” (10) Rabbit Production Pg 90 “The nest box should …contain bedding of hay, straw, shavings, or similar material.” Pg 93 “If the does are being fed a ration consisting only of pellets, they may eat any palatable material used for bedding, and in this case softwood shavings…may be used” (9) If the use of softwood bedding was dangerous why on earth would any of these books mention it as good bedding material. All of these books are recent publications and the studies many cite showing a “danger” were published closer to 30 years ago.

Finally we have evidence treated pine is safe from the scientific studies pet owners often quote from (1,3,4,19). The process of heat treating removes the HME inducing agent as demonstrated in the above mentioned studies. It is also mentioned in the National Institute of Health guide to Laboratory animals “Heat treatments applied before bedding materials are used to reduce the concentration of aromatic hydrocarbons” (6). “By two different experimental approaches Wade et al. (47) showed that cedrol and cedrene were active agents in the inductive response of mice to cedarwood bedding. In the first experiment cedar shavings from which cedrol and cedrene had been extracted…produced hexobarbital sleeping times indistinguishable from those observed in control mice housed on inert corncob bedding.” (4). I also offer this quote from an HRS educator I wrote to “There are some shavings which are safe, and these are the kiln-dried pine.”

I have also heard the rumor cedar causes cancer. I found three studies (11,12,13) and none of them came to the conclusion cedar bedding caused or contributed to the occurrence of cancer. “From these results, the high incidence of cancer in the C3H-AvyfB strain could not be attributed to the routine use of cedar shavings in the bedding material.” (11). “Hepatoma incidence in males at 18 months of age was not affected by the presence or absence of cedar shavings in the bedding ” (12). “There was no evidence that the cedar shavings were carcinogenic.” (13).

Sorting Through Rumors The arguments presented by those against softwood bedding often sound convincing on the surface, however closer inspection reveals discrepancies. For example the HRS has made statements that softwood bedding has caused liver disease in rabbits they have fostered and caused the death of rabbits during surgery. I have read the article by HRS founder Marinell Harriman, “Litterboxes and Liver Disease” and question her conclusions. Apparently HRS began investigating softwood bedding after one rabbit died during a routine spay surgery. They maintain that rabbits housed on pine or cedar may risk death during surgery, however they also have made statements that they have not lost many rabbits during spays or neuters. They stopped using softwood bedding after Sarah the rabbit died in 1989 so prior to her death they must not have had problems with surgery on other rabbits exposed to softwood. The article also discussed several foster rabbits had elevated liver enzymes and some had liver disease. Dr Hawley points out that the enzymes tested by veterinarians in a serum or plasma chemistry panel are “leakage enzymes” and not the same enzymes the researchers studied in the softwood bedding experiments (20).

So what could explain the liver disease in the HRS foster rabbits? I checked into liver disease in rabbits, there is very little about it but what I did find is hepatic coccidiosis, which causes an enlarged liver and it is contagious (7,8,9). I would assume the HRS members had adopted the rabbits that had liver disease so it is possible that the rabbits were exposed to hepatic coccidiosis, I feel it is a pretty big leap to assume untreated shavings caused their deaths. From TBLR: Pg 206 long section on hepatic coccidiosis, clinical signs included enlarged liver. pg 267: Liver cancer: “The tumor appears to have little potential as a research model, primarily because of the difficulty of case findings.” (8 ). The common causes of liver spots in rabbits are hepatic coccidiosis, migrating tapeworm larvae, Tyzzer’s disease, and colibacillosis (7). So there doesn’t seem to be any evidence linking untreated softwoods to liver disease or other problems in rabbits.

Another opponent of softwood bedding is Debbie “The Rat Lady” Ducommun who wrote a long article pointing out the “dangers” of softwood bedding. She stated “Because of the toxic effects of softwood shavings, laboratories have pretty much stopped using them for their animals.” Well as we now know this is not the reason some labs would not use them. Also where is the evidence that their effect is toxic? The liver disease connection was also brought up and she stated “unless these animals [rabbits housed on softwood] received full autopsies at death with no sign of enlarged livers or liver disfunction, respiratory infection, or altered immune system, how can they claim that the pine or cedar did not affect them?” I submit that even with a full autopsy how can you tell softwood did, afterall the animal died of something so we would expect to see problems. An enlarged liver is a sign of hepatic coccidiosis (8 ) so that can’t be used as proof. And we know there are other causes of respiratory infection and other things that can alter the immune system. Also obesity can cause elevated liver enzymes and contribute to problems. An autopsy showing the above problems would not be proof that softwood bedding or HME induction caused liver damage.

I think there has been too much “interpreting” of scientific studies and that is what is causing the great pine/cedar scare. As an example let’s look at chloroform. If you have municipal water then you and your animals are being exposed to chloroform. Is this harmful? What do the studies say, “Present in the water supplies of many of our cities in concentrations reaching 311ug/1, according to the Environmental Protection Agency, chloroform has also been identified as a contaminant of the air. Thus chloroform can gain entry and accumulate in organisms by both the oral and inhalational routes. From the point of view of this symposium, the question of the effects on laboratory animals of environmental exposure to chloroform is raised. Chloroform is toxic to both the liver and kidney of laboratory animals (12), liver tumors arising after chronic chloroform administration (13).” (4).

