Physiology and Health
This page is dedicated to all aspects of a hedgehog's physical well-being.
Scientific Classification: Kingdom: Animalia. Phylum: Chordata. Class: Mammalia. Order: Eulipotyphla. Family: Erinaceida. Genus: Atelerix. Species: A. Albiventris.
Tip: Order: Hedgehogs used to be in the Order Insectivora but are now in the Order Eulipotyphia. This order is still made up of insectivorous mammals. Hedgehogs are not rodents (Rodentia) as they do not have constantly growing incisors.
Life Span: Domesticated hedgehogs typically live 4-6 years, with some reported to live 8-10 years. Hedgies are fully grown around 6-8 months about the equivalent of an 18 year old human. 2-3 years is mid life and you might see some health changes and decreased activity. 4-6 years is senior and anything over 6 is geriatric.
Physical Characteristics: Aside from the obvious quills (roughly 3,000 to 5,000 of them), African pygmy hedgehogs have front feet with 5 toes and back feet with 4 toes, shallow set eyes, a tiny tail, and long whiskers. The have 36 teeth in general, but can have 44, they are pointy but blunt and include incisors, canines, molars, and premolars. Hedgehogs also have what we call a "reverse mohawk" which is a bald spot on top of their heads that allows them to cross their visor quills. They have claw-like toenails on the front feet and longer squared off toenails on the back. They walk on the pads of their feet like a cat or dog, but the pads are soft. Every hedgehog I've ever seen has a single mole on their chin, sometimes with long hairs growing out of it (I don't know if the mole is always present or just highly probable). Hedgies come in a variety of colors, mask patterns, and body markings. Until recently, no one had done any research on genetic colors for hedgehogs. Thanks to the wonderful work of Judith Bos over at The Hedgehog Program (THP), we now have a comprehensive and predictive color guide, which can be found here.
Boy or Girl: Hedgehogs can be sexed as soon as they can be held. It is easy to tell boys from girls, boys will have a "belly button" which is actually a sheath for the penis. Males have all of their reproductive bits on the inside just like females (sometimes the testicles can appear distended (swollen) making it look like your hedgehog has developed tumors behind his legs, but it's probably just that and nothing to worry about).
Tip: Sexual Maturation: While a female is sexually mature at 6 months, she can get pregnant at any time and because she is not fully developed yet, this will cause a lot of problems for her and any young. Males are mature around 4 months, but can impregnate a female as young as 6 or 7 weeks. Never, ever, ever house males and females together at any age for any length of time. The same goes for "play dates", just don't.
Senses: Hedgehogs have poor eyesight, they see outlines of objects, only see in cream and brown, and while they have excellent binocular vision, they have poor depth perception. They have excellent hearing and smell and this is how they primarily navigate. There are many many blind hedgehogs in the world and they manage just fine, I myself have a one eyed pirate!
Tip: Aromatherapy: Because a hedgehog has an acute sense of smell and a propensity for respiratory issues, it is advised that you do not use fragrances, candles, sprays, or oil warmers. If you choose to use any of these, please know that essential oils such as tea tree and eucalyptus are toxic to hedgehogs. I would avoid anything with cedar as well.
Healthy Weights and Body Shapes: Hedgehog weights are tricky, your hedgie can be healthy at 300g or 500g, you should still monitor for ups and downs, but what's more important is body shape. Hedgehogs come in a few shapes that I will now compare to vegetation: cucumber, pear, apple, etc. What's important is that no matter your hedgie's natural shape, that shape doesn't get distorted like a funhouse mirror. If your hedgie is a round apple, don't let it become a cantaloupe, if you've got a cucumber, don't let it become a butternut squash. Ok, all fruit jokes aside, if your hedgie can't roll into a ball with its head tucked in, it's obese and that can cause a wide range of issue. If your hedgie is slimmer in the butt than the shoulders with hip dips, it's anorexic, which is usually (not always) a sign of an underlying problem.
Digestion: Hedgehogs have a very short digestive tract, it takes 12-16 hours for anything ingested to come out the other end. As a comparison, it takes humans 24-72 hours. Don't be surprised if you find green poop every once in a while, especially when a hedgehog is stressed due to a move, when bringing home for the first time, or when changing the diet. Green poop is actually poo mixed with stomach acid, your hedgie has fast tracked whatever it was digesting and thus green poop is born.
