My friend Kevin just pointed me at this YouTube video, which shows a dog grooving to some guitar music.
The dog is definitely appreciating the music (and Kevin was particularly interested in the fact that he smiles while the music is playing). I, on the other hand, am curious about the fact that the dog seems to actually be moving his head in time to the music. This could just be coincidence, and the human tendency to anthropomorphize. Or the dog could be reacting to motions of the guarist off-screen. Or it could be real.
I have never seen a dog demonstrate an understanding of musical rhythm before (though I saw a parrot do so on another YouTube video). Of course dogs will howl along, but feeling the beat is something different. I can’t remember ever seeing a journal article about the rhythmic abilities of canids!
Sunday, February 26, 2012
Saturday, February 25, 2012
Should veterinarians recommend pet heath insurance?
Over the last few days I have been privy to what I’ll describe as a “lively discussion” on a veterinary ethics mailing list. One vet on this list commented that she felt that more veterinarians should encourage pet owners to carry pet health insurance policies. She was frustrated by the number of animals she sees euthanized for financial reasons. Other veterinarians responded that health insurance policies are a waste of money: owners are likely to pay out much more over the course of the animal’s life than they will regain in payouts. After all, the insurance company has to make money.
There are several ways of looking at this issue. One is to argue that the question is not whether a pet health insurance policy saves an owner money, but whether it saves the animal’s life. Does it matter if the owner spends $2000 over ten years, so long as the necessary $1500 is available when the dog is hit by a car? Who is the veterinarian advocating for — the owner or the pet?
Of course, even if a pet insurance policy costs more than it returns, it may still have a benefit. Many people have trouble saving money for “just in case” scenarios, and a policy makes sure the money is available when it’s needed. And of course, even if you’re an excellent saver, your pet may have an unexpected health crisis before you’ve had time to save enough to cover it.
I feel that the real problem, though, is that so many people just don’t realize how much veterinary care can cost, particularly because their own health insurance shields them from the true cost of human medical care. Veterinarians can be hesitant to broach these issues with new owners; after all, discussing finances is always awkward, particularly when you tell someone that you might end up charging them a great deal of money some day. But I think veterinarians do owners a disservice to withhold this information. Far too many owners are deeply shocked by the cost of care when their animal has a broken leg, and are completely unprepared to find the money. I don’t know how many of them would have saved some money just in case if they had known, but they should at least have been given the chance.
As I said on the mailing list, I imagine a poster in a veterinary clinic:
Pet insurance: $20/month
One broken leg repair: $3000
Stomach bloat/twist surgery: $4000
Serious "hit by car" patient: $5000
Knowing you will always be able to afford your pet's emergency
medical care: priceless
The more I think about it, the more I realize how very little information is out there about the effectiveness of pet health insurance in saving animal lives. I propose a study. In two veterinary clinics, record the number of euthanasia decisions influenced by financial reasons for several months. (This would be difficult to do, but I think possible, if one could get owner cooperation.) Also record the number of insurance claims submitted through each clinic. (These claims usually require a veterinarian’s signature, so should be easy to track.) Then provide information, using handouts or posters, about pet health insurance in one of the clinics. Record the same data for several more months, and look for changes.
But even without evidence that providing information about costs and payment options is effective, I think it is part of a veterinarian’s job to educate owners about the responsibilities of pet ownership. Finding ways to afford health care is part of that. Provide owners with the information about costs, and let them make their own decisions about how to prepare for the worst.
There are several ways of looking at this issue. One is to argue that the question is not whether a pet health insurance policy saves an owner money, but whether it saves the animal’s life. Does it matter if the owner spends $2000 over ten years, so long as the necessary $1500 is available when the dog is hit by a car? Who is the veterinarian advocating for — the owner or the pet?
Of course, even if a pet insurance policy costs more than it returns, it may still have a benefit. Many people have trouble saving money for “just in case” scenarios, and a policy makes sure the money is available when it’s needed. And of course, even if you’re an excellent saver, your pet may have an unexpected health crisis before you’ve had time to save enough to cover it.
I feel that the real problem, though, is that so many people just don’t realize how much veterinary care can cost, particularly because their own health insurance shields them from the true cost of human medical care. Veterinarians can be hesitant to broach these issues with new owners; after all, discussing finances is always awkward, particularly when you tell someone that you might end up charging them a great deal of money some day. But I think veterinarians do owners a disservice to withhold this information. Far too many owners are deeply shocked by the cost of care when their animal has a broken leg, and are completely unprepared to find the money. I don’t know how many of them would have saved some money just in case if they had known, but they should at least have been given the chance.
