Are veterinary emergency clinics really crazier during full moons and Friday the 13ths? What about football games?

When I was an intern at the University of Pennsylvania’s School of Veterinary Medicine (way back in 1990), I had to cover quite a few emergency shifts. Some nights were quiet, and some nights were busy. Some were insanely, crazy busy. During those nights, invariably someone would say, “hey, it must be a full moon out tonight.” I never took notice of the phase of the moon on those hectic nights, but I always did wonder if there was any rhyme or reason to the spurts of craziness that we experienced on our emergency shifts.

The lunar cycle has long been implicated with influencing medical conditions. In fact, it is from the Roman goddess of the moon, Luna, and the belief that the power of the moon can influence the human mind that we get the term lunacy. The lunar cycle is characterized by periodic variation in the lit surface of the moon that is visible from Earth. One lunar cycle is 29.5 days. There are 8 phases of the cycle, as shown in the table below (insert the fuckin’ table here). A full moon occurs when the sun, the Earth, and the moon are aligned.

The first study that I’d seen published on the topic was in the July 15th ,2007 issue of the Journal of the American Veterinary Medical Association. This study reported on 11,949 dogs and cats presenting to Colorado State University’s emergency service over an eleven year period, from February 1992 to December 2002. (Full disclosure: I did my small animal internal medicine residency at CSU.) The results: the number of daily emergencies on full moon days was not significantly different from non-full moon days for either cats or dogs. There were, however, significant differences in the number of emergencies observed on fuller moon days compared with other days. The risk of emergencies on fuller moon days, compared with other days, was 23% greater in cats and 28% greater in dogs. Before we get all mystical and werewolfy about these findings, keep in mind that during fuller moon days, there is increased lunar luminosity. Cats and dogs may have more nocturnal activity during the fuller moon phases, leading to a higher likelihood of injury. It’s a good theory, and if it were true, you might expect more feline trauma cases on these nights. But this wasn’t evident. Well, wait a second. If it’s lighter out, you might actually expect LESS automobile trauma, no? Well, that wasn’t seen either. Okay, you can get werewolfy now.

Some more interesting observations were presented in a more recent report in the Journal of Veterinary Emergency and Critical Care. The article, “Association of holidays, full moon, Friday the 13th, time of day, day of week and time of year on case distribution in an urban referral small animal emergency clinic” assessed the case load over 5837 days. These included 212 full moons, 28 Friday the 13ths, and 147,295 emergency visits. There were a few interesting findings. Over the years that the study was conducted, the proportion of cats and dogs remained consistent, which was odd considering that cats have become more popular as household pets. One would have expected the percentage of cats presenting to the emergency clinic to have increased. Anyway…Sunday was the busiest day of the week. Saturday was next. The busiest holiday was Memorial Day, followed by New Years Day. As for Friday the 13th, Halloween, and full-moon days, they were NOT significantly busier than any other day. So… full moons, no. Fuller moons, yeah. Witches, pumpkins, Freddie Kruger, no.

In the July 2009 issue of the Journal of the AVMA, there was an article entitled “Effect of National Football League games on small animal emergency room caseload”. The objective of the study was to evaluate whether games of popular professional football teams have an effect on the small animal emergency room caseload and percentage of dogs and cats that subsequently are hospitalized, euthanized, or die following admission to veterinary emergency rooms located within a dedicated fan base. During the New England Patriots 2007 season, small animal emergency room caseload was recorded for Sunday in four-hour blocks (from 8:00 a.m. to 12 midnight) and Monday night (7:00 pm to 11:00 pm). The number of dogs and cats that were hospitalized, died, or were euthanized was recorded. They even ranked the importance of the game (1 was mildly important, 3 was greatly important).

The results: Looking at the day overall, i.e. comparing Sundays with a Patriots game vs. Sundays without a Patriots game, there was no effect on the number of small animal emergency visits (33.8 visits on Sundays without a game, 33.3 visits on Sundays with a game).

What about emergency admissions during the actual game time? Well, five games with a so-so importance (1.7 on the game importance ranking scale) were played on Sunday at 1:00. Twelve Sundays during the season did not have a game at 1:00. The game time ended up not having any effect on emergency room visits. The average number of dogs and cats brought to the emergency room from 12 to 4 pm on Sundays during Patriots games vs. the 12 to 4 pm period on Sundays where there was no Patriots game did not differ.

