The 55-year-old star of Springwatch - who lives in South Africa - told how her pets Rio and Timmy became unwell after eating human faeces contaminated with Class A drug methamphetamine while out on a walk.
Watch: Can Dogs Get Poison Ivy?
Strachan explained on Instagram: "After walking my dogs through a ruined fort on the mountain yesterday, a few hours later they looked like they were both having seizures and couldn’t stand up.
"We rushed them to the vet and she recognised the symptoms as an overdose of a drug called Tik, Crystal meth, apparently the ruined fort is where a lot of homeless people hang out and take tik so the dogs must’ve eaten human poo with Tik in it! Extraordinarily The vet has come across the problem before."
The former Splash contestant said she spent a "rough night" nursing her two dogs as they suffered seizures, vomiting and incontinence while suffering from the side effects of the drug.
Strachan said they woke up, "confused, disorientated, paranoid and spaced out."
She later shared a video of the two dogs running on the beach, saying they appeared to have made a full recovery from their traumatic experience.
Strachan said: "Rio and Timmy on the beach and back to their old selves. Tails wagging, noses wet, tongues out and chasing seaweed. Seemingly none the worse for their guest appearance in Breaking Bad! Thank you for all your comments and support. Weird experience!!"
The TV presenter - who rose to fame on BBC children's programmer The Really Wild Show - relocated to South Africa in 2002 with her partner Nick and 16-year-old son Oliver.
Both Rio and Timmy are rescue dogs and Strachan recently said they had been "fantastic companions during lockdown".
Watch: Man films deer in his garden after Springwatch hosts complain of lack of deer