Housing Considerations for Hedgehogs
Wild hedgehogs are solitary; as pets they are usually housed in individual cages. Minimum floor dimensions of 2 × 3 feet (0.6 × 0.9 m) are recommended. Hedgehogs are able to climb and can escape through small holes, so the cage must be secure and preferably lidded. Sufficient ventilation is important when selecting an enclosure. Large, plastic storage containers or single-level, plastic-bottomed wire cages are suitable, provided that the wire is appropriately spaced. Widely spaced wires can result in limb entrapment or death. Glass aquariums are not recommended because of poor ventilation.
Providing a hiding place is essential. The cage substrate should be soft and absorbent. Recycled newspaper bedding is a good choice; other acceptable bedding options include aspen shavings, alfalfa pellets, and hay. Rough, dusty, or scented substrates are not recommended. Pieces of string or loose fibers of cloth can entrap hedgehog digits and limbs. The substrate should be 3–4 inches (8–10 cm) deep in at least some areas of the cage to allow for burrowing.
Ambient temperature should be 72°–90°F (22°–32°C); 75°–85°F (24°–29°C) is optimal. Hedgehogs may go into a torpid state if they are too cool or too warm; this is believed to be unhealthy. A heating pad placed underneath the enclosure or a ceramic reptile heater may be used. Low humidity (< 40%) is preferred. Hedgehogs avoid bright light; however, a photoperiod of 12 hours light and 12 hours dark should be provided.
Healthy hedgehogs are very active. Exercise wheels are highly recommended; running surfaces should be solid metal or plastic. Hedgehog legs can become entrapped in wire wheels; solid wheels are also easier to clean. Hedgehogs can be let out of their enclosures for supervised exercise. Plastic or paper tubes, hay, safe climbing structures, swimming tubs, and other toys provide enrichment.
Diet Considerations for Hedgehogs
The ideal diet for a hedgehog is a commercially prepared hedgehog or insectivore food. If hedgehog or insectivore-specific food is not available, a high-quality weight-management cat or dog food is an alternative. Food should be rationed to prevent obesity. Depending on the animal’s weight and activity, 3–4 tsp (15–20 mL) of the main diet is typically fed daily. Growing animals and reproductively active females may be fed ad lib, and supplementing calcium-rich foods is recommended.
In addition to the main diet, ~1–2 tsp (5–10 mL) of varied moist foods and/or invertebrate prey (eg, canned cat or dog food, cooked meat or egg, low-fat cottage cheese, mealworms, waxworms, gut-loaded crickets) and ~1 tsp (5 mL) of vegetable/fruit mix (eg, beans, cooked carrots, squash, peas, tomatoes, leafy greens, banana, grape, apple, pear, berries) should also be provided daily. Hiding invertebrate prey and dry food items in bedding promotes foraging. Hedgehogs should not be fed raw meat or eggs because of the risk of Salmonella Salmonellosis in Animals read more . Milk can cause diarrhea. Vitamin or mineral supplementation is not necessary for hedgehogs fed a balanced commercial diet. Hedgehogs are often slow to accept new foods, and diet changes must be made with care. Fresh water should be available at all times. Most hedgehogs quickly learn to drink from water bottles or bowls.
Breeding and Neonatal Care of Hedgehogs
Female hedgehogs should be at least 6 months old before breeding. A weight gain of ≥50 g within 3 weeks of having access to a male suggests pregnancy. Abdominal and mammary enlargement may be detected at 30 days. Risk of infanticide and cannibalism of the young can be reduced by providing the female with strict privacy from other hedgehogs and humans starting a week before delivery and for 1–2 weeks after parturition.
In cases of lactation failure or abandonment, fostering of the hoglets by another dam with similarly aged young is usually successful. If a surrogate dam is unavailable, a canine milk replacer may be fed through a feeding tube or syringe; however, hand-rearing of hedgehogs is associated with high mortality. Weaning generally occurs at 5–6 weeks, and the young may be moved to separate cages at 8 weeks. Daily handling starting at 3 weeks can help the hedgehog develop into a tame adult.
Restraint and Examination of Hedgehogs
Because most hedgehogs readily adopt a defensive posture (roll up into a tight ball) when handled or restrained, a thorough examination requires chemical restraint. Before handling, the hedgehog should be observed in the examination room. A superficial examination may be done while the hedgehog moves about within a transparent container (eg, evaluation of the ventrum is possible), in its cage, or on the examination table. Healthy, unstressed hedgehogs, even if initially shy, should be active and eventually unroll and attempt to explore their environments. Healthy hedgehogs normally walk with their ventrum raised off the ground, but weak or wary hedgehogs may crouch. When exploring, hedgehogs constantly lick a normally moist nose. Respiration is normally silent, except when the hedgehog hisses or huffs in defense. Normal feces are dark brown and very soft. In the spiny areas, skin may appear slightly dry or flaky, but excessive flaking, quill loss, erythema, and crusting are abnormal.
The rest of the examination can be done once the hedgehog is heavily sedated or anesthetized. Hydration may be assessed by eyelid and haired skin turgor. The eyes should be clear, and the pinnal margins free of crusting or ragged edges. African pygmy hedgehogs have small (≤3 mm diameter), long, horizontal ear canals, making routine otoscopic examination difficult and otoscopic examination of the tympanic membranes impossible. The oral cavity and tongue should be inspected for masses, signs of periodontal disease, dental fractures, ulcers, and foreign material. The teeth should be white, and the gingiva a uniform pink. Lymph nodes are normally difficult to palpate, but lymphadenomegaly may be present with neoplasia or infection. The heart should have a regular rhythm and no murmurs, and a femoral pulse should be palpable. The abdominal contour should be flat but may be distended by obesity, organomegaly, masses, or fluid.
