Ah, the irony. So many animals – mostly beagle puppies, rats, mice, and rabbits – are used in animal testing, purportedly to protect human health, and yet we humans don’t use any of the resulting data to protect our pets from toxic chemicals in their toys, bedding, and other products.
Be it phthalates or lead in dog toys and wheels for pet hamsters, or formaldehyde in cat beds, there are plenty of chemicals lurking in the objects our pets interact with every day, not to mention other potential hazards. So, if you’re looking for safe dog toys or cat toys and other eco-friendly, non-toxic pet products, what should you watch out for?
See also: The CDC’s phthalates Fact Sheet.
What does the industry say?
In a fun case of circular thinking, some industry representatives at the American Pet Product Association (APPA) noted in one interview that because there’s no clear scientific evidence showing problems linked to chemicals in dog chew toys, there’s no basis for investigating safety limits on such chemicals in pet toys. Er, yeah, that’s not how science should work. That’s like covering your eyes and walking towards a cliff edge while claiming there’s no danger because you can’t see you’re about to fall. Open your eyes, industry!
And anyway, there is evidence of harm to animals from exposure to chemicals in everyday household objects. Indeed, dogs (and cats and other non-human animals) share the same home environment we do but may have even greater exposure to some chemicals because they tend to explore their environment with their mouths and spend more time in close contact with household textiles and dusty or dirty floors.
As such, some scientists have even proposed that dogs should be seen as sentinels for human exposure to toxic chemicals, especially as the incidence of certain types of cancer has increased in dogs as their exposure to these chemicals has increased.
Harkening back to Rachel Carson’s seminal book, Silent Spring, some researchers have also suggested that cats should be seen as sentinels for exposure to toxic chemicals in house dust. This dust is far from harmless as it contains phthalates, formaldehyde, heavy metals, and other plasticizers, flame retardants, and chemicals that disrupt normal physiological processes.
Why does it matter?
Dogs are mammals like us humans and suffer from many of the same diseases and health issues we face. For example, mammary adenocarcinoma is pretty similar in humans and dogs, with both species seemingly facing a higher risk of this type of cancer when exposed to high levels of polychlorobisphenyl (PCB) congeners, a type of persistent organic pollutant (POP) (R).
POPs include dioxins, dioxin-like and non dioxin-like polychlorobisphenyls, organochlorine pesticides, brominated flame retardants, and perfluorinated alkylated substances. All of these have been found in dogs diagnosed for mammary adenocarcinoma (R).
In humans and dogs, these POPs are stored predominantly in blood and adipose (fat) tissue, and it’s highly likely that they are transmitted to puppies through the umbilical cord and maternal milk just as human infants are exposed to these chemicals (R, R).
Chemicals such as dioxins not only increase risk for certain cancers, they are also linked to reproductive problems and developmental problems, as well as immune system damage. This means that puppies and kittens are made more vulnerable to illness and disease even before they’re born. For more information, see the CDC Fact Sheet on Dioxins.
Why dogs and cats face a higher risk of problems than humans
POPs accumulate the higher up you go in the food chain. This means that dogs that eat a meat- or fish-only diet are likely ingesting higher amounts of toxic chemicals than dogs eating a predominantly plant-based diet. Similarly, cats fed a largely meat or fish diet also have a higher proportional degree of exposure to these chemicals than humans or cats eating lower amounts of animal products.
Dogs and cats also interact with toys in a way that increases their exposure to toxic chemicals, such as by carrying toys in their mouths or chewing on toys for hours at a time. The mechanical pressure of chewing, plus a good amount of slobber, and some heat from warm dog breath and friction, all contribute to increased leaching of chemicals from chew toys (R).
Dogs and cats may also swallow small pieces of toys too, with veterinarians often noting the hardness of previously rubbery plastics retrieved from animals during surgery. This hardness indicates that the plasticizers, often phthalates, that made a toy more flexible and softer have leached into the animal.
And, because dogs and cats tend to sleep on the floor or on beds or blankets made with non-organic cotton, or synthetic fabric, they are also exposed to chemicals through this route too. As for rats, mice, and other smaller critters, because they tend to chew everything in sight, they may be exposed to significant amounts of toxic chemicals. Given their relatively small size, this can quickly lead to harmful concentrations of toxic chemicals in blood and other tissues.
Are toxic chemicals really an issue in pet products?
