by Sinead Cox | Mar 3, 2021 | Artefacts
Take a closer look at the Huron County Museum & Historic Gaol and its collections as staff share stories about some well-known and some not-so-well-known features, artifacts, and more. The Huron County Museum’s two-headed calves are perhaps our most recognizable artifacts, and attract a lot of questions from visitors.
Although familiar with the two-headed calves’ history, Acting Senior Curator Sinead Cox wanted to know more about the genetic causes of polycephaly: the condition of a single animal having more than one head. How and why does this rare phenomenon happen?
Sinead talked to veterinarian Dr. Alaina Macdonald to find out more from an expert on animal health.
Sinead Cox: Can you share a little bit about yourself and your professional background?
Dr. Alaina Macdonald
Dr. Alaina Macdonald: I graduated from the Ontario Veterinary College in 2019 and have worked in mixed animal practice since graduation. I have always carried an appreciation for agriculture, and love being able to help animals and their humans live healthy lives. My newest interest is learning how to incorporate aspects of human, animal and environmental health in problem solving of worldwide issues.
SC: The Huron County Museum has two taxidermied calves in our collection with two heads and two tails. How on earth does an animal end up having two heads?
AM: The rare development of two-headed offspring is directly related to the formation of identical twin embryos early in the pregnancy. This phenomenon is seen in reptiles, birds, amphibians, and mammals (including humans). In fact, much of what we know about two-headed animals can be better understood by studying human conjoined twins, as it is a very similar process! When an egg becomes fertilized, a tiny embryo is formed. Occasionally, the embryo divides in a way which produces a second embryo with the same genetic material. This process must occur in a very delicate and specific balance of gene expression and the correct environmental conditions. Most often, it occurs before day 10 of gestation, and the result is two identical twins. Rarely, this process occurs late (around day 13-14), and the process of mitosis (cell division) is interrupted, resulting in two identical embryos which did not fully divide. Some literature indicates that polycephaly is due to a disruption of the primitive streak, which is an organized embryonic structure of cells present towards the second week of gestation.
SC: Could there be environmental factors that would cause this?
AM: No one knows the exact mechanism behind the abnormal splitting of the embryo. Trace mineral deficiencies and environmental factors such as increasing water temperatures and toxin exposure have been implicated in some species, but there are likely many causes. Anything that disrupts that delicate timing of gene expression (including random chance) can cause abnormalities in embryonic development.
SC: How often does this happen?
AM: There is no way to truly know how often this occurs, as this event would generally result in the early loss of pregnancy, and those pregnancies often are undetected. Indeed, it is exceptionally rare for the embryo to develop into a full-term fetus, and to survive the length of the gestation. It is not considered an inherited trait, because the offspring almost never live to reproductive age. In humans, development of identical twins is not considered genetic, which would also indicate that polycephaly in animals and conjoined twins in humans is a “chance” event with possible implications for environmental factors.
SC: Wow. That really puts into perspective how rare and special these calves are. Both of the calves at the museum were born in the early twentieth century. Is polycephaly more likely to happen now than in the past?
AM: Interestingly, fossil evidence indicates that polycephaly has been present in some species for the last 150 million years!
SC: I always think it’s sort of lovely that our two-headed calves are so loved and live on forever at the museum, when they had very short lives (less than a day). Why doesn’t a two-headed calf live very long?
AM: Calves with two heads often have many other congenital abnormalities. For example, the cardiovascular, neural and digestive systems may be malformed, which makes it nearly impossible for the calf to carry out normal vital functions. A live birth of any two-headed animal is rare, and many of them die shortly after birth. There was one calf who survived with intensive care for several months, which is likely the longest any polycephalic calf has lived.
SC: Have you ever seen any two-headed animals in your work life?
AM: No, I have never seen a two-headed animal myself. I am sure it comes as quite a surprise to everyone involved! There is some evidence to suggest that the many-headed creatures described in Greek mythology may have been inspired by polycephalic animals observed during those times.
SC: What is the strangest or most unexpected thing you have seen as a veterinarian?
AM: I have seen some animals in strange predicaments; from the kitten who ate pieces of a couch, to the dog with a piece of tooth embedded in his leg and the cat with a fishhook in his lip, all had something to teach me about veterinary medicine. The most startling moment of my career was when I was standing beside a horse, taking her temperature, and as we stood looking out the barn door the farm was struck by lighting! Everyone was fine, but the farmer needed to replace his electric fence. Nature always has a way of surprising us!
Thank you to Dr. Alaina Macdonald for answering our questions and making us appreciate the uniqueness of these unforgettable artifacts even more! For more information on polycephaly, Alaina suggests these references:
https://pubmed.ncbi.nlm.nih.gov/15278382/
http://www.bbc.com/earth/story/20161018-the-two-headed-creatures-that-may-have-inspired-hydra
https://www.nationalgeographic.com/news/2016/11/two-faced-calf-lucky-becomes-oldest-on-record/#:~:text=A%20young%20cow%20calf%20with,a%20farm%20in%20Campbellsville%2C%20Kentucky.
FURTHER READING:
by Sinead Cox | Jun 4, 2020 | Investigating Huron County History
Curator of Engagement and Dialogue Sinead Cox shares the story of a historical quarantine in the summer of 1916.
