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Musings from Dr. Craig
On this page you can find occasional postings on a variety of topics. If you have any suggestions or comments, please email them to firstname.lastname@example.org
Missing teeth may not really be missing
I spayed a very cute boxer puppy yesterday named Kai. The spay was uneventful but during the oral exam, I noticed that there was a missing premolar.
Sometimes when a tooth is missing, it is truly missing and other than causing a gap in the dental arcade, there is no other problem. But the lower first premolar is the most commonly impacted tooth in a dog’s mouth, so when it is missing, shooting a dental x-ray is always indicated. In this case, Kai’s mom consented to getting a dental x-ray and we found that the “missing” premolar was actually present under the gum line.
In a situation like this when the tooth is in a normal orientation and not trapped down in the bone, a simple procedure called an operculectomy can be performed and the tooth becomes functional.
In some cases, the tooth is trapped in the bone and extraction is indicated to reduce the formation of a dentigerous cyst: a fluid pocket in the bone that can lead to pain and even jaw fracture. Below is an x ray image from a dog named Kirby that I took a few weeks ago. His first premolar was impacted and required extraction to prevent dentigerous cyst formation. My own dog had this problem and when we neutered him, we were able to perform an operculectomy on one side, but had to extract the premolar on the other side.
If you have any questions or comments, please feel free to contact us.
Craig Adams, DVM
Pet Food Recalls
Pet food recalls are not uncommon. Here is some information about a previous Diamond Pet food recall due to Salmonella risks. What may be surprising is how many different brands come out of the same factory, several of which are promoted as being "Premium" diets. There have now been human cases of salmonellosis linked to contaminated pet foods. Click here to receive information from the CDC about the recent Diamond Foods recall which included the brands:
Chicken Soup for the Pet Lover's Soul
Kirkland Signature Nature's Domain
Taste of the Wild
Vaccinations...why we recommend what we do.
Vaccinations and vaccine protocols are controversial areas of veterinary medicine that we share in common with our human physician counterparts. Most people understand that vaccinations help to reduce the incidence of disease but may not fully understand how. Vaccines present the disease (antigen) to the immune system in a form that is unlikely to cause illness, and therefore allow the body to produce antibodies to the disease. With antibodies in circulation, the body is able to fight the disease if the antigens are encountered again. The antibodies will bind with the antigen and through various mechanisms the antigen will be neutralized.
Vaccinations are classified in three different categories: killed (or sometimes euphemistically called inactivated), modified-live, or recombinant. Killed vaccines are self explanatory, the organisms are dead but still may be recognized enough by the immune system to cause an immune response. In order for the immune system to have the best chance at developing an immune response, killed vaccines typically have adjuvants added. Adjuvants are ingredients that cause inflammation. They can be cell walls or other products. Their actual composition is typically a trade secret and is different between the various vaccine manufacturers. Killed vaccines are unlikely to cause the disease, but they may not give the best immune response. With diseases such as rabies, killed vaccines are favored, often by law, so that we do not inadvertently cause disease.
Modified-live vaccines contain organisms that would generally cause disease, but they have been attenuated. Attenuation is a process whereby the organisms are reproduced in a laboratory for numerous generations until a version is identified that does not cause disease. The benefit of a modified-live vaccine, such as a bordetella intranasal vaccine for dogs, is that once it is administered, the organisms will reproduce and will stimulate an immune response, but not cause disease. Therefore, modified-live vaccines do not have a requirement for adjuvants to be present to cause additional inflammation. This is of benefit because adjuvants have been linked to possible side-effects in some patients. Some people worry that modified-live vaccines will cause the disease we are trying to prevent. In rare cases, a patient may develop mild clinical symptoms associated with a modified-live vaccine, but the symptoms are usually very mild and quickly resolve. The long-term protective effects of these vaccines definitely warrant taking this slight risk in most cases.
The third category of vaccines is recombinant. Such a vaccine is really a cross between a modified-live and killed vaccine. They push the boundary of how we define the word "live". Are viruses actually alive? Some would argue that they are not because they cannot reproduce on their own, but that is a philosophical discussion for another time. With recombinant vaccines, a snippet of DNA or RNA (the genetic material that forms the basis for life) is removed from the disease-causing organisms and is spliced into the genetic material of a "live" but harmless virus. That way it can reproduce once injected, not cause disease, but also stimulate a good immune response. An example of this would be the canarypox rabies vaccine for cats. The canarypox is the harmless virus that has had a bit of rabies spliced into it.