Tip: Cecum: Hedgehogs do not have a cecum, which is the part of the intestines that digest plant matter. You can read more about that here.
Hibernation/Aestivation/Torpor Attempts: Strictly speaking, torpor is a period of extreme metabolic reduction due to changes in body temperature, water balance, and light cycles. Hibernation is a prolonged torpor brought on by cold periods, while aestivation is a prolonged torpor during hot and dry periods. European hedgehogs hibernate for about 4 months, it is thought that wild African pygmy hedgehogs enter brief states of torpor during heat waves and drought. Hibernation is about survival of the species, not the individual, every wild animal that is capable of hibernation does not make it out of hibernation. Domesticated hedgehogs should not hibernate/aestivate. If your hedgehog gets to hot or too cold it will attempt a torpid state. Inappropriate light/dark cycles can also trigger an attempt. This is very dangerous and could result in the death of your hedgehog. If you notice your hedgie becoming lethargic, not eating or drinking, having trouble walking, the first thing you need to do is check the temperature and feel it's belly. If the belly feels cool to the touch, start warming them up immediately but slowly, do not put them in a direct blast of hot air. Never put them in water to warm them up. Hot Hands are perfect for this, or put them under your shirt, belly to belly if you can. If you cannot bring your hedgie out of the attempt, seek veterinary care immediately. Monitor your hedgie closely for the next few days to a week, I would advise to set their thermostat a few degrees higher and leave it there, they are now more likely to trigger torpor easier. Attempts can also have lasting ramifications by compromising your hedgehog's immune system.
Diseases/Ailments: Hedgehogs can develop a wide array of aliments, illnesses, and diseases. They are very good at masking their symptoms and pain, so catching things early is difficult. In general, if your hedgehog has stopped eating, drinking, peeing, or pooping, or has become lethargic or unresponsive, take it to the vet and get to the source of the problem. Some common issues are: Tooth decay/chipping, ulcers, cankers, tumors, cancers, diabetes, respiratory infections, skin infections, ear infections, fungus, toe/foot injuries, eye displacement, eye infections, eye injuries, neurological disorders, stroke, seizure, arthritis, metabolic bone disease, and many more.
Tip: MBD: Metabolic bone disease can be prevented by always feeding the correct Ca:P ratio. Phosphorus binds to Calcium and if there is not enough free calcium, it will take it from the body causing brittle bones. More information on correct Ca:P ratios can be found under the Nutrition page located here.
Tip: Injuries: The most common injuries for hedgehogs are of the eyes, feet, and teeth. 90% of these injuries are avoidable/preventable. Please be a responsible pet owner and do everything you can to maintain proper care, equipment, and nutrition to ensure you don't have any accidental injuries.
Tip:Spay/Neuter: There is no reason to have a hedgehog spayed or neutered as a preventative treatment. This type of operation is used only when absolutely necessary as it carries a lot of risk for hedgies. A prolapsed uterus, uterine or testicular cancer, etc, would be examples of when this surgery would be necessary.
Depression: Hedgehogs can suffer from depression, signs of depression include lethargy, not eating or drinking, self mutilation, bar chewing, cage clawing, running in circles around the cage or an object, etc. Make sure your hedgie has adequate space and enough enrichment. You can find information on cage requirements here and information on enrichment here.
Quills: Hedgehogs can get misshapen quills from time to time, this is nothing to worry about and unless it is poking the hedgehog or irritating them in some way it is best to leave it alone to shed naturally. Hedgehogs can also get ingrown quills, these you will likely have to tease out and pluck with tweezers. They may bleed a little when doing so. Hedgehogs can also stab or pierce their own ears and eyes, if an ear is pierced, try to remove the quill from the ear and dab the ear with an antibacterial wash if needed, if an eye is damaged seek veterinarian care immediately. While hedgehog quills do not have nerves or blood inside them, you shouldn't cut, trim, or otherwise purposefully damage them. No only are quills a hedgehog's main defense mechanism, but they are full of small air chambers and help keep your hedgie insulated as well as absorb shock from falls. If you can't deal with a spikey potato, don't own a spikey potato.
