Hedgehog Health and Care Information
In the wild, hedgehogs are omnivorous and feed on a variety of insects, small animals, fruits and vegetables. They are very prone to obesity and the captive diet should be high in protein and low in fat. Hedgehogs should be fed once daily in the evening. Only a small amount of food is offered during the day as a snack. They are able to drink from a water bottle.
The following are examples of good hedgehog diets:
- 3 tsp of cat food, 2 tsp of fruit/veggies, 6 mealworms, 1-2 crickets
- 1 tsp of commercial insectivore diet, 1-1/2 tsp of cat food, 1 tsp of fruits/veggies, 6 small mealworms, 1-2 crickets
- Good vegetable and fruit choices include spinach, kale, carrots, apple, and bananas.
Biology and Medicine
The spiny hedgehogs consist of two main species. These are the African pygmy ( Atelerix albiventris ) and the European ( Erinaceus europaeus ). African pygmy hedgehogs are the ones most commonly kept as pets in the United States . They are native to central Africa , whereas the European hedgehog is found throughout Europe and Great Britain . The spiny hedgehogs received their name from the coat of spines, which cover their back and crown of the head. In contrast, the hairy hedgehog possesses hair, not spines, and a long, rat-like tail. They are indigenous to the forests of Southeast Asia .
The spines are actually modified hairs made of keratin. They range in length from 0.5 to 2 cm in length. Most are brown and white, but color variants, such as all white, have been bred. These spines are connected to the underlying layer of fat and subcutaneous tissue. Beneath this is a powerful muscle, which acts as a purse string, rolling the hedgehog into a tight ball. This acts as a means of defense when the animal becomes threatened.
Their life span generally ranges from 3 to 5 years. They reach sexual maturity by about 2 months of age and will breed year-round. Their gestation period is 34-37 days. Litter size can range from 1-7 (average of 3). The male should be removed just prior to birth. Females will cannibalize their young if they are stressed. Hedgehogs are born spineless, but spines develop within 24 hours after birth. Eyes open at 13-16 days of age with weaning at 4-6 weeks of age.
Sexing hedgehogs is fairly straightforward, although more difficult in very young animals. In females, the vagina is located very close to the anus. In older males, the penis and prepuce are located on mid-abdomen. However, in baby male hedgehogs, the penis is closer to the anus and moves forward as the animal matures. The testicles are located in the abdominal cavity.
Hedgehogs are naturally nocturnal and are generally frightened by bright lights and loud noises. They are solitary animals and should be housed alone.
When they encounter new items in their environment, hedgehogs begin to salivate profusely and rub the saliva on their spines. This is called "self-anointing" or "anting" and is a normal behavior.
Hedgehogs make a variety of sounds including grunts, squeals, and sneezing sounds which may be confused with respiratory tract disease. However, these vocalizations are usually made only when the animal is disturbed or upset, while abnormal respiratory sounds are heard when the animal is at rest.
Overall, young hedgehogs and females are more docile than adult males. If handled frequently, however, these animals can become quite tame and are wonderful pets.
As stated earlier, hedgehogs are best suited to solitary housing. If placed in groups, it is best that only one male be placed per group to decrease fighting.
Wire cages are not recommended. Feet can easily get caught in the wire. Hedgehogs are also excellent climbers. Smooth walled enclosures are the best choice (20 gallon aquarium). Shredded paper serves well as bedding. The oils in cedar and pine shavings can be irritating to hedgehogs. Bedding should be changed at least weekly. The optimum temperature range is 75-85 degrees Fahrenheit.
Hedgehogs should be provided with enclosures for sleeping and hiding. These can be as simple as a small box, flowerpot, or PVC pipe. Hedgehog wheels are available to provide exercise. Wheels designed for rodents are not acceptable, as hedgehogs can get their feet caught easily. Toys can also be provided and are often appreciated. Hedgehogs are also excellent swimmers and may be provided with a small swimming pool.
Some hedgehogs will unroll by gently stroking the spines. Another method involves holding the rear end in the palm of your right hand while placing the left palm beneath the hedgehog's front end. Gently bouncing the animal up and down will cause it to lift up its head. Then, with the thumb and index finger of the left hand, you can grab the back of the neck. By placing some pressure on the small of its back, one is able to gently open the animal up by flexing it backwards. A third method involves placing the hedgehog on a flat surface and waiting for it to unroll as it reaches for the edge.
