I am sorry to hear about Khloe. I am a veterinarian and will do my best to help.
Were any blood tests done when you went to the veterinarian? Seizures can be from many things, liver disease, hormone imbalances, low blood sugar, heart disease
. Ivermectin can cause seizures, but usually in higher doses than is in the heartworm preventative medications. How much ivermectin did she get?
Since Khloe's mother has seizures,it is very likely that this is epilepsy
, an inherited condition. If she were my dog, I would do some basic blood tests to rule out liver disease and other things. If that were all normal, I would probably start her on seizure medication.
If epilepsy is not treated, the seizures usually get worse and if you wait too long, she is less likely to respond to medication. If she has had a cluster of seizures, 4 in one day, or if she seizes more than once a month, that is when I recommend starting medication after some basic blood work.
Let me know what else I can answer or help with.