Cathy A. Johnson-Delaney, DVM Clinical Veterinarian Regional Primate Research Center University of Washington Box 357330 Seattle, WA 98195-7330

Atelerix albiventris (also known as A.pruneri or A.faradjius) has become a popular pet. Common names include: African hedgehog (AF), West African hedgehog, African pygmy hedgehog, White-bellied, Four-toed hedgehog. Color varieties include: White and gray/brown ticked quills = “salt & pepper” and those with all white quills =”snowflake”.

Males have a large percentage of elongated white spines. The African pygmy hedgehog has absent in narrow tract running cranial to caudal on head. Other hedgehogs appearing in the literature are the Erinaceus europaeus the European hedgehog, Pruner’s (Cape) hedgehog which has a darker or masked face; and the Egyptian (Long-eared) hedgehog which has long ears and tends to be more aggressive.

The average lifespan is probably about 3 years. European hedgies seem to live 8-10 years.

The adult male AF weights 500-600 g, female 250- 400 grams.

Rectal temperature: 36.1-37.20 C (97-990F).

They have a simple stomach and no cecum. AF do not hibernate.

Adult dentition: 36:3.1.3.3. with formula 2.1.2.3.

Sexual maturity is reached around two months of age, breeding can be year-round. Males have a mid- ventral penis. Testicles are abdominal.

Gestation length is 34-37 days, with litter size ranging from 1-7 pups (avg. 3). Cannibalism is common if female is stressed or disturbed. The male should be removed prior to parturition. Birth weight depends somewhat on litter/dam size, but average is 10 g. Spines develop within 24 hours. Eyes are open 13-16 days after birth, with weaning occurring at 4-6 weeks of age. If hand-raising is necessary, milk replacement formulas for either puppies or kittens works.

Behavior:

Hedgehogs are nocturnal and are quite active in the evenings. If allowed to run in the house, they tend to skirt the walls, furnishings, and hide in corners or under furniture. May dig in carpets, or in houseplants and dirt if accessible. While young hedgies may be easy to handle and do not mind being held, many adults resist handling, and struggle to be let loose. Adult females tend to be more handleable than adult males.

Many hedgehogs seem aloof and to not interact with humans, no matter how much handling they received when young. Very few bite – most just puff up like a pin cushion. Adult males are more likely to hiss.

Many hedgehogs will forage for spiders and insects in the home. Hedgehogs will use exercise wheels, but do not “play” with toys as do many other small mammals. They are solitary animals except for mating, and usually must be housed separately even if raised with a same-sex littermate.

While these animals are being bred domestically, they are essentially non-domesticated, which influences many of their behaviors particularly interactions with humans and other animals.

When a hedgehog encounters something new – a new taste, object in the environment, carpet, etc. it may “taste” it, then begin hypersalivating creating a foam. The hedgie then spits this foam onto itself. The process is called “anting” or “anointing”. Hedgies will sometimes also do this with food. There is speculation that this behavior of accumulating saliva, food bits, etc. onto the spines accumulates toxins which allows the hedgie to inflict more damage on a predator. Most owners will promptly rinse or bathe the hedgehog to get rid of the material.

Most hedgehogs prefer quiet environments, and may react with fright at loud noises. They prefer dimmed lighting to bright sunlight, room lights.

Housing:

Smooth-walled enclosures are best. They should be high enough to prevent escape. Aquariums (20 gallon or preferably larger) are acceptable. Wire caging is not recommended as hedgies get their feet caught easily. Bedding can be newspaper or recycled pelleted/absorbable material. Avoid cedar shavings. Bedding must be kept dry and changed frequently. AF must be kept at 75-85 F using an undertank heater/heating unit, heating pad on low on one section to provide a heat gradient.

Accessories may include a cut-out box, plastic log, or flower pot to hide under. Toys may include exercise wheels specially constructed for hedgies (can be constructed out of wooden 12″ popsicle sticks and cross stitch circle; axle is a thin dowel, spokes are lengths of plywood 1″ X 0.5″. Hedgies fall through wire rodent wheels. Cage accessories should be cleaned frequently. Some hedgies enjoy a pan or shallow tub of warm water for swimming.

