How do I keep my boa healthy?

What should I know about boas at a glance?

The boa constrictor is a large, calm snake from Central and South America, native to Brazil, where it is called jiboia. Boas give birth to live young and never lay eggs. The figures below come from the Royal Veterinary College's boa care sheet unless another source is named.

What health problems do vets see most in boas?

Inclusion body disease, respiratory infections, mites, mouth rot, stuck sheds, burns and, in adults, obesity. Refusing food and regurgitating a meal are signs that come with several of them. Most are linked to the setup: temperature, humidity, hygiene and how often the boa eats.

• Inclusion body disease (IBD): a virus of boas and pythons with no cure. Boas can carry it for years without looking sick and pass it to other snakes. More on it below.
• Respiratory infection: common in reptiles, according to the Merck Veterinary Manual. Breathing with the mouth open and a runny nose are the usual signs.
• Snake mites: tiny parasites that are visible to the eye but hard to spot in small numbers. They can also spread IBD.
• Mouth rot: an infection of the lining of the mouth. Early signs are tiny purplish red spots in the mouth.
• Stuck shed and eye caps: a healthy snake sheds in one piece. A shed that comes off in patches usually means the temperature or humidity is wrong, and eye caps left on can cause blindness in the long run, according to VCA.
• Burns: a snake looking for warmth can rest on a spot that is too hot, like an unguarded lamp or a heat rock, and get burned.
• Obesity: the British Veterinary Association's president, a small animal and exotics vet, said in 2020 that she saw many overweight pet snakes, from overfeeding and too little space to move, and that obesity can lead to liver problems.
• Regurgitation: bringing a meal back up. Merck advises not handling a snake for 3 days after it eats to prevent it. In boas it can also be the first sign of IBD, and the parasite Cryptosporidium can cause it too.

Do boas need vaccines?

No. There are no vaccines for boas or any other reptile. What protects a boa is a yearly check-up with a fecal exam, keeping mites out and keeping a new boa apart from your other snakes.

• Fecal exam: worms and protozoa show up in the droppings. The Merck Veterinary Manual notes that Cryptosporidium can cause regurgitation, marked weight loss and long-term weakness in reptiles. Treatment follows what the exam finds, so ask your vet before giving any dewormer.
• Mites: Merck advises using no mite product without your vet, because some aren't safe for all reptiles. Your vet can tell which mite it is and pick a safe treatment.
• Salmonella: the CDC says even healthy reptiles can carry Salmonella. Wash your hands with soap and running water after touching your boa, its food or its enclosure. Children under 5 shouldn't handle reptiles or their things, and the snake and its equipment stay out of the kitchen.

What is inclusion body disease?

IBD is caused by reptarenaviruses and affects boas and pythons. The Merck Veterinary Manual describes boas as typical hosts that can carry the virus for months to years with few or no signs, says IBD should be considered in every sick boa, and says it has no cure.

LABOKLIN, a veterinary lab, says regurgitation is often the first sign in boas, with a slight head tremor, dullness and less tongue flicking early on. Purdue University's vet school adds "stargazing", when the snake holds its body still with its head raised, along with respiratory infections, weight loss and mouth rot. Later, a boa may fail to turn back over when placed on its back.

The virus passes through body fluids: mating, bites, droppings and snake mites, according to the Merck Veterinary Manual. Your vet diagnoses it with PCR tests on blood or swabs, and sometimes sees the inclusions on a blood smear. LABOKLIN finds swabs from the oesophagus especially useful for PCR in boas.

One negative test doesn't rule it out. In a study at an Australian zoo, mostly of pythons, each infected snake tested positive in only one of its samples, and testing several samples over time found more carriers. Ask your vet which samples to send and how often to repeat them.

• Quarantine: Purdue University advises keeping a new snake apart for 3 to 6 months, and washing your hands between snakes.
• A positive boa: keep it apart from other boas and pythons for life. The Merck Veterinary Manual asks owners never to sell infected snakes or their young, because that spread IBD around the world. Your vet can help with supportive care.

Which signs in a boa can't wait?

Call your vet or an emergency clinic now if you see any of these.

• Breathing with the mouth open or a runny nose: signs of a respiratory infection, which needs treatment from a vet.
• Stargazing, head tremors, or not turning over when on its back: in boas these can be signs of IBD. Keep it away from other snakes and call your vet.
• Regurgitating a meal: in boas this can be a sign of IBD. Keep it away from other snakes and call your vet, right away if it happens again.
• A burn or blister: call your vet, and guard or fix the heat source before your boa goes back in.
• A bite from live prey: call your vet now. VCA says bite wounds need immediate veterinary attention.
• Red or purple spots in the mouth: an early sign of mouth rot, which needs treatment from a vet.

Find a reptile vet, and an emergency clinic that sees snakes, before you need one.

How do I set up a boa's enclosure?

Most boa illness comes from the setup, so the habit that prevents the most is reading the thermometer and the hygrometer every day. The Royal Veterinary College's care sheet sets out the basics.

