The most common snake bite patients present to our animal hospital is from the Night adder. The Common Night adder or Rhombic Night adder (Causus rhombeatus) is a small to medium snake (about 40 – 60 cm with a maximum of about one metre in length) with a distinctive V-shaped marking on the head.
With their tissue-destroying (cytotoxic) venom, bites can range from causing no damage at all (i.e. a dry bite), to a single mild bite, to several serious bites to your dog. Other venomous snake bites presented to our animal hospital for treatment include Puff adder (Bitis arietans) and Mamba (Dendroaspis spp.) bites.
Night adder bites in dogs usually present with a moderate to severe swelling, mainly around the face, front legs or chest area. Due to the size of the fangs and the fact that dogs are mainly covered with hair, distinctive teeth marks are not always seen on or near the affected area. Dogs are most often in a lot of pain even when touching non-affected areas. Upon presentation, most owners will have seen the encounter with the snake, or at least report seeing a Night adder in their surroundings within a short period before or after the encounter.
Tissue destructive venom
Like Puff adders, Night adders has relatively large fangs which contain cytotoxic venom. This can cause significant tissue damage. The severity depends on the size of the dog, the size of the snake and where or how many bites occurred.
Although human literature suggests the opposite, in my experience Night adder bites in dogs and cats should be considered serious and even life-threatening.
Why a rise in spring & autumn?
In our experience, as probably with most snakes, there seems to be a rise in Night adder bites in dogs during autumn and spring – before and after their winter rest or hibernation period. Night adders like to hide in old termite mounds, under logs and stones and among building rubble. They are often found near human dwellings with plenty of hiding opportunities around houses.
Night adder description
The Common Night adder is grey-brown on top with a series of rhombic markings and a distinctive brown or black forward-directed V-shaped marking on the head. It is easily confused with the harmless, toothless Common (or Rhombic) Egg-eating snake (Dasypeltis scabra) as both have similar markings. Click here for a beautiful collection of Night adder photos.
Night adder distribution
The Common Night adder prefers damp environments including savannah, forest and fynbos areas. They are mainly distributed along the eastern third of Southern Africa which almost includes the entire KwaZulu-Natal. On the south coast, Night adders have been seen all over, including urban and rural areas.
Why multiple bites?
Night adders are generally considered only moderately dangerous to humans. Their poison is considered to have low potency, causing pain and swelling.
If cornered or provoked, the Night adder will inflate and coil its body, hissing and striking violently at the same time. This will be enough to deter most humans, but not dogs – which will continue to attack the snake.
Proper treatment for dogs and cats
Night adder bites may be indistinguishable from Puff adder bites. If a positive identification of the snake is not made, general supportive treatment will be recommended. This will address potential shock due to hypovolaemia and tissue damage. Prescription sedation, tranquilisation and pain killers are also used depending on the severity, location and habitus (response) of the dog patient.
Specific treatment against Night adder venom involving immunotherapy using the South African polyvalent antivenom (snake serum) is not indicated as it does not contain immunoglobulins against Night adder venom.
Human bite victims should consult medical advice and treatment immediately after a bite.
What to do after your dog has been bitten by a snake
Very often owners do not witness their dog being bitten by a snake. If pain and swelling is observed, it is better to consult an experienced veterinarian. If possible, the snake should be presented for identification. It is not recommended to attempt treatment yourself as dogs often bite upon touch.