Diet:

Commercial complete hedgehog diets are just becoming available. While these may prove to be good nutrition for the pet hedgehog, current diets are based on zoo formulations that have been used for years. Hedgehogs are insectivore/omnivores in the wild.

Diets should be fairly high in protein and low in fat. To minimize obesity, ad-lib feeding of adults should probably be discouraged. Feed in the evening, portion size that is mostly consumed by morning.

Only a small amount of food need be present during the day for a snack. Water should be available at all times. Many hedgehogs will use a water bottle. A low dish, crock is also utilized.

Suggested diet guidelines:

For one adult male hedgehog (550 g). Slightly lesser quantities for adult females. Younger hedgies may eat the adult quantity, depending on stage of life and activity.

1 heaping teaspoon bird of prey diet or insectivore diet

1.5 heaping teaspoons high quality cat/kitten chow like Science Diet,Iams, C/D cat food, ferret chow. (for younger hedgies or pregnant/lactating, use kitten or ferret formulations; adult hedgies – may use “Lite” adult cat foods)

1 heaping teaspoon fruit/vegetable mixture* (see below) 6-10 small mealworms or 1-2 crickets (larger number if pregnant, lactating)

*Fruit/vegetable mix: chop together 1/2 tsp. diced leafy dark greens (spinach, kale, leaf lettuce), 1/4 tsp. diced carrot, 1/4 tsp. diced apple, 1/4 tsp. diced banana, 1/4 tsp. diced grape or raisin, 1/4 tsp. Vionate vitamin/mineral powder or 1/4 Feline Favor tab (SmithKline Beecham). Note: crush vitamin tablet and mix in or offer completely separately – some hedgehogs readily eat cat vitamins.

2. Alternate diet formulation: amount for an adult per day: 3 heaping teaspoons of high quality cat/kitten chow like Science Diet, Iams, C/D cat food, ferret chow. (for younger hedgies or pregnant/lactating, use kitten or ferret formulations; adult hedgies – may use “Lite” adult cat foods); 1 heaping tsp. of above fruit/vegetable mix; 6 small mealworms or 1- 2 crickets.

3. Alternate diet formulation: amount for an adult per day: 3-4 teaspoons commercial insectivore diet (Reliable Protein Products, Pretty Bird Intl); 5-6 mealworms or 1-2 crickets.

4. Woodland Park Zoo Diet (amount feeds several adults – can be mixed and frozen or refrigerated): 1 TB Insectivore diet (1); 1 slice cooked carrot; 5 crickets; 30 small mealworms; 1 TB Fruit mix (2); 1 slice cooked yams; 1 pinch chopped romaine or leaf lettuce. (1) Insectivore diet: 1 Cup chopped non-domestic feline diet (frozen Nebraska brand); 1 Cup chopped hard- boiled egg; 1 TB what germ flakes; 1 tsp. powdered milk; 1/2 tsp. Vionate vitamin mineral powder; 2 tsp. wheat germ oil.

(2)Fruit mix (dice and mix together):2 medium sized apples (peeled); 1 orange; 1 small tomato; 1/2 melon; 1/2 papaya; 1/2 cup carrots; 1/2 cup yams; 1/2 cup blueberries; 1/2 cup raisins; 1/2 cup sunflower seeds (shelled, non salted)

Remember:

Individuals may be somewhat resistant to new diets, and the new foods need to be gradually phased in by mixing with the old. It helps to have all chunks or pieces of new and old diet the same size and relative consistency. Cat or dog foods alone do not seem to be adequate as the sole diet.

Restraint and Handling:

Examination is best done in subdued light. Provide a towel on the table and eliminate loud noises. Lightweight leather gloves may help. A clear acrylic “ferret tunnel” can be used to do a preliminary visual examination. Everyone develops their favorite method for uncurling a hedgie: back stroking of rump spines; gentle but firm rolling of mantle outward, head down suspension,dorsal positioning.

Some will need to be lightly sedated with isoflurane to facilitate the examination. Some will vocalize with squeals!

