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Sunday, July 27, 2014

Does Trap-Neuter-Release Help Feral Cat Populations?

TNR programs (Trap-Neuter-Release) are common in many Western countries as a way to control feral cat populations.  The idea is that when there is a community of wild, unowned domesticated cats we can help reduce and eliminate this population by capturing them, testing for certain diseases, vaccinating, spaying and neutering them, then returning them to the wild.  Advocates of this policy believe that simply capturing and euthanizing these cats provides a vaccuum in the population which allows new cats to enter and continue the process.  They also believe that this is the most human method of handling feral cats.  But does this really work?
Unfortunately a growing number of studies is casting considerable doubt on the efficacy of such programs.  The stated goals of reducing the number of feral cats is rarely reduced unless there is considerable effort made.  In fact, studies have shown that in these cases populations tend to remain stable rather than decreasing.  The more that researchers have looked at the issue, the less support there is for the idea that TNR programs reduce feral populations.
Yet you'll find that most humane societies, animal control departments, and rescue groups support this idea, and even promote the position that it really does work.  If you simply look at the logic of procedure it really should work since you're removing breeding cats from a population yet keeping them there to compete for resources.  Unfortunately the reality of the situation doesn't tend to support this, and many of the studies quoted by such groups really don't provide data as the grops think they do.
Does that mean that TNR shouldn't be done?  Honestly, I'm on the fence about it.  You'd be hard-pressed to find anywhere in the world where an average TNR program has eliminated a population of feral cats.  By this evidence it really is a waste of money.  At the same time, we must be affecting populations by spaying and neutering, and hopefully reducing cats with FIV or feline leukemia by testing for and euthanizing those who are positive.  Maybe it's my heart rather than my mind that wants to believe in continuing them.  I still wonder if there are better ways to spend limited resources.
For more information here are a few links.  Read through them, compare the data, and make your conclusions.

Thursday, July 24, 2014

Dogs And Sunscreen

Most people don't think about it but animals actually can get sunburned.  It's not as common as in humans because their fur is typically so dense that direct sunlight doesn't make it to the skin.  They can still become overheated but true sunburn is uncommon.
That doesn't mean that it can't happen.  Breeds that are hairless are absolutely at risk for getting burned.  The same is true with a dog that has a thin coat where skin is exposed through the hair, or one that has a localized patch of hair loss due to another disorder.  Geography can also increase the risk, due to an area having a lot of direct sunlight or at higher elevations where the atmosphere is thinner and allows more ultraviolet rays. 
Excessive sunlight can carry the same risks as it does with humans.  You can have physical burns that can be painful or become infected.  You can increase the risks of certain kinds of cancer, especially squamous cell carninoma on the face and head of primarily white animals (dogs, cats, and horses).  Obviously these are things that we want to avoid.  The reason that pigs wallow in mud is to coat their skin and help block sunlight. 
Thankfully there are ways to help.  First, don't shave your dogs too short for the Summer.  The longer hair coat actually helps prevent sunlight from directly hitting the skin, so if the coat is too short you can increase the risks of burns.  As with humans, provide plenty of shaded areas for your dogs and try to avoid them staying in the direct sun for prolonged periods.  There are sunscreens specifically designed and approved for dogs, but in a pinch you can use plain zinc oxide sunblocks.  However, be careful not to let the dog lick at this kind of sunscreen as zinc can be toxic in high enough doses.  The key is to not ignore the potential for problems and burns.
Summer sun and heat can carry as much risk for our pets as it does for us.  Don't forget about them!

