Thanks to the world’s largest ancient human gene bank — which includes bones and teeth from nearly 5,000 humans who lived across western Europe and Asia as long as 34,000 years ago — it’s no longer a mystery.

A United Kingdom-led research team traced the spread of multiple sclerosis, or MS, from its origins in what is now Ukraine, southwest Russia and west Kazakhstan to northwestern Europe.

The disease walked its way across the land, traveling along with the Yamnaya [Yum-nye-uh] people, who with their sheep, cattle and newfangled wheeled wagons were a population-defining migration.

Europeans today are a genetic mixture of three ancestral populations: hunter-gatherers, first farmers and what had been considered an unknown “Ancient North Eurasian population” from the east. Those were the Yamnayans.

The Yamnayans carried with them the genetic variants associated with a risk of developing MS. In their case,  the genes were a blessing, likely shielding them from infections they might otherwise have caught from their herded animals.

The researchers analyzed data from a new gene bank of ancient DNA, created in the past five years.

The gene bank is the first of its kind in the world. The tested bones and teeth are in museums that span from Europe to western Asia. The researchers hope to glean more from the relics about the roots of autism, bipolar disorder, ADHD,  depression and schizophrenia.

So spare a moment, if you will, for our hunter-gatherer, iron-tool wielding and even our marauding Viking ancestors. What they left behind may help us all.

Rhabdomyolysis [rhab-doe-my-AL-uh-sis], or rhabdo for short, occurs when muscles damaged during strenuous activity release proteins into the bloodstream. As these toxins travel to other organs, they can be deadly. Apart from working dogs or racing hounds, canine rhabdo is rare — except in sled dogs.

Ever since rhabdo was implicated in sled dog deaths in the 1980s and ’90s, it’s sometimes referred to as sled dog myopathy. With growing awareness of other risk factors, rhabdo incidence is down, but it still crops up in sled dog teams.

Now, veterinary researchers are collecting blood, urine and saliva samples from affected sled dogs to see if genetics plays a role.  If so, the information gleaned may help root out rhabdo at its source.

Chances are you’ve heard a lot about ways to protect your pets from wildfires. But what about keeping them safe from the dangers that lurk afterward?

Smoke, ash and heat can put pets in a world of hurt, so try to keep your buddies indoors as much as possible. That includes using pooch pads instead of having dogs do their business outside. If you must take them out, use booties or clean their paws with a baby wipe before you come back in. Doggie goggles and masks are available to protect them from polluted air.

It’s even more crucial to keep windows closed if you have birds, since they’re more sensitive than our furry friends to airborne irritants.

If your pet has respiratory distress, fatigue or a reduced appetite during or after a fire, call your veterinary clinic.

If you presume that your pet’s supplements, treats, toys and other accessories have met safety and regulatory benchmarks, don’t be so sure. These items are not regulated by the Consumer Product Safety Commission for one simple reason. Our pets aren’t considered consumers.

That means the onus is on you to assure the quality of your pet’s products. You can start by avoiding products bought from unknown sources. Instead, opt for those with transparent sourcing. That’s because some countries have relatively lax rules about potentially toxic ingredients.

If your pet ever shows abnormal symptoms after exposure to a new item, set it aside and contact your veterinarian. Testing is key to diagnosing the problem.

Now that it’s spring, flowers will take center stage. While we enjoy them, some can be deadly for pets.

When it comes to cats, lilies top that list. Any exposure to lilies — including licks of water from a vase or pollen from fur or toes — can kill a cat. What’s more, lilies of the valley are toxic to both cats and dogs.

Daffodils, especially their bulbs, are also poisonous. And that goes for tulip bulbs, too. That’s why it’s crucial to keep dogs from digging in gardens.

Hydrangeas are off limits too, because a chemical they contain releases cyanide when eaten. Even exposure to carnations can give your pet an upset stomach.

If you think your furry friend has ingested any of these floral beauties, call your veterinary clinic or the Pet Poison Helpline right away.

Rocky Mountain Spotted Fever is the deadliest tick-transmitted disease in the United States. It affects dogs and people — especially children — and for decades has ravaged southwestern Native American lands.

Rocky Mountain Spotted Fever is mostly spread by ticks living in woodland, but in desert areas it’s spread by the brown dog tick. Because reservations often have dogs that live around kids, a perfect storm has been raging.

That is, until community-led teams grew public awareness, sprayed around homes and provided tick collars for dogs. Ticks have all but vanished in these areas, and fatality rates of Rocky Mountain Spotted Fever have plummeted.

One Health is more than a concept linking animal, human and environmental health. It’s key to saving lives.

During migrations over thousands of miles, songbirds rest during daylight hours and fly at night. In contrast to the many larger birds flying in flocks, songbirds tend to fly solo. How do they find their way and stay safe in the process?

Researchers may have found some clues. After analyzing over 18,000 hours of audio from microphones placed across the U.S., they noticed chirp patterns from flying songbirds. Coupled with information from a bird call identification program, it appears that different species of songbirds occasionally fly near each other, potentially communicating social, navigational and weather information.

Mixed species of songbirds have been known to team up to forage and avoid predators, so perhaps they’re onto something.

Horses develop wounds in many ways. One is by infection with a water-loving microbe.

Pythium [PITH-ee-uhm] insidiosum [in-sid-ee-OH-sum] is an aquatic mold that thrives in warm climates, like the Gulf coast. But now, in the face of global warming, it’s spreading farther afield. Horses can develop pythium infections from exposure to swamps, standing water — any water body that doesn’t freeze over.

Wounds from pythiosis often affect a horse’s lower limbs, but they can crop up anywhere. These wounds grow dramatically over hours, turning into painful, draining lesions that don’t respond to common medications. Without timely surgical intervention, pythiosis can be deadly.

If you see suspicious signs, there’s no time to waste.

As the weather warms, horses are shedding their winter coats. But if your buddy is still sporting a warm shaggy look, it could be a sign of something more serious.

Pituitary pars [parz] intermedia [in-tur-MEE-dee-uh] dysfunction, or P-P-I-D for short, is caused by a tumor in the brain’s pituitary gland, which is a key player in regulating the body’s hormones.

The classic sign of PPID in many horses is delayed or lack of shedding after winter. However, PPID often causes more serious problems, such as laminitis (that’s hoof inflammation), skin infections, Type 2 diabetes or a weakened immune system.

Most horses with PPID are over 15 years old, but there are outliers. Regardless of age, contact your veterinarian if your horse has symptoms.

Honeybees are critical to pollination and therefore key to agricultural crops. However, bees are under relentless attack, especially from mites that can collapse entire bee colonies.

There are effective topical treatments for mite infestations, but inaccurate timing of applications may do more harm than good. Treatment schedules are designed to break the mites’ reproductive cycle. Premature application can let mite populations rebound before the growing season ends, while late application gives mites more time to attack bees.

Poor timing also drives treatment resistance, which can be passed along to neighboring hives.

So, when looking for culprits in honeybee colony collapse, it may be all in the timing.