It looks like it is, and if you have been giving your animals municipal water you are killing them! Make sure you get a full autopsy done after they die and check for liver and kidney damage as well as respiratory problems to “prove” the chloroform was the cause. Oh wait a minute the study says a little more, “Chloroform is only one of a large number of newly identified environmental pollutants to which laboratory animals are being continuously exposed: continuous exposure of laboratory animals to chloroform, as well as to many other environmental pollutants, could affect the responsiveness of these animals under a wide range of experimental conditions.” (4). Well I guess the scientists weren’t warning us of the dangers of using municipal water afterall, just discussing how it could affect experimental data.

We and our animals are exposed continually to different “pollutants” in our environment, what matters is the health of an individual and the concentration of pollutants they are exposed to. Some chemicals in small concentrations are harmless but in larger doses are lethal. An example of this is benzoic acid in Listerine. Benzoic acid is toxic if ingested in large enough quantities, the amount in Listerine is well below that amount and therefore is safe for use in humans. It is important not to over-interpret what scientific studies are showing us.

In closing I just want to say I still have not read, experienced, or heard anything that leads me to believe the use of pine shavings are harmful to rabbits. What I have read and experienced shows me they are safe. I still won’t use cedar because in the past I heard it could be toxic for a rabbit if they ingest too much of it, plus it has a very strong odor. I included many quotes in this article so you are able to read exactly what the scientists have discovered about softwood bedding and the effects on HME. If one closely looks at the evidence offered that pine shavings are harmful you will see the arguments are weak and lack evidence. Dr Hawley reports pet retailers are being subjected to anger from animal rights advocates who accuse them of selling “dangerous” bedding material (20). It’s too bad these people didn’t first read the studies instead of subscribing to the “I heard it was bad, so it must be true” theory. But those of you reading this now know more than you ever wanted to about softwood shavings and HME!

References: (1) “Induction of Drug-Metabolizing Enzymes in Liver Microsomes of Mice and Rats by Softwod Bedding” Vesell 1967, Science. (2)”Hepatic Drug Metabolism in Rats: Impairment in a dirty Environment” 1973 Vesell, Lang, White, Passananti, Tripp, Science (3) “Barbiturate Sleeptime in Mice Exposed to Autoclaved or Unautoclaved Wood Beddings.” Cunliffe-Beamer, Freeman, Myers 1981, Laboratory Animal Science (4)”Environmental and Genetic Factors Affecting the Response of Laboratory animals to Drugs” Vesell, Lang, White, Passananti, Hill, Clemens, Liu, Johnson. 1976, Federation Proceedings Vol 35 #5. (5)Bacterial counts associated with recycled newspaper bedding. 1990 Hogan, Smith, Todhunter, Schoenberger (6) From the”Guide for the Care and Use of Laboratory Animals” formerly called the NIH Guide (7) Harkness & Wagner Biology and Medicine of Rabbits and Rodents 4th ed 1995. (8 )TBLR 2nd Ed, Manning, Ringler, Newcomer 1994 (9) Rabbit Production 7th ed., McNitt, Patton, Lukefahr, Cheeke 1996 (10) Ferrets, Rabbits, and Rodents: Clinical Medicine and Surgery; Hillyer and Quesenberry 1997 (11) Possible Carcinogenic effects of cedar shavings in bedding of C3H-Avy fB mice. Vlahakis G, J Natl Cancer Inst. 1977 (12) Spontaneous hepatomas in mice inbred from Ha:ICR Swiss stock: effects of sex, cedar shavings in bedding, and immunization with fetal liver or hepatoma cells. Jacobs BB, Dieter DK. J Natl Cancer Inst. 1978 (13) Testing for possible effects of cedar wood shavings and diet on occurence of mammary gland tumors and hepatomas in C3H-A-vy and C3H-Avy-fB mice.Heston WE, J Natl Cancer Inst, 1975 (14)Bacterial counts associated with recycled newspaper bedding, Hogan JS, Smith KL, Todhunter DA, Schoenberger PS. J Dairy Science 1990 (15) Comparison of in vitro drug metabolism by lung, liver, and kidney of several common laboratory species. Litterst CL, Mimnaugh EG, Reagan RL, Gram TE, Drug Metab Dispos, 1975 (16) The effect of praziqunatel on the activities of some drug-metabolizing hepatic enzymes in rabbits. Kheir WM, Elsheikh HA, Hapke HJ, DTW Dtsch Tierarztl Wochenschr, 1995 (17) Dose related effect of aflatoxin B1 on liver drug metaboling enzymes in rabbit. Guerre P, Eeckhoutte C, Larrieu G, Burgat V, Galtier P, Toxicology 1996 (18 ) Comparison of hepatic and extrahepatic drug metabolizing enzyme activities in rats given single or multiple challenge infections with Fasciola hepatica.Biro-Sauveur B, Eeckhoutte C, Baeza E, Boulard C, Galtier P. Int J Parasitol 1995 (19) Effects of cage bedding on microsomal oxidative enzymes in rat liver. Weichbrod R, Cisar J, Miller R, Simmons A, Alvares A, Ueng T. Laboratory Animal Science 1988 (20) “Bedtime Story” by Dr S. Blake Hawley, Pet Age magazine, Nov. 1997 pg. 14-19

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-- The Duman's Ark Team
Sun, 05 Sep 2010 03:46:40 -0400