Dog Toothed Cat Snake – Venomous – Not Dangerous

Really amazing snakes, the Dog-toothed Cat Snake (species Boiga cynodon), which I don't get to see near often enough here in Southern Thailand. These are bird, egg, and lizard eaters primarily - but this one was seen heading for the frog pond.
Really amazing snakes, the Dog-toothed Cat Snake, which I don’t get to see near often enough here in Southern Thailand. These are bird, egg, and lizard eaters primarily – but this one was seen heading for the frog pond.

Boiga cynodon (Dog-toothed Cat Snake)

Thais say: ngoo sy hang ma

Length: As large as 2.75 meters (8+ feet) Recently I caught one that was about 2.5 meters. They are thin snakes and have a pronounced vertebral ridge and color bands of tan, yellow, brown and black.

Range: These Dog toothed cat snakes are found only in southern Thailand from Prachuap Khiri Khan and southward to Malaysia. We found two Boiga cynodon in Krabi and one in Nakhon si Thammarat over the past year. Other countries B. cynodon is present: Indonesia, Singapore, Philippines.

Habitat: Though they shy away from locations humans frequent they can be found on resorts in southern Thailand especially where there are chickens, eggs, and birds in cages. Typical habitat for the Boiga cynodon is the edge of rainforest where they are arboreal, spending most of their time in the trees and bushes waiting on the perfect bird meal to land. They are known to live in palm plantations as well.

Active Time? Nocturnal, active at night usually – but, we found one during the day as well.

Dog-toothed Cat Snake found in Southern Thailand.
Dog-toothed Cat Snake – Venomous – Not Dangerous. This one is darker than usual – it has an abundance of melanin, and is ‘melanistic.’ Photo by Tom Charlton.

Food: Birds of all sorts, and their eggs. Birds, chickens, and quail in captivity. When hungry will also eat other animals – lizards are most likely. Recently we caught a large specimen of 2.4 meters in length which was crawling across a road toward a frog pond. There are herping forum postings of a captive animal eating mice.

Defensive Behavior: Rarely bites, this is a big snake that can be hand held until aggravated.

Venom Toxicity: Though they rarely bite – even when physically attacked – they can inject venom. They are rear-fanged colubrids and a prolonged bite could cause swelling and pain at the bite site. The venom can cause problems with circulation. A simple bite from this snake is not usually dangerous because the rear fangs don’t sink in during a typical bite. There are two larger than average front teeth resembling fangs.

Offspring: Six to twelve eggs laid.

I've hand-held the dog-toothed cat snakes before and no problem... but this one struck at me repeatedly.
I’ve hand-held the dog-toothed cat snakes before and no problem… but this one struck at me repeatedly.
Amazing colors and eyes on the Boiga cynodon - yes?
The melanistic snakes can be really stunning. ©2010 ThailandSnakes.com

Notes: These are beautiful snakes here in Thailand – perhaps more so than the rest of Asia where they are known to be found. A couple of specimens were found locally in Krabi in southern Thailand at night and near a chicken farm in one case, in a tree on another herping field trip. These snakes are known to eat local Thais birds in the cage, and then not be able to get back out through the slats in the bird-cage, and so entrap themselves.

Coloring on these snakes varies greatly. You can see the two snakes in these images here, they were both from the same area. They are dramatically different in coloration, the darker one having an excess of melanin.

Dog-toothed cat snakes are sometimes confused with vipers because their head is quite pronounced in size from the size of their necks where it meets the head. There is no viper that gets anywhere near this big – so, you can discount vipers if the snake is 1.5 meters or longer. Only the Chain Viper (Russell’s Viper) reaches 1.5 meters, and it is considerably thicker in size at the neck. If you are in Thailand’s deep south,the Sumatran Pit Viper can reach around 2 meters in length.

A lighter-shade of Dog-toothed cat snake found in a palm tree at night in Krabi province. This one was nearly 3 meters long.

Scientific classification: Boiga cynodon

Scientific Classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Colubridae
Subfamily: Colubrinae
Genus: Boiga
Species: B. cynodon

Scientific classification: Boiga cynodon
(Classified by Boie, in year 1827)

Page Updated: 7 September 2016

Video of Release of Dog-toothed Cat Snake

About Vern Lovic

Snake posts by Vern Lovic. Amateur herpetologist roaming about Thailand on field herping tours and events to find king cobras, kraits, vipers, corals, keelbacks, and other snakes native to Thailand. FYI - Thailand has over 200 snake species. Here's our latest book with detailed information on Thailand's 35 Deadly Snakes. "Is That Snake In Your House Dangerous? Identify Deadly Thailand Snakes In Under 5 Minutes!" INFO HERE.

3 thoughts on “Dog Toothed Cat Snake – Venomous – Not Dangerous”

  1. Just met one of this near my house in Phuket late evening time. At first couldn’t guess any of known snakes because of her size 2+ metres long. I knew only pythons and king cobras at such size here localy. Though the large skin scales and posture looked if not dangerous but something to consider. Very happy to know now that this snake is rather harmless for humans so I can tell to locals not to kill it with no reason.
    Thanks for the article!

    1. Yeah, these snakes can get large! I’ve seen one well over 2 meters before. They do look a bit scary, but very thin. The head looks a bit like a triangle, but it is not venomous. Rear fanged, and some mild venom, but humans do not seem to have any reaction to this snake’s venom. I have been bitten on the hand for a long time – over a minute, and no reaction at all. I have never seen someone get a bad reaction from this snake. Cheers!

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