Final answer:
In margin of safety studies for dogs and cats, the most common reactions include diarrhea, abdominal pain, vomiting, and nausea, with lethargy also being observed.
Step-by-step explanation:
In studies on the margin of safety for treatments or drugs in dogs and cats, the most common reactions noted tend to be gastrointestinal and systemic in nature. The reactions include symptoms such as diarrhea, abdominal pain, and in more severe cases, vomiting and nausea.
These side effects are similar to common adverse reactions seen in instances of food poisoning due to preformed bacterial toxins or infections acquired from various sources, including animal bites or contaminated needles.
Moreover, other symptoms like lethargy, restlessness, aggression, and neurological issues have been observed in animals with diseases like rabies.