Two beagles called Alfie and Bailey lack the main protein that causes allergic reactions to dogs, thanks to CRISPR gene editing. The dogs will be 2 years old in September and show no signs of adverse effects, according to , the company behind them.

“I’ve lived with allergies my whole life. They prevented me and my family from ever having a dog,” says Kindred co-founder Matt Walker. “And my wife, Maggie, has always wanted a dog.” Walker previously worked as a researcher studying neuron development in worms by using CRISPR gene editing to disable specific genes. He realised it might be possible to use the technique to prevent dogs causing allergies, and founded Kindred in 2020.

How were Alfie and Bailey created?

Previous studies have found that the main allergen that triggers reactions to dogs is a protein called Can f 1. It is secreted by the tongue and by glands in the skin, so it is present both in the fur of dogs and in their saliva.

The Kindred team took skin cells from a female beagle and used the gene-editing tool CRISPR Cas9 to mutate the Can f 1 gene – the result was an extra DNA letter at the start of the gene that shifts the way the recipe for making the Can f 1 protein is read by cells, turning it into gibberish. Once the team members had confirmed they had made the desired change without introducing unwanted mutations, they cloned the cells. Altogether, the team transferred 25 embryos to a surrogate, of which two implanted and developed to term.

Does removing this protein really prevent allergies?

Bailey is Walker’s pet dog, and he says he has no reaction to her at all. She was cavorting in the background when New Ů��С��Ƶ spoke to him. Kindred has also showing that Can f 1 is undetectable in Alfie and Bailey, and that there are no allergic reactions to samples from them in skin-prick tests, whereas samples from normal dogs do provoke a reaction.

However, Can f 1 isn’t the only protein in dogs that can trigger allergic reactions – there are also so-called minor allergens, such as Can f 2. “If we do find that there’s a substantial population that is still responding to the dogs, then that is something we could address,” says Walker.

And could the process be harmful to dogs?

We don’t know for sure what the function of Can f 1 is, but Walker says he was confident from experiments on mice that there would be no serious consequences from deleting it. So far, both dogs appear normal and healthy, he says. “Of course, that’s something that we’re monitoring very closely, and will continue to monitor over the animals’ lives.”

Isn’t it already possible to buy “hypoallergenic” dogs?

Some breeds, such as poodles and goldendoodles, are said to be less likely to trigger allergic reactions, but Walker says he responds just as much to the goldendoodle his parents bought after he left home as he does to any other dog. In the paper, his team shows that Can f 1 is detectable in both breeds, and that samples from them trigger reactions in skin-prick tests.

This is in line with independent evidence. The American Academy of Asthma, Allergy and Immunology says some “hypoallergenic” breeds .��

Free newsletter

Sign up to Health Check

Sign up to newsletter

When will these dogs be commercially available?

Not for some time. Kindred first needs regulatory approval from the US Food and Drug Administration. If it gets that, it then needs to create lots more of these dogs. For each dog breed, the company will have to create a genetically diverse set of “founder” dogs that can then be bred normally. Walker couldn’t say how many founder dogs would be required per breed.

Is it ethical to genetically engineer dogs just to prevent allergies?

“We aren’t using gene editing for novelty or some cosmetic reason,” says Walker. “Allergies are a real health problem. They affect a significant portion of the population, and lead to serious conditions such as asthma triggering asthmatic attacks.”

By contrast, conventional dog breeding is often done purely for the sake of appearance, and can introduce mutations that cause serious harm, such as those found in breeds like pugs .��Nevertheless, Kindred is altering dogs for the benefit of humans rather than the benefit of the animals themselves. In response to this, Walker says people discovering they are allergic to dogs is a leading reason for animals having to be rehomed.��

Is Kindred planning to gene-edit cats, too, to prevent allergies?

“Right now, we’re focused exclusively on dogs,” Walker says. The main allergen in cats, called fel d 1, is encoded by two genes rather than one, so getting rid of the protein is more complex. Another company called InBio announced plans to create cats free of fel d 1 in 2022.

Don’t treat your pets for parasites such as ticks and fleas unless they actually need treating. We can’t be sure that these treatments are safe for you and your family, and there is growing evidence that they pose a danger to wildlife.

So says a by the Environment and Climate Change Committee of the UK’s House of Lords. It is calling for the sale of these treatments to be restricted, so people can only buy them after consultation with a vet, pharmacist or qualified pet shop staff.

