It’s challenging to breed purebred dogs well. You have to balance appearance, health, and temperament, and of course by “health” I actually mean “2598237 different possible inherited diseases.” You breed or buy the best animal you can (no small task in itself), you compete with it to prove its ability and conformance to the breed standard, and then when it is an adult the time comes to breed it. Before you breed, you have to make sure the animal is physically healthy. You perform perhaps thousands of dollars worth of tests towards this goal. If your star fails any one of them, you should consider not breeding it, even if it is otherwise a great breeding prospect. If it fails a really important test — like the assessment of the likelihood of developing hip dysplasia in a breed that is notorious for its hip problems, like the golden retriever — then you really shouldn’t breed the animal.
Time was, dog breeders had big kennels, with dozens of dogs. If one of them turned out to have an inheritable health problem, it was fairly easy to just remove that animal from the breeding program. After all, if you have 50 dogs and can only breed 49 of them, what’s the big deal? These days, people have less land, and dog breeders tend to have smaller numbers of dogs. So what happens if you are the owner of a single, beloved pet and you really want to try to improve the breed by having a litter from this pet? You show, you compete, you have health tests, and the animal fails the test for healthy hips. Now it’s not just a question of not breeding a single animal. Instead, it’s a question of not being able to breed at all, unless you get another dog and start over. What if that one has a health problem too, and you really don’t want to have three dogs in your house?
It’s a tangled issue. Personally, I think dogs do better in homes than in kennels, generally speaking (although I recognize that there are some private kennels out there containing some very happy dogs). But I also think that if we are going to be selecting dogs for beauty, as we do with show dogs, we have a responsibility to not let health fall by the wayside. Making the breeding of healthy dogs easier is a good thing. It’s sad to think that the fact that more dogs are living inside as pets makes breeding responsibly more difficult.
Saturday, July 23, 2011
Tuesday, July 19, 2011
The art of dog breeding: Puppy has two daddies
Not just every puppy has two daddies. How would it happen?
It’s a long story, so stick with me. Let’s say you’re deeply involved in the dog world, and love a particular breed of dog. You breed to improve that breed. You have a young bitch that you are considering breeding. You start out by taking this bitch to dog shows, doing that circuit until the bitch has earned her championship after a number of wins at different shows. This shows that the bitch is conformationally excellent enough to be worth breeding. You may also work with the bitch in some other area, like competition obedience, tracking, or agility.
When the time comes to breed, there is more work to do. You have to make sure the bitch is genetically good material. You know what problems are common in the breed, so you test for those. There are some problems (like hip dysplasia) which are so common that breeders test for them in almost every breed; there are some that are more rare. Some tests are genetic tests done on DNA samples. Some are just the sorts of tests any vet might do to see if the levels of different chemicals in the blood are within normal ranges, or if they are suggestive of certain conditions. All these tests have to be done on both sire and dam.
Who’s the sire? You should pick out a sire that complements this bitch well. No animal is perfect. If the bitch’s biggest failing is her less than perfect hip conformation, then the sire should have really exceptional hip conformation, to balance that problem out. They should not be too closely related, either.
The right sire may live across the country or across the world from the bitch. If he’s far away, artificial insemination will be necessary (although some animals get transported quite a distance for sexual liaisons, and some bitches are artificially inseminated even though the dog is in the next room). When exactly should this occur? If the dog is prime breeding material, his semen will be very expensive, not to mention the fees for implanting it (more on that later). So you want to do it as few times as possible.
It’s also important to know as precisely as possible when the bitch ovulated, because this helps predict when she will give birth. So ovulation prediction is an important part of this process. It involves blood tests over multiple days, done by a veterinarian.
Once you know what the bitch’s three fertile days will be, how will you get the semen in? You can choose natural service (the old fashioned method), artificial insemination into the vagina, or intra-uterine insemination (surgical insemination directly into the uterus). This last approach is the most reliable, although of course it is also the most invasive and expensive.