Although you may have heard (to the point of cliché) that we are living in ‘unprecedented times’ during today’s COVID-19 pandemic, communities across Huron County have seen quarantines and the temporary closure of schools and businesses before. Although usually on a much smaller and localized scale, these actions in the nineteenth and twentieth centuries were in response to contagious illnesses that included influenza, measles, diphtheria, scarlet fever, smallpox, whooping cough and typhoid among others.
From The Brussels Post, July 27th, 1916.
In 1916 an outbreak of infantile paralysis (polio or poliomyelitis) hit North America. The poliovirus is most dangerous to children under five years of age and in serious cases can cause permanent and debilitating nerve and muscle damage to survivors if non-fatal. The 1916 epidemic was particularly devastating in New York and then appeared in Canadian cities like Montreal before eventually arriving in southern Ontario. In Ontario, the provincial Medical Board of Health enacted quarantine regulations and required doctors to report all cases or face prosecution.
The outbreak had reached Huron County by July, when a fourteen-month-old girl in Varna died: only the second fatal case confirmed in Ontario up to that point. Panic hit the next month when three young children in Hullett Township contracted the much-feared disease. The children had come to live temporarily in Hullett (now part of the Municipality of Central Huron) with their parents during the flax harvest, but their permanent home was reported as ‘Muncey Reserve.’ Indigenous families from Southwestern Ontario reserve communities, including those on the shore of the Thames River south of London and also Saugeen First Nation to the north, were a crucial labour force for annual flax harvests in the early twentieth century. Entire families moved seasonally to pull flax for Huron growers; they worked and lived in close contact with each other, camping alongside their worksites.
The sick children belonged to a group of about 15 families living in tents roughly six miles from Clinton when the infantile paralysis struck-eventually infecting two five-year-olds and a two-year-old. A local Blyth doctor treated the first cases and told the area newspapers that the farm workers’ living situation presented a challenge for protecting the lives of the other 23 children in the camp: “Isolation and quarantine, so necessary for the treatment of infantile paralysis, are something hard to enforce in any Indian reservation or encampment…We are doing what we can to prevent any spread of the disease, and watching for further symptoms, but it is next to impossible to enforce the requisite isolation.” The vast majority of poliovirus cases are completely asymptomatic. The disease can spread through direct contact or via contamination by human waste.
From the Wingham Advance, August 31st, 1916.
For one of the five-year-olds, the virus was tragically fatal on August 25th, but the other two children soon appeared to be recovering. Local newspapers did not identify any of the camp members by name, but a death registration reveals that the little girl who lost her life was Annie Corneolus, the five-year-old daughter of Abram and Elizabeth. She was ill only one day, but the polio had caused lethal ‘paralysis of respiration.’ Her birthplace is recorded as Oneida Reserve (Oneida Nation of the Thames). Annie’s burial took place at Burns Cemetery, Hullett. Local health officials separated the families with sick children from the rest of their neighbours and they proceeded to quarantine at a farmer’s house on the 11th Concession. School Section # 11 at Londesborough cancelled classes for all students as a precaution.
Fortunately, their quarantine appeared successful and there were no further cases reported. The Clinton New Era announced that “the infantile paralysis scare in Hullett Township has pretty well blown over.” When health authorities lifted quarantine the families impacted returned to their reserve community, and the rest of the camp moved on to Blyth to continue their flax-pulling work. The Huron newspapers make no mention of whether or not the surviving children suffered any long-term health effects. Later reports listed the total number of province-wide infantile paralysis cases at 64 for July and August of 1916, with 8 resulting deaths–meaning that 25% of those total polio deaths occurred in Huron County.
From the Signal (Goderich), July 20th, 1916.
There is no cure for polio, but the Salk vaccine of 1955 would eventually be effective and widely used to prevent the disease; after continuous deadly outbreaks throughout the first half of the twentieth century, childhood vaccinations have eradicated polio in Canada.
The living and working conditions of temporary farm workers in 1916 would have made following advice about precautionary hygiene and social distancing almost impossible to follow-and many people in Canada are facing those same challenges today, without equal housing or opportunities to practice self-isolation under novel coronavirus. Although the 2020 COVID-19 pandemic is not the same as polio, the reality that Indigenous communities continue to be disproportionately impacted by pandemics, and that temporary and migrant workers are at a higher risk because of a lack of resources and opportunities to safely distance is absolutely precedented.
More Info about the history of polio in Canada: https://www.cpha.ca/story-polio
*Note: I wrote this blog post using contemporary newspaper accounts including the Wingham Times, The Wingham Advance, The Lucknow Sentinel, The Clinton New Era, The Clinton News-Record, the Signal (Goderich) and others, all accessed from Huron’s free historical newspaper database: https://www.huroncountymuseum.ca/digitized-newspapers/ Annie’s death documentation was accessed via Ancestry.ca (Archives of Ontario; Toronto, Ontario, Canada; Collection: MS935; Reel: 220). All of these accounts were written from a settler point of view (as is my own), and the newspapers did not include the voices or even the names of the community members impacted. If you have any further information you’d like to share about this outbreak or similar outbreaks in the past contact museum@huroncounty.ca.
SC: Wow. That really puts into perspective how rare and special these calves are. Both of the calves at the museum were born in the early twentieth century. Is polycephaly more likely to happen now than in the past?
Thank you to Dr. Alaina Macdonald for answering our questions and making us appreciate the uniqueness of these unforgettable artifacts even more! For more information on polycephaly, Alaina suggests these references:
