The main early signs in dogs in decreasing frequency are:
* Salivation (drooling)
* Enlarged pupils
* Hind limb weakness
* Rapid breathing
It should be noted that following a snake bite, the signs vary greatly depending on the dose of venom received.
Dogs receiving low doses of snake venom may only show enlarged pupils and avoid bright sunlight for several days.
Dogs receiving larger doses of venom may show drooling and vomiting within 2 hours, have enlarged pupils by 4 hours and develop muscle paralysis later.
Dogs receiving massive doses of venom, as from multiple bites, may begin vomiting in 5-30 minutes, be paralysed and have enlarged pupils in 2-4 hours, and can die 2-5 hours after being bitten
Info from ARVU