A brief physical examination or short treatment can be performed with the animal awake. However, more thorough examinations or medical procedures require sedation with isoflurane/sevoflurane gas.
Conditions Requiring Veterinary Attention
Preventative health care involves a review of diet, husbandry and handling of the hedgehog on first visit to the veterinarian. Without sedation, the veterinarian will be able to observe the hedgehog for abnormal gait or behavior, discharge from the eyes or nose and sometimes listen to the chest. Bloodwork under sedation may be recommended at this time, if indicated.
Mites are probably the most common clinical disease of hedgehogs. Affected animals may show no signs at all or present with flaky skin, quill loss, or severe itching. Mites are diagnosed by the veterinarian through a skin scrape. Treatment involves ivermectin injections at 2 week intervals for at least 3 treatments. Follow-up skin scrapings are recommended to rule out recurrence of mites.
All animals housed together are that are in contact should be treated for mites. It is imperative that mites also be eliminated completely from the environment. This requires thorough cleaning and discarding and replacing any nonessential items.
Hedgehogs may also be afflicted with fungal infections. Many show no visible signs of infection, while others show crusting of the skin, quill loss, and itching. The type of fungus, which infects hedgehogs, is less likely to infect humans than other types of ringworm. The treatment of choice is an oral anti-fungal agent called griseofulvin.
Otitis (ear infections) are also seen in hedgehogs. Clinical signs include scratching, discharge, head shaking, and balance disturbances. Diagnosis involves examination of exudates under the microscope and culture and sensitivity to guide therapy. Skull radiographs are important in cases of middle or inner ear infections.
Diarrhea in hedgehogs, as in other species, may be caused by parasites, gastrointestinal disease, and dietary change. Diagnosis is based on bloodwork, fecal exam and possible fecal culture. Before therapy can be initiated, the cause of the diarrhea must be established. In many cases, supportive care (fluids) and dietary change are necessary. Salmonella has been reported in hedgehogs. Whether it causes diarrhea or the animal remains asymptomatic, it may still become a carrier and shed this organism intermittently in its feces. For this reason, strict hygiene is emphasized when handling.
Obesity is a common problem in hedgehogs and is often related to overfeeding, lack of exercise, or feeding a high fat diet. This problem may result in liver and cardiopulmonary disease as well as dermatitis secondary to excessive skin folds. Owners should monitor the weights of their hedgehogs on a regular basis and alter diet as necessary. Exercise should also be provided.
As mentioned earlier, hedgehogs will often exhibit a normal behavior termed "anting" in which they hypersalivate in response to new items in their environment. Sometimes, however, excessive salivation can be a sign of more serious disease. In these cases, a complete physical exam under sedation is necessary to evaluate the teeth. Skull radiographs may be necessary to establish a diagnosis and to rule out aggressive tumors of the oral cavity. Teeth, which are loose or infected, should be extracted and the animal placed on antibiotics. A change in diet to harder foods may be helpful in maintaining good teeth. Nausea is yet another cause of excessive salivation. A workup as described earlier for diarrhea is necessary to establish a cause.
As in other species, signs of respiratory disease include sneezing, coughing, and wheezing.
Hedgehogs are susceptible to a number of respiratory bacteria and viruses, including Bordetella, Pasteurella, and cytomegalovirus, as well as respiratory parasites (Capillaria). A complete workup includes bloodwork, radiographs, and tracheal/nasal cytology and culture. Therapy includes treatment with the proper antibiotics and supportive care, including fluid and oxygen therapy.
Hedgehogs are prone to the development of cancer, especially when they exceed 3 years of age. A virus is now thought to play a role in disease. Radiographs, bloodwork, and ultrasound can be used to get an overall picture of the animal's health. A biopsy is necessary to confirm a diagnosis. If malignant, determine the stage of disease. This allows us to establish a prognosis. Unfortunately, no chemotherapy protocols have been described for hedgehogs at the present time.
Hedgehogs demonstrating an inability or reluctance to move may be weak or showing signs of neurologic or orthopedic disease. Often these animals are obese, have overgrown nails, or some type of nutritional deficiency. Older animals may develop arthritis or tumors which may hinder their ability to move. Paralysis or incoordination may be difficult to assess in hedgehogs. In most instances, it is important to obtain bloodwork to evaluate electrolyte and calcium levels and radiographs to look for fractures or dislocations.