WHS: Wobbly Hedgehog Syndrome is a progressive degenerative neurological disease that causes complete paralysis and ends in death. WHS is thought to be genetic, viral, bacterial, even nutritional, but not enough research has been done to confirm any of this. There is no cure for WHS, there is also no test for WHS. The only way to confirm WHS is a necropsy, which is a dissection and microscopic examination for brain lesions after death. WHS typically occurs sooner rather than later, usually around 2 years, but can be seen around 1 year, any younger is rare, any older is extremely rare. It often starts with ataxia (loss of full control or paresis, muscular weakness) in the hind legs and progressively moves its way upward. Typically onset of symptoms to death is 18-24 months, it is not a fast progression. If you see any sort of muscle weakness, dragging hind legs, walking in circles, etc, seek veterinarian care immediately. Your vet should want to do a full exam and extensive tests for all possible other illnesses before diagnosing WHS without a necropsy. WHS while devastating, is rare, occurring in only an estimated 10% of all domesticated hedgehogs in North America.
Tip: Similarities to WHS: There are many, many, many diseases that can mimic symptoms of WHS, even something as simple as an ear infection. If you or your vet suspects WHS, have them run full tests for other possible diseases. If you get a diagnosis of WHS from a vet without ruling out other diseases, consult another vet for a second opinion.
Tip: Necropsy: If you suspect your pet of dying from WHS or your vet has diagnosed WHS and your pet died, you must follow a few steps if you would like to have a necropsy performed. Put your deceased pet in a zip lock bag and into the refrigerator (DO NOT freeze). Call your veterinarian and make sure they can perform a necropsy before showing up. If your veterinarian can't perform a necropsy, they may be able to send out to have it done or there are online resources that you can overnight ship your pet to with instructions on how to do so.
Pests and Parasites: Hedgehogs can be infested with mites, fleas, ticks, and parasitic worms. These can all be prevented with proper hygiene and food preparation. Information on preventing mites can be found here. Fully cooking meat and clean cultured insects will prevent internal parasites. When you buy live bugs from the pet store, immediately change the bedding they come in to a clean (pre-treated via deep freezing) source of oats, wheat germ, etc. If allowed outdoor play, inspect your hedgehog for fleas and ticks. Common canine fleas do not usually infest hedgehogs (doesn't mean they can't), but there is a hedgehog flea common to where there are wild hedgehogs. North America has no native hedgehogs and therefore no native hedgehog fleas. If you find fleas near your hedgie or in their cage, they will most likely be feeding on you or your other pets and breeding in your hedgehog bedding or litter box. The medication given for mites is the same medication given for fleas, so whether you think you have mites or fleas, the prescription is the same.
Tip: Pests in Cages: The most common thing you will see (especially in late summer/early fall aka harvest time) is gnats/drain flies/fruit flies and house flies/green bottle flies. The easiest way to combat any and all of these flies is to daily spot clean and keep things dry as all of these flies are attracted to any kind of moisture. If you are struggling with these pests, hanging fly traps in the room (not your hedgehog's cage), setting up gnat traps, and window sprays are great options.
When to see the Vet: It is my advice that you should always take your hedgehog to the vet for any lump, bump, injury, or wound. Anytime your hedgie stops eating, drinking, peeing, or pooping for more than a day. Prolonged torpid attempts. It is recommended to have a preventative checkup once or twice a year. Please also do your own research, there are great vets and there are horrible vets, unfortunately you won't know which one you have until its too late unless you do your own self educating.
Tip: Vet Locations: The Hedgehog Welfare Society has an extensive list of Exotic Vets that treat hedgehogs and can be found here.
Vet Fund: It is important to note that Hedgehogs are considered exotic animals and thus need exotic vets which comes with exotic prices. It would be wise to set aside an emergency vet fund, I would recommend $500 to $1000. If you can't afford a vet, there are usually credit options and there are organizations that can help. There is also insurance specifically for hedgehogs. Please contact me if you have purchased a hedgehog from me and cannot afford your vet care.
Tip: Surrenders: The Hedgehog Welfare Society has satellite locations all over the US, if you must surrender a hedgehog or find one in need of help, you can contact them for assistance here.
Medications: Many medications commonly prescribed are considered "off label" because they are not tested for hedgehogs. This means that even if a medication seems harmless for a cat, it could be potentially fatal for a hedgehog. Whatever medications your vet decides to prescribe for your hedgehog always ask questions like: what are the potential side effects and how common are they? what are the risks of overdose? are there safer alternatives? Always research the medicine yourself before administering it to your pet, remember that google is free and your vet is not infallible, even the good ones.
