Nearly 50% of all calls to the Pet Poison Helpline involve pet ingestions of human medications. Birth control pills are among the 10 human medications most frequently consumed by pets.
Here’s some useful information on why no dog should have access to birth control pills, and what to do if you suspect your pet may have eaten them.
Is Birth Control Toxic to Dogs?
While it is never ideal for your dog to eat any human medication, birth control pills have a very low concentration of hormones and are generally not considered very toxic. In fact, a blockage from ingesting the packaging of the birth control pills can often be a bigger concern than ingesting the pills themselves.
Types of Birth Control
Although there are a variety of birth control pills on the market, most of them have similar ingredients: estrogen and progesterone in very low concentrations. However, some birth control pills contain iron, which can be more problematic.
Birth control pills are typically dispensed in containers of 21 or 28 tablets with four to seven inert pills, but some manufacturers will dispense up to 84 tablets in a package.
It is important to note that birth control pills are quite different from hormone replacement pills, which can contain much higher levels of estrogen. When discussing with your veterinarian any medication your pet may have ingested, it is crucial to have the packaging and/or full product information.
How Much Birth Control Does It Take to Poison a Dog?
In most birth control pills; the active tablets contain 0.035 milligrams or less of estrogen and varying amounts of progesterone. In general, if a toxicity does occur, it is the estrogen content of the tablets that is of concern. Estrogen doses of greater than 0.45 milligrams per pound (or 1 milligram per kilogram) can be toxic. For example, a 25-pound dog would have to eat more than 300 active birth control tablets for the ingestion to be considered toxic.
A single ingestion of high doses of progesterone in birth control tablets is also unlikely to cause any toxicity.
For iron-containing tablets, a dose of greater than 9 milligrams per pound (or 20 milligrams per kilogram) is considered toxic. Not all birth control pills contain iron, and those that do tend to vary in the amount of iron in each and the number of pills in the pack that contain iron (sometimes only the blanks or inert tablets contain a small amount of iron).
Symptoms of Birth Control Poisoning in Dogs
Even a small, non-toxic ingestion can cause mild upset stomach such as mild vomiting or diarrhea. However, with small ingestions of birth control pills, dogs will typically have no clinical signs.
If a moderate to large ingestion of birth control pills has occurred, you can see signs, including:
Anorexia (loss of appetite)
In female dogs: vulvar edema (swelling of genitals), vaginal bleeding
If a dog ingests an extremely large amount of estrogen, there are rare reports of possible estrogen-induced bone marrow suppression, which means a decrease in production of red blood cells, white blood cells, and platelets. This can be a very serious complication, so if your pet does eat a large number of pills, contact your veterinarian immediately.
If the birth control pill has iron and iron toxicity occurs, the most common first clinical signs are also vomiting, diarrhea, and anorexia. It is important to figure out if the ingested birth control contained iron to determine how to proceed.
What Should I Do if My Dog Eats Birth Control?
If your dog any has eaten birth control pills, try to determine how many were consumed and if any packaging was consumed as well. Next, it is important to verify which drugs (estrogen, progesterone, or iron) were consumed, and how much of those drugs are in the pills ingested.
Try to gather as much information as possible and then call your veterinarian to discuss whether your pet needs to be seen. You can also call the Pet Poison Helpline at 855-764-7661 or the ASPCA Animal Poison Control Center at 888-426-4435 for help in deciding if your pet needs to go to the emergency room.
Should I Induce Vomiting if My Dog Ingests Birth Control?
Do not induce vomiting at home unless you have been instructed to do so by a veterinarian. If you think your pet ate birth control pills or you saw them eat birth control pills, call your veterinarian to determine the next course of action. Even if the amount of birth control pills is considered non-toxic, your veterinarian may recommend that you pay a visit if your dog ate any packaging.
Treatment of Birth Control Poisoning in Dogs
If you see your pet eat birth control pills or packaging or find evidence of this, it is important to immediately call your veterinarian. They will collect a thorough history, so it is very helpful to have the packaging (or what is left of it) from any product your pet consumed.
If your pet ate the birth control pills within the previous two hours and it was a large amount, your veterinarian may recommend inducing vomiting at the hospital as a means of decontamination. They may also give activated charcoal to bind any additional toxin. In severe cases (such as ingestion of a large number of pills or iron toxicity), your pet may need to be hospitalized for IV fluids and additional therapy.
Most dogs recover from eating birth control pills without any short-term or long-term complications. However, it is very important to find out which active drugs are in the birth control pills and if any of the packaging was consumed.
Prognosis of Birth Control Poisoning in Dogs
Prognosis for birth control poisoning in dogs is considered excellent. With mild to moderate ingestion, most dogs will not need treatment and will fully recover.
Prevention of Birth Control Poisoning in Dogs
Prevention is key. Dogs are naturally very curious and are often drawn to investigate, and sometimes eat, human medications. Do not leave medication in easily accessible places such as purses or countertops. Never put medication in baggies or unsecured containers. The best way to prevent medication poisoning in dogs is to keep all medication in a safe and secure area away from easy access to pets.
Pet Poison Helpline. Top 10 Human Medications Poisonous to Pets.
Peterson, ME, Talcott P. Small Animal Toxicology. 3rd edition. Elsevier Saunders; 2001.
Sontas HB, Dokuzeylu B, Turna O, Ekici H. Estrogen-induced myelotoxicity in dogs: A review. Canadian Veterinary Journal. 2009;50(10):1054-58.
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