ADVERTISEMENT

Hedgehog medicine (Proceedings)

source-image
Nov 01, 2010

Description

The African pigmy hedgehog (Atelerix albiventris) has become a very popular pet in the early 1990's. They were a fad that hit the 'get rich quick' crowd initially but now has a small but very loyal following. At first these pets sold for $120-200, but as more people bred them the prices dropped and everyone who wanted them had them. It is not difficult to find them given up for adoption now. Now color variations exist, hedgehog clubs have been formed, and shows are held. Clinical information is becoming more abundant and easy to find.

Hedgehogs are members of the insectivore family. They possess 36-44 teeth with the first incisors being notably longer than the rest and are spaced apart. The lower incisiors "fit" into this space when the jaw is closed. {Dental formula: 2(3/2,1/1,3/2,3/3)}. Their teeth are brachyodontic like carnivores. The most obvious feature of the hedgehog is the dermal spines. These are modified hairs that provide protection from predators. Beneath the spines is a thick layer of subcutaneous fat. Hedgehogs will roll up when alarmed into an impermeable ball of spines, making them clinically challenging. They have sharply pointed snouts and typically small eyes. All possess a collarbone (clavicle). They are nocturnally active, and like to hide during daytime hours. The olfactory and auditory senses of all insectivores are highly developed, making them good hunters and foragers. Hedgehogs have a plantigrade gait, meaning that they walk on the entire soles of the feet rather than the toes alone. The most common pet species in the United States is the African pigmy hedgehog. Adults of this species generally weigh 300-600 grams. Longevity is about 5-7 years in captivity. Some color varieties are available now and if the pattern follows true, many genetic defects and a generally weakening of the species may follow from the inbreeding practices used to produce these. Hedgehogs are easy to sex, because males have a distinct prepuce like in dogs but testicles are abdominal. Females have a vulva. Hedgehogs are induced ovulators year round. Litters of 3-6 young are produced following a gestation of 34-37 days. The offspring have a protective coating over the spines during parturition, which is lost in the first 24 hours to expose the spines. Babies wean in 30-40 days and become sexually mature at about 2-3 months of age.

Diet

In the wild, hedgehogs consume insects, small vertebrates, and carrion. In captivity, hedgehogs fare well on formulated hedgehog or low fat dog or feline diets. Some recommend soaking the dry food prior to feeding. Reduced calorie formulations should be used, as obesity is the most commonly encountered nutritional problem. Fruits and vegetables should be added to the diet to dilute out the high calorie foods and to offer extra fiber. Cottage cheese, eggs, and other such protein sources can be given to breeding hedgehogs, but should be avoided or limited in sedentary animals. Insects are relished and can be given as a treat, but are calcium deficient and due to improper Ca:P ratio should not be the sole diet. Recommend feeding once daily in the evening. Also encourage evening exercise to prevent obesity.

Housing

Usually caged alone but can be housed in groups if given enough space. Excellent climbers so cages need to be smooth walled and high enough to prevent escape. It is recommended to avoid wire floors. Solid floors should have bedding such as newspaper, recycled newspaper, or wood shaving (pine or aspen). A

hide/sleeping area should be provided. One can be creative in the type of hide/sleep area provided.

Examination

Hedgehogs can be very difficult to work with as patients. Their ability to roll up into a ball makes them impossible to examine if they do not want to be examined. Lightweight leather gloves should be used to prevent the spines from pricking the handler's hands. Sometimes, an aquarium with a shallow layer of water can be used to allow for visual examination. When the hedgehog is placed in the water, it must unroll so as to not breathe the water. This helps keep the hedgehog unrolled for examination. Some hedgehogs uncurl with back stroking of the rump spines. Anesthesia is almost always required for a complete examination. Isoflurane or Sevoflurane are the recommended gas anesthesia. A small mask, fashioned from a syringe case can be slipped into the opening of the ball and over the snout. Alternatively, the hedgehog can be placed in an anesthetic chamber for induction. Once anesthetized, the mask can be positioned better or an endotracheal tube can be placed (very challenging). At this point the hedgehog can be easily examined. The examination should be systematic. A visual of the eyes, nose, ears, oral cavity, teeth, spines, anal and urogenital openings, palpation of lymph nodes and abdominal cavity, and auscultation of the thorax and abdomen will detect most disorders. In many cases, the problem will require further evaluation.

Clinical Pathology

Hematology and serum biochemistry are often the first stop in evaluating more vague illnesses in hedgehogs. Blood collection can be a bit challenging but can be mastered with a bit of practice. The jugular or cranial vena cave is generally used for venipuncture. The jugular is relatively short and runs from the thoracic inlet to the ear. A large lymph node lies just lateral to the jugular. It usually cannot be palpated, but can be blindly entered in the anesthetized hedgehog. With the hedgehog anesthetized and in dorsal recumbency, the neck should be extended. While it cannot usually be visualized, the jugular vein will generally course from the manubrium sterni to the ear. Large lymph nodes lie just lateral to the vein and serve as a landmark. The jugulars should be entered blindly with slight suction on the syringe until a flash is seen. Slow and steady pressure is used until the desired quantity of blood is obtained. One percent of the body weight can be taken, but 1ml should be adequate for routing analysis. Pressure should be applied briefly following venipuncture. Fecal examination, urinalysis, cytology are run and interpreted in the same manner as the more familiar mammals. Clinical pathology data is limited but empirically, most values are similar to canine and feline patients.