SIBERIAN HUSKY UpdateA NESTLÉ PURINA PUBLICATION DEDICATED TO SIBERIAN HUSKY ENTHUSIASTS VOLUME 15 | SUMMER 2017

2

A dedicated Siberian Husky enthusiastwho enjoys conditioning and workingher dogs for sledding sports, KarenYeargain of Prineville, Oregon, frequentlyposts pictures of her winning sprint andmid-distance racing dogs. The powerful,muscular dogs stand out against beautifulsnowy mountainous scenery. Yeargain’spride is seen in her smile.

She fell in love with the breed 30 yearsago and started breeding Siberians underthe Tumnatki prefix in 1994. In 2008,her friend and fellow enthusiast, SherylO'Rourke, asked to breed her mainleader racing male, “Fisbo” (Tumnatki’sFor Sale By Owner), to a leader female,“Shelby” (Tumnatki’s Shelby). Yeargainwas excited about the breeding and the puppies that would be owned byO'Rourke.

Although the litter appeared normalin the beginning, two of the six puppiesdeveloped an unusual neurological dis-order never before seen in the breed.The first puppy affected, “Dade,” hadan abnormal gait that began around 5months of age. He would lose his coor-dination and had little muscle strength.Despite his condition, the puppy didnot appear to be in pain.

“Since Dade was so young, we thought itwas because he was still a pup,” Yeargain says.

When the litter was 1 ½ years old,another male puppy, “Tyee,” began tohave the same unusual gait and muscleweakness. Tyee would become the mostseverely affected and die from a massiveseizure at age 5 1/2.

Rare Siberian HuskyPolyneuropathy CHALLENGES RESEARCHERS

Summer 2017

Tumnatki Siberian Husky breeder Karen Yeargain is shown with “Stetson,” a 5-year-old malefrom the second litter she bred affected by Siberian Husky polyneuropathy. Although Stetson isthe most severely affected dog from his litter, his condition has been stable since adulthood.

PH

OT

O:

DE

B B

LA

IR

3

SIBERIAN HUSKY Update

O’Rourke of SierraWind Siberians inLa Pine, Oregon (formerly Bishop, Cali-fornia), took the male dogs to her localveterinarian, who could not definitivelydiagnose the condition and referred her tothe Veterinary Medicine Teaching Hospitalat the University of California-Davis.

The cost for a diagnostic evaluationwas estimated at $4,000. “This was notaffordable for us at the time,” says Year-gain. “The rest of the litter was unaffected,so we thought some sort of ‘event’ musthave occurred during the dam’s preg-nancy that caused the abnormality inthe two male dogs.”

Yeargain avoided breeding the litter’ssire and dam as well as the affected dogsand their littermates. Then, in 2012, fourand a half years later, a littermate sisterto the sire of the first litter, produced alitter in which three puppies showed signsof the unusual neurological condition.Two males and a female were affectedin this litter.

“This was disheartening,” Yeargainsays. “I had to know if any other Siberianbreeders had produced this in their litters.I wanted to figure out what was going on.”

She used Facebook community pagesto reach out to Siberian Husky breedersand owners. Tapping into pages dedicatedto conformation, sled dog sports and petenthusiasts, she received several reportsabout similar conditions, but none wereexactly the same as what the Tumnatkidogs were experiencing.

A Brain Disorder in Alaskan Huskies As Yeargain and O’Rourke began

researching neurological disorders, theycame across one causing gait abnormal-ities in Alaskan Huskies (a general termused to describe sled dogs, not a breedname). Researchers at the University of California-Davis had discovered themutation for Alaskan Husky encephalopa-thy (AHE). The genetic analysis, publishedin 2013 in PLOS ONE, detailed a defectin a thiamine transporter protein in thebrain responsible for the fatal diseaseaffecting young Alaskan Husky dogs,often occurring in multiple dogs of thesame litter.

Dogs affected with AHE may have acuteclinical signs or their condition may waxand wane. Besides gait abnormalities,these dogs may have seizures, difficultyswallowing, blindness, difficulty walk-ing, and abnormal mentation (mentalreasoning and thinking abilities). Themutation discovery led to the develop-ment of a DNA test for the autosomal recessive condition. A condition withsimilar neuropathological features,Leigh syndrome, occurs in people.

Yeargain reached out to the lead inves-tigator, Karen M. Vernau, DVM, MAS,DACVIM (Neurology), clinical professorof neurology/neurosurgery at the Uni-versity of California-Davis, telling herabout the condition in her Tumnatkidogs. They began working as a team andnamed the mystery condition SiberianHusky polyneuropathy (SHPN), whichdescribes the multiple (poly) nerve(neuropathy) groups affected.