In males of reproductive age, the large seminal vesicles may be mistaken for an abdominal mass because they extend from the pelvic inlet to the kidneys, dorsal to the bladder. The prepuce or vulva should be evaluated for evidence of inflammation, discharge, or adherent debris. Testicles are usually palpable in the para-anal area.
Digits should be inspected for encircling fibers and overgrown nails.
Clinical Techniques for Hedgehogs
Collecting sufficient quantities of blood from hedgehogs for blood testing can be challenging. Although the jugular veins can be used, they are difficult to locate because hedgehogs have short necks; a blind stick is required in most animals. Peripheral vessels (saphenous, cephalic, and femoral veins) can be used for small samples. Collection from the cranial vena cava should be done with caution because of the risk of inadvertent cardiac puncture; short needles and chemical immobilization should be used when collecting blood from this vessel. The proximal jugular veins can be used to collect large volumes of blood while avoiding inserting a needle into the thoracic cavity. The needle is inserted and advanced perpendicular to the skin surface at a palpable notch formed by a clavicle, the manubrium, and the cervical vertebral column.
Subcutaneous injections can be given in the spiny or furred areas; the furred skin is more elastic and vascular but less accessible. The dermis under the mantle is poorly vascularized, so superficial injections in this location may mean that medication will take longer to be absorbed. The junction of the haired and spined skin can also be used for subcutaneous injections. Intramuscular injections may be given in the triceps, quadriceps, gluteal, or orbicularis muscles. Intravenous catheters are usually dislodged if the patient curls. An intraosseous catheter may be placed in the tibial crest using a 22- or 25-gauge needle or a 1-in spinal needle; the catheter remains accessible even when the patient is curled.
Radiographic examination may be useful, but the spines in the hedgehog's mantle can obscure detail. For lateral views, the spines can be pulled away from the chest and abdomen and secured with a large plastic clip or taped down. Ultrasonography Ultrasonography in Animals Ultrasonography is the second most commonly used imaging format in veterinary practice. It uses ultrasonic sound waves in the frequency range of 1.5–15 megahertz (MHz) to create images of body... read more is a useful imaging modality in hedgehogs, especially to evaluate the abdomen. A CT Computed Tomography in Animals In computed tomography (CT), an x-ray tube moves around the body and continuously projects a thin fan of x-rays through the body. Electronic detectors opposite the tube continuously monitor... read more scan is helpful to image a variety of anatomic locations in hedgehogs and is most useful for dental, otic, respiratory, and skeletal disorders. Anesthesia or heavy sedation is generally required for proper positioning.
Oral medication is often difficult to administer. Some hedgehogs accept liquid medications that have been compounded with fruit flavor. Alternatively, medication may be injected into mealworms or mixed with a small amount of preferred food. Applying topical medications is complicated by the presence of spines and self-grooming behavior, and some odors may initiate self-anointing behavior Anatomy, Physiology, and Behavior .
A cage temperature of 80°–85°F (27°–29°C) is recommended for ill hedgehogs. Voluntary feeding is facilitated by providing the animal’s customary diet and by offering live invertebrates. Anorectic animals should be fed a canned, high-calorie canine or feline diet via syringe. For ongoing assisted feeding, an esophagostomy tube can be used, although anorexia can occur while the tube remains in place.
Hedgehogs are not bacterial hindgut fermenters, and there are no particular concerns regarding antimicrobial use. For appropriate drugs and dosages in hedgehogs, consult the Exotic Animal Formulary, 5E (2018) or other sources.
Anesthesia and Surgery for Hedgehogs
A 1–2 hour fast is recommended before anesthesia. Isoflurane is commonly used for induction and maintenance. After a period of preoxygenation, a common approach is to use 4%–5% isoflurane via chamber for induction, then 1%–2% via facemask for maintenance. Hypersalivation may occur, and premedication with atropine can be used. Although injectable agents may be used, recovery may be longer than with inhalant anesthesia alone. For heavy sedation, a combination of alfaxalone (3–5 mg/kg) and midazolam (1 mg/kg) SC can be administered and is partially reversed with administration of flumazenil (0.05 mg/kg, SC). Tracheal intubation may be indicated for longer or oral procedures and is accomplished with a 1–2 mm internal diameter endotracheal tube, intravenous catheter lined with polytetrafluoroethylene (PFTE), or modified feeding tube.
Spines are removed by clipping or pulling from the base with steady traction. Hedgehogs may self-mutilate traumatic or surgical wounds; prompt primary closure with subcuticular sutures should be done whenever possible. Bandages and dilute chlorhexidine baths are well-tolerated. If the cutaneous muscle is damaged, it must be closed in a separate layer. Contraction of the musculature used for rolling-up can cause wound dehiscence. Elizabethan collars are not practical.
Ovariohysterectomy is similar to the procedure in other mammals, although substantial fat surrounds the ovaries and mesosalpinx, making their identification difficult. Castration is performed via a para-anal skin incision over each testicle; a closed technique is recommended.
Preventive Medicine for Hedgehogs
Hedgehogs have a short life span and often hide signs of illness; therefore, complete examination and blood testing with chemical restraint are recommended every 6 months. There are currently no vaccines labeled or recommended for use in hedgehogs. Because hedgehogs are not usually housed in mixed-gender groups, castration and ovariohysterectomy are not generally requested. However, because of the high incidence of uterine disease reported in this species, prophylactic ovariohysterectomy should be strongly considered.