Here’s where it gets interesting:

Five games that were deemed pretty important (2.4 on the game-importance ranking) were played at 4:15 on Sunday. The average number of dogs and cats brought to the emergency room during these important Patriots games, during the 4:00 to 8:00 time slot was 18. On Sundays where there wasn’t an important Patriots game at 4:15, the number of admissions was 25. This is a significant difference.

Three games were played on Sunday at 8:15 pm. The number of emergency room visits during the 8 pm to midnight time slot during Patriots games did not differ when compared to admissions during 8:00 to midnight on non-Patriots game Sundays.

When they looked at game importance only, the importance of the games had no significant effect on the number of small animal emergency room visits. And there was no significant increase in emergency room caseload immediately following the conclusion of the 1:00 or 4:00 football games. It’s not like people were saying, “dang, my dog just vomited for the 19th time in the last hour, but I’m going to wait until the game is over before bringing him in”. In fact, there was no difference in severity of illness in the dogs and cats brought to the emergency room right after a game, suggesting that cats and dogs were not deteriorating medically at home while their owners were watching the football game.

The conclusion reached in the article was this: “Popular professional sporting events, particularly in geographic regions with a dedicated fan base, may affect the caseload of a veterinary emergency room and that staffing alterations may be warranted.” The finding that there were less admissions to the emergency room during important Patriots games kind of mirrors the findings in a recent study from the UK which showed a significant decreased in admission of children to a pediatric emergency room the weekend that a new Harry Potter book was released, presumably because children were busy reading rather than running around poking a stick in their playmate’s eye. They figure that dogs and cats are less likely to be traumatized while their owner are engrossed in a football game than perhaps they might be if they were out hiking with the dog.

In any event, the influence of football games, Halloween, lunar cycles and Friday the 13th on veterinary emergency visits looks pretty minimal at best. I’m just glad that my days of covering emergencies are over. As far as I’m concerned, all of those days were crazy and hectic and stressful. I much prefer my quiet, mellow non-stressful private kitty practice.

Quiet. Mellow. Non-stressful. Yeah, right.

When I was an intern at the University of Pennsylvania’s School of Veterinary Medicine (way back in 1990), I had to cover quite a few emergency shifts. Some nights were quiet, and some nights were busy. Some were insanely, crazy busy. During those nights, invariably someone would say, “hey, it must be a full moon out tonight.” I never took notice of the phase of the moon on those hectic nights, but I always did wonder if there was any rhyme or reason to the spurts of craziness that we experienced on our emergency shifts.

The lunar cycle has long been implicated with influencing medical conditions. In fact, it is from the Roman goddess of the moon, Luna, and the belief that the power of the moon can influence the human mind that we get the term lunacy. The lunar cycle is characterized by periodic variation in the lit surface of the moon that is visible from Earth. One lunar cycle is 29.5 days. There are 8 phases of the cycle, as shown in the table below (insert the fuckin’ table here). A full moon occurs when the sun, the Earth, and the moon are aligned.

The first study that I’d seen published on the topic was in the July 15th ,2007 issue of the Journal of the American Veterinary Medical Association. This study reported on 11,949 dogs and cats presenting to Colorado State University’s emergency service over an eleven year period, from February 1992 to December 2002. (Full disclosure: I did my small animal internal medicine residency at CSU.) The results: the number of daily emergencies on full moon days was not significantly different from non-full moon days for either cats or dogs. There were, however, significant differences in the number of emergencies observed on fuller moon days compared with other days. The risk of emergencies on fuller moon days, compared with other days, was 23% greater in cats and 28% greater in dogs. Before we get all mystical and werewolfy about these findings, keep in mind that during fuller moon days, there is increased lunar luminosity. Cats and dogs may have more nocturnal activity during the fuller moon phases, leading to a higher likelihood of injury. It’s a good theory, and if it were true, you might expect more feline trauma cases on these nights. But this wasn’t evident. Well, wait a second. If it’s lighter out, you might actually expect LESS automobile trauma, no? Well, that wasn’t seen either. Okay, you can get werewolfy now.

Some more interesting observations were presented in a more recent report in the Journal of Veterinary Emergency and Critical Care. The article, “Association of holidays, full moon, Friday the 13th, time of day, day of week and time of year on case distribution in an urban referral small animal emergency clinic” assessed the case load over 5837 days. These included 212 full moons, 28 Friday the 13ths, and 147,295 emergency visits. There were a few interesting findings. Over the years that the study was conducted, the proportion of cats and dogs remained consistent, which was odd considering that cats have become more popular as household pets. One would have expected the percentage of cats presenting to the emergency clinic to have increased. Anyway…Sunday was the busiest day of the week. Saturday was next. The busiest holiday was Memorial Day, followed by New Years Day. As for Friday the 13th, Halloween, and full-moon days, they were NOT significantly busier than any other day. So… full moons, no. Fuller moons, yeah. Witches, pumpkins, Freddie Kruger, no.