The main issue is that there is no rigorous assessment of pet treatments before they are approved, the report says. It has simply been assumed by national and international regulators that they are safe, but this assumption is turning out to be wrong.

In particular, at least two potent pesticides found in tick and flea treatments are getting into UK rivers at levels high enough to affect wildlife. These pesticides can break down into other substances that are even more harmful.

“There is also worryingly insufficient evidence to assess whether or not [pet parasite medicines] are harmful to human health,” says the report.

Free newsletter

Sign up to The Earth Edition

Sign up to newsletter

It also says regulators aren’t sufficiently independent. Both UK and international regulators “appear to be too influenced by and beholden to the views of the industry”, it states.

While the report focuses on the UK, the same tick and flea treatments are sold in many countries. “This is a worldwide issue,” says at Imperial College London, one of the experts who gave evidence to the committee.

“There’s been a historical assumption that any veterinary medicine used in non-food animals – cats and dogs, companion animals – is associated with negligible environmental risk,” she says. “Effectively, they have no meaningful environmental risk assessment.”

But recent research shows they do pose a risk, says Perkins. “It’s really opened up a Pandora’s box, because we have dozens of these products that have been approved based on this assumption that we now know is not scientifically valid.”

For instance, two common pesticides found in products such as spot-on flea treatments are fipronil, a broad-spectrum insecticide, and imidacloprid, a neonicotinoid. “They’re incredibly potent at extremely low levels,” says Perkins.

Both pesticides used to be used on farms until they were banned a few years ago. But they have continued to be found in rivers. In fact, with the development of more sensitive tests, they are turning up “pretty much everywhere in waterways”, says Perkins.

Initially, it was thought this was a legacy of their use by farmers, but work by Perkins and others suggests parasite medications are now the main source of these pesticides in waterways. In many cases, levels are high enough to harm invertebrates such as mayflies, dragonflies and caddisflies, with knock-on effects on the fish and birds that feed on them.

We don’t know how big a problem this is, says the report. “The true scale of environmental harm resulting from pet parasite medications is not known.”

How are the pesticides getting into rivers? Once they are applied to pets, they end up all over the home, says Perkins. When people bathe their pets or wash pet bedding, they can end up in wastewater.

Product packaging currently recommends that dogs are not bathed for four days after treatment, but this needs to be extended to 28 days, the report recommends.

Another major source of the pesticides in water is hand-washing, says Perkins. “We detected [pesticides] in the wash-off even before we asked people to stroke their pets, so they’re just constantly on the hands of pet owners.”

Products containing fipronil and imidacloprid are now being replaced by ones containing isoxazolines, typically sold in the form of chewable tablets. Isoxazolines are less water-soluble but can bind to sediments and accumulate in soils and sewage sludge. They might be ending up in fields when sewage sludge is sprayed as fertiliser and harming pollinators.

“There has not been much work done to date to assess this,” says the report.

Shed dog fur is yet another way these chemicals can end up in the environment. The report says contaminated fur has been found in bird nests.

In light of these findings, the use of pet parasite medications should be minimised until there is independent research clarifying their risks, says the report. At present, manufacturers of parasite treatments are promoting the idea that routine treatment for parasites is required, and encouraging pet owners to get them via monthly subscriptions. “However, the benefits of routine, and certainly monthly, pet parasite medicine usage are not supported by scientific evidence.”

It is an excellent report, says Perkins, but she hoped it would go further and recommend making these products prescription-only. Some wildlife groups, meanwhile, want .

Yet another reason for restricting their use is to slow the development of resistance, says Perkins. She sees a lot of animals treated with old spot-on treatments containing fipronil that still have fleas. “We need effective parasite treatments, and we need to make sure we preserve their efficacy,” she says.

A male jaguar has made an unprecedented trek, skirting 2100 kilometres of the southern edge of the Amazon rainforest. The journey – which crossed highways, farms, ranches and other human-modified landscapes – expands our knowledge of what these big cats are capable of.

was about 60 to 100 kilometres, says at University College Dublin in Ireland. Knowing these animals are capable of travelling much longer distances reveals further challenges in protecting them. “Individuals that are travelling so far are more exposed to human-related risks like hunting or killing because of attacks on livestock,” says Morant.

He and his colleagues have been tracking jaguars in Brazil via GPS collars as part of a larger ongoing project that started in 1999. The researchers wanted to better understand how jaguars use their environments along the Araguaia river, a potential wildlife corridor connecting the Cerrado grasslands with the Amazon.