Monday, July 21, 2014

Dental Floss Doesn't Remove Skin Tags, But Thanks For Trying

After over 17 years in practice it gets difficult to surprise me or for me to see things I haven't seen before.  But today it happened.  It caused more of a sigh and face-palm than a true surprise, but it was still a variation that was new to me.
One of my other doctors saw a dog that has been a regular at our clinic for years.  He is an older beagle and generally in pretty good health.  He has had a rather large and long, but otherwise benign, skin tag for a long time.  We have talked to them about removing it while he was under anesthesia for a routine dental cleaning, but they had always declined.  It seems as if they had an inkling to try it themselves.
Today they brought him in to remove the dental floss they had placed around it. Yes, you read that correctly.  Dental floss.  About a month ago they had tied it tightly around the base of the skin tag, hoping that it would cut off blood supply and cause the tag to fall off without surgery.  The floss dug into the skin and tag, but didn't actually result in enough blood occlusion to cause the tissue to die and slough off.  But it did dig in enoug that they couldn't remove it themselves.  So our doctor had to use some suture scissors to get underneath it, cut it loose, and then clean the infected tissue around it.  All while the skin tag flapped around like it always had.

While this may be the first time I've seen dental floss used, this is an old (and rather bad) way to try and remove masses or even castrate an animal.  Usually rubber bands are used tightly around the offending growth or testicles, constricting the blood supply and eventually causing the tissue to fall off because the cells have died.  For some reason some people think that this is a perfectly acceptable substitution for surgery.

Using floss, string, or rubber bands in this way is one of the worst things you can do.  If the tissue is large enough, such as the scrotum and testicles, there will be pain and discomfort.  Would any man feel fine with having his family jewels tied off and left to rot for a month or two?  If the procedure actually does work, it's doing so because the tissues are dying from lack of blood supply.  It is literally dying and rotting off the body.  Who thinks this is a good thing?  There is a big risk of infection or having more tissue than desired be affected.  In the case of a mass or polyp you leave the base in the skin so it has a chance of regrowing.  In order to completely resolve the problem you have to cut away the attached skin, not just remove the dangling part.

Thankfully this was a relatively minor irritation and the dog is going to be fine.  And he's coming in later this week to have the skin tag properly removed.

Sunday, July 20, 2014

Questioning A Veterinary Career Choice

Here's a question from Ingelin.  Though she's in Norway (I love having an international readership!), her frustrations and concerns are universal and really shows some of the challenges for veterinarians world-wide.  I could take out the country references and completely believe that she is here in the US.
I am a Norwegian veterinary student, studying in Budapest, starting on my 5th year this fall.
I am currently - and have been for the last year or so, afraid that I have chosen the wrong profession.
Ever since I was a little girl (yep, as "all the others" also say..), I have imagined that nothing in the entire world would be better than doing veterinary medicine. My love for animals hasn't changed at all - I would almost say it has become stronger by seeing all the cruel things going on in research, labs and especially in the farm industry. Though, i sit here - closer to the goal than ever, feeling nothing but sad and frustrated.
This summer I am doing my practice in, so to say, the only horse clinic in Norway. The past months i have spoken to every vet i could, asking them about their working life and what they have to say about it. As I really really want to do horses, as this is where I feel most confident, I know the horse sport and I have been a horse owner myself for many years, and I feel like this is where I could do best - I have mostly spoken to horse practitioners. In general, most of them tell me: Life is tough. They spend hours and hours working their a**** off, earning nothing compared to what they do. They walk around in horse s*** all day long, one got his arm broken by a horse and a year later his mandibula. Another got her collar bone broken by a horse and actually, just after recovery - her knee got crushed by a horse. One got back problems after just working a year and is now in a lab.
Working 70-80 hours a week, one of them were in a period of 7 years in three car accidents due to driving from farm to farm - being so tired and falling asleep behind the wheel. They tell me that driving around day in and day out all alone without a supporting team around you is very hard. The physical work is tough, the organization of equipment that you need is both expensive and lots of work, all the billing/invoice work is time consuming and you would optimally need some knowledge in economics to do it well, it's hard with customers/owners not being willing to pay, or arguing with you that the treatment is too expensive, and especially as a woman you will meet many tough physical challenges and farmers can be very "oh jesus are YOU gonna do that - I could do it better". Ok, I think you got my point.
Some veterinarians tell me: do an internship straight after graduating, choose exactly what field you want to specialize in and stick to that. (For example not just equine surgery, but equine orthopedics). Others tell me that doing internships is "lethal": the salary is very little, you get to do very little "hands on" if you are at a big clinic with lots of specialists ect, maybe you wont get work in that field when you finish.. Do a mixed practice and learn a bit of everything so you can fall back on things if you have a hard time to get a job. Oh everyone is giving me different advises.