In the July 2009 issue of the Journal of the AVMA, there was an article entitled “Effect of National Football League games on small animal emergency room caseload”. The objective of the study was to evaluate whether games of popular professional football teams have an effect on the small animal emergency room caseload and percentage of dogs and cats that subsequently are hospitalized, euthanized, or die following admission to veterinary emergency rooms located within a dedicated fan base. During the New England Patriots 2007 season, small animal emergency room caseload was recorded for Sunday in four-hour blocks (from 8:00 a.m. to 12 midnight) and Monday night (7:00 pm to 11:00 pm). The number of dogs and cats that were hospitalized, died, or were euthanized was recorded. They even ranked the importance of the game (1 was mildly important, 3 was greatly important).

The results: Looking at the day overall, i.e. comparing Sundays with a Patriots game vs. Sundays without a Patriots game, there was no effect on the number of small animal emergency visits (33.8 visits on Sundays without a game, 33.3 visits on Sundays with a game).

What about emergency admissions during the actual game time? Well, five games with a so-so importance (1.7 on the game importance ranking scale) were played on Sunday at 1:00. Twelve Sundays during the season did not have a game at 1:00. The game time ended up not having any effect on emergency room visits. The average number of dogs and cats brought to the emergency room from 12 to 4 pm on Sundays during Patriots games vs. the 12 to 4 pm period on Sundays where there was no Patriots game did not differ.

Here’s where it gets interesting:

Five games that were deemed pretty important (2.4 on the game-importance ranking) were played at 4:15 on Sunday. The average number of dogs and cats brought to the emergency room during these important Patriots games, during the 4:00 to 8:00 time slot was 18. On Sundays where there wasn’t an important Patriots game at 4:15, the number of admissions was 25. This is a significant difference.

Three games were played on Sunday at 8:15 pm. The number of emergency room visits during the 8 pm to midnight time slot during Patriots games did not differ when compared to admissions during 8:00 to midnight on non-Patriots game Sundays.

When they looked at game importance only, the importance of the games had no significant effect on the number of small animal emergency room visits. And there was no significant increase in emergency room caseload immediately following the conclusion of the 1:00 or 4:00 football games. It’s not like people were saying, “dang, my dog just vomited for the 19th time in the last hour, but I’m going to wait until the game is over before bringing him in”. In fact, there was no difference in severity of illness in the dogs and cats brought to the emergency room right after a game, suggesting that cats and dogs were not deteriorating medically at home while their owners were watching the football game.

The conclusion reached in the article was this: “Popular professional sporting events, particularly in geographic regions with a dedicated fan base, may affect the caseload of a veterinary emergency room and that staffing alterations may be warranted.” The finding that there were less admissions to the emergency room during important Patriots games kind of mirrors the findings in a recent study from the UK which showed a significant decreased in admission of children to a pediatric emergency room the weekend that a new Harry Potter book was released, presumably because children were busy reading rather than running around poking a stick in their playmate’s eye. They figure that dogs and cats are less likely to be traumatized while their owner are engrossed in a football game than perhaps they might be if they were out hiking with the dog.

In any event, the influence of football games, Halloween, lunar cycles and Friday the 13th on veterinary emergency visits looks pretty minimal at best. I’m just glad that my days of covering emergencies are over. As far as I’m concerned, all of those days were crazy and hectic and stressful. I much prefer my quiet, mellow non-stressful private kitty practice.

Quiet. Mellow. Non-stressful. Yeah, right.

reade more... Résuméabuiyad

Reader Question: What Vaccines Should My Kitten Have?

What Vaccines Should My Kitten Have?
CatChannel veterinary expert Arnold Plotnick, DVM, discusses pediatric vaccination series for cats.

Dr. Arnold Plotnick is one of CatChannel's feline health experts.

Q: I have a kitten. She is 12 to 16 weeks of age. She has not had any shots yet. What shots should I give her? Also, are the shots that you apply into eye & nose as effective as those given with a needle? I will be administering these shots myself and wanted to know the safest and easiest way.

