Here's why:
* Safety for the Fetus: Some dewormers can be harmful to a developing foal, potentially causing birth defects or complications.
* Specific Dewormers: Different dewormers have varying levels of safety during pregnancy. Your vet can recommend the safest option based on your horse's needs and stage of pregnancy.
* Dosage: Incorrect dosage can be dangerous for both the mare and the foal. A veterinarian can calculate the appropriate dosage.
* Underlying Health Conditions: A vet can assess your horse's overall health and any pre-existing conditions that might influence the choice of dewormer.
It's never worth the risk to administer medications without professional guidance. Contact your veterinarian immediately for advice on deworming your pregnant horse.