I feel really lost and I would almost say depressed. I have worked so hard to get where I am now and I want to feel nothing but proud and happy. I spoke to my supervisor at the horse clinic today which is on of the only horse surgeons in Norway. I have thought about doing and externship, and then hopefully get an internship, at the horse clinic in Kentucky, which my surgeon professors at my university has recommended me to do. Today my supervisor told me that the need for horse surgeons in Norway are very very limited, and if I want to work in Norway, DON'T do it. He recommended me small animals - but in Norway, believe it or not, the salary for a small animal practitioner is worse than working on the supermarket. Although there are opportunities to start your own clinic, get a good job if you do specialization first etc - so well, there are always options.
So to my conclusion: I have strongly considered changing to human medicine. In one way it makes me feel as an egoistic and cynical person - I always lived for the animals. They give us so much and I want to give back to them. But I see all the advantages as a human doctor compared to a veterinarian. You have a huge support team and always someone to ask, you never have limitations in treatments (so to say), I would have the chance to specialize in Norway and not having to do many more years abroad, you don't have to deal with everything on the economic aspect but can rather focus on your own profession, and you actually get paid for the hard work you do, which I think is important to a certain point for quality of life. To a human at least they can understand why you are doing what you are. To an animal however, I get a feeling of hopelessness. I know I am helping of course, but it's like: "hey this is gonna hurt like hell but don't worry it's to help you". They get angry, afraid, frustrated and aggressive, and I have never seen so many unhappy and suffering animals and I never thought it would be this tough. (Not that seeing severely ill people is easy..)

