Giving Pregnant Dogs Medication

Ask PHP Pete!

Dear PHP Pete,

I just found out my dog is pregnant. Is it safe to give her medications during her pregnancy?


Pups in the Oven

Dear Pups in the Oven,

A dog’s body experiences many changes during pregnancy. Developments, such as decreased digestion speed, increased and redirected blood flow, increased fluid volume, and increased kidney function, can change how the body processes a drug. Drug availability in the body may increase, decrease, or remain the same because of these changes caused by pregnancy. Not only can the drug impact the mother differently, but the drug may cross the placenta and impact the puppies. It may be best to assume that any given drug will reach the puppies.

Few studies have explored which drugs are safe in pregnant and lactating dogs and cats. Reasons for this include ethical implications, differences between species, changing body conditions throughout pregnancy, and lack of a model that replicates pregnancy. The general tendency to avoid using drugs in pregnant animals means there is little prior experience available for a frame of reference.

Although researchers still have much to learn about the effects of medications on pregnant dogs and cats, thus far they have gathered the following information:

  • It is safe to continue using heartworm prevention and topical flea/tick controls.
  • Some antibiotics are considered safe, such as beta-lactam antibiotics (e.g., penicillin, amoxicillin, ampicillin, and cephalosporins).
  • Opioid pain relievers such as morphine or hydromorphone can be used if needed.
  • Insulin should be continued for diabetic dogs and, thyroxine (e.g., Synthroid) should be continued in dogs with hypothyroidism. However, dogs with these conditions should not be bred because these conditions are hereditary.
  • Antifungals such as ketoconazole, itraconazole, or fluconazole should be avoided when possible because they can cause birth defects.
  • NSAID pain relievers such as Aspirin or carprofen should be avoided due to the risk of bleeding and fetal injury.

If possible, avoid giving your dog any medications during pregnancy. You should have your veterinarian examine your dog. Feed her good-quality food, and do not supplement with vitamins unless directed otherwise. Sometimes the benefit outweighs the risk, and drugs that carry risks may be needed to keep the mother healthy. Your veterinarian can help you decide what is appropriate in your case.

Congratulations and Best Wishes,

PHP Pete