A: Ideally, the kitten vaccination series should begin when kittens are 9 weeks of age. Kittens should be vaccinated against  panleukopenia virus, herpesvirus, and calicivirus (These viruses are usually combined into a single vaccine, commonly abbreviated “FVRCP”). A second vaccine is given 3 to 4 weeks later, and another 3 to 4 weeks after that. You’ve already gone past that ideal first vaccination age. Let’s assume she’s 12 weeks old. Give her the first FVRCP now. In about 4 weeks, give her another FVRCP vaccine, and her rabies vaccine. That should complete her pediatric vaccination series.

The intranasal vaccine is not the ideal vaccine for your cat. The intranasal vaccine is usually given to cats in multi-cat environments, e.g. shelters or catteries that are experiencing or are at increased risk for an outbreak of viral upper respiratory infections. The intranasal vaccine induces more rapid immunity than the injectible vaccine, and can be given to kittens as young as 4 weeks of age. For a pet kitten in a clean, noncrowded environment, the injectable vaccine is preferred. Most people feel that although the intranasal vaccine provides a more rapid induction of the immune response, the immunity conferred is not as durable, especially in regard to the panleukopenia virus component of the vaccine.

What Vaccines Should My Kitten Have?
CatChannel veterinary expert Arnold Plotnick, DVM, discusses pediatric vaccination series for cats.

Dr. Arnold Plotnick is one of CatChannel's feline health experts.

Q: I have a kitten. She is 12 to 16 weeks of age. She has not had any shots yet. What shots should I give her? Also, are the shots that you apply into eye & nose as effective as those given with a needle? I will be administering these shots myself and wanted to know the safest and easiest way.

A: Ideally, the kitten vaccination series should begin when kittens are 9 weeks of age. Kittens should be vaccinated against  panleukopenia virus, herpesvirus, and calicivirus (These viruses are usually combined into a single vaccine, commonly abbreviated “FVRCP”). A second vaccine is given 3 to 4 weeks later, and another 3 to 4 weeks after that. You’ve already gone past that ideal first vaccination age. Let’s assume she’s 12 weeks old. Give her the first FVRCP now. In about 4 weeks, give her another FVRCP vaccine, and her rabies vaccine. That should complete her pediatric vaccination series.

The intranasal vaccine is not the ideal vaccine for your cat. The intranasal vaccine is usually given to cats in multi-cat environments, e.g. shelters or catteries that are experiencing or are at increased risk for an outbreak of viral upper respiratory infections. The intranasal vaccine induces more rapid immunity than the injectible vaccine, and can be given to kittens as young as 4 weeks of age. For a pet kitten in a clean, noncrowded environment, the injectable vaccine is preferred. Most people feel that although the intranasal vaccine provides a more rapid induction of the immune response, the immunity conferred is not as durable, especially in regard to the panleukopenia virus component of the vaccine.

reade more... Résuméabuiyad

Ragdoll Cardiomyopathy and Little Tular - The Ongoing Story

Hypertrophic cardiomyopathy (HCM) is the most common heart disease in cats. In most cats the condition develops spontaneously, for no known reason. In Maine Coons and Ragdolls, however, the disease has an inherited basis, and the genetic mutations responsible have now been identified in both breeds.

The mutation responsible for HCM in Maine Coons has been identified in the gene that codes for a protein called myosin binding protein C (MYBPC3). This protein is necessary for the heart to contract properly. Maine Coons who have this genetic mutation produce an abnormal form of this protein, resulting in dysfunctional contraction of the cardiac muscle.

The Ragdoll cat also has an inherited form of HCM. The genetic mutation also involves the gene that codes for myosin binding protein C (MYBPC3). The mutations in these two breeds did not arise from a common ancestor, because on a molecular level, the mutations are very different and are located in very different regions of the gene for each breed.

The genetics behind HCM in Ragdolls and Maine Coons is complicated. Cats have two copies of every gene – one from each parent. The inherited form of HCM in Maine Coons is an “autosomal dominant” trait. This means that males and females are equally susceptible; every affected cat has at least one affected parent; and the trait is observed in every generation. Maine Coons may carry the mutation on one or both copies of the gene. If they have the mutation on both copies of the gene, they are said to be “homozygous” for the mutation. If bred, they will pass one copy of the mutated gene to all of their offspring. If only one copy of the gene has the mutation, with the other copy being normal, they are said to be “heterozygous” for the mutation. Heterozygous cats, if bred, will produce offspring with a 50% chance of having the gene. Note that this does not mean that 50% of the kittens will carry the gene. Rather, each kitten has a 50% chance of having the mutation. Some litters may end up with 0% having the mutation; others may have 100%. To further complicate matters, the gene is inherited with “incomplete penetrance”. This means that cats who have the mutation will have different degrees of severity of HCM, depending on the “penetrance” of the trait. Some cats with the gene may develop severe cardiac disease, while others may never show any clinical signs of illness. The mode of inheritance has not been completely elucidated in Ragdolls but it is believed to be autosomal dominant as well.
Maine Coons who are homozygous for the gene (two copies of the mutated gene) may develop a more severe form of HCM, often showing signs of the disease before the age of 4. Heterozygous cats (one copy of the mutated gene) develop HCM at a later age and tend to have milder disease.

