Management of Hedgehogs
Wild hedgehogs are solitary; as pets they are usually maintained in individual cages. Some fanciers successfully house multiple animals together, but this can lead to disproportionate feeding and injuries from fighting. Healthy hedgehogs are very active; 2 × 3 ft are minimal floor dimensions. Hedgehogs are able to climb and can escape through small holes, so the cage must be secure and lidded. Glass tanks and plastic-bottomed cages with wire walls are suitable, provided that the wire spacing is sufficiently close. Widely spaced wires can lead to limb entrapment or death if the hedgehog’s head becomes ensnared by its spines. A hiding place is essential. The cage substrate should be soft and absorbent. Recycled newspaper bedding is a good choice; aspen shavings, alfalfa pellets, and hay are other options. Wire, cedar, corncob, and dusty or scented substrates are not recommended, and cloth bedding poses a risk of limb entrapment. The substrate should be 3–4 in. deep to allow for digging.
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 too cool or too warm; this is believed to be unhealthy for pet hedgehogs. 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 day cycle of 10–14 hr of mild light should be provided. Although some owners may attempt to convert their pets to a diurnal schedule, most remain nocturnal.
Some hedgehogs use a litter tray; natural plant litters used for cats make the best litter substrate. Clay, clumping-type litter, or sand may stick to the animal and should not be used. Many hedgehogs defecate in their hide boxes and exercise wheels, so daily spot cleaning is often necessary. Exercise wheels with solid metal or plastic running surfaces are highly recommended. Hedgehog legs can become entrapped in wire wheels. Hedgehogs should be let out daily for exercise. Cardboard tubes, straw, safe climbing structures, swimming tubs, and other toys provide interest. Dirty hedgehogs may be bathed with a mild pet shampoo and use of a soft-bristle vegetable brush.
The ideal diet is a commercially prepared hedgehog food. If hedgehog food is not used, premium food for less active cats or dog food are alternatives. 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 calcium-rich foods are 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, earthworms, 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. Invertebrate prey and dry food items may be hidden in the bedding to promote foraging. Hedgehogs should not be fed raw meat or eggs, which may harbor Salmonella. Milk can cause diarrhea. Vitamin or mineral supplementation is not necessary for hedgehogs fed a 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 can learn to drink from water bottles.
Females should be at least 6 mo old before breeding. A weight gain of ≥50 g within 3 wk of breeding suggests pregnancy. At 30 days, abdominal and mammary enlargement may be detected. Infanticide and cannibalism of the young can occur; the female needs strict privacy from other hedgehogs and people starting ~5 days before delivery and continuing 5–14 days after parturition.
In cases of lactation failure or abandonment, fostering of the pups (or “hoglets”) to another dam with similarly aged pups 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 wk, and the young may be moved to separate cages at 8 wk. Daily handling starting at 3 wk will result in hedgehogs that remain tame.
Because most hedgehogs roll up when restrained, a thorough examination usually requires chemical restraint. Before sedation, the hedgehog should be observed in the examination room. Healthy, untroubled hedgehogs should be active and walk with the ventrum raised off the table, but weak or wary hedgehogs tend to crouch. The nose is normally moist and active. Respiration is normally silent, except when the hedgehog hisses in defense. Normal feces are dark brown and very soft to pellet-like. The skin in the spiny areas may have a mildly dry or flaky appearance, but excessive flaking, quill loss, erythema, and crusting are abnormal.
Once the hedgehog is sedated or anesthetized (eg, with isoflurane at a light plane), the remainder of the examination can be performed. Hydration may be assessed by eyelid turgor. The eyes should be clear, and the pinnal margins should be free of crusting or ragged edges. The teeth should be white and the gingiva a uniform pink. The oral cavity and tongue should be inspected for ulcers, foreign material, and masses. Normal lymph nodes are difficult to palpate, but they may become enlarged in cases of 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. The prepuce or vulva should be checked for inflammation, discharge, or adherent debris. Testicles may be palpable in the para-anal area. The toes should be inspected for encircling fibers and overgrown nails.
The jugular vein can be used to collect blood samples; its anatomic location is similar to that in other small mammals. Alternatively, the cranial vena cava may be used, but there is a greater risk of cardiac puncture because of the relatively cranial position of the hedgehog heart. The femoral, lateral saphenous, or cephalic veins may be used for injections or to collect small samples (up to 0.5 mL).
SC 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 spiny skin is poorly vascularized, so drugs or fluid given in this location may not be absorbed for several hours. The junction of furred and spined skin provides an accessible and reliable site. IM injections may be given in the triceps, quadriceps, gluteal, or orbicularis muscles. IV catheters are usually dislodged if the animal curls. An intraosseous catheter may be placed in the tibial crest using a 22- or 25-gauge needle or 1-in. spinal needle; the catheter remains accessible even when the animal is curled.
Radiography may be useful, but the hedgehog’s spines can obscure detail. For lateral views, the spines can be pulled away from the chest and abdomen and secured with a large plastic clip. Anesthesia is generally required for proper positioning.
Oral medication may be difficult to administer. Some animals accept liquid medications that have been compounded with fruit flavor. Alternatively, medication may be injected into mealworms or mixed with a favorite food. Applying topical medications is complicated by the presence of spines and self-grooming, and some odors may initiate anting behavior (see Hedgehogs: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 high-calorie canine or feline diet via syringe or tube. For ongoing assisted feeding, a pharyngostomy or esophagostomy tube can be placed.
Hedgehogs are not bacterial fermenters, and there are no particular concerns regarding antibiotic use. For appropriate drugs and dosages in this species, consult the Exotic Animal Formulary (2013) or other sources.
A 4- to 6-hr fast is recommended before anesthetic procedures longer than 20 min. Isoflurane is commonly used for induction and maintenance. Hypersalivation may occur, and premedication with atropine is advised. Ketamine, diazepam, midazolam, xylazine, and toletamine/zolazepam have also been used but may prolong recovery. Tracheal intubation may be indicated for longer or oral procedures and is accomplished with a 1.0–1.5 mm endotracheal tube, Teflon IV catheter, or feeding tube.
Spines are removed by clipping or with steady traction. Hedgehogs may self-mutilate traumatic or surgical wounds; prompt primary closure with subcuticular sutures should be used 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 rolling-up musculature 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. Castration is performed through a para-anal skin incision over each testicle; a closed technique is preferred.
Hedgehogs have a short life span and often hide signs of illness; therefore, examinations (under isoflurane anesthesia) every 6 mo with blood testing are recommended. A 2-yr-old hedgehog should be considered geriatric. There are currently no vaccines labeled for use in hedgehogs. Because hedgehogs are not usually housed in mixed gender groups, castration and ovariohysterectomy are not generally requested or recommended. The incidence of uterine and mammary tumors is a concern; however, the effect of early age ovariohysterectomy on tumor reduction is unknown.