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VetInfo Digest    March 2002

This Month:
Remote Access Second Opinions
What's the Latest?
        Allergy Testing Cats
        Treating Adrenal Tumors
        Fleas and Flea Allergy
        Erythropoietin for Pets
        Fever or Not?
        Rapid Weight Gain and Insulin Resistance
        Titers for Cat Diseases
Hospitalization in Vet Medicine
URLs on our Site

This month's note:
Tick season is coming soon in much of the United States. This generally brings about an increase in tick borne diseases. At the present time there are a number of diseases that ticks are known to carry. Among these are Rickettsial diseases such as Rocky Mountain Spotted Fever, ehrlichiosis, Bartonella diseases such as Cat Scratch Fever, bacterial illnesses including Lyme disease (borreliosis) and possibly Babesia. For many years veterinarians have looked for these diseases individually. It is becoming increasingly clear that many dogs (and possibly cats) with one of these diseases are likely to have more than one of them since ticks are reservoirs for multiple disorders. Therefore, it is important when testing for these disorders to consider screening for all that are likely to occur in your area. Testing for antigen (disease particles) based on polymerase chain reaction (PCR) technology allows a more specific diagnosis than older serology tests, although this is more costly. The Tick-Transmitted Disease Laboratory at North Carolina State University offers a tick disease panel using PCR technology and many commercial laboratories offer tick disease panels utilizing PCR technology, as well.
Tick diseases are frustrating because the clinical signs can be very vague to very dramatic, making them a potential problem whenever a dog is obviously ill for no apparent reason. Tick borne disease is less common in cats but still has to be considered in areas in which ticks are a problem.

Get a Second Opinion Without Leaving Home
Keeping up with available information in veterinary medicine can be an overwhelming task. We subscribe to a number of journals, belong to the Veterinary Information Network (tm), have access to the Network of Animal Health (NOAH, tm) and attend continuing education conferences on a regular basis. Having access to information is only part of the problem, though. Deciding which information is valid is difficult, especially when there is conflicting evidence. A very persuasive speaker at a continuing education conference can pass on erroneous information, or personal bias disguised as expertise. New surgical or anesthetic procedures can provide great benefit, but learning new techniques without the opportunity for "hands on" instruction can be very hard and is sometimes actually dangerous for patients when first attempted. Balancing tried and true veterinary procedures or information against potential benefits of the "new and improved" versions will always be a difficult task.
Putting the information that you have acquired or that your veterinarian or veterinary hospital staff has acquired into practical use is also difficult. It really doesn't help much to know that examination of a fecal smear stained with an acid fast stain can reveal Camplyobacter infection if you don't know how to make an acid fast smear or what Campylobacter organisms look like after staining. Watching a video of a great new surgery for cruciate ligament repair clearly isn't the same thing as actually doing the surgery, even if it looks easy on the tape. After stumbling through a surgery, lab test procedure or new therapy that proved to be much more difficult than advertised, many veterinarians become a little more reluctant to dive into new techniques, at least for a while. It isn't a bad thing when your vet recognizes that there is a better way but that he or she isn't the person to provide the more advanced service. If your vet suggests referral to a specialist for treatment it is usually best to seek the specialist's care.
This situation is compounded by the availability of new and complex equipment and diagnostic procedures that can provide much more information, both good and bad. Those of you who have looked at ultrasound scans can understand this statement a little better. While trained ultrasonagraphers really can gather valid information from sonograms it is sometimes hard for untrained observers to see anything at all in the images. I can still remember a friend of mine passing out a Polaroid (tm) photo of an ultrasound image and saying "They tell me there's a baby in that picture somewhere." To purchase an ultrasound machine and attempt to use it without training is just as likely to produce bad information as good information. Endoscopy, skin testing for allergies and many other more advanced diagnostic procedures have similar learning curves. Even though you may prefer for your vet to offer these services it is often better if your pet is referred to a specialist whose training and case load helps to ensure more accurate interpretation of this sort of testing. For diagnostic imaging, though, there is also the option of referring the image only.
When there is any question about the interpretation of an X-ray, sonogram or other diagnostic testing procedure it is often possible to have a specialist review the image, microscope slide, confirm culture results or help with other diagnostic procedures from transmitted data or simply by putting the image in a mailer and sending it off. This is often possible without any need for the pet to be reexamined or transported to the specialist. Most veterinary schools offer consultation services for veterinarians practicing in the state or region the school is in. There are several companies that also offer these types of services. The commercial providers will often evaluate images or information transmitted by phone or via the Internet.
