Degus

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Introduction

What is a Degu? The jury is still out. The first Europeans to set eyes on them in the eighteenth century regarded them as some type of squirrel. That is now known to be way of the mark. More recently the consensus has been that it is an aberrant rodent more closely related to the chinchilla or the cavy, with which it shares certain similarities, although the latest generic research does seem to suggest that it is not a rodent at all, but a lagomorph and therefore more closely akin to rabbits, hares, and pikas. But maybe we shouldn’t make too much of this. Classifying organisms into strict zoological groupings is largely a man-made discipline and there will always be a few species that cannot be so conveniently pigeonholed. But, for the sake of this article, I will continue to address them as rodents until more research yields the truth. 

Occasionally referred to as Octodonts (on account of the shape of the grinding surface of their molar teeth, which form a figure of ‘8’), the degu is active and inquisitive (hallmarks of the worldwide success of rodents). It is also rising in popularity. Five years ago few people had heard of them, even less had encountered one, but now more and more often it is offered for sale in pet shops. 

The Octodont family evolved in the early Oligocene (some 36 million years ago). There are three species in the genus ‘Octodon’, of which O. degus is the only one seen in captivity in Great Britain. O. degus is slightly smaller than the other two species in the genus. They rarely bite but, like many other rodents, the tail is easily shed, so avoid grabbing or restraining it by the tail. If the tail is grabbed, the skin and fur is stripped off (leaving the degu apparently none the worse for wear), leaving just bare bones behind. Sometimes the animal will bite of the naked vertebrae and tendons. If it does not, the bone, deprived of blood supply, will drop off. The tail does not re-grow.

In the wild the degu is found in the Andes Mountains in northern and central Chile. Reports in earlier zoological tomes that the species also occurs in neighbouring Peru are thought to be a mistake due to an escaped specimen having once been found there.

It is found in relatively open habitat where it constructs a maze of burrows. Debris at the entrance holes in the form of sticks, stones and droppings may serve as territorial markers. It does not hibernate, but a certain amount of food may be stored for winter use, when food is otherwise scarce.

Feeding

Like some other rodents, degus are sugar-intolerant – they are especially prone to diabetes – so the food must be free of fructose (fruit sugars). In the wild they eat seeds, grasses and other plant material. In captivity, rather than feeding ordinary rodent mix (which can be high in sugar); give a good base food of chinchilla pellets to which may be added a small quantity of Gertie Guinea-Pig™ or Charlie Chinchilla™. Some people offer, as a treat, broccoli, sweet potato, raisins, or sugar-free water biscuits. Obesity is another common cause of diabetes, as it is with the human animal.

Good quality hay is essential, both as a food and bedding material, but remember to replace it regularly before it gets damp or soiled.

It has been suggested that Vitamin C should be added to the drinking water every other day as this, whilst being beneficial generally, may also help prevent mouth diseases, to which they seem quite susceptible.  As with so much about degus, that has yet to be proved.  But, even in fairly large quantities, Vitamin C is normally quite safe.  Being one of the water-soluble vitamins, it breaks down easily in the body, unlike the fat-soluble vitamins, which are stored in the body and can, in excess, prove toxic.

There is a lot of controversy regarding the type of drinking water safe for degus.  This is a matter that needs to be urgently clarified.  Some keepers suggest hyperchlorinated water (i.e. water with added chlorine), whilst others adamantly claim that only hypochlorinated water (water with chlorine removed) should be used.  Some even buy bottled or mineral water to give to their degus.  So what is the truth?  Admittedly, tap water does contain high levels of chlorine, but I have always used tap water and never had any problems.  To date, I have not lost a single adult degu from this or form any other cause, whereas at least one person I have spoken to, who buys large quantities of expensive bottled water for his degus, has lost several from various causes.  If you are worried about the chlorine content of tap water, I suggest leaving it to stand in a bucket overnight.  Chlorine is a very unstable chemical and soon evaporates into the atmosphere.  Matthew Wright and I would welcome more information about the confusing and thorny dilemma of degus’ drinking water.