Ragdolls that are homozygous for the mutation develop a severe form of the disease, often succumbing to heart failure before the age of 2. Heterozygous cats develop a much milder form of the disease.

In early November of 2009, I examined Tular, a 14 month-old Ragdoll belonging to Laura Piskin. Ms. Piskin was concerned because Tular kept getting upper respiratory infections that responded to antibiotics initially, but never seemed to fully resolve.

On physical examination, the cat was 8 ½ lbs. She had mild upper respiratory signs – a few sneezes, but hardly any eye or nasal discharge. No fever. All body systems checked out okay except… she had a heart murmur. We like to grade heart murmurs on their intensity, on a scale from 1 to 6. This was a 2 out of 6. Not very loud, but definitely present. And, the fact that she was a Ragdoll had me concerned. I recommended a cardiac ultrasound, and Ms. Piskin readily agreed.

Two weeks later, the ultrasound was performed. The mitral valve (the valve on the left side of the heart that separates the left atrium from the left ventricle) wasn’t closing perfectly. This was the cause of the murmur, and is a pretty minor problem. Of potentially greater consequence, however, was another finding: the wall of left ventricle was a little bit thicker than normal. Thickening of the ventricle is the cardinal sign of hypertrophic cardiomyopathy (HCM). Also, the papillary muscle (a piece of muscle that branches off the inside wall of the ventricle) was a little thickened as well.

Was this the start of a progressive heart problem? Or was this normal for this particular cat? It’s hard to say, based on just one ultrasound. In order to tell, you have to repeat the ultrasound in a few months and see if there is any progression. The ultrasonographer noted that the heart was functioning perfectly normally, and he recommended no medicine at this time.

I was curious, though. Heterozygous Ragdolls (those with only one copy of the mutated gene) often develop only a mild form of HCM, with one of the features being mild papillary muscle thickening. Homozygous Ragdolls (those with two copies of the mutated gene) usually develop a more severe form of the disease and tend to go into heart failure at a very young age. So how do we know if Tular was heterozygous or homozygous?

Genetic testing is available to test Maine Coons and Ragdolls for the presence of the mutation. A DNA specimen is required. This is accomplished using blood, or using a cotton swab that has been rubbed on the gums or inside the cheek. The cheek swab is especially useful for testing young kittens from whom it might be difficult to obtain a blood sample. Testing will determine whether the cat is heterozygous, homozygous, or negative for the mutation. If a Maine Coon or Ragdoll tests negative for the mutation, it does not mean that the cat will never develop HCM. Rather, it means that they will not develop the form of HCM that is known to be caused by the specific gene mutation.

Results reported from genetic testing laboratories have revealed that the worldwide prevalence of the gene in Maine Coon cats is 35%, i.e. approximately 1 out of 3 Maine Coons carry the gene. Of the Maine Coons carrying the gene, only 9% are homozygous. The prevalence in Ragdolls is 28%, with only 8% being homozygous.
I asked Ms. Piskin if she wanted me to test her cat. I guess this is where the internal philosophical debate begins. If you have the opportunity to run a test that tells you if your cat is doomed, do you do it? Or would you rather not know? Ms. Piskin was undecided. She said she’d get back to me with her decision.

A few weeks later, she called. “Let’s do it”, she said. “Not knowing is making me crazy.”

I obtained a blood sample from Tular and sent it to Washington State University . Given the statistics – 92% of Ragdolls with the mutation are heterozygous, and only 8% are homozygous – I was feeling optimistic that Tular would be heterozygous and that we would ultrasound the heart every six months and track the progression, prescribing or adjusting medication as necessary. Unfortunately, this was not to be. Tular was homozygous; she had two copies of the mutated gene.

