A new HRT topic is in the spotlight.
Every owner knows the risks of pet poison through human medication, the most common including ibuprofen and aspirin. However, there is a new drug threat for pets that is becoming increasingly prevalent.
Ploof founder and dog owner Gill Bennett talked to me about her journey with Hormone Replacement Therapy in combatting the adverse effects of peri-menopause. After years of little sleep, extreme tiredness and incontinence, she began to research her symptoms, knowing that the time of sacrificing her everyday well-being needed to end. Gill swears by the benefits HRT brings to women; basic sleep and exercise are just two of many things that no woman should have to give up.
What came with this choice to take control of her body came an insight for Gill into HRT’s complex history within the market. After 2002’s government scaremongering around connections to cancer, she noticed there was a newly emerging concern: this time about our pets.
Last year, the National Press took the pet world by storm. A series of incidents were published in the national press regarding dogs and cats experiencing what can only be described as unexplained and unnatural puberties.
Abnormal puberties? Come again!
In West Yorkshire, dachshund puppy Lilly went into season at only 12 weeks old. In Surrey, male dogs became obsessed with Jack Russell Rosie despite being spayed. A Sphynx kitten with enlarged mammary glands and a seven-year-old neutered short-haired cat that developed symptoms of ‘oestrus’ were reported by vets in 2022. So, what caused all of this?
Last year alone, Surrey’s North Downs Specialist Referrals diagnosed five dogs with accidental HRT exposure.
What is HRT?
Hormone Replacement Therapy (HRT) is a medication used by women to ease the negative effects of perimenopause and menopause through repleting and balancing the body’s supply of hormones – namely oestrogen, progestogen and sometimes testosterone.
Hormone Replacement Medidogions come in multiple forms: sprays, gels, patches, and oral tablets, with the method of use, dosage, and hormone ratio specific to the needs of each woman. England has seen a 22% increase in patients being prescribed HRT through public services in the last year, with 13 million prescriptions across the country in 2023/2024.
Now HRT, I hasten to add, has been called a ‘game changer’ for women’s health and can be positively life-changing for helping them through the realities of peri - menopause and menopause.
There is no denying the incredible benefits of the therapy for the thousands of women every day who choose to take it and can only laud progression in female healthcare. However, as HRT gains deserved popularity, it’s critical that doctors and pet owners are knowledgeable about the potential risks and how to prevent them.
HRT toxicity
What is it, and how on earth is it getting into our pets?
In medical jargon, dogs and cats are seen to be experiencing secondary exposure to hormones through contact with transdermal HRT products. This can cause toxicosis in animals as they absorb unwarranted hormone excesses, resulting in what would be called precocious puberty in humans. Long-term exposure to doses of ≥1 mg/kg of oestrogen can lead to potentially fatal effects involving bone marrow suppression, subsequently aplastic anaemia, and mammary tumours.
To put it in simpler terms, when HRT users’ little ones snuggle in their laps or give them a good ol’ lick of love, they are at risk of absorbing the hormones through physical contact.
How does this work? HRT in its gel or spray form is most often applied to the fore or upper arms and inner thighs. If not absorbed properly, the residue can be transferred onto a pup or cat’s fur and enter their bloodstream. Pets getting their paws on birth control tablets is a more established issue, yet the strength of HRT transdermal meds makes the problem more concerning.
What exactly does this look like?
This all sounds a bit daunting, so an idea of what HRT exposure might look like can help clear things up. Here are the main symptoms:
Females:
Enlarged vulva with potential bloody discharge
Raised hindquarters
Bloody discharge from the vulva
Uterine infection
Going into the season, despite being spayed
Males:
Shrunken penis
Small/undescended testes
Inflamed penis
Unisex:
Hair loss
Excessive vocalisation
Restlessness
Stunted growth
Increased attention to/from other sex
Enlarged and/or ulceration of the mammary glands
I creased attraction to/by other dogs
Decreased appetite
Increased affection levels
Indoor urination
Restlessness
Aggression
Vomiting and/or diarrhoea
Mood changes
So, how dangerous is HRT exposure?
It’s not common
It’s easily reversible
Awareness and prevention are key
It’s important to know that this short-term hormone exposure is easy to treat and quickly reversible over a few months at maximum, solely through stopping any more exposure; more severe cases of ongoing exposure are yet to be observed. So, to make sure owners keep staying alert, it’s critical to raise awareness around triggers, correct medication usage, and environmental management.
Prevention pointers
Menopause Specialist Dr Carys Sonnenberg explores how HRT gets around the house and how to avoid spreading any of the medication. You can check out her interview with pet trainer Hanne Grice here, but I’ve summarised the top tips:
GEL and SPRAY
Wash your hands after applying the medication to the skin.
Wait two hours before skin-to-skin contact with any other animals/people, as this is the maximum time it takes for the hormones to be fully absorbed into the body.
ORAL MEDICATION
Keep pills out of reach of children and pets. They’re also tiny tablets, so they are easy to lose if dropped and mistakenly snuffled up by a dog or cat; make sure to keep track of them.
PATCHES
Throw them away immediately after removal, after sealing the patches in a package; you never know where they might fall out of the bin and end up!
Wear them under clothing to ensure that your pet won’t accidentally pull them off the skin.
While patches pose less risk than gels or sprays, they can be devilishly mobile. Dr Sonnenberg says she’s experienced multiple cases where it has fallen off a woman’s skin in the night and been transferred to her partner, so watch out if you and your pet snooze in the same bed! The key takeaway is that some women absorb the hormones slower and less effectively than others, so it’s important to follow the guidelines for exposure prevention and wait the right amount of time before cuddling your pup.
What’s more, pets with thinner fur have less of a barrier for protection from secondary exposure. The times when they’re getting a well-deserved belly rub are when they could be at the most risk
Opening up the conversation
HRT does some amazing things for countless women every day. In fact, one-third of the entire female population in the UK is going through perimenopause or menopause. Exactly what Hormone Replacement Therapy is, as well as the best ways to take it around pets, is so important and deserves healthy discussion between owners, health practitioners, and vets. This means it’s important that doctors discuss secondary exposure with pets in the prescription process. Gill’s practitioner told her that HRT can be prescribed as early as thirty-five – this isn’t just a discussion to push away until later in life.
We can also keep educating ourselves on peri - menopause and menopause in our own time. Have a look at Ginni Mannsberg’s powerful summary of the alarmist rumours propagated by multiple governments around HRT’s relation to cancer. Chatting with our GPs, as well as friends and family, helps open an empowering discussion around the realities of peri - menopause and menopause because – if I’m being honest – we are nowhere near where we need to be in terms of awareness.