First Visit/Annual Examination:

Review of diet, husbandry, habitat, behavior, methods for handling, bathing. PE includes visual inspection, auscultation, oral exam, temperature and weight. Fecal flotation, direct smear. Optional (depending on history): Salmonella culture, Skin scraping & fungal culture, CBC, Chemistries.

Anesthesia may be required to do full dental examination, ear examination, radiographs, toe nail trim, etc. Microchip transponder implantation recommended for permanent identification.

Blood Collection Sites: Lateral saphenous vein, , cephalic vein, jugular vein, cranial vena cava. Injection sites: Subcutaneous: back, flank. Be aware of fat layers – fluids may be slowly absorbed, but large volumes are possible. Intramuscular: in thigh; Intravenous: lateral saphenous, jugular vein via catheter.

Normal Radiographic Appearance:

Lateral: pericardial mediastinum encloses the thymus and heart. Ventrodorsal projection makes differentiation between individual organs more difficult due to superimposition of the muscle packets of the orbicular muscles, the cutis and spines. The skull is broad with pronounced cheek bones.

Secondary dentition is complete with a year. Older animals: teeth are worn down at a comparatively early age.

Rule Out Chart for Hedgehogs based on Clinical Signs

ANOREXIA:

Diff: Dental disease, gastrointestinal disease or parasites, fatty liver, neoplasia, pneumonia, chilling, behavioral (mating distraction, diet change, husbandry change)

Dx: Physical exam (under sedation), radiographs, CBC/chemistries, fecal flotation/smear, C&S feces/exudates if present. Ultrasonography if masses found

Rx: Appropriate per etiology

DIARRHEA:

Diff: Gastrointestinal disease or parasites, fatty liver, dietary change Dx: Physical exam, fecal flotation/smear, C&S; CBC/chemistries

Rx: Supportive care, fluids. Antibiotics/antiparasitics per etiology. GI protectants as necessary. Stabilize diet. If fatty liver, decrease fat in diet, supportive with B complex vitamins.

FLAKY/SCALY SKIN, BROKEN QUILLS:

Diff: Chorioptes mange mites, Ixodid ticks, fleas, flea allergic dermatitis, fungal dermatitis, bacterial dermatitis

Dx: Skin scraping and microscopic exam; fungal/bacterial culture,

Rx: Appropriate therapeutics per etiology. Bathing, complete sanitation of habitat.

For fleas, environmental control in house and on other pets.

Chorioptes mange: Ivermectin at 0.2 mg/kg/PO or SQ for 2-3 treatments, 2-3 weeks apart.

HYPERSALIVATION:

Diff: Anting behavior, response to novel taste or substance, defensive behavior, dental disease (gingivitis, periodontitis, fractured teeth), oral neoplasia, nausea (gastrointestinal disease)

Dx: Physical examination, history, oral exam (may need radiographs), biopsy oral lesions, fecal flotation/smear/C&S if gastrointestinal disease.

Rx: Appropriate per etiology. Dental care as in carnivores.Gastrointestinal protectants, therapies as indicated.

LACERATIONS/WOUNDS:

Diff: Fighting when housed with other hedgehogs; injuries from other animals,environmental

Dx: Physical exam and husbandry review

Rx: Systemic/topical antimicrobials, repair as in other species

LUMPS, MASSES, SWELLINGS:

Diff: Neoplasia – squamous cell carcinoma, fibromas, fibrosarcomas, papillomas; abscess, cyst, abdominal – rule out pregnancy

Dx: Physical exam, CBC/Chemistries, Radiographs, Biopsy, Cytology, Histopathology

Rx: Surgical excision if possible. Chemotherapies untried.

Abscess: drain, antimicrobials.

Cyst – drain and/or excise. Antimicrobials if necessary.

If pregnancy, discuss delivery, care on infants with other.

RELUCTANCE TO MOVE/LAMENESS:

Diff: Any debilitating systemic disease, geriatric changes (spondylosis, arthritis), fractures, luxations, nutritional deficiencies affecting bone, muscle; chilling, obesity, neoplasia,overgrown toenails, pododermatitis

Dx: Physical exam, husbandry review, CBC/Chemistries, radiographs Rx: Appropriate per etiology. Skeletal repair of fractures as in other mammals. Analgesics if necessary. Trim nails, change husbandry/bedding if necessary. Antimicrobials if pododermatitis.