Ms. Piskin was very upset, as you could imagine. She called the breeder. The breeder felt terrible about it. She tried to make amends by offering her another Ragdoll, but this was no consolation, of course. In fact, Ms. Piskin found the offer insulting, as if you can simply replace a cat, months after you’ve lived with it and bonded with it. Given Tular’s results and the poor prognosis that comes with it, we elected to do another ultrasound, three months after the initial one.

The second ultrasound, unfortunately, showed significant progression of the heart disease. The thickness of the ventricle went from 0.84 cm to 1.03 cm. The left atrium increased in size from 1.5 cm to 1.7 cm. The increased size of the atrium is a concern because if the atrium gets too big, blood has a tendency to swirl around in the atrium rather than flow through it, and a blood clot can form. If a blood clot forms and a piece of the clot breaks off and travels down the aorta, it can be disastrous. Unfortunately, Ragdolls who are homozygous for the mutation are prone to these type of events.

The plan: we started Tular on heart medication. One drug we’re giving is enalapril, a drug that will dilate the aorta, encouraging more blood to flow out of the aorta rather than back through the leaky mitral valve. The other two drugs we’re giving are a baby aspirin every three days, and Plavix. The aspirin and Plavix are intended to make the blood less likely to clot.

It would be ideal if all cats carrying the mutation could be removed from breeding programs, however, the high prevalence of the mutation in both Maine Coons and Ragdolls would make this difficult. Bearing in mind that not all cats carrying the mutation (especially heterozygous cats) will develop a clinical form of the disease, a more realistic approach would be to remove homozygous cats from the breeding population, because they have the highest risk of developing HCM and they will pass the mutation to all of their offspring. Heterozygous cats, if bred, should be used only if they have exceptional breed attributes and are free of clinical disease at the time of breeding (suggesting that the cat may have a less penetrant form of the disease).

If they develop clinical HCM later in life, they should be removed from the breeding program. Ideally, they would be bred only to cats that are free of the mutation. Kittens born from the mating of a heterozygous and a negative cat should be genetically tested. If a mutation-negative kitten has the desirable traits of the parents, the kitten should be chosen to replace the mutation-positive parent in the breeding colony. In this fashion, the mutation can be slowly eradicated from the breed without drastically altering the genetic makeup of the breed.

Tular is doing well at the moment. Her next cardiac ultrasound is scheduled to be performed in 3 months. I will keep my readers updated as to Tular’s progress.

Hypertrophic cardiomyopathy (HCM) is the most common heart disease in cats. In most cats the condition develops spontaneously, for no known reason. In Maine Coons and Ragdolls, however, the disease has an inherited basis, and the genetic mutations responsible have now been identified in both breeds.

The mutation responsible for HCM in Maine Coons has been identified in the gene that codes for a protein called myosin binding protein C (MYBPC3). This protein is necessary for the heart to contract properly. Maine Coons who have this genetic mutation produce an abnormal form of this protein, resulting in dysfunctional contraction of the cardiac muscle.

The Ragdoll cat also has an inherited form of HCM. The genetic mutation also involves the gene that codes for myosin binding protein C (MYBPC3). The mutations in these two breeds did not arise from a common ancestor, because on a molecular level, the mutations are very different and are located in very different regions of the gene for each breed.

The genetics behind HCM in Ragdolls and Maine Coons is complicated. Cats have two copies of every gene – one from each parent. The inherited form of HCM in Maine Coons is an “autosomal dominant” trait. This means that males and females are equally susceptible; every affected cat has at least one affected parent; and the trait is observed in every generation. Maine Coons may carry the mutation on one or both copies of the gene. If they have the mutation on both copies of the gene, they are said to be “homozygous” for the mutation. If bred, they will pass one copy of the mutated gene to all of their offspring. If only one copy of the gene has the mutation, with the other copy being normal, they are said to be “heterozygous” for the mutation. Heterozygous cats, if bred, will produce offspring with a 50% chance of having the gene. Note that this does not mean that 50% of the kittens will carry the gene. Rather, each kitten has a 50% chance of having the mutation. Some litters may end up with 0% having the mutation; others may have 100%. To further complicate matters, the gene is inherited with “incomplete penetrance”. This means that cats who have the mutation will have different degrees of severity of HCM, depending on the “penetrance” of the trait. Some cats with the gene may develop severe cardiac disease, while others may never show any clinical signs of illness. The mode of inheritance has not been completely elucidated in Ragdolls but it is believed to be autosomal dominant as well.
Maine Coons who are homozygous for the gene (two copies of the mutated gene) may develop a more severe form of HCM, often showing signs of the disease before the age of 4. Heterozygous cats (one copy of the mutated gene) develop HCM at a later age and tend to have milder disease.