Idexx Information Services (tm) maintains Cardiopet (tm) and Radiopet (tm), available through the web site http://www.idexx.com/AnimalHealth/Laboratory/UnitedStates/ and consultation services with specialists in other fields through the web site http://www.idexx.com/AnimalHealth/Consultation
Remote Vet (tm) provides review of radiographs, sonograms, clinical pathology samples and consultation in several other specialty areas. Their web site is www.remotevet.com and their phone number is 800-553-3265.
Sound Technologies (tm) offers reviews of ultrasound and radiographic images. Their website is www.soundvet.com and phone number is 800-268-5354. This service may be restricted to veterinarians who have purchased their ultrasound machines through Sound Technologies at the present time.
The Veterinary Information Network (tm), www.vin.com, offers limited image interpretation and a great deal of advice on interpreting laboratory values, history and clinical signs of disease.
It is likely that there are other companies offering these services, as well. It is often useful to have an opinion from a specialist in interpreting radiographs, clinical pathology specimens, laboratory test results and sonograms. This expertise can be accessed by most veterinarians without having to refer your pet. This is an option to think about when it seems like getting a second opinion would be helpful but it is not possible to transport a pet long distances for a second examination.

What's the Latest?
As I answer questions and research topics during the course of the year I save information on the reference sources in a large file on my computer. I was reviewing this list last week and it occurred to me that there was a lot of new information that contributed to my understanding of problems in veterinary medicine and some older information I had simply missed in the past. All of it helped me to understand some aspect of practice. There is some information that helps to resolve conflicts between old and new information that has become available in the last few years. Some of this is just information that helped me expand my understanding of how a disease process or medication worked. This month I'd like to review the information that I found interesting enough to save for future review with you.
Allergy testing Cats
We attended a seminar in which Dr. Robert Kennis from Texas A&M spoke on skin testing. He advocated skin testing in cats. In the past this has been a somewhat controversial topic, for several reasons. The main one, from a general practitioner's perspective, is that cats do not usually react as much as dogs in skin tests and so the test is harder to interpret. Oddly, there is also the problem of occasional reports of really severe skin reactions to the testing procedure in cats with self trauma as an outcome, which also makes us hesitant to do it, or recommend it. Dr. Kennis felt that the interpretation problems were just a matter of doing enough tests to be familiar with cat reactions and didn't mention problems with severe reactions in his work. Since many of the skin problems in cats produce similar symptoms, an accurate diagnosis of allergic skin disease would be helpful. We will remember to include the option of referral to our local veterinary dermatologist for skin testing for our cat patients more often in the future.
Treating Cushing's Disease Caused by Adrenal Gland Tumors.
Approximately 10% of dog with Cushing's disease have the disease as the result of adrenal gland tumors. For many years this variation of Cushing's disease was considered to be a disorder best treated surgically. However, it has been recognized for some time that it was possible to destroy adrenal gland tissue, including tumor tissue, with mitotane (Lysodren Rx). Drs. Kintzer and Peterson (1994) showed that the success rate for medical treatment was at least as good for medical treatment as for surgical removal of the tumors, with less risk of sudden death for the patient. At this time, I think that most internal medicine specialists and endocrinologists lean towards medical treatment for dogs with adrenal gland tumors leading to Cushing's disease.
Airway disease
Some dogs with airway disease have audible sounds during inspiration. This is most common in the short nosed dog breeds and usually indicates upper airway obstruction. Other dogs with airway disease have audible sounds during expiration. In this case, there is usually a disorder affecting the smaller airways in the lungs or the lung tissue itself. The timing of respiratory wheezing can be a very helpful differentiating factor between the types of airway disease and is easy to assess in some dogs.
Understanding Fleas and Flea Allergy
The warming trend across the country this year has produced more questions about fleas surviving the winter than we usually have. Fleas are susceptible to cold. In most circumstances adult fleas will die if exposed to temperatures below 37 degrees Fahrenheit for more than 5 days in a row. Flea larvae also die at this temperature but are usually killed by changes in humidity in the house, as the larvae can not survive when the humidity is less than 50%. In warm weather states, such as Florida, as many as 20% of newly hatched fleas might survive to become adults while in cold weather states the number is more like 5%. A warm winter can drastically increase the number of fleas the next spring and summer because of this difference in survival rates.
