Dopamine agonists (bromocriptine / cabergoline)

What is this medication for?

• Cabergoline: pseudopregnancy, estrus induction/synchronization, second-half pregnancy termination, mastitis, pre-mammary-tumor-surgery; bromocriptine: same niche but adverse-effect-heavy
• Pseudopregnancy/estrus manipulation (cabergoline); acromegaly (bromocriptine — weak)
• Cabergoline in pituitary Cushing's

How is it given?

Give exactly as your veterinarian prescribed — never change the dose or stop on your own unless your veterinarian has told you to.

• Prolactin pharmacology in one line: dopamine is the prolactin brake → agonize D2 → prolactin falls → pseudopregnancy/mastitis/termination physiology follows.

What if I miss a dose?

• Give it as soon as you remember — unless it is almost time for the next dose (then skip the missed one; never double up).
• Call your clinic if you miss more than one dose in a row.

Side effects — what should I watch for?

Effects listed as common in this handout

• Emesis (prominent), stomach/intestinal upset, low blood pressure, CNS depression (Bromocriptine)
• Occasional vomiting only (Cabergoline)
• Galactorrhea-cessation/udder changes (Both (desired in pseudopregnancy))

Worth a phone call to your veterinarian

• Any new symptom that worries you.

⚠️ Contact your veterinarian or an emergency clinic IMMEDIATELY if you notice

• Trouble breathing, collapse, seizures, severe vomiting or diarrhea, facial swelling, or pale gums

Before starting (or refilling), tell your veterinarian if your pet:

• has or has had: Intact desired pregnancy; bromocriptine in vomiting-prone patients
• has or has had: Hypotension-prone patients; concurrent dopamine antagonists (metoclopramide-logic conflicts)

• is pregnant, nursing, or used for breeding
• is taking any other medications, supplements, or flea/tick products, including:
  • Dopamine antagonists (metoclopramide, some antipsychotics)
  • Erythromycin/CYP3A4 inhibitors (human)
  • Other hypotensives

Storage and handling

Cabergoline tablets — compounding usually needed for micrograms/kg accuracy; expensive in large dogs (generics improving).

Good to know

• The same-axis pair with opposite tolerability: cabergoline = clean modern tool (5 micrograms/kg daily); bromocriptine = the emesis-laden ancestor — the lesson repeats across the library (compare alprazolam/sertralol-generation thinking).
• Prolactin pharmacology in one line: dopamine is the prolactin brake → agonize D2 → prolactin falls → pseudopregnancy/mastitis/termination physiology follows.
• Pre-mammary-tumor-surgery prolactin suppression is the quirky reproductive-oncology crossover use.