• Size: as large as you can, at least 1.8 by 0.9 by 0.6 m for an adult, so the boa can stretch out and move between a warm end and a cool end. Wooden or fibreglass enclosures give a sense of security, with ventilation at snake level.
• Hides and climbing: a hide at the warm end and one at the cool end, and sturdy branches, since boas like to climb.
• Heat: a basking spot of about 31 to 33 °C and a cool end of about 24 to 27 °C, according to Yarmouth Veterinary Center, with nights a few degrees cooler but not below about 21 °C. The Merck Veterinary Manual puts the boa's preferred range at 28 to 31 °C, so ask your vet if you're unsure. Use a basking bulb that is on during the day and off at night, and background heat (a heat mat on the back wall, a tubular heater, a heat plate or a ceramic heater) for the night. Put every heat source on a thermostat and guard it, so your boa can't touch it.
• Checking: a digital minimum and maximum thermometer at each end, separate from the thermostat. Never use heat rocks, which VCA names as a common cause of burns.
• Humidity: 50 to 70% most of the time, according to Yarmouth Veterinary Center, checked with a hygrometer, with a humid hide of damp moss to help shedding. The Merck Veterinary Manual gives a higher range, 70 to 95%, and more during a shed, so ask your vet. Raise it by misting or fogging, or by moving the water bowl.
• Light: boas don't need UVB, but low-level UVB for about 12 hours a day can help, according to Yarmouth Veterinary Center. If you use it, place it at the distance the maker gives, and change the bulb at least as often as the maker says, or have its UV output checked.
• Water: a bowl big enough for your boa to soak its whole body in, changed every day.
• Substrate and cleaning: aspen, orchid bark or wood chips, or paper towels for a short time, and never cedar or pine shavings, which Yarmouth Veterinary Center says have toxic oils. Spot clean as soon as you see waste, and clean the whole enclosure once a month with a reptile-safe disinfectant.

How much and how often should a boa eat?

Boas eat whole rodents, and the prey grows with the snake, from pinkie mice to rats. Feed thawed prey, not live: VCA warns that live prey can bite a snake before it is eaten.

• Thawing: the Merck Veterinary Manual recommends thawing prey in the fridge and never feeding it cold. The Royal Veterinary College warms it to about 37 °C, blood temperature, and feeds off the substrate so your boa doesn't swallow any.
• Prey size: prey should not be much wider than the snake's head, according to Merck, while Yarmouth Veterinary Center gives about 1 to 1.5 times the widest part of the snake's body. Ask your vet which size suits your boa.
• How often: the Merck Veterinary Manual says most snakes are fed every 1 to 2 weeks, and some large, less active snakes go 6 weeks between meals. Yarmouth Veterinary Center's boa care sheet gives young boas a meal every 7 to 10 days and adults every 10 to 21 days. Adult boas put on weight easily, so ask your vet for a rhythm that fits your boa's age, size and shape, and adjust it by weight.
• After a meal: don't handle your boa for 3 days, to make regurgitation less likely.
• Refused meals: snakes may stop eating while shedding, in the breeding season or when the enclosure is too cold, according to VCA. A boa that refuses food and loses weight needs a vet.

How do I handle a large boa safely?

WikiVet, a veterinary teaching wiki, says large constrictors should be handled only with two people present, and that every 3 to 4 feet (about 1 m) of snake needs another handler to support the spine.

• Never put a snake around your neck.
• Support the body along its whole length.
• Wash your hands after every handling, and keep children under 5 away.
• Leave your boa alone for 3 days after a meal.

Is it legal to keep a boa?

It depends on where you live, so check the rules there before you get one.

• Brazil: the jiboia is native wildlife, and keeping one without the authorities' permission is a crime under Law 9,605/1998. Buy only from a breeder or shop licensed by IBAMA or your state's environmental agency. A news item from the Paraná government calls the invoice (nota fiscal), the certificate of origin and the marking certificate, with the microchip number, indispensable. Keep all three for your boa's whole life.
• International trade: the boa constrictor is in CITES Appendix II, and the Argentine boa (Boa constrictor occidentalis) in Appendix I, according to Species+. Boas sold as Boa imperator fall under the same Appendix II listing.
• European Union and United Kingdom: the boa is in Annex B of the wildlife trade rules and the Argentine boa in Annex A. The UK government says you need no certificate to own or sell an Annex B animal but must be able to show you got it lawfully, while an Annex A animal needs a certificate before it is sold. Keep the breeder's papers.
• United States: the US Fish and Wildlife Service removed the boa from consideration as injurious wildlife in 2015, so there is no federal ban. Check your state and city rules.
• Japan: the boa constrictor is on the Ministry of the Environment's list of dangerous animals (特定動物). Since 1 June 2020, no one may start keeping one as a pet. People who already had a pet permit before then may keep that same animal, according to the Tokyo Metropolitan Government, and keeping one for other purposes, like a zoo, needs a permit.

How do I keep my boa's health record?

VetVitae, a pet health record app, keeps your boa's feedings, refused and regurgitated ones too, with the prey (frozen and thawed, pre-killed or live), and tells you after two refused meals in a row. It logs each shed and where a stuck one stuck, and keeps your enclosure setup (temperatures, humidity, heat source, UVB lamp and substrate) ready for your vet.

It weighs your boa in grams and warns you when a weigh-in falls 10% below the highest of the last 3 months. Fecal exams go in exams and tests, IBD results go there as a test under Other, and it suggests a daily Mist the enclosure routine. See reptile records and weight. VetVitae is free on iPhone, Android and the web.

This guide is general information, not veterinary advice. Your vet knows your pet.

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