If you’re skeptical as to the extent of the problem of toxic chemicals in pet products, consider the case of Nancy Rogers. Over a decade ago, Nancy, a nurse, sent two dozen of her dogs’ chew toys for testing at a laboratory. This was at her own expense and followed the deaths of two of her relatively young dogs and her increasing suspicion that their deaths were linked to their repeated exposure to chemicals in training toys.
What the tests revealed was that one of the dogs’ favorite tennis balls contained 335.7 parts per million (ppm) of lead, below the allowable lead level for children’s toys at the time, but now far higher than the allowable level of just 90 ppm in Europe.
A couple of years after Rogers sought her own testing of toys, so did the Michigan-based Ecology Center, a non-profit organization that analyzes toxic chemicals in consumer goods including children’s toys. The organization had hundreds of pet toys tested, including tennis balls, as well as pet beds, collars, and leashes. Almost half of these products (45%) had detectable levels of at least one hazardous chemical. Those chemicals included heavy metals such as arsenic and lead, as well as bromine and chlorine.
Lead was found in a whopping 48% of the tennis balls tested. One dog ball had 2,696 ppm of lead and 262 ppm of arsenic just in the lettering on the ball. The researchers found that tennis balls intended for use by humans did not contain lead, however, but these tennis balls often contain fiberglass in the cover and can cause problems of their own, such as filing down a dog’s teeth.
Some retailers set their own standards for pet product safety. PetSmart, for instance, claim to test and review products periodically to ensure safety, but these standards and testing methods are not public, nor are they standardized across the retail industry, which leaves manufacturers somewhat confused.
Some manufacturers have voluntarily adopted standards for European lead levels in children’s toys and/or other types of consumer product safety standards. Again, though, companies are inconsistent with this and don’t make the results of any testing, or their processes, public. None of this inspires much confidence that the work is actually being done.
Part of the problem here is that the Consumer Product Safety Commission (CPSC) has no jurisdiction over pet products. This stems from the simple fact that dogs, cats, and other non-human animals are not granted personhood and consumer status or the rights that go with those things. And, even if the CPSC jumped in to safeguard the health of humans interacting with pet products, the reality is that we don’t interact with pet products in the same ways as our pets.
How can you minimize risk for your dog and cat?
As always, one of the best ways to avoid toxic chemicals is to see if a toy passes the sniff test. If it smells like chemicals, chances are that it contains things you and your pet are best to avoid. Toys treated with stain resistant compounds or fire retardants are definitely to be avoided, and I’d also avoid toys made with conventionally grown cotton (unless it is post-consumer recycled cotton).
Some dangers are a bit more obvious, such as small parts or decorations on toys that could constitute a choking hazard for a dog. It’s also not unheard of to find sewing needles, pins, or other foreign objects in plush toys meant for dogs. As such, it’s best to check all toys through visual inspection and by squishing them before giving them to an animal.
I’ve already mentioned some of the issues with tennis balls, such as high levels of lead in balls intended for use by dogs. Tennis balls are also a choking hazard for some dogs, so it’s important to make sure you use the right size ball for your dog or, if your dog can easily fit a whole tennis ball in their mouth, avoid tennis balls altogether and go for something bigger.
Synthetic rubber and ‘natural’ latex
Many dog toys are made with synthetic rubber (basically a type of plastic) or ‘natural’ rubber. The problem is, there are no marketing standards governing the term ‘natural’, which means consumers have no way of telling if a dog toy is similar to the 100% natural Dunlop latex in mattresses and pillows or is some chemical composite with a dash of rubber tree latex in there to ease a manufacturer’s conscience.
Frankly, I don’t know enough about chemical engineering to know if it’s possible to make a natural rubber dog toy without harmful chemicals that would withstand the rigors of being a chew toy or similar. Talalay and Dunlop latex would, to my mind, be too soft to hold up against an enthusiastic dog.
What I do know is that many rubber dog toys do contain toxic dyes, lead, formaldehyde, dioxins, and other chemicals that you and your dog are best to avoid. Unless a toy clearly states that it has been tested by a third-party organization and has been found to be free of or have very low levels of problematic chemicals, I’d stay away.
Stuffed toys that are intended for use by children are typically not a great idea for dogs, cats, or other pets. These toys are less robust than necessary for use by a dog and will likely contain things such as small plastic pieces for eyes, hands, noses, and so on, as well as ribbons that could become a choking hazard or cause a digestive obstruction for any animal. Even tags, squeakers, buttons, and other elements of toys sold in pet stores can be hazards for pets and should be removed (in most cases) before giving your dog, cat, rabbit, rat, or other pet a new toy.