They captured the male, dubbed Gaspar, as part of this work, fitting him with a collar on 11 November 2024. The 8-year-old jaguar then spent some time in his established range, about 700 square kilometres along the Araguaia river, before setting out on a massive southward trek, skirting the border of the Amazon to inland Cerrado.

Subscriber-only newsletter

Sign up to Editor’s Highlights

Sign up to newsletter

The researchers recorded that Gaspar travelled 2122 kilometres, until his collar stopped transmitting locations in late Novemeber 2025, but that is as the crow flies. The actual distance is probably much more, says Morant.

While Gaspar mostly stuck to forested areas, he also crossed through heavily modified human landscapes, such as farms, ranches and roads. Dispersals, albeit shorter ones, are common in individuals aged 1 to 3 years old that are looking to establish a new territory, but it is unclear why an older adult like Gaspar made this move. He might have been searching for better food resources, mating opportunities or a better habitat in general, says Morant.

A three-legged lion has learned to hunt in a completely unexpected way

Jacob, an 11-year-old lion, has defied expectations by surviving for years after losing a leg – now we know his success is down to an innovative hunting strategy

“Beyond the extraordinary distance travelled, I find [it] especially intriguing that he apparently did not establish a territory despite more than a year of continuous 
movement through areas that were, at least in part, potentially suitable for jaguars,” says at the Spanish National Research Council.

The findings also reveal an additional challenge in protecting such wide-ranging cats. In these human-modified areas, jaguars face threats from poaching, as ranchers often kill them to protect livestock. “Maybe we need to rethink how protected areas are framed and organised,” says Morant.

Gaspar’s fate is now uncertain. He may have been shot or poisoned, or the collar may have just stopped working, says Morant, which could mean Gaspar is still traversing the Brazilian landscape.

Jaguar and wildlife adventure in the Pantanal: Brazil

Explore the Pantanal on an intimate expedition, encountering jaguars, giant river otters and rich birdlife across the world’s largest tropical wetland.

Find out more

Extraordinary underwater videos have captured orcas making sunfish explode by ramming them at high speed. The behaviour may help juvenile orcas feed by breaking the prey into many small pieces, but it also appears that the orcas may enjoy playing with their food.

“It’s a hunting tactic, but that involves a play game in the process,” says , an independent marine biologist in Mexico. “There’s ‘high-octane’ adrenaline and a lot of other hormones rushing through their bodies, so, of course, there’s got to be some sort of excitement.”

Sharp-tail sunfish (Masturus lanceolatus) are among the largest bony fish, weighing up to 2000 kilograms. Higuera had already seen groups of orcas (Orcinus orca) attacking sunfish in the Gulf of California, ripping off parts of their flesh and tossing them around to each other in a playful manner. In the past few years, he had even witnessed them .

Then, in July 2024, his colleague at US non-profit organisation Beneath the Waves caught an explosive interaction on her GoPro camera while diving in the Gulf of California. An adult female orca held onto a dead sunfish while an adult male orca swam upside down towards it at full speed. The female released the sunfish at the last second, and the male hit it with so much force that the fish burst into a flurry of small fragments.

A year later, tourist Hector Franz shot a similar underwater scene in the same bay. This time, an adult female rammed right-side-up into a sharp-tail sunfish held in place by another adult female, popping it into pieces. Combined, the two events mark the first time scientists have seen such behaviour by orcas, say Higuera, Ayres and their colleagues.

Sunfish have “an incredibly dense, rubbery, collagenous” outer layer that’s harder to bite through, so bursting them open could be an effective way to feed on them, says Higuera.

Free newsletter

Sign up to The Earth Edition

Sign up to newsletter

“The explosive fragmentation seemed mostly to be of the stiff gelatinous capsule that makes up a high percentage – more than 80 per cent in large fish – of the body mass of the sunfish,” says at University College Cork in Ireland. “I suspect that calves cannot achieve enough force to do this, as their mass is too low. But they can exploit a cloud of objects that contain tasty morsels.”

Earlier sightings without full footage indicated that the entire pod was involved in a strategic attack process leading up to the rammings, says Higuera. The findings point to advanced cooperative hunting skills and even planning – especially adapting their techniques for different kinds of prey, he says.