If you don’t choose natural service, you may be getting either fresh semen (from the dog in the next room), fresh chilled and shipped overnight (from somewhere on your continent, collected the previous day), or frozen (from anywhere in the world, and possibly as venerable as twenty years old). Why would you artificially inseminate fresh semen, if the dog is right there? Some bitches can be cranky if they don’t approve of the dog on offer, and there can be violence. The owner of an expensive (or well loved!) stud dog might not wish to risk his injury.
Now it comes down to it. Many breeders will have spent thousands of dollars to get to this point. Some will have spent tens of thousands. They really, really want to have a successful impregnation. The fresher the semen, the more reliable it is. If the best possible sire is only providing frozen semen for whatever reason, the chances are significant that the bitch will not get knocked up. So what do you do?
On the bitch’s first fertile day, you use the frozen semen from the preferred sire. You hope that all her eggs get fertilized by this semen, but if some are left over, you call in the backup sire, someone local who can provide fresh semen. Hopefully any eggs that failed to get fertilized by the first sire will get handled by the second. You may well end up with puppies from each sire in the litter, but that’s fine; you can DNA test them to know who’s sired by whom. And that is how a puppy can have two daddies, or, at least, a litter can.
(Note: I skipped over the numerous ethical issues brought up in this story. For today, I just wanted to share with you some of the surprising tools available to dog breeders today.)
It’s a long story, so stick with me. Let’s say you’re deeply involved in the dog world, and love a particular breed of dog. You breed to improve that breed. You have a young bitch that you are considering breeding. You start out by taking this bitch to dog shows, doing that circuit until the bitch has earned her championship after a number of wins at different shows. This shows that the bitch is conformationally excellent enough to be worth breeding. You may also work with the bitch in some other area, like competition obedience, tracking, or agility.
When the time comes to breed, there is more work to do. You have to make sure the bitch is genetically good material. You know what problems are common in the breed, so you test for those. There are some problems (like hip dysplasia) which are so common that breeders test for them in almost every breed; there are some that are more rare. Some tests are genetic tests done on DNA samples. Some are just the sorts of tests any vet might do to see if the levels of different chemicals in the blood are within normal ranges, or if they are suggestive of certain conditions. All these tests have to be done on both sire and dam.
Who’s the sire? You should pick out a sire that complements this bitch well. No animal is perfect. If the bitch’s biggest failing is her less than perfect hip conformation, then the sire should have really exceptional hip conformation, to balance that problem out. They should not be too closely related, either.
The right sire may live across the country or across the world from the bitch. If he’s far away, artificial insemination will be necessary (although some animals get transported quite a distance for sexual liaisons, and some bitches are artificially inseminated even though the dog is in the next room). When exactly should this occur? If the dog is prime breeding material, his semen will be very expensive, not to mention the fees for implanting it (more on that later). So you want to do it as few times as possible.
It’s also important to know as precisely as possible when the bitch ovulated, because this helps predict when she will give birth. So ovulation prediction is an important part of this process. It involves blood tests over multiple days, done by a veterinarian.
Once you know what the bitch’s three fertile days will be, how will you get the semen in? You can choose natural service (the old fashioned method), artificial insemination into the vagina, or intra-uterine insemination (surgical insemination directly into the uterus). This last approach is the most reliable, although of course it is also the most invasive and expensive.
If you don’t choose natural service, you may be getting either fresh semen (from the dog in the next room), fresh chilled and shipped overnight (from somewhere on your continent, collected the previous day), or frozen (from anywhere in the world, and possibly as venerable as twenty years old). Why would you artificially inseminate fresh semen, if the dog is right there? Some bitches can be cranky if they don’t approve of the dog on offer, and there can be violence. The owner of an expensive (or well loved!) stud dog might not wish to risk his injury.
Now it comes down to it. Many breeders will have spent thousands of dollars to get to this point. Some will have spent tens of thousands. They really, really want to have a successful impregnation. The fresher the semen, the more reliable it is. If the best possible sire is only providing frozen semen for whatever reason, the chances are significant that the bitch will not get knocked up. So what do you do?
