Steroids
by Julia Hands
General
Steroids are very potent drugs, with several known side effects, so vets may often seem reluctant to prescribe them for rats, but when prescribed correctly, can give the impression that they really are 'miracle drugs'. Sometimes, if a rat has had a stroke, or is struggling with certain breathing problems, one injection of a steroid (along with other meds usually) can be enough to help the rat towards full recovery.
The most common uses of corticosteroid steroids in rats are for respiratory problems, neurological problems such as stroke, pituitary tumour and ear infections which have symptoms of torticillosis (head tilt).
One of the most problematic side effects for rats being given steroids is that longer term use can weaken the immune system, leaving the rat susceptible to getting infections, and for this reason antibiotics are also prescribed when the steroid needs to be given for any amount of time. Steroids are not always needed to be given long term - as already mentioned - with ear infections, some respiratory problems and in some strokes - only 1 or 2 injections are necessary (often alongside other drugs), and then the rat should be on the road of recovery.
What are steroids?
The most commonly prescribed steroids for rats are prednisone and dexamethasone. Vets may call them by various trade names such as Prednicare or Decadron. Dexamethasone is more effective than prednisone for use in rats, presumably because of their fast metabolism.
Steroids are a type of hormones called Glucocorticoids and are produced naturally in the adrenal glands, and unlike the anabolic steroids that we hear about in relation to sports medicine; these are "catabolic" steroids. Instead of building the body up, they are designed to break down stored resources (fats, sugars, proteins) so that they may be used as fuels in times of stress. We do not use the glucocorticoids for their influences on glucose and protein metabolism; we use them because they are also the most broadly anti-inflammatory medications that we have. Glucocorticoids are not used for curative purposes but as an aid to help alleviate symptoms. Their uses include all kinds of anti-inflammatory uses, use on central nervous system disorders, to reduce the swelling around brain tumours and to improve circulation after shock, immunosuppression of allergic responses and so on.
Steroid use for respiratory problems
Sometimes when a rat is experiencing respiratory problems there may be an awful lot of inflammation present due to infection or other irritation - and this can cause the rat to gasp for air. As well as prescribing drugs such as antibiotics, diuretics and bronchodilators - the vet may give an injection of prednisone - one is often enough to make the rat more comfortable and breath more easily until the antibiotics and/or other medicines take effect.
Steroid use for ear infections and strokes
Both these problems in rats can display symptoms of a tilted head known as torticillosis. With a stroke the rat may be paralysed down one side of the body, this is more common in elderly rats. With ear infection the rat may lose balance altogether and circle or 'corkscrew' - this is due to inflammation and possible damage around the labyrinth structure of the inner ear, and inflammation to the vestibular nerve.
Treatment is the same for both problems - a course of systemic antibiotics to combat infection, as well as one or two injections of a steroid to reduce the swelling of the tissues. Generally, the sooner a rat with an ear infection is given the steroid, the less likely it will be left with a permanent head tilt, although rats that are left with a tilt cope with them perfectly well as long as the infection is gone completely.
Steroid use for pituitary tumours
A pituitary tumour is located in the brain and can cause various symptoms. Mot every rat will display them all, but it is common for them to have paralysis of the limbs, which manifests itself firstly as an inability to grip food with the hands. Eventually all 4 limbs will display stiffness. Sometimes a headtilt will also be present. These symptoms are caused as the tumour grows and presses on important areas of the brain. The tumour can be surrounded by inflammation and fluid, and prescribing a steroid will reduce the fluid and inflammation, to the point where the rat loses the symptoms of paralysis and headtilt initially. There is no cure for these tumours, and eventually the rat will lose quality of life as the tumour grows, but in the early stages of the disease, a strong steroid such as dexamethasone can greatly improve quality of life. It will be prescribed for the remainder of the rats life, and for this reason is best given orally by the rat's owner in food daily, and antibiotics will also need to be given the whole time.
Steroid use for other less common illnesses
Other more rare diseases that a vet may prescribe steroids for:
- treatment of conditions where the immune system is overactive, eg allergies which manifest as - skin problems where antiparasitic treatments have made no difference;
- cancer chemotherapy, for example the treatment of a lymphoma;
- shock;
- trauma to the spine which involves paralysis from inflammation around the discs.
Administration
It is important to work with your vet on prescibing and dosing, and I must stress the importance of weaning the rat off steroids gradually where they have been given for any length of time, and the rat has recovered - steroids should not be stopped suddenly unless the dose was very low and for a short period of time. Sudden withdrawal of drug may be fatal if it has been given over an extended period of time.
For most conditions a dose of 0.5 mg to 2.2 mg/kg is prescribed for both prednisone and dexamethasone. Dexamethasone use is preferable for rats for most of the above conditions. It is many times stronger than prednisone. The higher dose is usually necessary for pituitary tumours. For shock an even higher dose as a one-off is prescribed.
Steroids should never be given at the same time as NSAIDs such as Metacam or Rimadyl. At least 24 hours should be left between the two if a presciption is changed from one to the other.
Side effects
The side effects of administering steroids are many, and so I will not list them all. Suffice to say that they will not all necessarily show in each patient when prescribed. Each patient is individual and their body will react accordingly. Monitor your rat carefully and communicate with your vet straight away if you notice any changes, such as excessive thirst or urination, or symptoms of any type of infection. |