Home Remedies: While there are a number of things you should see a vet about and you should at least consult with your vet before beginning any home treatment if not taking your hedgehog in to the vet, there are a limited number of things you can do at home to nurse a sick hedgie.
Heat: Always raise your heat settings a few degrees if your hedgehog is ill. This will help keep their immune system strong enough to fight things like infections and such. Recommendation is 80-85 degrees.
Pumpkin: Your hedgehog should be pooping everyday, multiple times a day. If your hedgie hasn't had a bowel movement, try giving them a small amount of canned plain pumpkin. Pumpkin works as a laxative for hedgehogs. If your hedgie still doesn't poop, seek immediate veterinarian care.
Manuka Honey: While all honey gets most of its antibacterial properties from the hydrogen peroxide it contains, Manuka honey made from bees that pollinate the manuka bush in Australia and New Zealand has higher concentrations of the antibiotic compound methylglyoxal (MG) than all other honey. This is mostly used topically to treat infected wounds, or as an infection preventative for wounds and ingrown quills. You can also feed manuka honey in very small amounts for infections. There is a medical/veterinarian grade manuka honey that you should be able to get from your vet with instructions on how and when to use it. If your vet can't supply it, anything labeled over 10 UMF is considered strong enough to be effective.
Polysporin: This is an antibiotic ointment sold at your regular pharmacy. This can be applied to shallow and minor wounds. Only use the regular kind, not the extra strength or anything with pain relief. Neosporin is a similar ointment, but there have been reports of terrible side effects and even death when used incorrectly. Never use this on your hedgehog's face and do not get it in the eyes. Use with caution.
Antibacterial Wash or Soap: You can use this to flush out a fresh cut or wound to prevent bacteria and infection. Always rinse with clean water afterwards and dry completely. DO NOT ever let a wound or cut remain wet, you must take steps to always keep it dry as it heals.
Protein Boosters: If your hedgehog is struggling with nutrition, you can give them Ensure, Boost, PediaSure, Critical Care Carnivore by Oxbow, etc. DO NOT give them the chocolate flavors. Again, please consult your vet before use as they will be able to tell you the best dose and frequency.
Pedialyte: If your hedgehog has stopped drinking and becomes dehydrated, you can give them a solution of 1 part pedialyte to 1 to 3 parts water. Simply replace their regular water with this solution. If your hedgehog is not drinking on their own for more than a few days, seek veterinarian care immediately.
Styptic Powder: This can be used to stop bleeding, primarily for accidental nicks to the quick while trimming toes. Apply a small amount onto a q-tip and use the q-tip to apply to the wound. More can be applied as needed, always dip into the bottle with a fresh q-tip.
Mite Treatment: There is a recipe out there for the treatment of mites. I do not have it nor do I use it so I cannot attest to its effectiveness. I am not against alternative treatments for pest problems, I very much preferred them for my other animals, I feel the same about my herd. Chemical treatments are highly toxic, they have to be by their very nature, that means there is risk involved in their use. If there is an alternative, I will take it every time. Mites are very easy to avoid/prevent, you can read more about that here. In the event I ever do get mites I will be hunting down the recipe and trying it out. If it shows to be effective I will list it here and recommend. I have seen diatomaceous earth used on the hedgie and in the enclosure. I have used it myself on larger animals and in my own carpet (for fleas). However, I would not recommend using it for a hedgehog (or any small animal) as the powder is too fine.
First Aid Kit: Other handy things to have in a first aid kit include: q-tips, dull tweezers, tiny scissors, gauze, multiple sizes of oral syringes, flashlight, magnifying glass.
Your Own Two Eyes: You should be inspecting your hedgehog everyday when you get them out and when you put them back in their cage. Hedgehog diseases progress quickly, one day they will be/look fine and the next day they have a lump the size of a golf ball on their back (not even joking). Look for anything odd, swollen, redness, anything hot to the touch, blood, loose teeth, tattered ears, sores on feet, signs of self gnawing, human hair wrapped around feet or nether bits, ingrown quills, loose or damaged/deformed quills, excessively dry skin, excessive ear wax, eye damage. Make sure that your hedgehog is eating, drinking, pooping, and peeing everyday.
Emergency Caretaker: It would be wise to talk to someone about being an emergency caretaker for your pet in case something should happen to you. Write up a care guide of all the products you use and things that you do everyday, what vet sees your pet, etc. Remember to update it periodically as things change and leave it somewhere obvious or let them know where it is.