Optimum conditions for flea survival are temperatures above 80 degrees Fahrenheit and relative humidities over 70%. In these conditions fleas develop more rapidly and are more likely to live to be adults. This is the reason that the flea population tends to grow slowly over the early months of the summer but then peaks in late August to October in temperate climates as the number of surviving adults from midsummer breeding makes the flea population much more noticeable. Once winter hits, flea survival drops off and the flea season ends, except for people who support the growth of fleas indoors by keeping the temperature and humidity in the region that fleas can reproduce, or who live in climates in which it never gets cold enough to interrupt the flea life cycle.
Flea allergy is usually a seasonal disorder, in which there is itching in dogs or cats that is usually centered in the rear half of the body. Dogs often have a "Christmas tree" hair loss pattern that has a wide base right where the tail meets the body and then comes to a point at about the level of the dog's ribcage. Cats tend to have scabbiness in the same area and may also have hair loss on the back of the rear legs or over the base of the tail. In climates in which fleas live all year, flea allergy is also a problem all year. It takes approximately 3 weeks for the allergic effect of a single flea bite to wear off in extremely sensitive patients. In studies of cats and dogs with flea allergy it is often noted that fleas are not found on the body of patients when examined. Pets who are really bothered by flea bites tend to get really good at finding and removing the fleas, especially cats.
Skin testing for sensitivity to flea bites can be a good way to determine if flea allergy is present when there is any question about it. Many pets with flea allergy also have other skin problems but knowing that flea allergy is part of the problem and taking appropriate steps to control fleas will often improve the quality of a pet's life dramatically, especially when flea hypersensitivity is a problem.
There are a number of very good flea control products on the market at the present time. For flea allergic pets it is best to use an product that kills adult fleas such , as imidocloprid (Advantage Rx), fipronil (Frontline, Frontline Topspot Rx), selamectin (Revolution Rx). These can be combined with products that control the egg or larval stages of the flea's life, such as lufenuron (Program Rx) for more efficient flea control but it is important to use an adulticide if flea allergy is present.
Many clients do not believe that their pet, or their home, might harbor fleas. The denial of this possibility results in long delays in pursuing proper treatment. Fleas prefer to be on dogs and cats. The flea burden in the house usually has to get quite high before humans are attacked. Give your pet a break and treat for this problem, even if you don't want to believe that it exists!
Erythropoietin for Cats and Dogs
Erythropoietin is a hormone produced in the kidneys that stimulates the bone marrow to produce red blood cells. When there is kidney failure the production of this hormone drops off and many pets with chronic renal failure have anemia due to the lack of erythropoietin. This can also happen if the hormone production declines for other reasons. There are two human origin erythropoietin products, ProCrit (Rx) and Epogen (Rx). These products work in cats but antibodies form rapidly in some cats due to the human origin of the erythropoietin and the antibodies sometimes attack both the human origin product administered and the cat's own naturally produced erythropoietin. This is a severe complication of the use of the human origin products since the result is a total lack of blood production and there need for repeated blood transfusions to maintain life. There are two promising alternatives to human erythropoietin being researched at the present time.
At the James Baker Institute of Cornell University the production of feline and canine origin erythropoietin has been studied. Clinical trials for patients utilizing these hormones were closed in January of this year. Hopefully these products will be available commercially in the not too distant future. For information on this research: http://www.news.cornell.edu/releases/June01/FelineEPO.hrs.html
There is also research on gene therapy to stimulate erythropoietin production in cats. There was a report of this in Gene Therapy from March of 2000 (Beall et al) and a research project at the University of Florida on this therapy. The gene therapy has been demonstrated to work to stimulate erythropoietin production, but control of the hormone still needs to be worked out and it may take some time for this therapy to make it into clinical use.
Fever or Not?
When a dog or cat has a fever, there is a change in the brain's regulation mechanism for body temperature caused by a disease or disorder so that the body tries to maintain a higher temperature as its "set point". So the pet actually feels as if it is cold despite the high body temperature because it is hard to maintain the higher temperature. Pets with fevers tend to huddle up, try to find warm spots, shiver and do not exhibit panting or other behaviors associated with attempting to lose heat.
When a pet has hyperthermia from heat exposure, exercise induced myopathy or conditions in which the increase in body temperature rises without a change in the brain's set point the pet will exhibit behaviors associated with trying to lose heat, such as panting, laying out in positions that increase body surface area, drooling or seeking shade.
It is important to make the correct distinction between these conditions because fevers have to be treated with medications that help the brain reset, such as non-steroidal anti-inflammatory medications, while hyperthermia has to be treated by cooling the pet down with cool water baths or other external methods and it is important to do this as quickly as possible once signs of hyperthermia occur.
