ABSTRACT: There are many causes of life-threatening illness in rabbits and good nursing, palliative treatment and supportive care are important aspects of their treatment. Rabbits hide signs of serious disease and may be in a critical state before they are presented for veterinary treatment. Emergency care is often needed and an assessment of the rabbit's condition is necessary to decide on appropriate treatment. Radiography and blood sampling are important parts of this assessment. Rabbits are also prone to gut stasis, which is a preventable life- threatening condition that is often a secondary complication of other diseases.

Critical care is defined in Saunders Comprehensive Veterinary Dictionary as ‘the care of a patient in a life- threatening situation of an illness’.'Critical care in rabbits is further complicated by the fact that any painful or stressful situation can trigger a sequence of events that may result in death. Immediate palliative care and preventive supportive care are required. Both require good nursing skills.

Rabbits hide serious illness. In the wild, it is not in a rabbits interest to alert a potential predator to them if they are unwell, so sick rabbits tend to sit quietly, out of view (Figure 1). There are many life-threatening conditions that are common in rabbits and it can be difficult to know when they require critical or emergency care, or whether the rabbit is just sitting quietly.

Figure 1: Rabbits that are seriously ill will unresponsive and totally anorexic

 A triage system can be used to place a sick rabbit into one of three groups:

Cold, shocked and moribund

These cases are emergencies and the signs are non-specific. Immediate palliative treatment is necessary, just to keep the rabbit alive. Treatment is often given in the absence of a diagnosis

•   Depressed and unresponsive: These cases are urgent but immediate care is not vital. There is time to start diagnostic procedures and consider what the diagnosis might be

•   Rabbit alert and responsive: These cases require further investigation and treatment, but there is time to come to a diagnosis before treatment is started.

Effects of stress and pain

A major effect of stress or pain in rabbits is slow gut motility, which is an ever-present threat in this species. Gut stasis is potentially fatal, but can be prevented or treated.

Reduced food intake decreases absorption of nutrients from the digestive tract and results in a negative energy balance, so fat is broken down as an energy source instead. Free fatty acids are transported from the fat to the liver where a metabolic bottleneck easily develops and causes liver failure from hepatic lipidosis (Figure 2).

Figure 2: Fatty infiltration and degeneration of the liver is the end stage of untreated gut stasis. Figure 2 shows the liver of a rabbit that was cold and ataxic when it was brought for treatment. It died shortly after admission. The owner didn't know when it had last eaten

Fat in the blood (lipaemia) is a sign of this condition (Figure 3).

Figure 3: The milky appearance of the plasma in this blood sample is indicative of lipaemia, which carries a poor prognosis. It is often seen in association with hepatic lipidosis

Gastric ulcers readily occur in stressed rabbits. Shock develops rapidly in seriously ill rabbits and is manifested by hypothermia, bradycardia, poor peripheral circulation, a drop in blood pressure, mental confusion and ataxia.

Assessment of the critically ill rabbit

It can be hard to know how seriously ill a rabbit is. They do not vomit, kick, sweat, tremble or show obvious signs of abdominal pain and there can be problems with measurable parameters in rabbits. For instance, a rabbits pulse is hard to find and their normal heart rate is often uncountable.

Their respiratory rate is easily increased by the stress of a car journey or sitting next to a barking dog in the waiting room. A rabbits rectal temperature can vary normally over a wide range. Feeling its ears and feet can is quick and can be as useful as using a thermometer.

Despite the problems with interpretation of measurable parameters, monitoring the mental state, heart rate, rectal temperature, mucous membrane colour, respiration and blood pressure are all useful to assess a critically ill rabbit and its response to treatment.

In order to make a definitive diagnosis, a thorough clinical examination by a vet is necessary, but abdominal radiography and blood samples can yield valuable information and these procedures can easily be carried out by a nurse.

Radiography

Abdominal radiography is often diagnostic and can be performed without sedation. To take a conscious lateral abdominal radiograph, the rabbit should be picked up gently, without scruffing, and quietly positioned on the cassette. A long sandbag over the neck and a towel over its head are all that is needed to restrain it as most rabbits quickly go into a trance and lie still (Figure 4).

Figure 4: The rabbit shown in this picture is not sedated or anaesthetised. It is lying quietly on the cassette and is positioned for a lateral abdominal radiography, which can be diagnostic in many cases

Switching off the lights, moving slowly and making a quiet ‘shooshing’ noise help to keep the rabbit calm. Loud noises, sudden movements, firm restraint or leg ties are counterproductive as they stimulate the rabbit to move and try to escape.

Blood screen

Only two to three drops of blood are required for a useful 'mini-blood screen’, which can be performed in any practice. The marginal ear vein is an easy site from which to collect blood.

Blood glucose is a useful parameter that can be measured with an inexpensive portable glucose meter, designed for human use and available from most pharmacists (Figure 5).

Figure 5:Blood glucose is a useful parameter that is easy to measure in rabbits. Diabetes is rare but blood glucose levels can rise rapidly in response painful abdominal conditions. Levels above 20mmol/l signify conditions that carry a poor prognosis and may require prompt surgery

In addition to blood glucose measurement, a few' drops of blood can be collected into a heparinised capillary tube and spun to measure PCV (packed cell volume) and to look at the colour of the serum which may show lipaemia or jaundice (Figure 6).

Figure 6: Collecting blood from the ear vein is a simple procedure. Only a few drops are required for glucose measurement, total protein, packed cell volume IPCV1 and visual assessment of the serum

Serum total protein can be measured by breaking the spun haematocrit tube and expelling a couple of drops of the serum on to the spectrometer.

Palliative care of critically ill rabbits

Maintaining body temperature

Providing warmth is absolutely essential for the treatment of moribund rabbits. Raising body temperature increases heart rate and blood pressure. Heat pads, hot water bottles or blowing the rabbit with a hair dryer can help to increase the body temperature.

Analgesia

All ill rabbits require analgesia. This is a fundamental rule of rabbit medicine. Pain is stressful and stress kills rabbits. NSAIDS and opioids are well tolerated and can be used in a number of combinations.

Fluid therapy

Intravenous fluid therapy is recommended for shocked rabbits, although care is needed not to over perfuse them, which causes pleural effusion, pulmonary and peripheral oedema and is very difficult to reverse.

The marginal ear vein is the simplest to access and the cephalic vein is an alternative. In the absence of electrolyte and acid/base blood results, Hartmanns (lactated Ringers) solution is the best choice of fluid and must be warm.

A 22/24g butterfly set or intravenous catheter and a paediatric giving set (60 drops/ml) are used to administer the fluids. An initial infusion rate of approximately 10ml/kg/hour is recommended – one drop every two to three seconds for an average’ (approximately 2.5kg) pet rabbit. If necessary, this rate can be increased to 15mls/kg/hour after 10-15 minutes when the rabbit has warmed up.

The total volume of fluid is <100ml/kg but this amount varies with the clinical condition of the rabbit and its response to treatment.

Maintaining rabbits on fluids for more than a few hours is seldom necessary. Once they are rehydrated and warm, most rabbits start to interfere with the drip so it is preferable to electively take it down and maintain fluid balance orally. Nutritional support with syringe feeding will be required anyway, unless the rabbit starts eating and drinking on its own.

Oxygen

Oxygen can be life-saving for dyspnoeic rabbits. Ideally an oxygen cage should be used, but it is easy to make a makeshift oxygen tent by placing a cat basket containing the rabbit in a ventilated plastic bag or covered basket with towel. One hundred per cent oxygen can be piped in close to the rabbit's nose. The sPO, may be monitored using a pulse oximeter with the probe on the edge of the ear.

Dyspnoeic rabbits require minimal handling as any exertion makes it harder for them to breath. It can be difficult to control their body temperature. Hyperthermia occurs readily because rabbits cannot pant effectively to dissipate the heat and is made worse if the rabbit cannot move away from a heat source.

Conversely, many rabbits with cardiorespiratory disease are shocked and hypothermic; so common sense, consideration and monitoring are required to control the rabbit s body temperature within a comfortable range.

Supportive care

Nutritional support

Syringe feeding is necessary for any rabbit that does not eat on its own (Figure 7). Various foods are available but the author prefers a 50:50 combination of commercial product (such as Oxbow Critical Care or Supreme Recovery) and baby cereal (Heinz cereal for babies aged 4-6 months, for instance).

Figure 7: Syringe feeding is recommended for any rabbit that has not eaten for more than 12 hours. It is a simple, safe procedure but requires time and patience. Most rabbits tolerate it well and will take food from a syringe even if they are not eating voluntarily

The cereal is fruit flavoured, palatable and helps the mixture go through a syringe easily. Approximately 10-20ml/kg of the mixture three or four times daily is a satisfactory amount. In the authors opinion, nasogastric or nasoesophageal tubes are seldom (or never) necessary. It is not possible to administer fibrous foods through them. Damage to the nasal mucosa, inhalational pneumonia, regurgitation or gastric reflux are potential serious risks.

General nursing care

Providing tempting food, a comfortable environment and keeping a rabbit clean and medicated are all very important steps to recovery. For example, cleaning the nostrils of a rabbit that has a nasal discharge and applying nose drops can be beneficial, especially before it is fed. Rabbits with soiled wet fur around the tail benefit greatly from having all the fur carefully removed with clippers and scissors (Figure 8).

Figure 8: Clipping away wet soiled fur from under the tail, around the perineum and on the inside of the hind legs is essential for rabbits with urine scalding, fly strike or faecal contamination of the fur

Removing all the matted, soiled fur allows the skin to dry out and heal. Soothing ointments can be applied easily. If the rabbit has ‘fly-strike’, the maggots can be seen and removed. 

Author

Frances Harcourt-Brown

BVSc DipECZM(Small Mammal) FRCVS

Frances Harcourt-Brown graduated from Liverpool University in 1973 and has been in general practice ever since. In partnership with her husband Nigel, she owns and runs a small animal practice in North Yorkshire. She has lectured in many countries around the world, has received many awards for her work and is the author of the Textbook of Rabbit Medicine.

To cite this article use either

DOI: 10.1111/|.2045-0648.2011.00119.x or Veterinary Nursing Journal Vol 26 pp 443-446

Reference

1 BLOOD. D C . STUDOERT. V P and GAY. C. C [2007] Saunders Comprehensive Veterinary Dictionary 3rd Ed Saunders Elsevier Edinburgh

Further Reading

HARCOURT • BROWN. F M [2002] Textbook of Rabbit Medicine Butlerworth-Heinemann. Oxford

• VOL 26 • December 2011 • Veterinary Nursing Journal