Ok i'm gonna put the finish line here. Sorry for all my thoughts and the very long email, but I would really really appreciate an answer! Maybe you have some encouraging thoughts to share.
Thank you very much in advance.
I thought it was worth printing all of Ingelin's email, as her thoughts, feelings, and experiences are actually pretty common.  I think that any veterinarian or vet student reading this will be nodding their heads in agreement, having run through the same scenarios in their mind.  I also think this is very important for pet owners to understand, as vets aren't sitting on their duffs just counting their wads of cash.  This is a hard, often thankless profession for which we are significantly underpaid for our level of skill and knowledge.
I'm a small animal veterinarian and haven't worked with horses in about 18 years.  I've never practiced on them and have never considered a career in large animal medicine.  But I'm at least basically familiar with that part of the profession and know that Ingelin's experiences are shared here in the US also.  I do think that the typical 70-80 hour work week is gradually going away as we graduate new vets who realize that they can't be everything to everyone, and are trying to have a decent work-life balance.  But it's still long hours.  You often find yourself in creeks in the dead of winter and in shadeless fields in blazing summers.  While most horse vets I've known manage to get away with few major injuries, it is still a much higher risk than with small animals.  There is absolutely the risk of serious injury and broken bones when dealing with animals this large and strong.  It is definitely a physically demanding profession and not one for the faint-hearted.
The business aspect depends on where you work.  Many vets, especially younger ones, are learning the benefits of hiring an office manager to handle the financial side of things.  A solo equine practitioner is in for an incredible amount of work if they do everything by themselves.  But if you get into a practice with a physical location and hire a good staff, you can get an office manager to handle payroll, billing, ordering, invoices, and so on.
Customers not wanting to pay?  Welcome to veterinary medicine!  Certainly you can get a bias against females among some farmers, as well as sometimes an attitude that they know more than you do because they're older and the farm has been in their family for generations.  You won't find as much of that in small animal medicine.  But if you are seeing client-owned animals you will quickly become frustrated with people who can't or won't pay for needed care.  The species of the patient is irrelevant.  I deal with at least a few clients like this every single day that I work, and have for my whole career.  Because pretty much all of animal health care comes straight from the owner's pocket you see them holding tighter to their purse strings than when it comes to their own medical expenses that are generally covered by insurance. 
Animals suffering breaking your heart?  Having a hard time dealing with animals in pain when you can't explain things to them?  Again, welcome to the profession.  It takes a special kind of person to be objective and distant enough to handle sick and injured animals while still maintaining compassion and empathy.  Working in any medical field can be emotionally draining and requires some good mental resilience. 
Internships and residencies are indeed brutal.  If you don't really, truly want to specialize I don't think I'd recommend it.  You make less than half of what you would make being in practice and the hours are much longer.  Should you consider going into a specialized field?  Only if you really have a super-strong interest in that area.  When I was in vet school I spent a few weeks working side-by-side with a board-certified surgical specialist.  He told me that he did make more than a general practitioner, but it took him about six years after vet school doing internships and residencies to reach that point.  For those six years he made about 1/3 of what his classmates made.  His lifetime earnings were going to be no different than a general practitioner due to the significant delay in finally practicing his speciality.
From what I understand in the US, your prospects of finding a good job in equine medicine may be better than in Norway.  It would certainly depend on where you wanted to live and work, as some areas are more under-served than others.  The areas with fewer vets working with horses and other large animals unfortunately tend to be areas where the salaries would be lower and you'd be working hard due to a lack of qualified vets.  But you may not want to leave your home country, especially for an entire career, so this is something you'd have to think hard about.
Personally I could never work in human medicine.  Humans gross me out and I can't handle that sort of thing.  I get feces and urine on me every single day and it's not a big deal.  But the idea of getting human feces on me makes my stomach churn.  Yes, the pay is higher, you have much more support staff, and you get to do more things without worrying about money.  But I'm not willing to make that trade because I can't handle seeing human illness and injuries.  It digusts me and makes me uncomfortable.  That may seem strange to some people, but it's actually a common thing among those in veterinary medicine.
Ingelin, I had to be a downer but you have actually expressed the same frustrations shared by the majority of the profession.  You have expertly described the daily problems we have and why this is not the best profession in the world.  I actually agree with everything you said, as it's true here in the US as well as other countries.  That is the depressing nature and harsh reality of veterinary medicine.
So why do it?
There are moments of greatness every day.  You will meet wonderful clients who think the world of you and will follow your every instruction.  Today we had a client bring us fresh, homemade eggrolls, still warm when she brought them in.  I got to work with some incredible cute and sweet puppies.  I was able to tell an owner that her cat didn't have a blocked bladder and had a treatable infeciton.  I helped comfort a client by easing the passage of their terminal cat.  I got to teach an eager veterinary student.  I can walk out of my clinic today proud of the fact that I helped to change and improve lives. 
It isn't an easy job and I frequently question my career choice.  But I've also reach the point in my life where I can see the joy in the day and be able to smile when I've helped someone.  Would I do it all over again if I had the chance to go back and make changes?  Probably not, except for the fact that I love my wife, family, and faith, and I wouldn't have those if it wasn't for my choices in and after vet school.  I would definitely pick a completely different career.  But I also don't hate my job (most days) and am very content where life has taken me.  It's a good job and I've been successful at it.
This probably doesn't help, and if you go back through the archives of my blog you'll find that I think this is a bad time to try and get into veterinary medicine.  Should you change your career, Ingelin?  It depends on how much passion you feel about veterinary medicine, how desperately you want to work with animals, and how well you can deal with the long hours and low pay.  That's certainly not a simple, easy choice and I don't have an easy answer.