Higuera suspects that popping the sunfish offered a learning experience for the calves, while providing them with bite-sized snacks. Simultaneously, these events could also reinforce social bonds through “play” and social learning in this highly intelligent species, he adds.

at the University of Tennessee in Knoxville says it is possible the orcas were having some fun in demolishing the fish, but play wouldn’t be the only goal, as there is clearly cooperative foraging going on as well.

“One of the fascinating things about play is that it can be a driver of behavioural innovation,” says at the University of Pisa, Italy. “It’s possible that a behaviour like this may have originated in a playful context and later acquired a feeding function, or vice versa. At this stage, we simply don’t know.”

A monkey with a distinctive mask-like face, found in a remote part of the Democratic Republic of the Congo, has been declared a new species – only the fifth new species of monkey documented from Africa in the past 75 years.

The monkey is known as likweli to local people who hunt it for bushmeat, and it has been given the scientific name Colobus congoensis. It lives in one of the most inaccessible parts of Africa, without paved roads or infrastructure.

“A typical expedition involves multiple modes of transportation: a flight, followed by a motorcycle ride, two days of hiking on foot and finally travel by dugout canoe to reach the monkey’s range,” says at Florida Atlantic University.

One of the most intriguing features of likweli is its facial appearance, says Detwiler. The light-coloured skin around the mouth and beneath the nose is unlike that of any other African colobus species, but resembles the facial pattern seen in some Asian colobine monkeys.

Detwiler and her colleagues believe the species’ mask-like face may represent ancestral traits that were present before the African and Asian colobine lineages diverged over 8 million years ago. “If so, likweli may have retained characteristics that were subsequently modified or lost in the other African colobus species,” says Detwiler.

Free newsletter

Sign up to The Earth Edition

Sign up to newsletter

Like other colobus monkeys, likweli also has a distinctive body odour that defies description, she says.

Ů��С��Ƶs first became aware of the species in 2008 when a team surveying on the banks of the Lomami river, in what is now Lomami National Park, took a photo that showed only a part of a monkey that had not been seen before, high in the canopy.

Then, in November 2018, another group again spotted the monkey, which is about 1.3 metres long and weighs around 7 kilograms. Between 2018 and 2022, there were 114 recorded observations of the new species, 25 of which were from vocalisations.

In 2021, several monkeys that had been killed by hunters for bushmeat were confiscated and handed over to researchers. Detailed morphological and genetic analysis confirmed they were indeed a wholly separate species. Genetic tests and recordings of their vocalisations also added to the evidence of their uniqueness.

“The genetic analyses revealed that likweli is a deeply divergent lineage that split from its closest known relative, Colobus satanas, approximately 4 to 5 million years ago,” says Detwiler. “That was much older than we expected and provided strong evidence that likweli represents a distinct species.”

Likweli is isolated from C. satanas by more than 1200 kilometres and several major river barriers. Unlike most other members of the genus, which have habitats exceeding 60,000 square kilometres, likweli is only known to exist in 1700 square kilometres of rainforest.

“Hunting is one of the primary threats facing likweli, particularly because the species has such a small known range and appears to occur at low densities,” says Detwiler.

Because of the risk of poaching and the monkey’s small population and home range, the team is proposing that the species should be listed as endangered. “Now that likweli has been recognised as a distinct species, another important step would be to grant it protected status under national law,” says Detwiler. “This would make it illegal to hunt the species, including in the buffer zone surrounding the park.”

There’s one scent to rule them all – and we now know what it is. A series of experiments has shown that a single molecule released by the queen of naked mole rat colonies prevents all the other females in a colony from breeding.

“It’s a super-contraceptive, if you’re a mole rat,” says at the Max Delbrück Center in Berlin.

Naked mole rats (Heterocephalus glaber) have a social structure like that of bees and ants, with colonies made up of soldiers and workers, and a single queen ruling each colony. Only the queen can breed, but how she maintains her long reign – Lewin’s team’s oldest queen is 39 – hasn’t been clear.

“The theory was that the queen is larger and more aggressive than the other animals, exerting her dominance through pushing and shoving,” says Lewin. “But we never found that very satisfying as an explanation.”

So team member , also at the Max Delbrück Center, proposed identifying the mole rat bouquet – the molecules in the air around them that create their scent. Comparing the scents of hundreds of animals revealed that only the queens produce a molecule called isopropyl myristate.

Free newsletter

Sign up to The Earth Edition

Sign up to newsletter

“It’s made in the reproductive organs, basically the vagina of the reproductive female,” says Lewin.