When we recommend a vaccine for one of our patients at Poulsbo Animal Clinic, we have already taken the characteristics of various vaccines into account prior to making our selection and suggesting it to you. We strive to choose vaccines with safety and efficacy in mind. We also take your pet's health status, lifestyle, and other factors into account before we make a recommendation. Vaccination is not a one-size-fits-all proposition. There are core vaccines that all animals should have, such as Rabies, the DAPP combination for dogs (Distemper, Adenovirus, Parainfluenza, Parvovirus) and the FVRCP combination for cats (Feline Viral Rhinotracheitis, Calicivirus, Panleukopenia). There are also non-core vaccines such as Bordetella, Canine Influenza, or Feline Leukemia that are recommended based on risk factors.
Vaccinations are controversial but of critical importance in our efforts to reduce disease in our veterinary patients. There are a lot of factors that we consider every time we recommend a vaccine. We truly have your pet's best interest in mind when we vaccinate them. There are numerous vaccines that are on the market that we could sell but that we do not even carry in our inventory because they are not effective, not necessary, or not safe enough to justify their use. This is a detailed subject that cannot be fully explored in a short article. I would enjoy any questions you may have or suggestions for any clarifications I can try to make.
Craig Adams, DVM
Pet Nutrition: Reading Labels
Few areas of veterinary medicine are as confusing and filled with marketing hype as nutrition. If you pick any aspect of nutrition, you will find proponents for or against it. Some of the controversies today include: grain vs. grain free; good grains vs. bad grains (corn seems to be especially unpopular); protein content; protein sources; "raw" vs. "processed"; use of undefined terms like "holistic" or "human grade" ingredients. Labels on pet foods are not as easy to interpret as the labels on our human food, so comparing diets is difficult. There are only a few companies that actually perform research. Most of the other "nutrition" companies use the published data from the big companies to formulate their diets, and then bad mouth those companies in their marketing in order to gain a market share. Pet food is a big industry, so there is a large incentive to do so. One company I contacted was doing just that. I was interested in using their diets for patients if the diets were medically indicated. Several of their diets were marketed for certain conditions (urinary health, gastrointestinal health, etc.). When I asked for the supporting literature, the only things provided were the original studies from the big nutrition companies, and nothing that was done with their own diets. When I pressed further, they downplayed the effectiveness of the AAFCO feeding trials. There are limitations to a 26 week feeding trial, to be sure, but in my opinion, it beats just following a recipe and calling it good. When I pointed that out, this particular company finally said that they do not believe in animal research! So in essence, they took their untested product to market, made medical claims about the diets' effectiveness, and use our pets as test subjects. I recently ran across an interesting article from Hill's, the makers of Science Diet and a number of popular prescription diets. Regardless of what you think about Hill's, I think you will find the article interesting: Pet Food Labels Only Tell Part of the Nutritional Story.
Craig Adams, DVM
Feline leukemia (FeLV) is a retrovirus (like HIV in people) that is highly contagious between cats. It is present in our feral cat population, so any cat that goes outside or comes into contact with a cat that goes outside should have the FeLV vaccine. I got some sad news today that highlights the potential risk. One of our very best clients has a 6-year-old cat that is absolutely the greatest cat in the world (just like your cat!) who we will call "Gary". Her brother's cat was exposed to the feline leukemia virus and became positive. Gary is indoors only and lives alone and was therefore not previously vaccinated for FeLV. He had nose-to-nose contact with her bother's cat several months ago, perhaps on more than one occasion. In April 2011, Gary tested negative for feline leukemia. We decided to vaccinate Gary for FeLV in July 2011, so just to be sure, we retested. This time, the ELISA test (the most common test run in-clinic) came back positive. The ELISA test is very good at ruling out FeLV (there are very few false negatives), but there can be false positives. So, any time we have an ELISA positive, we should run an additional test that we send to the lab called an IFA (immunofluorescent antibody test). If this test is positive, there is persistent viremia in the bone marrow. Gary's IFA result came back today and it is positive. Gary is not sick right now, seems to feel great, and is pleasant and full of life. But, he has a persistent FeLV infection that we cannot cure. He is potentially at risk for secondary infections or even some types of cancer. The average survival is less than 2 years from the time of diagnosis, but I would like to think that Gary will beat the odds and live a long, long time. So, even if your cat is indoors "most of the time" or "rarely escapes and gets outside", really consider your cat's risk and think about getting a FeLV vaccine. FeLV is easy to get, but impossible for us to cure.
Craig Adams, DVM