Friday, July 18, 2014

Being A Better Customer

As the lead doctor and a manager in my practice I have to deal with a lot of odd or cranky clients.  Over the years I've had this blog I've talked about many of them.  I also am a fan of the website Not Always Right ( because of the plethora of stories about strange, unruly, and unreasonable customers.  It's kind of therapeutic for me to read about other people's encounters with the bad customers and clients, as I see similar situations almost daily.  As in any profession we often have to handle clients who are impatient, make unreasonable demands, have a short temper, seem determined to blame us for their negligence, or simply have an inability to understand very simple things.
Over the years I've gotten better at handling these situations.  They don't bother me and sometimes I'm downright amused rather than upset by the client.  I've learned a lot of ways to talk to people, help them understand, and overall calm them down.
But one of the best things about being a manager and working with the public is that it has made me a better customer and consumer.  When I talk to my team about excellent client service I make people give examples from their own lives of experiences where they were blown away by service and ones where they were so poorly treated that they would never go back again.  I have my own stories, especially of stellar service.  While I use this to teach my staff how to treat our clients, it also helps me understand how to be a consumer myself.
I try to smile at cashiers and acknowledge their greeting.  I try not to be upset at someone who merely works at a the desk or answer the phone, realizing that they were not involved in a mistake that was made.  When there is a problem I try to be patient and see how it is handled and rectified rather than jumping straight into yelling.  I try to remember that everyone is human and makes mistakes, so it's more important to see what happens after the mistake rather than being upset just at the mistake.  I try to give businesses time to look into a problem and try to fix it.  When someone gives me exceptional service I always try to remember to thank them, and then find a manager to acknowledge that service.  When I go to a doctor's office I bring a book or something to work on as I know that delays can happen and are often beyond the doctor's control.
I'm not perfect and I get as frustrated as the next person.  The difference is that I and my staff have been on the receiving end of bad clients many times, and I don't want to be that kind of client.  I try to remember how those situations made me feel and why I thought the client was unreasonable, and then avoid acting the same way.  I'm in a service industry and have sympathy for others who deal with customers, especially the cranky ones. 
I just wish everyone could learn the same lessons.

Wednesday, July 16, 2014

TPLO For A Dog's Knee

One of the most common orthopedic injuries in dogs is a rupture of the cranial cruciate ligament (CCL).  In humans this is the anterior cruciate ligament, or ACL, and is a very common sports injuries.  Just about everyone I've met has known someone who ruptured their ACL or did so themselves.  Dogs and cats can also cause damage to this structure, especially certain breeds such as Labrador retrievers.  When we see a dog come in with acute single hind limb lameness this is the first injury that we consider.

The main function of this ligament is to give the knee joint stability in a forward-to-backward motion.  The knee should have minimal movement in this direction and if the ligament is torn you have sudden instability.  You also get significant inflammation due to the damaged tissues.  In really bad cases the meniscus (cushioning pad in the joint) can also be torn, further heightening the damage.  This kind of injury typically occurs suddenly and after activity such as running or jumping.  The patient is painful, the joint becomes swollen, and there is usually noticeable movement of the joint (something called "drawer motion").  The combination of these symptoms results in the pet not wanting to put any weight down on that leg.  The nature of the damage also means that this does not get better in a day or two.

As with humans this virtually always needs surgery to correct.  Cats actually may not need surgery due to their size, less stress on the joints, and some minor differences in the flexibility of their joints.  If a dog doesn't have surgery they are looking at months of slow, gradual recovery and a joint that will always be unstable and possibly always be painful.  I have seen dogs go on to be normal after a CCL injury without surgery, but the it too a long time and the joints always developed arthritis earlier than would otherwise have happened.