The disorder, which develops between3 months and 1 ½ years of age, affectsthe peripheral nerves that send sensoryinformation to the brain and spinal cordand carries signals from the brain andspinal cord to the muscles to generatemovement. Peripheral neuropathy dis-torts and sometimes interrupts messagesbetween the brain and spinal cord andthe rest of the body.

Funding was needed to support theresearch. Yeargain began promoting theeffort on social media, where it was noticedby Mary Uhlir, head of the Siberian HuskyClub of America Trust. Yeargain and Uhlirwent to Dr. Sheila Morrissey, chair of theSiberian Husky Club of America GeneticsCommittee, to make sure she was awareof SHPN. The Trust provided a $400 grantto help start the research and developeda flier with the University of California-Davis to explain SHPN and encouragedonations.

Yeargain also created a Facebook Grouppage where she could post photos, videosand information that could be shared.The page currently has about 100 mem-bers. Yeargain and O’Rourke began aGoFundMe campaign to raise money forthe research.

“Although this is a seriousproblem for Siberian Huskies with this disorder, it is uncommon.” Karen M. Vernau, DVM, MAS, DACVIM(Neurology), clinical professor of neurology/neurosurgery at the Universityof California-Davis

“Tyee,” one of the first dogs affected bySiberian Husky polyneuropathy, eventuallyneeded a wheelchair to walk.

4

Summer 2017

In May 2013, Yeargain and O’Rourketook four of the five dogs affected by SHPNto be examined by Dr. Vernau at theUniversity of California-Davis. Dr. Vernaureviewed their medical histories. Sheperformed electrophysiological testingand tissue biopsies on two dogs andgathered physical and neurological infor-mation on the other two dogs. The Univer-sity of California-Davis provided fundingfor this work.

The rarity of SHPN-affected dogs madeit challenging to examine and do diag-nostic testing from affected dogs outsideYeargain’s kennel. “Although this is aserious problem for Siberian Huskieswith this disorder, it is uncommon,” Dr. Vernau says.

“My dogs are the only ones we knowthat are affected by this condition,”Yeargain says.

Sadly, she produced another affectedlitter in 2015. Of the six puppies in thelitter, all showed signs of SHPN beforethey were 4 months old. This litter made10 Siberians in total affected by polyneu-ropathy. Tyee from the first litter passedaway in 2014 at 5 1⁄2 years old. Fortunately,none others have been affected sincethis litter.

A Look at Alaskan Malamute Polyneuropathy Meanwhile, a collaborative study at the

University of Minnesota with researchgroups in Norway, Finland, Sweden,Switzerland, and the University of Cali-fornia-San Diego, led to the discovery ofthe gene mutation for Alaskan Malamutepolyneuropathy (AMPN). First recognizedin Norway in the 1980s, this condition isdepicted by slowly worsening exerciseintolerance, gait abnormalities, andhind-limb muscle wasting. Noisy breathing,changes in a dog’s bark and difficultybreathing occur due to involvement ofthe larynx and laryngeal folds in thethroat. The study included AlaskanMalamutes from Denmark, Norway,Sweden, Finland, and the U.S.

The autosomal recessive mutationwas found in a gene known as NDRG1(N-myc downstream regulated gene 1).The research, published in 2013 in PLOSONE, yielded a DNA test to help breedersselectively breed against AMPN. Thisdisorder is one of several canine inher-ited neuropathies described in 22 breedsof dog that share features with the Charcot-Marie-Tooth group of diseases in peoplecausing motor weakness and sensory loss.

Polyneuropathy/Encephalopathy Disorders of Northern Breeds of Dog Disorder

Siberian Husky Polyneuropathy (SHPN)

Alaskan Husky Encephalopathy(AHE)

Alaskan Malamute Polyneuropathy(AMPN)

Alaskan Husky Polyneuropathy, Ocular Abnormalities and NeuronalVacuolation (POANV)

Gene Mutation

Unknown

SLC19A3.1mutation in the thiaminetransporter 2 gene (autosomal re-cessive)

Gly98Valmutation in the N-mycdownstream regulated gene 1 (auto-somal recessive)

218-bp SINE insertion into exon 7 ofthe RAB3GAP1 gene (autosomal re-cessive)

Clinical Signs

Progressive, debilitating nerve diseasein which dogs eventually are unableto walk, causes unsteady gait, muscleatrophy, loss of coordination

Gait abnormalities, seizures, difficultyswallowing, blindness, difficulty walk-ing, abnormal mentation

Slowly worsening exercise intolerance,gait abnormalities, hind-limb muscleweakness, noisy and difficulty breath-ing, changes in their bark

Visual problems, altered voice, regur-gitation, gait abnormalities progress-ing to severe loss of muscle control,dogs are often euthanized between8 and 16 months of age

5

SIBERIAN HUSKY Update

A member of the Alaskan MalamuteClub of America knew about Yeargainand O’Rourke’s work to learn about SHPN.She helped connect them with the Uni-versity of Minnesota AMPN research team,which included James Mickelson, PhD,professor in the Department of Veterinaryand Biomedical Sciences, and Katie Minor,the Canine Genetics Laboratory manager.Dr. Vernau also joined the efforts, sharingher information in hopes of helping toadvance the research.

