Pale, blue, and yellow gums
Some toxins might cause the body to experience a series of effects that can be seen only in the mucous membranes, such as the gums, tongue, eyelids, and oral cavity.
For instance, ingestion of onions might lead to anemia and even pale gums. Also, blood loss caused by rat poison and other toxins can be spotted early if you notice that the pet’s gums are paler.
Some toxins could also affect the liver, and you’ll be able to notice it in yellowish gums (jaundice). Toxins that harm the cardiovascular or even respiratory systems could lead to blue-colored gums.
Swelling
A dog’s face and limbs might get swollen after being exposed to toxins, and this occurs the most when it comes to snake or insect bites.
If you notice such an area in your dog’s body, then there’s trouble, and you should contact the vet’s office as quickly as you can. Also, bringing a photo of the symptom might help with a more rapid diagnosis.