Scientists are not entirely sure what exactly causes pancreatitis in animals, so there is a lot of debate. One possible reason is that pets have access to food waste when the winds blow open some garbage containers or knock them over.
Dietary indiscretion, such as eating rancid fatty scraps from the garbage, can also lead to pancreatitis, particularly when a dog accustomed to a low- or normal-fat diet ingests high-fat foods. That’s why canine pancreatitis incidents are thought to increase after Thanksgiving, when people may feed their dogs a meal of turkey skin and drippings.
Source: Whole Dog Journal: Dog Pancreatitis Symptoms, Causes, and Treatment
The same article hints at another possible cause: Typhoons usually bring heavy rain that can wash out toxins and other harmful substances that aren't usually encountered in such high concentrations. We humans put on waterproof boots, but our pets soak their fur in this water and later lick it to clean themselves.
Toxins, particularly organophosphates (insecticides used in some flea control products), as well as scorpion stings and toxic levels of zinc, may also lead to canine pancreatitis.
PetMD makes a clear statement that pancreatitis in cats is not related to their diet, but again we find insecticides as possible causes:
There are several possible causes of inflammation to the pancreas. Some of them are:
- Exposure to organophosphate insecticides
[...]
Unlike with dogs, inflammation of the pancreas is not related to nutritional factors in cats. In many cases, no underlying cause for pancreatitis can be determined.