Stuffed toys also typically contain polyester fill or some other kind of synthetic fibers and may have been dyed with harsh azo dyes or other chemicals linked to an increased risk of cancer. Even stuffed or fabric toys made with cotton or other natural material may have been treated with toxic chemicals such as flame retardants, antibacterial treatments, moth repellents, or other substances, and could contain residual pesticides from agricultural use.
In general, then, avoid buying stuffed or fabric toys made in China or other parts of Asia where manufacturing safety standards are much lower than in the US; only buy toys intended for specific use by dogs or cats or, at a push, by infants under the age of 36 months. The standards, especially in the EU, for these toys are higher than for toys intended for older children. Watch out for potentially toxic dyes or other chemical treatments and ask the company making the toy about their manufacturing processes and standards before buying.
In addition, inspect all new stuffed toys thoroughly. Manufacturing defects or mistakes can create hazards for your dog, cat, or other pet. In some cases, long sewing needles or other sharp objects have been left inside dog toys. Squeeze and feel around the toy to check for any potential problems.
Hazards of single air holes
One of the strangest concerns to have arisen in recent years over dog toys is the issue of single air hole toys. Any toy with a single air hole can become a potentially fatal hazard, especially if the toy is also slightly squishable. This is because a dog may put their tongue into the toy, to lick out some peanut butter, say, and simultaneously bite the toy. When they release the bite, this creates a vacuum that can suck their tongue further into the toy. If their tongue gets stuck, this can cause breathing problems, severe tongue damage, and the possibility of a dog requiring surgery or even dying from asphyxiation due to a swollen tongue and mouth obstruction.
If you do have a toy with a single air hole, consider drilling additional holes around the toy to reduce the risk of a vacuum occurring.
Avoid vinyl pet products
Many manufacturers make vinyl dog toys and other pet products and try to tell you that these are safe for your furry friends. They’re not. While vinyl itself is inert and unlikely to prove toxic to your dog, cat, guinea pig or other pet, I’m pretty sure you’re not going to give your pets old vinyl records to play with. Instead, these ‘vinyl’ toys are treated with a variety of chemicals to make them softer and more flexible, as well as to confer bright colors, flavors, scents, and other qualities deemed attractive to pets and their human companions.
Some of the chemicals used to manufacture pet toys made with vinyl include:
- Bisphenol-A – used as a stabilizing antioxidant in certain phthalate preparations, BPA stops phthalates from degrading, but BPA is a strong endocrine disruptor, mimicking estrogen and increasing the risk of reproductive cancers and other health problems. From an article in Time magazine, “the presence of BPA in dogs was associated with changes to their gut microbiome and metabolism”.
- Alkyl-phenols (nonyl and octyl) – these are also estrogen mimickers and are used to prepare phthalates for use in plastics or for the production of flexible PVC.
- Lead – a softening agent and sometimes present in paints. Lead causes nerve damage and cognitive and behavioral problems. There is no safe level of lead for humans or dogs and I’d recommend staying away from painted or plastic dog toys, especially those made in China and not certified lead-free. Dogs with lead poisoning typically exhibit signs and symptoms such as vomiting, weight loss, anemia, seizures, lack of appetite, salivation, jaw champing, constipation, anxiety, anxious barking, blindness, lack of coordination, muscle spasms, and issues related to permanent nerve damage. Ongoing exposure can affect multiple organ systems and prove fatal.
- Organotins – used as stabilizers in vinyl products, mono- and di-butyltins are widespread and are damaging to the immune system.
- Arsenic – a heavy metal sometimes found in vinyl dog toys and other pet products. Arsenic poisoning in dogs can lead to vomiting, loss of consciousness, and death in some cases.
- Melamine – a chemical (and a plastic) used to produce laminates, glues, molding compounds, coatings and flame retardants, as well as dinnerware. Melamine was linked to kidney failure in pets and led to a massive pet food recall by the FDA.
Polyvinyl chloride (PVC) production has long been linked to an increased incidence of cancer, especially liver cancer, in production workers, end users, and in pets (R). Liver cancer isn’t the only issue though, with many more problems associated with the chemicals noted above and with phthalates, a type of chemical commonly used to soften vinyl to make flexible dog toys and other pet products.
In one study, scientists simulated the action of a dog chewing a toy to assess how this affected the leaching of phthalates and BPA from toys. They looked at a range of dog toys including ‘bumpers’, a type of toy commonly used to train agility and service dogs.