On the bitch’s first fertile day, you use the frozen semen from the preferred sire. You hope that all her eggs get fertilized by this semen, but if some are left over, you call in the backup sire, someone local who can provide fresh semen. Hopefully any eggs that failed to get fertilized by the first sire will get handled by the second. You may well end up with puppies from each sire in the litter, but that’s fine; you can DNA test them to know who’s sired by whom. And that is how a puppy can have two daddies, or, at least, a litter can.
(Note: I skipped over the numerous ethical issues brought up in this story. For today, I just wanted to share with you some of the surprising tools available to dog breeders today.)
Monday, July 11, 2011
Neurology rotation
I just completed my two-week neurology rotation. You might think that, because I love dog brains, this would have been right up my alley. Actually, I love the parts of brains that help us learn, fear, trust, and love. Veterinary neurology, on the other hand, is a big game of Hunt the Lesion. A dog comes in uncoordinated and with a head tilt. Where in its brain, cranial nerves, or spinal cord is the problem?
A good neurologic exam can localize the problem to the cerebrum, the cerebellum, one or more of the cranial nerves, the spinal cord in front of the front legs, the spinal cord over the front legs, the spinal cord between the front and back legs, the spinal cord over the back legs, the spinal cord behind the back legs, or something more general (a diffuse muscle, nerve, or muscle/nerve junction problem). Once we had an idea where the problem was, we usually sent the animal in to the MRI scanner (a luxury at a large referral hospital; we received a lot of animals coming in just for the MRI, referred from places that don’t have them). This allowed us to see exactly where the lesion was, and to get some information about what kind of lesion it was (intervertebral disc extruded into the spinal canal? A stroke? Cancer?).
I did enjoy neurology, even though Hunt the Lesion isn’t my favorite game. There was a surprising amount of basic medicine to learn; I got a lot more comfortable with how to manage post-surgical animals (we did lots of vertebral surgeries), as well as how to approach a diagnosis (young animals are more likely to have congenital or infectious problems or to have eaten toxins; older animals are more at risk for stroke or cancer). Practicing basic medicine is always good! So it was an enjoyable rotation, but now I am really looking forward to my upcoming four whole weeks of elective time.
A good neurologic exam can localize the problem to the cerebrum, the cerebellum, one or more of the cranial nerves, the spinal cord in front of the front legs, the spinal cord over the front legs, the spinal cord between the front and back legs, the spinal cord over the back legs, the spinal cord behind the back legs, or something more general (a diffuse muscle, nerve, or muscle/nerve junction problem). Once we had an idea where the problem was, we usually sent the animal in to the MRI scanner (a luxury at a large referral hospital; we received a lot of animals coming in just for the MRI, referred from places that don’t have them). This allowed us to see exactly where the lesion was, and to get some information about what kind of lesion it was (intervertebral disc extruded into the spinal canal? A stroke? Cancer?).
I did enjoy neurology, even though Hunt the Lesion isn’t my favorite game. There was a surprising amount of basic medicine to learn; I got a lot more comfortable with how to manage post-surgical animals (we did lots of vertebral surgeries), as well as how to approach a diagnosis (young animals are more likely to have congenital or infectious problems or to have eaten toxins; older animals are more at risk for stroke or cancer). Practicing basic medicine is always good! So it was an enjoyable rotation, but now I am really looking forward to my upcoming four whole weeks of elective time.
Sunday, July 3, 2011
Bringing them back from the edge
When I was on my small animal medicine rotation a few months ago, I had a patient with bad kidney disease. This little dog was sixteen years old — about a hundred years in human terms — and very frail and thin. I got into the habit of calling her “Grandmother,” because she seemed so venerable. None of us had very high hopes for her long term recovery, not even her owner; we were just trying to give her a shot at a few more weeks of life by rehydrating her with IV fluids.
Two of the residents disagreed about our goals for this dog. One of them wanted to send her home as soon as possible, arguing that she didn’t have much time left and shouldn’t spend it in the hospital. The other argued that we should give the dog a few more days to wean her off of her IV fluids properly before sending her home, to give her the best chance. The second resident ended up handling the case, and the dog stayed in the hospital for those few extra days for some extra care before going home.