There are two common ways to fix this injury and several less common ones.  The most tried-and-true is what we call an "extra-capsular" repair.  In this case the surgeon goes into the knee, removes any damaged tissue, drills a hole in the tibial crest, and places high-test nylon wire or suture in a pattern around the knee joint.  Removing the tissue debris allows the inflammation to resolve.  The nylon provides stability to the joint and once healed allows normal movement and weight-bearing.  This is a surgery that can easily be performed by a skilled general practitioner and there is rarely a need to have a specialist surgeon involved.  But not all vets are comfortable doing this procedure.  I'm one of them!  I can take out a spleen or kidney, remove bladder stones, repair a ruptured diaphragm, and similar soft tissue surgeries, but I just do not like orthopedic surgeries and don't do them.  While possible for a non-specialist to perform, and while being the least expensive of the CCL repair surgeries, this technique does carry the highest risk of complications.  The nylon suture can rupture at some point and therefore would need to be taken out and replaced.  You can also have more likelihood of arthritis in the joint compared to other procedures, but not as likely as if surgery was not done.  This is still a viable option if you cannot afford a more complex procedure.

The other common technique, and one most recommended by surgical specialists, is "tibial-plateau leveling osteotomy", or simply TPLO.  This is a much more complicated surgery as it requires the bone of the tibia to be cut, rotated, and held in place with plates and screws.  The goal is to change the angle of the "plateau" of the tibia (the part at the joint with the femur), preventing the femur from sliding along an angle when weight is placed on the leg.  This change in angle provides more stability and less slipping stress than other procedures.  The long-term outcome tends to be much better than with an extra-capsular repair and recovery is much faster.  The down side is that it can cost around  twice as much and often requires going to a specialty facility.

Such a procedure needs to be done by someone highly trained in the technique and with good experience.  Definitely not something the average veterinarian will do!  Typically this is done by a board-certified surgical specialist, though in some areas your vet may know someone who is highly trained as a surgeon but isn't actually certified.  I use that kind of doctor in my area because he will come to my clinic, and he's an awesome surgeon.  

Besides education, why bring this up now?  One of my staff recently had this done.  What's interesting is that her dog had an extra-capsular repair on his left knee several years ago by a general practitioner.  Recently he tore the CCL in his right knee and needed another surgery.  The staff member is considering going to vet school in a few years and is well-versed in the field.  She did a lot of research and decided that she wanted a TPLO done on the newly injured knee.

The surgery went well and his recovery was fast.  I saw him around a week after the surgery and he was starting to bear weight on the leg.  Much faster than I've seen with techniques other than a TPLO!

A week or so after that he jumped up and down when someone came to their house, and then became lame again.  One of the most important parts of recovery for this surgery is keeping activity minimal until full healing has occurred.  We were worried that his jumping had torn apart the surgery and he'd have to go through it again.  Here are his x-rays, clearly showing the technique of the surgery (which is a main reason for the post....x-rays are cool!).  Please pardon any blurriness, as these were taken with my phone pointed at the computer screen.

Thankfully everything looked good.  We put him on pain medications and anti-inflammatories, then went back to earlier rest and physical therapy.  Within a couple of days he was feeling better.  His owner was very happy that nothing had moved and he wasn't going to have to have another surgery.

Personally I think the TPLO procedure is better than extra-capsular, especially in large breed dogs.  But many people can't afford the $2000-$3000 price tag (depending on regional variation in prices), in which cases the extra-capsular surgery is still acceptable.  

This is yet another reason why having pet insurance and setting money aside for pet emergencies is such a good idea!

Monday, July 14, 2014

Cheap Food Vs. Expensive

This email hit my inbox recently and brings up a great question....

Hi, your blog is great. Anyways, as someone who knows quite a bit about the beauty industry I know the cheaper products usually work better than more expensive bc the big brands like P&G and Loreal have more money for R&D and formulations between the cheaper and more expensive brands they own are almost identical. An Olay anti wrinkle cream is likely to work better than a cream that costs hundreds of dollars. Is it the same for pet food? What's the relationship between food price and quality?

In general I do believe that you get what you pay for.  More expensive products often are that way for a reason related to the quality of ingredients or manufacturing.  For example, there is a big difference in the cost and features of a Hyundai versus a Lexus.  A Mont Blanc pen is going to last longer and have better quality than a Bic.  But does that extend to pet foods?