Ragdolls that are homozygous for the mutation develop a severe form of the disease, often succumbing to heart failure before the age of 2. Heterozygous cats develop a much milder form of the disease.

In early November of 2009, I examined Tular, a 14 month-old Ragdoll belonging to Laura Piskin. Ms. Piskin was concerned because Tular kept getting upper respiratory infections that responded to antibiotics initially, but never seemed to fully resolve.

On physical examination, the cat was 8 ½ lbs. She had mild upper respiratory signs – a few sneezes, but hardly any eye or nasal discharge. No fever. All body systems checked out okay except… she had a heart murmur. We like to grade heart murmurs on their intensity, on a scale from 1 to 6. This was a 2 out of 6. Not very loud, but definitely present. And, the fact that she was a Ragdoll had me concerned. I recommended a cardiac ultrasound, and Ms. Piskin readily agreed.

Two weeks later, the ultrasound was performed. The mitral valve (the valve on the left side of the heart that separates the left atrium from the left ventricle) wasn’t closing perfectly. This was the cause of the murmur, and is a pretty minor problem. Of potentially greater consequence, however, was another finding: the wall of left ventricle was a little bit thicker than normal. Thickening of the ventricle is the cardinal sign of hypertrophic cardiomyopathy (HCM). Also, the papillary muscle (a piece of muscle that branches off the inside wall of the ventricle) was a little thickened as well.

Was this the start of a progressive heart problem? Or was this normal for this particular cat? It’s hard to say, based on just one ultrasound. In order to tell, you have to repeat the ultrasound in a few months and see if there is any progression. The ultrasonographer noted that the heart was functioning perfectly normally, and he recommended no medicine at this time.

I was curious, though. Heterozygous Ragdolls (those with only one copy of the mutated gene) often develop only a mild form of HCM, with one of the features being mild papillary muscle thickening. Homozygous Ragdolls (those with two copies of the mutated gene) usually develop a more severe form of the disease and tend to go into heart failure at a very young age. So how do we know if Tular was heterozygous or homozygous?

Genetic testing is available to test Maine Coons and Ragdolls for the presence of the mutation. A DNA specimen is required. This is accomplished using blood, or using a cotton swab that has been rubbed on the gums or inside the cheek. The cheek swab is especially useful for testing young kittens from whom it might be difficult to obtain a blood sample. Testing will determine whether the cat is heterozygous, homozygous, or negative for the mutation. If a Maine Coon or Ragdoll tests negative for the mutation, it does not mean that the cat will never develop HCM. Rather, it means that they will not develop the form of HCM that is known to be caused by the specific gene mutation.

Results reported from genetic testing laboratories have revealed that the worldwide prevalence of the gene in Maine Coon cats is 35%, i.e. approximately 1 out of 3 Maine Coons carry the gene. Of the Maine Coons carrying the gene, only 9% are homozygous. The prevalence in Ragdolls is 28%, with only 8% being homozygous.
I asked Ms. Piskin if she wanted me to test her cat. I guess this is where the internal philosophical debate begins. If you have the opportunity to run a test that tells you if your cat is doomed, do you do it? Or would you rather not know? Ms. Piskin was undecided. She said she’d get back to me with her decision.

A few weeks later, she called. “Let’s do it”, she said. “Not knowing is making me crazy.”

I obtained a blood sample from Tular and sent it to Washington State University . Given the statistics – 92% of Ragdolls with the mutation are heterozygous, and only 8% are homozygous – I was feeling optimistic that Tular would be heterozygous and that we would ultrasound the heart every six months and track the progression, prescribing or adjusting medication as necessary. Unfortunately, this was not to be. Tular was homozygous; she had two copies of the mutated gene.

Ms. Piskin was very upset, as you could imagine. She called the breeder. The breeder felt terrible about it. She tried to make amends by offering her another Ragdoll, but this was no consolation, of course. In fact, Ms. Piskin found the offer insulting, as if you can simply replace a cat, months after you’ve lived with it and bonded with it. Given Tular’s results and the poor prognosis that comes with it, we elected to do another ultrasound, three months after the initial one.

The second ultrasound, unfortunately, showed significant progression of the heart disease. The thickness of the ventricle went from 0.84 cm to 1.03 cm. The left atrium increased in size from 1.5 cm to 1.7 cm. The increased size of the atrium is a concern because if the atrium gets too big, blood has a tendency to swirl around in the atrium rather than flow through it, and a blood clot can form. If a blood clot forms and a piece of the clot breaks off and travels down the aorta, it can be disastrous. Unfortunately, Ragdolls who are homozygous for the mutation are prone to these type of events.