This week I encountered the same dog (and the same resident) in the hospital for a recheck. I hardly recognized the dog, and not just because I had never expected to see her again. She had put on weight and looked filled out and healthy. She was moving around the hospital under her own steam (when she was my patient, I had had to carry her outside to pee) with a happy trot. She was bright-eyed and curious. Her owner reported that she was even playing sometimes.
“Look,” the resident said, “sometimes we really can bring them back from the edge.”
At age sixteen, this dog doesn’t have much time left no matter how you look at it, but that doesn’t mean it was time to give up on her. The lesson had personal meaning for me. My fifteen year old cat, Kai, is currently battling kidney disease, heart disease, and stomach cancer (gastric lymphoma). Each of these diseases is serious; each has almost killed him at one point. Each time I have to decide whether to continue with him, I ask myself whether I am being silly, whether it is time to give up. The treatments are not invasive, but is there any point to them when I may just have weeks left with him? Then I look at how good his quality of life is (he steals food off my plate, sneaks outside when I am not looking and eats things he shouldn’t in my back yard, and uses foul language to tell the dogs what he thinks of them) and remember the lesson of the little sixteen year old dog. Sometimes, even when things look bleak, animals can make a remarkable recovery for a little while. If the treatments are not invasive and the animal is not in pain, it can be worth trying.
Two of the residents disagreed about our goals for this dog. One of them wanted to send her home as soon as possible, arguing that she didn’t have much time left and shouldn’t spend it in the hospital. The other argued that we should give the dog a few more days to wean her off of her IV fluids properly before sending her home, to give her the best chance. The second resident ended up handling the case, and the dog stayed in the hospital for those few extra days for some extra care before going home.
This week I encountered the same dog (and the same resident) in the hospital for a recheck. I hardly recognized the dog, and not just because I had never expected to see her again. She had put on weight and looked filled out and healthy. She was moving around the hospital under her own steam (when she was my patient, I had had to carry her outside to pee) with a happy trot. She was bright-eyed and curious. Her owner reported that she was even playing sometimes.
“Look,” the resident said, “sometimes we really can bring them back from the edge.”
At age sixteen, this dog doesn’t have much time left no matter how you look at it, but that doesn’t mean it was time to give up on her. The lesson had personal meaning for me. My fifteen year old cat, Kai, is currently battling kidney disease, heart disease, and stomach cancer (gastric lymphoma). Each of these diseases is serious; each has almost killed him at one point. Each time I have to decide whether to continue with him, I ask myself whether I am being silly, whether it is time to give up. The treatments are not invasive, but is there any point to them when I may just have weeks left with him? Then I look at how good his quality of life is (he steals food off my plate, sneaks outside when I am not looking and eats things he shouldn’t in my back yard, and uses foul language to tell the dogs what he thinks of them) and remember the lesson of the little sixteen year old dog. Sometimes, even when things look bleak, animals can make a remarkable recovery for a little while. If the treatments are not invasive and the animal is not in pain, it can be worth trying.
Tuesday, June 14, 2011
How to give a horse his eye medications, or, What is an SPL?
One of my patients on my Large Animal Medicine rotation had a very sick eye, for which he needed approximately 9187346 medications every few hours. Getting eye meds into a horse is not easy. Their eyelid muscles are so strong that we routinely nerve block their eyelids before doing eye exams, because otherwise it would be impossible to hold their eyes open. This is, of course, not practical for hourly medications. But they hate having things put in their eyes (who doesn’t?), and they can throw their heads up very high in addition to squeezing their eyes tightly shut. This particular horse was especially tall, as well, and could hold his head well out of my arm’s reach.
