ENVIRONMENTAL ESTROGENS Affect Dog’s Fertility & Reproduction

Attention Dog Breeders

Our Dog’s Fertility & Reproduction is Being Affected by Environmental Estrogens

By Dr. Jeannie Thomason

I was going to list as many of the reasons for and the many toxins being found to be affecting fertility and reproduction in our dogs with a comment on what effect each one has on our dogs and ourselves. However, it was getting to be crazy long and reading like a long scientific report or study, sure to bore even the more geeky dog breeders out there! lol

So I have re-written this and attempted to keep the information as condensed and concise as possible in the hope that if you want to know more and go deeper into study and research all of the toxic, synthetic chemicals that affect our dogs fertility and reproduction you would be able to use this information as a solid diving board to dive in from. So, In a nutshell, ladies and gentlemen, I present you with this article on:

ENVIRONMENTAL ESTROGENS and how they affect our dog’s fertility and reproduction.

Unfortunately, we and our companion animals are constantly being assaulted by estrogens in our environment—from the food we feed them (and the food we eat) to the household cleaning products, air fresheners, personal products, pesticides, herbicides and even vaccinations and medications. Estrogen in the form of chemicals (xenoestrogens), or foods and plants (phytoestrogens), mimic the action of estrogen produced in cells and can alter hormonal activity.

Current evidence suggest that xenoestrogens and other hormone-mimicking substances are contributing to a wide range of human, pets and wildlife health problems!

To name just a few of the problems caused by Environmental Estrogens include:

  • prostate problems (in both humans and animals)
  • lowered libido
  • impotency
  • infertility
  • birth defects


What are Xneoestrogens? Xeno literally means foreign, therefore xenoestrogens means “foreign estrogens”. Some of the 70,000 registered chemicals for use in the United States have hormonal effects in addition to toxic effects.

The synergistic effects of exposure to many xenoestrogens are well documented, but largely unknown. These substances can increase the estrogen load in the body over time, and are extremely difficult to detoxify through the liver; making this further compound the problems of estrogen dominance in the body.

Byproducts of the plastic and pesticide industries – called organochlorines – are one of the largest sources of xenoestrogens. These compounds – used in dry cleaning, the bleaching of paper products, and during the manufacture of plastics ranging from yogurt containers to baby bottles to pet food dishes – have been shown to exert hormone-disrupting effects.

What’s more, organochlorines are known to accumulate in fatty tissue and fluid such as breasts and breast milk.

Plastics also expose us to the chemical bisphenol A (BPA), a breakdown product of polycarbonate, widely used in many plastics. Bisphenol A, found in the lining of many food cans and juice containers, as well as plastic dog toys.

Many companies are now producing plastic products that are BPA-free. However, reducing the use of all types of plastics is recommended when possible.

Other bad news from scientists have suggested that environmental estrogens are most likely reducing sperm counts in men and causing breast cancer, fibroids and other reproductive dis-eases in women. Xenoestrogens can be found in many meats and dairy products in the form of chemicals and growth hormones that are given to the animals we then feed our dogs or eat ourselves. This is one of many reasons we should be feeding (and eating ourselves) pasture raised/grass fed animals instead of those raised on factory farms and available in the grocery store whenever possible.

Male reproductive health (both in men and male animals) has deteriorated in many countries during the last few decades. In the 1990s, declining semen quality has been reported from Belgium, Denmark, France, and Great Britain. The incidence of testicular cancer has increased during the same time incidences of hypospadias and cryptorchidism also appear to be increasing. Similar reproductive problems occur in many domestic pets and wildlife species as well. Research suggests that the adverse changes may be inter-related and have a common origin in fetal life or youth. Exposure of the male fetus to supranormal levels of estrogens, such as diethlylstilbestrol, can result in the above-mentioned reproductive defects. The growing number of reports demonstrating that common environmental contaminants and natural factors possess estrogenic activity presents the working hypothesis that the adverse trends in male reproductive health may be, at least in part, associated with exposure to estrogenic or other hormonally active (e.g., antiandrogenic) environmental chemicals.

Recently, dog foods were found to contain significant amounts of diethylhexyl phthalate (DEHP), seven types of polychlorinated biphenyl (PCB) and four types of polybrominated diphenyl ethers (PBDE).

Suggestions for avoiding substances and products that contain xenoestrogens:

Avoid ALL

  • pesticides (Flea, Tick, Heartworm medications)
  • herbicides, and fungicides
  • plastic containers, toys, etc. (they leach xenoestrogens into the environment)
  • shampoos, creams and cosmetics that have toxic chemicals and estrogenic ingredients such as parabens and stearalkonium
  • chloride (cheap brands tend to include more toxic ingredients)
  • nail polish and nail polish removers
  • new carpet (or any carpet at all if possible – it can give off or off gasses – noxious fumes)
  • fluoride – Use a water filter
  • don’t leave plastic containers, especially drinking water bottles, in the sun (plastic containers when heated up significantly, leach into the water and environment)
  • fabric softeners (they contain petrochemicals that are absorbed by inhalation and via the skin)
  • noxious gas such as from copiers and printers, carpets, fiberboards, synthetic material, material treated with fire retardants, etc.

Do whatever you can to minimize xenoestrogen exposure:


  • a high-quality water filter in your home
  • Pasture raised, hormone-free meats and dairy products
  • glass or ceramics for storing food
    homemade laundry, dish soap, cleaning products (lemons, vinegar, hydrogen peroxide, etc. or products with no chemical ingredients
  • natural skincare products and makeup
  • therapeutic grade essential oils instead of petrochemically-based perfumes, air fresheners,etc.
  • BPA free dog toys or toys made with organic materials.


Phytoestrogens (phyto meaning plant) are naturally occurring estrogenic compounds that are found in a variety of plant foods such as beans, seeds, and grains. Their chemical structure resembles estrogen. Phytoestrogens acting as estrogen may affect the production and/or the breakdown of estrogen by the body, as well as the levels of estrogen carried in the bloodstream.
These mimics can either have the same effects as estrogen or block estrogen’s effects.

Cruciferous vegetables,(including oily seeds such as flax, hemp, etc.) while extremely healthy for omnivores and some herbivores, have been found through controlled studies, such as at the University of Illinois at Urbana, that extracts of cruciferous vegetables and seeds act as anti-estrogen and estrogen agonists. These findings were published in 2000 by the American Chemical Society. Other university studies are available and indications are that over 300 studies with similar results took place.

Not only are these cruciferous plants and seeds NOT species specific for our carnivores in the first place, these substances are natural estrogen inhibitors, which interfere with thyroid hormone production as well.