Image: CT scanning at Davis Veterinary University, looking at 640 sabre-toothed cat sacrum bones
After completing my veterinary studies at Zurich University, I did a residency in small animal surgery, and then in 1995, I took the exam to become ECVS board-certified. I also completed a clinical PhD in 2004.
Since then, I’ve worked at different surgical referral centres, including three university hospitals, mainly as an orthopaedic surgeon, as well as teaching. I joined IVC Evidensia in 2013 at the Evidensia Specialist Animal Hospital, Strömsholm. I’m now affiliated with the Evidensia Academy (Scandinavia). It’s been a focus for me over the last ten years to increase my spinal surgery caseload.
I’ve always had an interest in palaeontology, but I had no chance to incorporate this into my veterinary work until I reached out to the La Brea Museum in Los Angeles and they gave me the opportunity to visit their collection. I’ve also visited the La Brea Tar Pits twice.
The Rancho La Brea asphalt seeps there primarily functioned as a carnivore trap: a large herbivore mired in the asphalt inadvertently would attract large carnivores and scavengers, which themselves would become entrapped in great numbers.
The uncommonly large sample sizes with very well-preserved bones enable documentation of the prevalence and distribution of bone and joint diseases, including chronic OA, in these fossil species from the late Ice Age. The pathologies found in the Pleistocene predators can be compared to the joint pathologies found in extant wolves large cats, and domestic dogs.
The welcome I received from the palaeontologic specialists there when I visited was great, they were very open and interested in my work.
During my first visit to Los Angeles, I concentrated on stifle diseases like cranial cruciate ligament rupture, which are very common in our modern-day dog companions. But in addition to cruciate disease, I also found OCD (osteochondritis dissecans) defects in the stifles and shoulders – which is again very common in modern dogs. My second visit was more focused on the changes in the spine of the dire wolf and the Sabre-toothed cat.
Some of the changes in the joints and the spine look very familiar. Some dire wolves had cruciate ligament ruptures, but it was uncommon compared to the most affected dog breeds. This is very similar to modern-day grey wolves which also suffer rarely from cruciate damage. In contrast, the prevalence of stifle OCD in these fossilised remains is amazingly high, especially in the sabre-toothed cat. This could indicate some degree of inbreeding, a factor which is predicated for species close to extinction.
The bones excavated from the La Brea Tar Pits cover the last few thousand years of the Ice Age predators after they dominated North America for millions of years. The tar pit ‘61/67’ contains bones from the very end of the extinction process.
Malformations of the lumbosacral area are linked to inbreeding in modern grey wolves, and I found that the sabre-toothed cat also had a high prevalence of the same malformations we see in these wild modern inbred wolves, and some dog breeds today.
In my work, I was able to document with CT scans other spine changes/diseases in these historic creatures, which are unfamiliar to us. Careful diagnostic work is necessary, and comparison to other animal species and human spine disorders before we can give a definitive diagnosis for these changes.
We can see that the biological answers to trauma to bones and joints are very old. We can use our evidence from the research and treatment of our cats and dogs to conclude some details of the circumstances and suffering which led to the same bone and joint changes during the Ice Age.
Of course, we must be very careful, and not forget that these were wild animals without medical treatment living in a harsh environment full of fierce competition. A dog with medical care can have an acceptable life quality, an Ice Age predator with the same injury had no chance to survive. However, the prevalence of genetic predisposition for some of our most common orthopaedic diseases in modern-day dog breeds is something that needs to be addressed, and the parallel to animal predators who were probably inbreeding due to population decline and ultimately extinction puts the whole disease history into a 100,000-year perspective!
The fact that some of the most common joint diseases in growing dogs can be found in the Ice Age under circumstances which could have caused inbreeding should alert pet owners and breeders to look out for inbreeding in our dog breeds. The inbreeding factor in all dog breeds is already very high, causing inherited diseases to affect them more. Careful evaluation and monitoring of dog breeding using DNA analysis could reduce painful joint damage, which I have to treat in my work as an orthopaedic surgeon every day.
IVC Evidensia supported me in taking my second research trip to Los Angeles. This gave me the opportunity to bring a selection of spine specimens to the University Hospital in Davis, California where I could CT scan them. Now we have high-quality CT pictures of these specimens which can be evaluated and shown to other experts. This will hopefully lead to a better understanding of the spine changes, which we do not see in our modern-day patients.
The grant funding from IVC Evidensia was used to cover the travel costs, and perhaps most importantly the costs of the CT scanning of the Sabre-tooth cat spine specimen at UC Davis.
The main challenge for me is the fact that I know a lot about bone, joint and spine trauma, and diseases in carnivores - but I am not a palaeontologist with all the knowledge they would have about the ecosystem during the Ice Age, and the evolution of these carnivorous animals. To reduce this gap, I’ve been in contact with the palaeontology department of Zurich University, which is a great opportunity to collaborate.
Combining veterinary surgery and palaeontology is not really a career path! But it was an old dream of mine. My advice to younger veterinarians more generally is: whatever your interests are, follow them.
The next step is the evaluation of all the data and pictures I collected during my last visit to the La Brea Museum, with the plan to publish some of that data, which will take two to three years. I’m looking to visit other Natural History Museums as well, in order to collect more data about spine diseases in living species of large cats, to allow comparison with the sabre-toothed cat.
I’d also like to use computerised models to show some of the changes in the dire-wolf spine, being able to view the load (and overload) of some muscle insertions could be very helpful for understanding these changes.
I like to be outside in nature, especially in the mountains. Sometimes I take my camera with me to take photographs of the wildlife.
At home, I like to discuss difficult surgery cases with my wife, who is an ECVS specialist herself - you can always learn more!
Don’t wait too long to turn your dreams into reality.