The solution in these cases is to put in a sub-palpebral lavage (SPL). “Palpebral” is the science word for “having to do with eyelids,” so an SPL enables you to lavage (wash) underneath an eyelid. This is how it works: you take a big needle, which you stick through the horse’s upper eyelid coming from the underside (the side facing the eye). You use the needle to pull a slender tube through the eyelid, so that its end is sticking just under the eyelid, and the rest of the tube runs up over the horse’s head and down its neck. You affix the far end of the tube to the horse’s mane, with an injection cap on the end. In my hospital, a popsicle stick is involved in the tube/injection cap/mane connection, to stabilize the entire apparatus.
Now when you want to give an eye drop, you can use a syringe and needle to inject it through the injection cap into the tube. You then inject air after it to push it through the long tube and into the horse’s eye. They do find this annoying, and once they learn the routine, will dance around in an attempt to not let you actually stick the needle into the injection cap on their neck. However, getting at their neck is worlds easier than getting at their eye. My patient was relatively good for the whole thing, so that I could do it without asking anyone else to hold his head. He always got a cookie after each medication administration (which added up to a lot of cookies in the end). When it was over he would immediately stick his nose agaist my shirt to get his treat. The SPL was annoying for all concerned, but so much better than the alternative.
The solution in these cases is to put in a sub-palpebral lavage (SPL). “Palpebral” is the science word for “having to do with eyelids,” so an SPL enables you to lavage (wash) underneath an eyelid. This is how it works: you take a big needle, which you stick through the horse’s upper eyelid coming from the underside (the side facing the eye). You use the needle to pull a slender tube through the eyelid, so that its end is sticking just under the eyelid, and the rest of the tube runs up over the horse’s head and down its neck. You affix the far end of the tube to the horse’s mane, with an injection cap on the end. In my hospital, a popsicle stick is involved in the tube/injection cap/mane connection, to stabilize the entire apparatus.
Now when you want to give an eye drop, you can use a syringe and needle to inject it through the injection cap into the tube. You then inject air after it to push it through the long tube and into the horse’s eye. They do find this annoying, and once they learn the routine, will dance around in an attempt to not let you actually stick the needle into the injection cap on their neck. However, getting at their neck is worlds easier than getting at their eye. My patient was relatively good for the whole thing, so that I could do it without asking anyone else to hold his head. He always got a cookie after each medication administration (which added up to a lot of cookies in the end). When it was over he would immediately stick his nose agaist my shirt to get his treat. The SPL was annoying for all concerned, but so much better than the alternative.
Saturday, June 4, 2011
Shelter medicine externship
I recently spent two weeks of elective time at a shelter medicine externship at a different vet school. Half the time was spent in academic pursuits on campus — going to journal club, going to talks and lectures about shelter medicine, etc. The other half was at the shelter, doing high volume spay/neuter, temperament tests, treating sick animals.
Highlights:
Highlights:
- Pulling worms out of a kitten’s butt (“Wow, can I?”)
- STRAY GOLDFISH. It is more amusing not to explain, but I will say that it was found in a ditch in a grocery store parking lot.
- Ratlings! Five week old foster rats came in for a visit. They had been well socialized and were extremely friendly. I badly wanted to adopt one, but suspected it would not get along with my cat.
- Seeing exactly how fast 8 week old kittens recover from spay/neuter surgery. Spay surgery is no small deal, but those girl kittens were literally climbing the walls of their cage 30 minutes later. I am sold on pediatric spay/neuter.
- Helping to set up play groups of shelter dogs and getting to watch them play together. It was lovely.
Sunday, May 29, 2011
$200 worth of oops
This Saturday I was “on duty” in the large animal hospital, meaning that I was in the hospital for about 12 hours, theoretically helping with the treatments on all the animals (mostly horses, but we have gotten a few baby alpacas, or crias), along with one of my rotation mates. I say ”theoretically” because in practice, I just worked on my actual patient, a post-colic surgery horse who was extremely time consuming. My rotation mate and the techs handled the other animals, who needed many fewer treatments.
