Rodents: physical examination and emergency care

image of Rodents: physical examination and emergency care
Online Access: £ 25.00 + VAT
BSAVA Library Pass Buy a pass


Unfortunately, as rodents are prey species, clinical signs are often masked until the course of the disease is far advanced and the pet is presented on an emergency basis. The principles of emergency and critical care apply equally to rodents, but the anatomical, physiological and behavioural differences of these species require careful consideration when developing an initial plan of emergency therapy. Many rodents are highly predisposed to stress and so rapid evaluation and patient stabilization are often required before complete evaluation for a definitive diagnosis can be performed. This chapter explains Patient handling and restraint; History and physical examination; Clinical techniques; and Triage of the emergency rodent patient.

Preview this chapter:
Loading full text...

Full text loading...



Image of 2.1
2.1 Restraint of a gerbil using the scruff-of-the-neck technique.
Image of 2.2
2.2 Restraint of a hamster by grasping the abundant skin over the back and shoulders.
Image of 2.3
2.3 Restraint of a mouse by grasping the base of the tail with one hand and the scruff of the neck with the other hand.
Image of 2.4
2.4 Restraint of a rat by placing a forefinger below the mandible on one side of the head and a thumb on the opposite side, above or below the forelimb, with the tail and hind limbs held with the opposite hand. (Courtesy of Angela Lennox.)
Image of 2.5
2.5 Proper restraint of a chinchilla, supported with one hand under the thorax and a second hand around the rump. (Courtesy of Emma Keeble)
Image of 2.6
2.6 An insulin syringe (0.3 ml) with a swaged small-gauge needle and the plunger removed can be introduced into the vein. The blood is then collected from the hub of the needle inside the syringe barrel into heparinized haematocrit tubes.
Image of 2.7
2.7 A small-gauge hypodermic needle can be introduced into the vessel and blood collected in the same manner; however, the use of the syringe barrel technique often provides greater stability of the needle in the vessel during blood collection.
Image of 2.8
2.8 The lateral tail vein can be used to collect small to moderate amounts of blood from a rat. A tourniquet may be applied to the tail base. The needle is inserted on the lateral surface of the tail to the level of the vertebrae. Gentle negative pressure may be applied to the syringe, or the sample may be collected by free flow into a suitable container. (Courtesy of The Comparative Biology Centre, Newcastle University.)
Image of 2.9
2.9 Correct positioning of the needle for vena cava puncture in a guinea pig cadaver. Larger rodents such as the guinea pig and chinchilla do not have a well developed clavicle. A 25 or 27 gauge 5/8 inch needle is inserted cranial to the first rib, lateral to the notch of the sternum and directed at an angle of 45 degrees towards the opposite hip. The cranial part of the mammal is where the needle and syringe are located in the photograph. (© Vittorio Capello.)
Image of 2.10
2.10 Correct positioning of the needle for vena cava puncture in a golden hamster cadaver. Most smaller rodent species have a well developed clavicle and placement of the needle cranial to the clavicle makes blood collection easier. Incorrect placement of the needle between the clavicle and first rib makes blood collection more difficult in all of the smaller rodent species (mouse, rat, gerbil, hamster) since the needle is forced laterally. The head of the animal is to the right of the photographs. (© Vittorio Capello.)
Image of 2.11
2.11 The femoral vein can be used for venipuncture in sedated or anaesthetized patients and often yields an adequate blood sample. The site is identified by palpation of the femoral artery and the needle is inserted and directed parallel and medial to this. The venipuncture site should be held off for several minutes after collection if the femoral artery is sampled inadvertently.
Image of 2.12
2.12 Intravenous catheters can be placed in the cephalic, lateral saphenous or femoral veins in larger rodents such as chinchilla, guinea pig and rat. Correct placement of an intravenous catheter in the cephalic vein the lateral tail vein of a rat. (b, courtesy of The Comparative Biology Centre, Newcastle University.)
Image of 2.13
2.13 Common sites for intraosseous catheter placement in the rodent include the femur through the trochanteric fossa, or the tibia (as shown here) through the tibial crest. Placement is similar to normograde insertion of an intramedullary pin and requires strict aseptic technique during placement and maintenance.
Image of 2.15
2.15 Cardiopulmonary–cerebral resuscitation flow chart showing the treatment protocol for respiratory arrest and treatment of common arrhythmias during cardiac arrest. PEA = pulseless electrical activity.
Image of 2.16
2.16 Guinea pigs have a palatal ostium that can easily be traumatized during intubation. To minimize trauma: an otoscopic cone can enhance visualization of the larynx; a stylet is then placed into the larynx, allowing the endotracheal tube to be manipulated gently past the palatal ostium.
Image of 2.17
2.17 If a rodent is showing signs of respiratory distress but does not require intubation, the patient should immediately be placed in a quiet oxygen-enriched environment. If a commercial oxygen cage is not available, one can be fashioned from a small pet carrier covered with a plastic bag or, if the animal is small enough, the patient can be placed inside a large anaesthetic facemask to provide an oxygen-enriched environment.
Image of 2.18
2.18 An electrocardiograph can be used to evaluate cardiac rhythm. Atraumatic alligator clips or clips attached to hypodermic needles placed in the skin can provide appropriate signal conduction while minimizing trauma.
Image of 2.19
2.19 Pulse rate and subjective changes in pulse quality by evaluating loudness of signal can be assessed using a Doppler ultrasonic probe placed over an artery. Indirect blood pressure monitoring can be performed using a Doppler ultrasonic probe to detect the arterial flow, a pneumatic pressure cuff to occlude arterial blood flow and a sphygmomanometer to measure pressures.
Image of 2.20
2.20 Administration of intraperitoneal fluids in a rodent. The needle is inserted in the left lower quadrant with the head of the patient lower than the abdomen to allow the viscera to slide forward. Sterile technique is recommended, to avoid peritonitis. (Courtesy of Emma Keeble.)
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error