RESPIRATORY NOISE (SNUFFLES, SNEEZING, CONGESTION:)

Diff: Defensive behavior vocalizations, bacterial/fungal/viral pneumonia, rhinitis, sinusitis (Bordetella bronchiseptica, Pasteurella, Cytomegalovirus, etc); foreign body inhalation (dusts, particulates)

Dx: Physical exam, radiographs, tracheal/nasal wash -C&S, cytology; CBC/Chemistries

Rx: Appropriate per etiology. Nebulization or oxygen therapy if severe congestion. If dyspneic, may be housed in a pediatric incubator to provide warmth. Bacterial infections

Rx: Trimethoprim sulfa 30 mg/kg BID PO or IM; Enrofloxacin at 2.5-5.0 mg/kg IM or PO

SUDDEN DEATH:

Diff: Fatty liver, cardiomyopathy, shock (severe trauma, fright), pneumonia, owner found dead, had not noticed antemortem signs

Dx:History, post mortem exam, necropsy, histopathology

Rx: None. Discuss with owner – particularly if evidence chronic disease

WEIGHT LOSS:

Diff: Neoplasia, anorexia, pain, chronic debilitating systemic disease, behavioral (competition), diet change and reluctant to eat novel food or poor diet, environmental changes.

Dx: Physical exam, diet and husbandry history, CBC/chemistries, radiographs. Rule out systemic diseases

Rx: Appropriate per etiology

WEIGHT GAIN:

Diff: Overeating (fat content/quantity), pregnancy, neoplasia, lack of exercise

Dx: Physical exam, history; CBC/Chemistries, radiographs, if masses found – biopsy, cytology, histopathology

Rx: Appropriate per etiology.

Common Disease Conditions:

Fatty Liver, Obesity Dermatitis (parasitic, fungal)

Parasites – Chorioptes, Intestinal nematodes, cestodes, protozoa (Rx: Ivermectin at 0.2mg/kg PO or SQ; Cestodes: praziquantel at 7 mg/kg SQ or PO; protozoa: Metronidazole at 25 mg/kg PO q 12 hrs for 5 days)

Trauma Neoplasia (squarmous cell carcinomas); papillomas. High rate in animals over 3 yrs old.

Respiratory infections: rhinitis, laryngitis, tracheitis, pneumonia: Bordetella bronchiseptica, Pasteurella spp.,Cytomegalovirus.

Ear Infections Dental problems including fractured/abscessed teeth: anorexia, weight loss, salivation; gingivitis., periodontitis

Zoonotic Diseases: Salmonella. Importation bans – can carry Foot & Mouth Disease, Mycobacterium tuberculosis

References: Anonymous. African pygmy hedgehog-associated salmonellosis – Washington, 1994. MMWR 1995 44 (24): 462-463. Hoefer, HL: Hedgehogs.

Vet Clin North Am Small Anim Practice. 1994 24 (1): 113-120. Isenbugel, E, Baumgartner, RA.

Diseases of the hedgehog. In Fowler, ML (ed), Zoo and Wild Animal Medicine Current Therapy 3, WB Saunders, Philadelphia, 1993, pp 294-301. Johnson- Delaney, CA: Hedgehogs.

In Exotic Companion Medicine Handbook, Wingers Publishing, Lake Worth,FL, in press. Keymer, IF, Gibson, EA, Reynolds, DJ.

Zoonoses and other findings in hedgehogs (Erinaceaus europaeus): a survey of mortality and review of the literature. Vet Record 1991 128(11): 245-249. Smith, AJ: Husbandry and medicine of African Hedgehogs (Atelerix albiventris).

Journal of Small Exotic Anim Med 1992, 2(1): 21-28. Smith, AJ: Neonatology of the hedgehog, (Atelerix albiventris).

Journal of Small Exotic Anim Med 1995, 3(1): 15- 18.

Cathy Johnson-Delaney, DVM University of Washington Primate Center