Results showed that leachates from toys were mostly made up of di-2-ethylhexyl phthalate (DEHP) and BPA. Other chemicals that leached from the toys included other phthalates such as benzyl butyl phthalate (BBP), dibutyl phthalate (DBP), diethyl phthalate (DEP), and dimethyl phthalate (DMP).
The researchers found that leachates from these toys had anti-androgenic activity and estrogenic activity, confirming that these dog toys are potential sources of endocrine disrupting chemicals. Interestingly, toys stored outdoors prior to study leached lower levels of BPA but higher levels of phthalates, suggesting a no-win situation.
DEHP and BPA have been banned for use in some children’s products in the US, including in baby bottles, but not in dog toys or toys for cats, rabbits, or other pets. In the tests mentioned a moment ago, the amount of DEHP and BPA in dog toys was at the high end of what might show up in some children’s toys.
Levels of these chemicals were much higher in bumpers than in other dog toys, which is worrisome considering how many service dogs carry these bumpers in their mouths for long periods when learning to retrieve.
Danish researchers stood up for the rights of dogs in a 2006 report published by the Danish Ministry of the Environment, noting that dogs can suffer the same adverse effects of phthalates as humans and other mammals. The researchers reviewed the results of a 2005 investigation into vinyl toys made for dogs and cats and sold in Denmark. This study found that two types of phthalates, DEHP and DINP, made up 10-54% of the content of the toys.
These two phthalates were both among the six already banned by the EU for use in children’s products, which prompted the researchers to look at the rate of transfer of phthalates to dogs and cats who play with the toys.
The Danish researchers also assessed the data on the health effects of DEHP and DINP on rats and dogs and found that the phthalates cause similar damage to the animals’ livers and reproductive health. The reason they compared to data on the two species was because there’s relatively little data on health impacts on dogs. Following their analysis, the researchers reasoned that they might be able to extrapolate results from studies on rats and humans to estimate health effects in dogs.
The key conclusions of the study were that dogs who consume even a small amount of PVC from toys can be exposed to hazardous levels of DEHP that affect reproductive health; the mechanical action of chewing, coupled with dog saliva, may increase exposure to toxic chemicals in dog toys; exposure to these chemicals during gestation could affect the reproductive health of puppies; liver damage may occur with even small amounts of exposure to DINP from these dog toys; and combined exposure to phthalates from toys, leashes, food bowls, bedding, carriers, crates, clothing, and household items like flooring may be significant and detrimental to dogs’ health.
Of course, dogs aren’t the only pets at risk of health problems related to phthalates and PVC. Researchers have long known that exposure to DEHP and di(n-butyl) phthalate (DBP) during sexual differentiation causes male reproductive tract malformations in rats and rabbits (R). DEHP exposure during development in mice has also been seen to affect the regulation of the AhR/Cyp1a1 brain signaling pathway and disrupt defense processes in brain cells, with the potential to increase susceptibility to environmental toxins in later life (R).
Other studies in rats have shown that maternal DEHP exposure appears to increase susceptibility to brain cell damage in male offspring in particular (R). And, in mice again, DEHP exposure decreased fertility via a variety of pathways, including oxidative stress, cell death, DNA damage, mitochondrial damage, reduced cellular energy, disturbed chromosomal alignment, adverse effects on sperm receptors on the cell membranes of eggs, and more (R).
In general, then, if a pet product has a #3 PVC or #3 V label or is clearly labelled as made with PVC or vinyl, it’s best to avoid that toy and go for something else. The same goes for any toy without clear labeling.
We’ve covered a lot of ground here, but the main thing to remember is that as long as our dogs, cats, and other animal companions aren’t protected by robust legislation and regulation, it’s up to us, as responsible human companions, to do our best to minimize their exposure to toxic chemicals.
This means choosing non-toxic dog chew toys and flying toys, eco-friendly cat trees and bedding, and safe, non-toxic cages and play wheels for our smaller pets such as guinea pigs, gerbils, rabbits, rats, and mice.
The good news
Given everything I’ve just mentioned as a potential hazard, it would be easy to think that there are no safe pet products. Happily, some companies are making non-toxic, eco-friendly dog toys, cat beds, and so on, and I’ll be posting reviews of these as quickly as I can to help you find the perfect pet product for your animal companions. As always, if you know of an eco-friendly, non-toxic product worthy of attention, get in touch so I can check it out.