Testing was done to see if the poly -neuropathy in Siberian Huskies was thesame genetically as the one in AlaskanMalamutes. The Siberian dogs testednegative for AMPN.

Little progress has been made in under-standing SHPN since the testing at theUniversity of California-Davis. The limitednumber of affected dogs and fundingshortage have contributed to delays.

Grassroot Efforts to Advance Research Reflecting on the three litters she has

bred over the past nine years affectedby SHPN, Yeargain says, “This has been

devastating and truly heartbreaking. Fromthe beginning as a breeder, I always triedto do the right things and carefully choosethe dogs I bred.”

“Karen (Yeargain) is to be applaudedfor being open about this disease in herdogs,” says Dr. Morrissey, the SHCA ge-netics chair. “This makes it possible todiscuss the disease openly and to tryand prevent it from spreading throughthe breed.”

“My goals in going public have beento increase awareness in the breed andto look for past unrecognized cases andresources for future cases,” Yeargain says.“Hopefully, this will generate a study ofthis mutation that can be compared tohuman neuromuscular disorders andpotentially benefit both species.”

As a public health nurse, Yeargain findsthe science of genetics and rare mutationsto be fascinating. As a breeder of these dogs,it has been heartbreaking. “If researchcan identify the DNA mutation so thisdisease never occurs again, I will be veryhappy,” she says. �

Purina appreciates the support of theSiberian Husky Club of America and particularly Sheila E. (Blanker) Morrissey,DVM, SHCA genetics chair, in helping toidentify topics for the Purina Pro ClubSiberian Husky Update newsletter.

PH

OT

O:

DE

B B

LA

IR

Tumnatki's Blue is the only male from thethird litter of six puppies in which all are affected by SHPN. Yeargain describes her 3-year-old house dog as charismatic andmischievous.

Want to Reach the Editor?Have comments about the Siberian HuskyUpdate? Send them to: Barbara Fawver, Editor,Nestlé Purina PetCare, 2T Checkerboard Square, St. Louis, MO 63164 or via email ateditor@purina.nestle.com.

Purina Pro Plan is integrating existing NATURAL formulas, as well as adding new formulas, to the already strong FOCUS,SPORT and SAVOR platforms. Containing no artificial colors, flavors or preservatives and no poultry byproduct meal, theformulas are made without corn, wheat or soy, and include

grain-free options. Additionally, two new formulasmade without corn,wheat, soy, artificial colors or flavors, orpoultry byproduct meal will be added to the BRIGHT MINDplatform. Look for theformulas this summer.

LEARN MORE

Check out upcoming Purina-sponsoredshow and sporting events at venuesacross the country. These events are

great opportunities to meet dog enthusiasts,canine experts and Purina representativeswho can answer questions about PurinaPro Plan dog food and Purina Pro Club.

VIEW OUR CALENDAR

Upcoming Events

Looking to Reprint?Purina Pro Plan Updatearticles may be reprintedprovided the article is used in its entirety andin a positive manner. To request permissionto reprint an article, please contact the editorat: editor@purina.nestle.com. Reprints shouldinclude the following attribution: Used withpermission from the Purina Pro Plan Updatenewsletter, Nestlé Purina PetCare Company.

Purina Pro Plan Incorporates NATURAL Formulas Into Existing Platforms

Record-setting entries at the Poodle Club of America National Specialty,held in April at the Purina Event Center in Gray Summit, Missouri, helpedconfirm to club officials that holding the event in the Midwest after many

years in the East was a good move. Recent upgrades to the classy dog showvenue include improved cellphone reception, expanded Internet service tosupport live streaming, and an enhanced Wi-Fi connection with increasedbandwith that allows for easy photo and video sharing on social media. Videomonitors throughout the facility allow exhibitors to watch the action in theshow rings in real time. Located about an hour from St. Louis, the Purina EventCenter, which was custom built to support the dog fancy, opened in 2010.

Purina Event Center Adds Amenities

TAKE A VIDEO TOUR

Handlers stack Standard Poodles during judging at the Poodle Club of America NationalSpecialty in April at the Purina Event Center in Gray Summit, Missouri.