All pet foods in America are required by law to meet certain nutritional standards.  But some of them do it better than others.  And just because a food meets a minimum standard doesn't mean that it meets the best standard.  There really is a difference in the quality of the different foods, though it's not easy to tell which is better.  Certainly you can't rely on the commercials and other advertisements, as those are written by marketing experts to deliberately convince you to buy the product.  Not all of them are deceitful but all are by their very nature manipulative.

You also have to be careful about the representatives you meet in pet stores.  Like advertisements these people are trained to make you think their company's food is the best thing ever and all other foods are no better than eating from a trash can.  They are taught all of the right talking points and how to win you over to their point of view.  Some of them even give misinformation, either deliberately or through poor training by the company.

There are definitely differences, though. Just looking at the ingredient list you can usually tell a difference between "good" and "bad" foods.  However, there is certainly both an art and science to reading labels so this isn't always the best determining factor.  As a few examples, by-products aren't bad, "fillers" really aren't used in pet foods, and the first ingredient may not be the ingredient with the highest percentage of nutritients in the food.  Even I have sometimes gotten confused as to which is a high quality brand and which isn't.

In my experience and based on my discussions with nutritional specialists the cheapest foods are lower in quality.  But the most expensive foods may not always be the best ones.  And regardless of the price of the food your pet can certainly survive.  The question is, will it thrive.  Eating a cheap food is similar to a human subsisting on pizza, hamburgers, and an occasional salad or carrots.  Can you live and survive on that diet?  Sure.  But you won't be doing the best thing for your body.

So how do you tell the difference between foods?  Which ones are best?  And what determines that?

Every few years I contact the board-certified veterinary nutritional specialist at the closest vet school and ask them about these issues (most recently in December 2013).  I want to hear from the ones teaching the classes and doing the research, and want to keep up with current information.  Every time I talk to a specialist I end up with the same recommended food list.  And their recommendations are consistently based on things that you can't find on the food label or on the food company's website.  Heck, even I can't get the best information without contacting a specialist!

For the nutritional specialists there are a few very important things they consider besides simply the ingredients.  One factor is whether or not the company is actively engaging in current research on veterinary nutrition.  These companies have a long history of spending money into research on nutrition in animals, both for well pets and to help treat diseases with the right nutrient balance.  They are the ones who help build the current knowledge we have of how nutrition relates to health and physiology in pets. 

The other factor, which in many ways is even more important, is the amount and type of quality control the company has over the manufacturing process.  The best companies test batches daily to ensure consistent nutritional quality and seek out the best quality ingredients.  Some food companies simply can't test their food this rigorously because they don't own the manufacturing plant.  Yes, there are plants that exist and will make a pet food based on the recipe they are given.  But since the company providing the recipe doesn't own the plant, that company can't check the food as well or as consistently.  And then there are those who simply don't bother checking the foods often enough.

So what foods?  What brands?  According to the specialists I've spoken to personally, the following companies' foods are the ones they recommend the most and which they feed their own pets.

Royal Canin

Personally I do think there are different "tiers" of foods within such companies, especially Purina. Of their foods I only typically recommend Pro Plan or Purina ONE as being better than their cheaper ones such as Dog Chow and Cat Chow. 

So I would never go with the cheapest foods, but you don't have to use the most expensive ones to still provide a great quality nutrition.  Hope that helps answer the question!

Here are links to some of my previous posts on nutritional issues with pets.

The Tricky Fine Print On Pet Food
The First Ingredient....It May Not Be The Most!
Corn In Food...No, It's Not Bad
The Great Veterinary Food Conspiracy?

 And inevitably a discussion on nutrition brings out people who are adamantly against manufactured foods, who think that I and other vets are buying into a bunch of hogwash promoted by the food companies merely to sell food, and who think that only their little community of friends and nutritionists know the "truth".  No problem.  I've handled those discussions before, so go ahead.

"Let food be your medicine and medicine be your food."