Ideally provide the water in a glass drinking bottle, or open ceramic dish, as plastic will invariably be gnawed.  Unlike plastic, there is no danger of the glass leaking harmful chemicals into the water.  Glass bottles, however, do not seem to be universally available and you might have to visit several pet stores before you find one.

They enjoy and occasional sand bath in chinchilla sand, available from pet stores.  A gnaw stone (similar to that given to chinchillas) can help prevent the incisors from becoming overgrown, and a cuttlefish wired to the inside of the cage can strengthen teeth and prevent broken teeth.

The incisor teeth are normally orange in colour.  A whitening of the teeth is usually indicative of a serious health problem.

Housing

A roomy tall cage is required. The degu is very destructive to plastic and wood, so the cage must be construct of weld mesh. The substrate can be wood shavings, but make sure they are coarse with minimal dust content. Excessive dust in the scatter material is irritating to mucus membranes and can even precipitate pneumonia. Avoid pinewood if possible, as there is some evidence this can harmful. Some rodent-keepers remain staunch advocates of wood-based cat litters (in the form of wood pellets). Personally I don’t like this material. I find that most rodents will chew it into a very fine and unpleasant dust. In doing so, they ingest a fair quantity of it and, being so desiccated, it can expand when it encounters the moist environment of the gut and, perhaps, cause impaction.

Furnish the cage with a wooden sleeping box (which may need replacing periodically), wide-diameter pipes (sections from sewage pipes are perfect), and branches for climbing. Wood from (unsprayed) fruit or willow trees is ideal. Scrub the braches well in mild soapy water to remove moss, lichen, bird dropping, etc, and then allow it to dry before placing in the cage. You can safely leave the bark on, as not only will it provide occupational stimulation for the degus to strip off the bark, but it provides valuable trace elements as well. And, of course, natural wood is invaluable as a knowing aid.

Their droppings are dry and innocuous; degus are generally clean animals, which will not offend the most house-proud of owners, and cleaning out the cage once a week is normally sufficient.  I do not clean out the cage when the degu babies are present.

Behaviour

It is common, with population densities varying from 10 animals per hectare to 260 per hectare, although 40-80 per hectare is probably nearer the average; and in some agricultural provinces it is considered a pest. It should go without saying that a communal species such as this should be kept in pairs or small colonies in captivity, not as single animals. They seem more tolerant than most other rodents to the introduction of strangers into the cage. If the cage is big enough, it is possible to allow them to share with another species, but, since degus must not be given standard rodent mix (for reasons I will expound upon in the Feeding section), any companion must be able to thrive on the degus’ diet. Recently I had a pair of degus living in an indoor aviary with two chinchillas and four African Striped Mice. This experimental mixing went well, although the grass mice did seem a little rather intimidated by their larger cage companions, and eventually I removed the mice.

Degus are diurnal, being most active in the morning and late afternoon, and thus the species appeals to the pet-keepers, who want to see their pet do more than just sleep.

Degus communicate with a variety of high-pitched whistling and growling noises.

Breeding

Sexing prevents few problems and, even in young animals, it should be quite easy to tell the sexes apart, the anal-genital distance being approximately twice as far apart in males as in females.  In mature specimens the testes of the male are also clearly visible.

In captivity the degu seems to breed throughout the year, whereas, in the wild, it appears to be a more seasonal breeder.  Sexual maturity is attained at about 6 months, although it can be considerably earlier.  My first pair of degus mated successfully at just 3 months of age.  Like the rabbit, the female degu does not have a regular breeding cycle, but seems to be an induced ovulator and thus it is the physical act of mating that stimulates egg production.  The gestation period is 90 days.  Litter size varies from 1-10, but I venture to suggest that large litters are rare, and 5-6 young is closer to the norm.  Babies are born fully furred with their eyes open and are capable of running around almost immediately.  You can safely leave the father with babies, as he will not harm them.  Weaning occurs at about 5-6 weeks of age, but the young should remain with their parents for at least 8 weeks. Longetivity is between 5-7 years.

By Russell Tofts