As I said on the mailing list, I imagine a poster in a veterinary clinic:
Pet insurance: $20/month
One broken leg repair: $3000
Stomach bloat/twist surgery: $4000
Serious "hit by car" patient: $5000
Knowing you will always be able to afford your pet's emergency
medical care: priceless
The more I think about it, the more I realize how very little information is out there about the effectiveness of pet health insurance in saving animal lives. I propose a study. In two veterinary clinics, record the number of euthanasia decisions influenced by financial reasons for several months. (This would be difficult to do, but I think possible, if one could get owner cooperation.) Also record the number of insurance claims submitted through each clinic. (These claims usually require a veterinarian’s signature, so should be easy to track.) Then provide information, using handouts or posters, about pet health insurance in one of the clinics. Record the same data for several more months, and look for changes.
But even without evidence that providing information about costs and payment options is effective, I think it is part of a veterinarian’s job to educate owners about the responsibilities of pet ownership. Finding ways to afford health care is part of that. Provide owners with the information about costs, and let them make their own decisions about how to prepare for the worst.
Tuesday, February 21, 2012
Spaying dogs and cats: how much should I take out?
Spaying of dogs and cats is such a common and important procedure that it is the only surgery you are guaranteed to get to do all by yourself (twice!) at my veterinary school. Traditionally, vets have taken out the whole package (the uterus and both ovaries). Leave the ovaries in, and the animal still goes into heat, even if she can’t get pregnant, and you are liable to have an irritated owner on your hands. But is there a good reason to take the uterus out, or can you leave it in? More and more veterinarians are starting to think that less is more.
The commentary “Ovariohysterectomy versus ovariectomy for elective sterilization of female dogs and cats: is removal of the uterus necessary?” provides an overview of the current arguments for and against ovariectomy (removing only the ovaries, abbreviated OVE) versus the more traditional ovariohysterectomy (removing the uterus and the ovaries, abbreviated OVH).
The reasons to leave the uterus in are pretty obvious. You can make a smaller incision if you are only taking out the ovaries, and smaller incisions are obviously preferable where possible. While you’re at it, you can center your incision over the ovaries instead of having to center it further towards the animal’s tail so as to get the uterus as well. The ovaries can be difficult to fully visualize, as they can be tucked deep into the abdomen; placing the incision further towards the animal’s head makes it easier to see what you’re doing, so you can be sure to get the whole thing and not leave little bits of ovary behind. If you leave little bits behind, the animal can still go through heat cycles. This happens more often than you might think.
Finally, removing fewer organs leaves fewer chances for the surgeon to make a mistake. Mistakes do happen, especially with less experienced surgeons. Specifically, a surgeon could ligate (tie a suture around) something that should not be ligated, like a ureter. (Tie a suture around a ureter and the animal is going to have significant problems with one kidney, to say the least.) Alternatively, a surgeon could fail to sufficiently ligate something that needed that ligation to stop bleeding, resulting in hemorrhage into the abdomen. These complications would theoretically be somewhat less common with OVE than with OVH, because, with fewer organs to tie off before removal in OVE, fewer ligations are required.
Unfortunately, research has not yet been done to assess the frequency of such complications with OVE, so the benefit is just theoretical. Moreover, we have no evidence that the smaller incision in OVE makes any difference to the animal’s pain levels. Post-spay animals do not appear to require less pain medication after OVE compared to OVH.
Another consideration in choosing OVH over OVE is pyometra, a disease most commonly found in unspayed animals. As an animal ages, its uterus becomes less able to fight off bacterial invaders, and infection of the uterus can be a big (life-threatening) deal. To avoid the problem, remove the uterus.
However, although the causes of pyometra are not fully understood, we do know that it doesn’t happen unless progesterone levels are elevated, as happens during the estrous cycle. And animals without ovaries don’t get elevated progesterone levels unless we give them progesterone, something we don’t generally do to dogs and cats. This means that animals who have only their ovaries removed won’t get pyometra, even though the uterus (the infected organ in this disease) is left behind, because they won’t be going through heat cycles which result in elevated progesterone levels.
In practice, veterinarians do sometimes see animals who had only their ovaries removed get pyometra — but only if little bits of ovary were mistakenly left behind (ovarian remnant syndrome). So if you remove the ovaries properly, the animal will not be at risk for pyometra. And, as discussed earlier, it’s theoretically easier to remove the ovaries properly if you center your incision over them and leave the uterus in place.
The authors conclude by arguing that OVE is the preferable procedure, due to the theoretically reduced complication rate. Personally, I really like the less is more approach to surgery; if you can leave it in, I think you should. But I do wish we had some more solid evidence in support of OVE. Time for some clinical studies comparing the two procedures!
DeTora, M., & McCarthy, R. (2011). Ovariohysterectomy versus ovariectomy for elective sterilization of female dogs and cats: is removal of the uterus necessary? Journal of the American Veterinary Medical Association, 239 (11), 1409-1412 DOI: 10.2460/javma.239.11.1409
The commentary “Ovariohysterectomy versus ovariectomy for elective sterilization of female dogs and cats: is removal of the uterus necessary?” provides an overview of the current arguments for and against ovariectomy (removing only the ovaries, abbreviated OVE) versus the more traditional ovariohysterectomy (removing the uterus and the ovaries, abbreviated OVH).The reasons to leave the uterus in are pretty obvious. You can make a smaller incision if you are only taking out the ovaries, and smaller incisions are obviously preferable where possible. While you’re at it, you can center your incision over the ovaries instead of having to center it further towards the animal’s tail so as to get the uterus as well. The ovaries can be difficult to fully visualize, as they can be tucked deep into the abdomen; placing the incision further towards the animal’s head makes it easier to see what you’re doing, so you can be sure to get the whole thing and not leave little bits of ovary behind. If you leave little bits behind, the animal can still go through heat cycles. This happens more often than you might think.
Finally, removing fewer organs leaves fewer chances for the surgeon to make a mistake. Mistakes do happen, especially with less experienced surgeons. Specifically, a surgeon could ligate (tie a suture around) something that should not be ligated, like a ureter. (Tie a suture around a ureter and the animal is going to have significant problems with one kidney, to say the least.) Alternatively, a surgeon could fail to sufficiently ligate something that needed that ligation to stop bleeding, resulting in hemorrhage into the abdomen. These complications would theoretically be somewhat less common with OVE than with OVH, because, with fewer organs to tie off before removal in OVE, fewer ligations are required.
Unfortunately, research has not yet been done to assess the frequency of such complications with OVE, so the benefit is just theoretical. Moreover, we have no evidence that the smaller incision in OVE makes any difference to the animal’s pain levels. Post-spay animals do not appear to require less pain medication after OVE compared to OVH.
Another consideration in choosing OVH over OVE is pyometra, a disease most commonly found in unspayed animals. As an animal ages, its uterus becomes less able to fight off bacterial invaders, and infection of the uterus can be a big (life-threatening) deal. To avoid the problem, remove the uterus.
However, although the causes of pyometra are not fully understood, we do know that it doesn’t happen unless progesterone levels are elevated, as happens during the estrous cycle. And animals without ovaries don’t get elevated progesterone levels unless we give them progesterone, something we don’t generally do to dogs and cats. This means that animals who have only their ovaries removed won’t get pyometra, even though the uterus (the infected organ in this disease) is left behind, because they won’t be going through heat cycles which result in elevated progesterone levels.
In practice, veterinarians do sometimes see animals who had only their ovaries removed get pyometra — but only if little bits of ovary were mistakenly left behind (ovarian remnant syndrome). So if you remove the ovaries properly, the animal will not be at risk for pyometra. And, as discussed earlier, it’s theoretically easier to remove the ovaries properly if you center your incision over them and leave the uterus in place.
The authors conclude by arguing that OVE is the preferable procedure, due to the theoretically reduced complication rate. Personally, I really like the less is more approach to surgery; if you can leave it in, I think you should. But I do wish we had some more solid evidence in support of OVE. Time for some clinical studies comparing the two procedures!
DeTora, M., & McCarthy, R. (2011). Ovariohysterectomy versus ovariectomy for elective sterilization of female dogs and cats: is removal of the uterus necessary? Journal of the American Veterinary Medical Association, 239 (11), 1409-1412 DOI: 10.2460/javma.239.11.1409
Thursday, February 16, 2012
Future of the Zombieverse
I matched at an academic shelter medicine internship in Florida! But I bet you don’t completely know what that means.
Internship: Like human doctors, many veterinarians do internships their first year out of school (I am graduating in May). Unlike human doctors, veterinarians are legally able to go straight into practice without passing through an internship first. Veterinarians who do this tend to try to find practices which are prepared to mentor them for a year or two. Internships provide loads of good clinicial experience, and are offered by hospitals or larger private practices with a high case load and access to specialists and expensive toys like advanced imaging modalities. This gives the intern a chance to see a variety of diseases and to work with a variety of specialists, to be very prepared to practice on their own if need be. Similarly to human medicine internships, veterinary internships are very poorly paid.
Match: As in human medicine, veterinarians don’t apply to internships as to a regular job. You apply through a match program. After you have filled out your applications, you rank the internships to which you’ve applied in your order of interest. They do the same for their applicants. Then a third party matches you with the internship you most want, which also most wants you (in theory).
Academic: Internships are offered by either veterinary schools or by private practices. The internships at veterinary schools are “academic” internships and do tend to be more academically oriented, with more emphasis on things like journal clubs, publishing, etc.
Shelter medicine: Traditionally, veterinary internships allowed the intern to specialize in small animals vs large animals, but nothing more specific than that. These rotating internships allow the intern to rotate through various sub-specialties (cardiology, neurology, ophthalmology...) with plenty of time spent as the primary clinician in the emergency room for a more general view of medicine. Recently, however, specialty internships have sprung up. Most of these are intended for veterinarians who have finished a rotating internship and want a year of specialization to make them more competitive for their residency application; competitive specialties like surgery and radiology were some of the first to have specialty internships. Shelter medicine internships started appearing a few years ago, with two new ones being offered for the first time this year, for a total of five that I know of in the US. It is fairly common for shelter medicine interns to approach their specialty internship less as a bridge between rotating internship and residency, and more as a year’s experience to allow them to go straight into shelter practice. This is what I am doing, except that I expect to continue my education in other ways after my internship. Shelter medicine residency programs do exist and some shelter medicine interns go on to those.
Florida: As an inveterate New Englander I am a little nervous about Florida. But it’s just for one year.
What kinds of things will I be learning about? Community cats (also known as feral cats), animal hoarders, veterinary forensics, managing disease outbreaks, disaster response... I will do my best to cover it all here.
Internship: Like human doctors, many veterinarians do internships their first year out of school (I am graduating in May). Unlike human doctors, veterinarians are legally able to go straight into practice without passing through an internship first. Veterinarians who do this tend to try to find practices which are prepared to mentor them for a year or two. Internships provide loads of good clinicial experience, and are offered by hospitals or larger private practices with a high case load and access to specialists and expensive toys like advanced imaging modalities. This gives the intern a chance to see a variety of diseases and to work with a variety of specialists, to be very prepared to practice on their own if need be. Similarly to human medicine internships, veterinary internships are very poorly paid.
Match: As in human medicine, veterinarians don’t apply to internships as to a regular job. You apply through a match program. After you have filled out your applications, you rank the internships to which you’ve applied in your order of interest. They do the same for their applicants. Then a third party matches you with the internship you most want, which also most wants you (in theory).
Academic: Internships are offered by either veterinary schools or by private practices. The internships at veterinary schools are “academic” internships and do tend to be more academically oriented, with more emphasis on things like journal clubs, publishing, etc.
Shelter medicine: Traditionally, veterinary internships allowed the intern to specialize in small animals vs large animals, but nothing more specific than that. These rotating internships allow the intern to rotate through various sub-specialties (cardiology, neurology, ophthalmology...) with plenty of time spent as the primary clinician in the emergency room for a more general view of medicine. Recently, however, specialty internships have sprung up. Most of these are intended for veterinarians who have finished a rotating internship and want a year of specialization to make them more competitive for their residency application; competitive specialties like surgery and radiology were some of the first to have specialty internships. Shelter medicine internships started appearing a few years ago, with two new ones being offered for the first time this year, for a total of five that I know of in the US. It is fairly common for shelter medicine interns to approach their specialty internship less as a bridge between rotating internship and residency, and more as a year’s experience to allow them to go straight into shelter practice. This is what I am doing, except that I expect to continue my education in other ways after my internship. Shelter medicine residency programs do exist and some shelter medicine interns go on to those.
Florida: As an inveterate New Englander I am a little nervous about Florida. But it’s just for one year.
What kinds of things will I be learning about? Community cats (also known as feral cats), animal hoarders, veterinary forensics, managing disease outbreaks, disaster response... I will do my best to cover it all here.
Wednesday, January 11, 2012
Classical conditioning: do try this at home
I used classical conditioning on my dog Jenny a few minutes before writing this post. She is in the process of developing an ear infection, but she hates to have her ears cleaned. I’m using classical conditioning to change her emotional reaction to the ear cleaner from fear or stress to anticipation and enthusiasm.
The unconditional stimulus (UCS) is the ear cleaner. When I show it to her, she has a natural response (fear, demonstrated by her sudden flight from my vicinity). I could pair this UCS (ear cleaner) with a neutral stimulus (a bell). The animal learns to apply its emotional response to the second stimulus (fear of the ear cleaner) to the first stimulus (the bell). In other words, the bell comes to predict the ear cleaner, and eventually, the dog would learn to run away when she heard the bell, as if she were afraid of the bell.
That’s not useful either. What I am doing is pairing something to which Jenny has a positive natural response (cheese) with the ear cleaner. The first thing she sees predicts the second thing, so I show her the ear cleaner first, then give her cheese. Over time, the ear cleaner comes to predict cheese, and eventually she will greet the ear cleaner with the enthusiasm previously reserved for cheddar. Of course, I have to build slowly up to actually cleaning her ears, but after one session she is enthusiastically touching her nose to the bottle when I show it to her instead of leaving the room. I expect the process to take several sessions, so I’m starting before I actually need to clean her ears.
Classical conditioning is also used frequently in behavior modification, to change the emotional response (fear) of dogs to a stimulus (strange people, strange dogs) into a new emotional response (enthusiasm). Again, pairing food with the approach of the stimulus works well, with a sufficiently gradual approach. This counter-conditioning approach is frequently used in the behavioral treatment of dogs who erupt into enraged barking at the sight of other dogs.
It is important to remember that the first stimulus predicts the second. If you get things backwards, you can break your dog! I have heard stories of people teaching their dogs to flee the room upon smelling peanut butter, because peanut butter had been overused as a lure before a variety of unpleasant stimuli (ear cleaning, nail clipping...). So remember, bad thing first, good thing second.
Go, try it if you have trouble cleaning your dog’s ears or clipping their nails!
[ETA: There is some very interesting discussion about the definition of classical conditioning in the comments. -DZ]
Saturday, December 31, 2011
The hearty ingredients of Canis soup
[Reposted from my post on Scientific American’s guest blog.]
The wolf is iconic and charismatic. We see him on t-shirts, on posters, and in fantasy novels. Conservationists do battle with ranchers to preserve populations of wolves. The coyote, on the other hand, is neither iconic nor loved. A newcomer to suburbia, he is feared as a suspected predator of cats, small dogs, and even small children. He is rarely seen on t-shirts; his name is not used to designate a rank of Boy Scout.
But now that we have the genetic tools to look at these animals’ genomes, it turns out that many of the populations of coyotes in North America are actually coyote-wolf hybrids, as are many of the populations of wolves. Unable to draw clear lines between these species, biologists have dubbed the populations of hybrids “Canis soup.”
What’s a Canis?
The term “canid soup” has also been used for this mess of wolf, coyote, and even dog genes that we find in some populations of canids. So what does Canis mean, and what is a canid?
These are terms related to the scientific classification of the species in question. Going through the hierarchy, we have Kingdom Animalia, Phylum Chordata, Class Mammalia, Order Carnivora, Family Canidae (canids), and Genus Canis. Wolves, dogs, jackals, and foxes belong to the family Canidae, but only wolves, dogs, and jackals (not foxes) belong to the genus Canis. We call the wolf-like canids “canines” and the fox-like canids “vulpines.”
As foxes do not interbreed with wolves, dogs, or jackals, what we’re talking about here is correctly Canis soup, or perhaps canine soup, but not canid soup.
Is it Canis or is it soup?
The more you dig into wild canines in North America, the more unclear it is where any species lines should be drawn. So who makes up our cast of characters?
The three species of wild canines in North America today, then, are Canis lupus, Canis latrans, and Canis lycaon. But we really have just two soup ingredients, wolf and coyote. There are pure wolves (Canis lupus) and there are pure coyotes (Canis latrans),
and there are populations that are mixtures of more or less wolf and
more or less coyote (Eastern wolves, Eastern coyotes, and red wolves).
There appears to be some dog mixed in there, too. You can think of gray
wolf and Western coyote as ingredients, and everything else as soup.
Coyote flavor versus wolf flavor
The 2011 paper “A genome-wide perspective on the evolutionary history of enigmatic wolf-like canids” analyzed the various soup flavors out there and presented their findings in some easy-to-understand charts (below). Here, the different colors represent different amounts of each ingredient. The first chart describes the Eastern wolf, here referred to as the Algonquin wolf, which is mostly gray wolf (green) and joint wolf/coyote (yellow), but also has significant coyote (red). The second chart describes the red wolf; at a glance, it is obvious that the red wolf has a much larger percentage of coyote genes (again, red in this chart). These charts both use τ to denote the number of generations since the most recent admixture with another species.
The two coyote recipes pictured below describe two subpopulations of what I have described as the Eastern coyote; this particular paper considers them split into Northeastern and Southeastern coyotes. At a glance, these populations are mainly pure coyote (red), with big dashes of mixed coyote/wolf (yellow), and small but notable amounts of our friend the dog (dark blue, light blue, and pink).
Wild canine populations challenge us to let go of our obsessive need to categorize. Instead of slotting a canine population into a single species category, we might instead think of it as existing on a spectrum from “wolf-like” to “coyote-like.” A strongly wolf-like canid would be larger, sixty to ninety pounds. He would require a larger range, and would be a deerivore, subsisting off of larger game. He is likely to be a shyer animal, found only in more rural or wild areas. Conversely, a strongly coyote-like canid would be much smaller, fifteen to thirty pounds, with a smaller range. He might eat deer as well as rabbits and et cetera (probably a lot of et cetera, as coyotes are more willing to scrounge than wolves are). He would be more likely to be found in suburban areas, with a greater tolerance for human proximity. A given population of canines might fall anywhere on the spectrum between the two. The fact that a spectrum actually exists is beautifully demonstrated by the Eastern coyote, who has mixed coyote/wolf ancestry, is mid-sized between coyote and wolf, and has a mid-sized range.
What’s your preferred flavor?
Does the intermixture of various ingredients in the formation of soupy populations matter as more than a gee-whiz story? To some people, the answer is very much yes. The conservationists who are committing significant resources to the preservation of the red wolf don’t want to see the wolves that they reintroduce interbreed with coyotes. If the reintroduced wolf population blends into a coyote population, then are these resources actually being spent just to support a bunch of coyotes (who have been doing fine on their own)? At the same time, evidence shows that the founder population of 19 red wolves was already significantly coyotified, and we’re not sure how long it’s been since there have been any pure Canis rufus specimens in North America.
It is, of course, possible to think about the problem without asking for genetics to provide the complete answer for us. The red wolf is a red wolf, a beautiful, iconic animal that has lived in the southeastern United States throughout living memory. We know what the red wolf looks like (and that hasn’t been changing much, no matter what is happening to his genes). We also know that he is important in a particular environmental niche, and that hasn’t been changing much either.
Practically, the mixture of coyote genes into fragile wolf populations may be a good thing. Because coyotes are better at living on smaller ranges and in closer proximity to humans than wolves are, they are better adapted to the realities of North America today. As their genes mix into wolf populations, these populations become demonstrably more robust, more able to tolerate human presence, and able to survive on smaller ranges. It is possible, in fact, that coyote genes are exactly what are eventually going to allow a red wolf population to flourish without human assistance.
Conclusions, if we can make any
Does it matter that some of what we think of as wolves have coyote genes? I think the answer comes down to a cultural perception of the wolf as a romantic and charismatic creature, and of the coyote as a pest. Perhaps any mixture of the two is perceived as diminishing the wolf. A friend of mine once made this analogy: if you have an entire bottle of fine wine, and you pour just a teaspoon of sewage into it, now you have a bottle of sewage. Does any amount of coyote, no matter how miniscule, make the wolf impure, and less worth conserving than it was?
As a culture, I hope we can come to appreciate the strengths that the coyote brings to Canis soup, in his ability to coexist with humans in the modern world. He may be what saves populations of charismatic wolves from permanent loss. As we look at populations of canines in North America, we should learn to say that one is more coyote-like and another more wolf-like, on a spectrum from one flavor of soup to another, and appreciate the benefits of both.
Canis soup has been used before as an example of the blurriness of some species lines and the inadequacy of many existing definitions of a species, but it also provides some interesting insights into the fluidity of canid morphology and behavioral characteristics. How did something as large and wild as a wolf become something as variably-sized and tame as a dog? Moreover, how did this change happen (presumably) without a carefully planned breeding program? Why is it so easy to breed types of dogs with such different behavioral and physical characteristics, especially compared to the much more limited variety of breeds of cat, horse, or cow? The canine genome clearly has the capacity for expression across a startlingly wide array of phenotypes. The evidence of this variety has always been right before our eyes, but we are just beginning to understand its implications.
References
Adams, J., Leonard, J., & Waits, L. (2003). Widespread occurrence of a domestic dog mitochondrial DNA haplotype in southeastern US coyotes Molecular Ecology, 12 (2), 541-546 DOI: 10.1046/j.1365-294X.2003.01708.x
Adams, J., Kelly, B., & Waits, L. (2003). Using faecal DNA sampling and GIS to monitor hybridization between red wolves (Canis rufus) and coyotes (Canis latrans) Molecular Ecology, 12 (8), 2175-2186 DOI: 10.1046/j.1365-294X.2003.01895.x
Hailer, F., & Leonard, J. (2008). Hybridization among Three Native North American Canis Species in a Region of Natural Sympatry PLoS ONE, 3 (10) DOI: 10.1371/journal.pone.0003333
vonHoldt, B., Pollinger, J., Earl, D., Knowles, J., Boyko, A., Parker, H., Geffen, E., Pilot, M., Jedrzejewski, W., Jedrzejewska, B., Sidorovich, V., Greco, C., Randi, E., Musiani, M., Kays, R., Bustamante, C., Ostrander, E., Novembre, J., & Wayne, R. (2011). A genome-wide perspective on the evolutionary history of enigmatic wolf-like canids Genome Research, 21 (8), 1294-1305 DOI: 10.1101/gr.116301.110
Way, J., Rutledge, L., Wheeldon, T., & White, B. (2010). Genetic Characterization of Eastern “Coyotes” in Eastern Massachusetts Northeastern Naturalist, 17 (2), 189-204 DOI: 10.1656/045.017.0202
Wilson, P., Grewal, S., Mallory, F., & White, B. (2009). Genetic Characterization of Hybrid Wolves across Ontario Journal of Heredity, 100 (Supplement 1) DOI: 10.1093/jhered/esp034
Zimmer C (2008). What is a species? Scientific American, 298 (6), 72-9 PMID: 18642545
The wolf is iconic and charismatic. We see him on t-shirts, on posters, and in fantasy novels. Conservationists do battle with ranchers to preserve populations of wolves. The coyote, on the other hand, is neither iconic nor loved. A newcomer to suburbia, he is feared as a suspected predator of cats, small dogs, and even small children. He is rarely seen on t-shirts; his name is not used to designate a rank of Boy Scout.
But now that we have the genetic tools to look at these animals’ genomes, it turns out that many of the populations of coyotes in North America are actually coyote-wolf hybrids, as are many of the populations of wolves. Unable to draw clear lines between these species, biologists have dubbed the populations of hybrids “Canis soup.”
What’s a Canis?
The term “canid soup” has also been used for this mess of wolf, coyote, and even dog genes that we find in some populations of canids. So what does Canis mean, and what is a canid?
These are terms related to the scientific classification of the species in question. Going through the hierarchy, we have Kingdom Animalia, Phylum Chordata, Class Mammalia, Order Carnivora, Family Canidae (canids), and Genus Canis. Wolves, dogs, jackals, and foxes belong to the family Canidae, but only wolves, dogs, and jackals (not foxes) belong to the genus Canis. We call the wolf-like canids “canines” and the fox-like canids “vulpines.”
As foxes do not interbreed with wolves, dogs, or jackals, what we’re talking about here is correctly Canis soup, or perhaps canine soup, but not canid soup.
Is it Canis or is it soup?
The more you dig into wild canines in North America, the more unclear it is where any species lines should be drawn. So who makes up our cast of characters?
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Next is the Western coyote, Canis latrans. This animal is also known as the American jackal or prairie wolf, suggesting that there has been some confusion about how to distinguish canine species for some time. The Western coyote is a significantly smaller animal than the gray wolf, weighing in closer to 20 pounds (7-14 kg). His coat color is less varied than the gray wolf’s, almost always a grey-brown as you see in the image here. | ||
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The red wolf or Southeastern wolf is subject to truly intense debate about species status. Is he his own species, Canis rufus? A subset of the gray wolf, Canis lupus rufus? Or a population of Eastern wolf, Canis lycaon? He has a beautiful red coat, and is smaller in size than the gray wolf. His range was historically the southeastern U.S., but he went extinct in the wild by 1980. A founder population of 19 animals survived in captivity, and a reintroduction project in North Carolina was begun in 1987. Here the red wolf is today enthusiastically interbreeding with coyotes, leaving conservationists to wonder what they are conserving. |
Coyote flavor versus wolf flavor
The 2011 paper “A genome-wide perspective on the evolutionary history of enigmatic wolf-like canids” analyzed the various soup flavors out there and presented their findings in some easy-to-understand charts (below). Here, the different colors represent different amounts of each ingredient. The first chart describes the Eastern wolf, here referred to as the Algonquin wolf, which is mostly gray wolf (green) and joint wolf/coyote (yellow), but also has significant coyote (red). The second chart describes the red wolf; at a glance, it is obvious that the red wolf has a much larger percentage of coyote genes (again, red in this chart). These charts both use τ to denote the number of generations since the most recent admixture with another species.
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| Two recipes for wolf flavored Canis soup (vonHoldt, 2011) |
The two coyote recipes pictured below describe two subpopulations of what I have described as the Eastern coyote; this particular paper considers them split into Northeastern and Southeastern coyotes. At a glance, these populations are mainly pure coyote (red), with big dashes of mixed coyote/wolf (yellow), and small but notable amounts of our friend the dog (dark blue, light blue, and pink).
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| Two recipes for coyote flavored Canis soup (vonHoldt, 2011) |
Wild canine populations challenge us to let go of our obsessive need to categorize. Instead of slotting a canine population into a single species category, we might instead think of it as existing on a spectrum from “wolf-like” to “coyote-like.” A strongly wolf-like canid would be larger, sixty to ninety pounds. He would require a larger range, and would be a deerivore, subsisting off of larger game. He is likely to be a shyer animal, found only in more rural or wild areas. Conversely, a strongly coyote-like canid would be much smaller, fifteen to thirty pounds, with a smaller range. He might eat deer as well as rabbits and et cetera (probably a lot of et cetera, as coyotes are more willing to scrounge than wolves are). He would be more likely to be found in suburban areas, with a greater tolerance for human proximity. A given population of canines might fall anywhere on the spectrum between the two. The fact that a spectrum actually exists is beautifully demonstrated by the Eastern coyote, who has mixed coyote/wolf ancestry, is mid-sized between coyote and wolf, and has a mid-sized range.
What’s your preferred flavor?
Does the intermixture of various ingredients in the formation of soupy populations matter as more than a gee-whiz story? To some people, the answer is very much yes. The conservationists who are committing significant resources to the preservation of the red wolf don’t want to see the wolves that they reintroduce interbreed with coyotes. If the reintroduced wolf population blends into a coyote population, then are these resources actually being spent just to support a bunch of coyotes (who have been doing fine on their own)? At the same time, evidence shows that the founder population of 19 red wolves was already significantly coyotified, and we’re not sure how long it’s been since there have been any pure Canis rufus specimens in North America.
It is, of course, possible to think about the problem without asking for genetics to provide the complete answer for us. The red wolf is a red wolf, a beautiful, iconic animal that has lived in the southeastern United States throughout living memory. We know what the red wolf looks like (and that hasn’t been changing much, no matter what is happening to his genes). We also know that he is important in a particular environmental niche, and that hasn’t been changing much either.
Practically, the mixture of coyote genes into fragile wolf populations may be a good thing. Because coyotes are better at living on smaller ranges and in closer proximity to humans than wolves are, they are better adapted to the realities of North America today. As their genes mix into wolf populations, these populations become demonstrably more robust, more able to tolerate human presence, and able to survive on smaller ranges. It is possible, in fact, that coyote genes are exactly what are eventually going to allow a red wolf population to flourish without human assistance.
Conclusions, if we can make any
Does it matter that some of what we think of as wolves have coyote genes? I think the answer comes down to a cultural perception of the wolf as a romantic and charismatic creature, and of the coyote as a pest. Perhaps any mixture of the two is perceived as diminishing the wolf. A friend of mine once made this analogy: if you have an entire bottle of fine wine, and you pour just a teaspoon of sewage into it, now you have a bottle of sewage. Does any amount of coyote, no matter how miniscule, make the wolf impure, and less worth conserving than it was?
As a culture, I hope we can come to appreciate the strengths that the coyote brings to Canis soup, in his ability to coexist with humans in the modern world. He may be what saves populations of charismatic wolves from permanent loss. As we look at populations of canines in North America, we should learn to say that one is more coyote-like and another more wolf-like, on a spectrum from one flavor of soup to another, and appreciate the benefits of both.
Canis soup has been used before as an example of the blurriness of some species lines and the inadequacy of many existing definitions of a species, but it also provides some interesting insights into the fluidity of canid morphology and behavioral characteristics. How did something as large and wild as a wolf become something as variably-sized and tame as a dog? Moreover, how did this change happen (presumably) without a carefully planned breeding program? Why is it so easy to breed types of dogs with such different behavioral and physical characteristics, especially compared to the much more limited variety of breeds of cat, horse, or cow? The canine genome clearly has the capacity for expression across a startlingly wide array of phenotypes. The evidence of this variety has always been right before our eyes, but we are just beginning to understand its implications.
References
Adams, J., Leonard, J., & Waits, L. (2003). Widespread occurrence of a domestic dog mitochondrial DNA haplotype in southeastern US coyotes Molecular Ecology, 12 (2), 541-546 DOI: 10.1046/j.1365-294X.2003.01708.x
Adams, J., Kelly, B., & Waits, L. (2003). Using faecal DNA sampling and GIS to monitor hybridization between red wolves (Canis rufus) and coyotes (Canis latrans) Molecular Ecology, 12 (8), 2175-2186 DOI: 10.1046/j.1365-294X.2003.01895.x
Hailer, F., & Leonard, J. (2008). Hybridization among Three Native North American Canis Species in a Region of Natural Sympatry PLoS ONE, 3 (10) DOI: 10.1371/journal.pone.0003333
vonHoldt, B., Pollinger, J., Earl, D., Knowles, J., Boyko, A., Parker, H., Geffen, E., Pilot, M., Jedrzejewski, W., Jedrzejewska, B., Sidorovich, V., Greco, C., Randi, E., Musiani, M., Kays, R., Bustamante, C., Ostrander, E., Novembre, J., & Wayne, R. (2011). A genome-wide perspective on the evolutionary history of enigmatic wolf-like canids Genome Research, 21 (8), 1294-1305 DOI: 10.1101/gr.116301.110
Way, J., Rutledge, L., Wheeldon, T., & White, B. (2010). Genetic Characterization of Eastern “Coyotes” in Eastern Massachusetts Northeastern Naturalist, 17 (2), 189-204 DOI: 10.1656/045.017.0202
Wilson, P., Grewal, S., Mallory, F., & White, B. (2009). Genetic Characterization of Hybrid Wolves across Ontario Journal of Heredity, 100 (Supplement 1) DOI: 10.1093/jhered/esp034
Zimmer C (2008). What is a species? Scientific American, 298 (6), 72-9 PMID: 18642545
Wednesday, December 21, 2011
Book review: Control unleashed
I recently finished Control Unleashed: Creating a focused and confident dog, by Leslie McDevitt. This book is designed for people training dogs in agility who are having issues with their dogs’ ability to focus, so you might imagine that the book isn’t useful to people with fearful dogs like mine. But it turns out, unsurprisingly, that if your dog is having issues focusing, he may well actually be nervous about something in his environment, such as strange people or other dogs. This book is full of exercises for helping your dog be more comfortable and relaxed, whatever his reason for being distractable. It was incredibly helpful to me in thinking through exercises for my shy dog Jenny, to help her learn to trust the world a little more. Even if you don’t do agility with your dog, this book may be helpful in making you a better trainer. It includes many examples of specific training exercises to try, and stories about situations in which they were particularly helpful. It was also an enjoyable enough read that I got through it while working long hours on some difficult rotations — I looked forward to finding ten minutes to read it before bed. I recommend this book to everyone who has has basic understanding of positive training and learning theory, and wants to learn more.
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