When the team sprayed isopropyl myristate daily into cages containing male and female pairs, none of the females became pregnant. Without it, almost all the females became pregnant.

Next, the team removed a queen from a colony and applied isopropyl myristate daily. There were no fights for succession and no females started breeding during the three months this was done. “We produced peacefulness,” says Lewin. “That’s probably the most dramatic experiment.”

When the team stopped applying isopropyl myristate, the high-ranking females started fighting within a week. After around three weeks one became pregnant: the new queen.

The team also showed that exposure to isopropyl myristate changes the levels of the hormones progesterone and prolactin. But they haven’t found out exactly how the molecule is detected and leads to these changes – that’s the next project, says Lewin.

The evidence for isopropyl myristate influencing reproduction is compelling, says at Linnaeus University in Sweden. “I think it’s an impressive and important study. And convincing.”

at Queen Mary University of London is also convinced. “But the paper raises many questions, like any interesting research,” says Faulkes. These include how animals detect it, and how behavioural interactions and queen dominance interact with the scent, he says.

There is something special about isopropyl myristate, says Lewin. Isopropyl myristate is volatile, meaning it can evaporate into the air, but it’s not highly volatile, so any traces left by the queen take time to evaporate and the scent persists for at least a day.

It’s known that a queen will patrol every part of her colony, which in the wild might extend underground for 3 kilometres. “We think the reason she does that is to deposit this molecule around the colony,” says Lewin. “To make sure that every member of her colony is exposed to her scent.”

Other experiments by the team suggest the animals can consciously detect the smell. For instance, highly ranked females with a chance of becoming queen try to avoid places where isopropyl myristate is present, whereas lower-ranked animals aren’t bothered.

The team also tested a number of other species of mole rat. They didn’t find isopropyl myristate in any solitary species but they did find it in a few species whose social structure is more like that of naked mole rats. “But I would be cautious about assuming that the same pathway has a comparable function across social mole rats without direct experimental evidence,” says Zöttl.

Isopropyl myristate is also widely used in cosmetics. It is described as odourless but Lewin says some women at his lab thought they could smell something when exposed to it. A 2008 study also reported that during pregnancy and after childbirth.

The jaws of some sea worms are made of an exceptionally hard yet lightweight material dubbed a “bio-metal” that could have applications in engineering.

Perinereis cultrifera is a type of ragworm with a long body adorned with bristles. Members of the species also have strong jaws that enable them to crush hard prey such as small crustaceans or other worms. Remnants of their jaws have been found in the fossil record dating back to hundreds of millions of years ago.

at TU Wien in Austria and his colleagues have been studying this worm’s jaws for almost a decade, leading them to propose that they are made of a novel material. The molecular structure of each jaw combines proteins and ions of metals such as zinc, giving it characteristics in between those of softer biological materials and metals.

Most recently, the team performed more than 3300 experiments in which small indentations were made in different parts of the jaw. The way its hardness changed under this pressure followed a pattern typical of metals like copper and silver. But the jaw also exhibited a kind of elasticity that metals cannot have, says Hellmich.

Finally, the researchers developed a mathematical model of bio-metals, which shows how they might respond to strain in a unique way in which microscopic forces arise from the metal ions becoming arranged into lines similar to certain defects in crystals.

Free newsletter

Sign up to The Earth Edition

Sign up to newsletter

The researchers were surprised to uncover so much novelty in the relatively simple animal. Performing mechanical tests on the millimetre-sized jaw was really challenging and required hundreds of hours of preparation and polishing, says Hellmich. “Basically, anything can go wrong,” he says.

“The jaws of bristle worms are incredibly hard yet very lightweight,” says at Kent State University in Ohio. “Many industries, from automobiles to aeronautics, are searching for new ways to develop hard and lightweight materials. The answers are provided in nature!”

“Somehow evolution figured out a way to coax a metal-like mechanical fingerprint out of protein-like ingredients, and studying the worm is how we ask what trick makes that possible,” says at the Massachusetts Institute of Technology, who didn’t work on the study. The long-term dream outcome of this research is to genetically program materials that would grow in biological systems, he says.

Hellmich and his colleagues are interested in pursuing this goal and their team already includes geneticists and biologists at the University of Vienna. “We are asking questions like, ‘If we knock out a few genes, then how will the jaws be different?’” he says.