My horse was hooked up to a bunch of bags of IV fluids. In our large animal hospital, we suspend all the fluids from a hanger on the ceiling, and they run along coiled (therefore extendable) lines into a catheter in the horse’s neck. This way the horse can walk around his stall without getting his legs tangled, although the lines will inevitably tangle among themselves if you have multiple of them, which this guy definitely does. And with horses, the amounts of fluids and medications going in are fabulous. He had two five-liter bags of fluids hung at all times, plus a one liter bag of antibiotics, and a one liter bag of painkillers. This is aside from the medications I needed to inject into his catheter periodically, plus the oral meds I had to put down the tube which runs from his nose into his stomach.
The time came to change one of the bags of fluids. One of the techs stood outside the stall and lowered the hanger with all the bags. I removed the empty bag and hung the new one (with much grunting, as it was over my head and heavy). I disconnected the line from the old bag and went to connect it to the new bag — but since the line was also still connected to the second bag of fluids, it immediately started spewing saline all over the stall. I stuck my finger over the open tube to stop the flow just as the tech yelled “It’s sterile, don’t touch it!”
Well, I did know that you shouldn’t be sticking your finger over a sterile tube opening, but I had panicked and done it anyways. I stood there looking sheepish while the techs conferred. Yes, the line would have to be replaced. A new line cost $100. We obviously could not charge the client for this. The hospital would have to eat it. (The hospital is currently not profitable, which made me feel extra guilty.) These things happen when you are learning, but it is still super embarrassing. Also, changing the line was very complicated, and therefore annoying for the tech who did it.
Later in the day I was giving my horse his IV medications, injecting them into the new line. The second medication started turning into a solid powder inside the clear tube. It was precipitating! Just like in chemistry class! Except that that is bad to put into a horse’s bloodstream. I stopped and called a tech. I should have flushed the line with saline between injections. Oops. I flushed the line again and again to get all the precipitate out, but some was just too firmly adhered to the side of the tube. So, you guessed it, we had to change the line a second time, for another $100 eaten by the hospital.
So much to learn! So many embarrassing mistakes to make! I will never make these two mistakes again, though, I am pretty sure.
My horse was hooked up to a bunch of bags of IV fluids. In our large animal hospital, we suspend all the fluids from a hanger on the ceiling, and they run along coiled (therefore extendable) lines into a catheter in the horse’s neck. This way the horse can walk around his stall without getting his legs tangled, although the lines will inevitably tangle among themselves if you have multiple of them, which this guy definitely does. And with horses, the amounts of fluids and medications going in are fabulous. He had two five-liter bags of fluids hung at all times, plus a one liter bag of antibiotics, and a one liter bag of painkillers. This is aside from the medications I needed to inject into his catheter periodically, plus the oral meds I had to put down the tube which runs from his nose into his stomach.
The time came to change one of the bags of fluids. One of the techs stood outside the stall and lowered the hanger with all the bags. I removed the empty bag and hung the new one (with much grunting, as it was over my head and heavy). I disconnected the line from the old bag and went to connect it to the new bag — but since the line was also still connected to the second bag of fluids, it immediately started spewing saline all over the stall. I stuck my finger over the open tube to stop the flow just as the tech yelled “It’s sterile, don’t touch it!”
Well, I did know that you shouldn’t be sticking your finger over a sterile tube opening, but I had panicked and done it anyways. I stood there looking sheepish while the techs conferred. Yes, the line would have to be replaced. A new line cost $100. We obviously could not charge the client for this. The hospital would have to eat it. (The hospital is currently not profitable, which made me feel extra guilty.) These things happen when you are learning, but it is still super embarrassing. Also, changing the line was very complicated, and therefore annoying for the tech who did it.
Later in the day I was giving my horse his IV medications, injecting them into the new line. The second medication started turning into a solid powder inside the clear tube. It was precipitating! Just like in chemistry class! Except that that is bad to put into a horse’s bloodstream. I stopped and called a tech. I should have flushed the line with saline between injections. Oops. I flushed the line again and again to get all the precipitate out, but some was just too firmly adhered to the side of the tube. So, you guessed it, we had to change the line a second time, for another $100 eaten by the hospital.
So much to learn! So many embarrassing mistakes to make! I will never make these two mistakes again, though, I am pretty sure.
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