The plan: we started Tular on heart medication. One drug we’re giving is enalapril, a drug that will dilate the aorta, encouraging more blood to flow out of the aorta rather than back through the leaky mitral valve. The other two drugs we’re giving are a baby aspirin every three days, and Plavix. The aspirin and Plavix are intended to make the blood less likely to clot.

It would be ideal if all cats carrying the mutation could be removed from breeding programs, however, the high prevalence of the mutation in both Maine Coons and Ragdolls would make this difficult. Bearing in mind that not all cats carrying the mutation (especially heterozygous cats) will develop a clinical form of the disease, a more realistic approach would be to remove homozygous cats from the breeding population, because they have the highest risk of developing HCM and they will pass the mutation to all of their offspring. Heterozygous cats, if bred, should be used only if they have exceptional breed attributes and are free of clinical disease at the time of breeding (suggesting that the cat may have a less penetrant form of the disease).

If they develop clinical HCM later in life, they should be removed from the breeding program. Ideally, they would be bred only to cats that are free of the mutation. Kittens born from the mating of a heterozygous and a negative cat should be genetically tested. If a mutation-negative kitten has the desirable traits of the parents, the kitten should be chosen to replace the mutation-positive parent in the breeding colony. In this fashion, the mutation can be slowly eradicated from the breed without drastically altering the genetic makeup of the breed.

Tular is doing well at the moment. Her next cardiac ultrasound is scheduled to be performed in 3 months. I will keep my readers updated as to Tular’s progress.

reade more... Résuméabuiyad

How To Store and Organize Your Cats (pics)

How To Store and Organize Your Cats

How To Store and Organize Your Cats

reade more... Résuméabuiyad

Pet Life Radio - www.PetLifeRadio.com

PET PODCASTS on PetLifeRadio.com

The #1 pet podcast radio network on the planet! Pet Life Radio offers free pet podcasts and downloads from the PetLifeRadio.com website, as well as pet podcasts through iTunes, Podcast Alley, Odeo, Pod-planet, Pod Nova, Podcast Pickle, Podcasting Station, Podanza and other major podcast portals! You can even subscribe to our pet podcasts with Foneshow and Melodeo and have them downloaded right into your cell phone!

Pet Life Radio is the ultimate audio pet lovers forum. Enjoy great pet podcasts, podcasts for pet lovers, and pet podcasts from the experts about everything for your dogs, cats, birds, fish or exotic pets! Every pet podcast features great information about pet care, pet health, and interviews with the top pet professionals!

Oh Behave ! - with Arden Moore
Check out Cat Man Do's episode "Sex and the Kitty"

Dr. Arnold Plotnick......................................

Shine the spotlight on cats – and discover why felines find Dr. Arnold Plotnick so fab-u-lous! Dr. Arnie, one of America’s renowned feline medicine experts, chats about the perks of being a gay vet in Manhattan, what it is like to be a guest on the Martha Stewart Show and why he digs cats so much. Are you ready? Then let’s get catty!

Follow PetLife Radio:

PET PODCASTS on PetLifeRadio.com

The #1 pet podcast radio network on the planet! Pet Life Radio offers free pet podcasts and downloads from the PetLifeRadio.com website, as well as pet podcasts through iTunes, Podcast Alley, Odeo, Pod-planet, Pod Nova, Podcast Pickle, Podcasting Station, Podanza and other major podcast portals! You can even subscribe to our pet podcasts with Foneshow and Melodeo and have them downloaded right into your cell phone!

Pet Life Radio is the ultimate audio pet lovers forum. Enjoy great pet podcasts, podcasts for pet lovers, and pet podcasts from the experts about everything for your dogs, cats, birds, fish or exotic pets! Every pet podcast features great information about pet care, pet health, and interviews with the top pet professionals!

Oh Behave ! - with Arden Moore
Check out Cat Man Do's episode "Sex and the Kitty"

Dr. Arnold Plotnick......................................

Shine the spotlight on cats – and discover why felines find Dr. Arnold Plotnick so fab-u-lous! Dr. Arnie, one of America’s renowned feline medicine experts, chats about the perks of being a gay vet in Manhattan, what it is like to be a guest on the Martha Stewart Show and why he digs cats so much. Are you ready? Then let’s get catty!

Follow PetLife Radio:

reade more... Résuméabuiyad