Before performing any clinical technique, the associated legal and ethical considerations should be consulted, knowledge of the potential complications/ limitations/ risk should be gained, and the level of expertise and qualification required must be ascertained.

A detailed description of fluid therapy is available. (See: Fluid Therapy for Hedgehogs)
Consult the pages in combination, as necessary.

• The subcutaneous route it the most frequently used injectable route for fluid therapy and drug administration in the hedgehog. (V.w26)
• Subcutaneous injection can be performed in the conscious or anaesthetised hedgehog.
  • General anaesthesia is not required for the technique.

• Subcutaneous injections can be given over the spined area of skin between parted spines (J15.21.w1); over the back and flank. (B156.7.w7, B291.12.w12)
• Injections are given superficial to the panniculus muscle. (B228.11.w11, V.w26, J138.60.w1) (see: Dermis, Subdermis and Epidermis - West European hedgehog Erinaceus europaeus - Appearance- Morphology- Skin-Coat-Pelage (Literature Reports) for more information about the panniculus muscle)

• Ensure that all equipment is available prior to starting the procedure.
• Ensure adequate restraint of the patient; subcutaneous injection can be performed in the conscious or anaesthetised hedgehog. 
  • (See: General Anaesthesia of Hedgehogs)
  • (See: Catching and Handling of Erinaceus europaeus - West European Hedgehog)
• Select an injection site without gross contamination (e.g. visible mud, faeces). 
  • Cleaning of the site is essential if the hedgehog is heavily contaminated.
  • Preparation of the surgical site is complicated in comparison with other mammals by the presence of spines.
• Some authors may recommend disinfection of the site with surgical spirit prior to injection.
• Select an appropriate needle size (gauge and length) and syringe size for the hedgehog casualty.
  • A 21-23 gauge, five-eighths inch hypodermic needle may be used for subcutaneous injection in the hedgehog. (V.w26, V.w44)
• A small area of skin should be raised by elevating a few spines by hand or using a pair of soft forceps. (B228.11.w11, B284.6.w6, B291.12.w12, V.w26, J138.60.w1)
• The needle can then be inserted orientated into the subcutaneous tissues of the fold of skin which is formed (parallel to the body surface (B291.12.w12))
• Draw back on the barrel of the syringe to make certain that the needle is not in a blood vessel.
• Deliver the injection slowly but steadily, checking for leakage around needle.
• Large volumes of fluids can be given at a slow continuous rate using an infusion pump.
• Large volumes of fluids should be split by injection at multiple sites to avoid excessive skin distension at a single site and to increase the efficiency of absorption.
• If an injection has been given on one side of the body, the next injection should be given on the other side.
• Check the patient for evidence of pain or discomfort if conscious during the injection, alternatively continue to carefully monitor the general anaesthetic.
• Withdraw needle slowly upon completion. If leakage occurs, attempt to apply pressure to the injection site with cotton wool, although the presence of spines may make this difficult.
• Carefully massage the site, where possible, to ensure optimal distribution of drugs. 
• Check for bleeding from the injection site and apply pressure to aid clotting if this occurs.
• Clean any excess blood from the area after clotting has been achieved. 

• This is the most frequently used injectable route for fluid therapy and drug administration in the hedgehog. (V.w26)
• Medications can be quickly and easily administered in the conscious hedgehog via the subcutaneous route.
• The subcutaneous route is the most commonly used for warm fluid administration to hedgehog casualties on arrival. (J60.1.w1, P8.3.w2, V.w26)
• Larger volumes can be given than by the intramuscular route (See: Intramuscular Injection of Hedgehogs)
• Large volumes of (isotonic: 270-310 mOsm/l) fluids can be given quickly and easily.
• Fluid types often selected for the subcutaneous route include dextrose/ saline or Hartmann's solution with 5% added Duphalyte^® (Fort Dodge Animal Health) solution. (P8.3.w2, V.w26)

• Manufacturer's data sheet recommendations should be followed as to the recommended rate of drug administration (subcutaneous, intramuscular, intravenous).
• Limited tissue trauma if volumes are appropriate.
• Fluids given by this route must be isotonic (270-310 mOsm/l).

• Subcutaneous fluids are absorbed slowly over a period of several hours. However, large volumes divided between several sites can be given at the same time. (B150.w1)
• Subcutaneous fluid absorption rates can be particularly slow in shocked patients with collapsed peripheral perfusion.
• Reduced efficacy in casualties with poor peripheral circulation (peripheral vasoconstriction) due to shock, hypothermia or severe dehydration. (D92)
• Large volumes of fluids may be uncomfortable or painful on injection.
• Multiple sites may be needed to deliver needed large volumes.
• Skin necrosis and ulceration may occur if irritating drugs are used.
• Over-distension of the skin with fluids may disrupt the local blood supply and therefore decrease the rate of fluid absorption.
• Care must be taken not to puncture the body wall and give an accidental intraperitoneal injection.(J138.60.w1)

• Appropriate sizes of needles and syringes.
• Required fluids/drugs.

• Procedure should only be undertaken by an individual with appropriate clinical training and practical experience; this would usually be someone with veterinary training.

• Inexpensive unless expensive drugs are being used.

Use of Drugs (Medication):

• Many drugs are not registered for use in particular species and care should be taken in their use, with proper regard for possible toxic effects. Consideration should be give to relevant legislation regarding the use of drugs.
• In the UK, guidelines regarding the use of drugs are set out in the Royal College of Veterinary Surgeons Guide to Professional Conduct 2000: (see: LCofC1 - RCVS Guide to Professional Conduct 2000 - Choice of Medicinal Products).