Rapid Weight Gain and Insulin Resistance
A recent study by Appelton, DJ, et al, from the Journal of Feline Medicine and Surgery demonstrated a greater than 50% decrease in insulin sensitivity in obese cats who gain weight rapidly over the course of several months. Obese cats with decreased insulin sensitivity are very prone to Type II diabetes. It is not clear from the study whether the weight gain is a symptom of the decrease in insulin sensitivity or if the weight gain causes the decrease in insulin sensitivity. In any case, a marked increase in weight gain that occurs over the course of several months to a year is a good reason to watch for other symptoms associated with diabetes, such as increased drinking and increased volume of urine in the litterpan. It is also a good reason to try to avoid obesity by using measures to control weight such as encouraging exercise and limiting calories. This is hard to do in cats but it could make a big difference for cats prone to diabetes.
Disease Titer Measurement in Cats as an Alternative to Scheduled Vaccinations
There is no question that vaccines can have serious side effects in a small number of cats, including inducing sarcomas (cancers) at the vaccine site. This is a devastating consequence of making the choice to try to protect a cat against diseases that might also have serious effects, including the death of the pet. Weighing the risks at the current time involves estimating the potential for the cat to be exposed to the diseases the vaccine protects against, considering the severity of the disease if it is acquired and comparing those things to the risk from the vaccine. We feel quite strongly that vaccinations are an important part of health care and that the risk of adverse reactions is still a minor concern compared with the risk of acquiring diseases in cats exposed to them. However, there is no reason to give vaccines more than is necessary.
In a recent study from the Journal of the American Veterinary Medical Association (Jan 02) by Michael Lappin and others, titers were measured to assess protection against disease in cats. After titer measurement cats were exposed to the viral illnesses and the protection assessed. Titer measurement was effective in determining whether cats would be protected against disease for feline calcivirus, feline parvovirus (panleukopenia) and feline herpes virus (rhinotracheitis).
Titer measurement is an option for determining vaccination intervals. It has some pitfalls, including additional expense, known failure at predicting protection for some diseases and a loss of the population protection. (Population protection is the decrease in the ability of a disease to spread based on many individuals in the population being protected against it.)
At the present time we still favor using vaccination at intervals that match the expected duration of protection but knowing that titer measurement is reliable for these diseases will still allow for better customization of vaccine intervals and may someday be a practical method for deciding when to vaccinate individual patients. Veterinary clients wishing to avoid vaccination except when demonstrated to be necessary, regardless of the expense or inconvenience, may wish to go ahead and pursue titer testing now.

Hospitalization in Veterinary Medicine
There are not very many veterinary hospitals that have an attending veterinarian on the premises twenty-four hours a day. Most veterinary hospitals do not even have a staff member on the premises at night. Despite this, hospitalization is not an uncommon procedure. It is important for pet owners to understand that hospitalization may mean that a pet stays overnight at the veterinary hospital that is not staffed at all.
We kept approximately ten pets overnight at our hospital last year. All but one of these patients were cats following declaw procedures. The other one was a dog with severe diarrhea that the owners felt they could not tolerate at home. We keep cats following declaws because there is a tendency to have minor bleeding the first night after the procedure. A cat shaking its paws can spread a little bit of blood over a very big area, so we keep cats as a convenience to their owners.
Our thinking is that pets should be home where there is someone to watch over them in case there is a post-surgical problem and to provide care at night when medical conditions warrant it. When we must provide care for more than a day this means that our clients have to come to the office and pick their pet up, then arrange to come back the next day and repeat the cycle until their pet is well. This does place some burden on the pet owners who come to our hospital and does seem to put some people off.
Veterinarians who believe in hospitalization think that the confined rest is important after surgery or feel that the risk of injury post-surgery may be higher at home. Some veterinarians are not worried about running intravenous fluids during the night when they are not at the hospital, feeling that the benefits of continuous therapy outweigh the risk to the patient of spending the night unattended. There is a recognition among some vets that there are veterinary clients who really value the convenience of having the veterinary hospital administer medications and clean up messes until the pet is well.

I can see that there are two sides to the issue of whether or not to hospitalize pets when it is not possible to be with them all night. I think that it is safer for the pet to be at home and I would rather be home when I am ill or injured so I opt to provide veterinary service in this manner. I am not sure that veterinarians who do hospitalize without someone being continually present at the hospital are wrong in their reasons for doing so. It is just not the approach that I prefer.
There are definitely some things that I think every pet owner should know before making the decision to leave a pet overnight at the veterinarian's, though.
The first question I would ask is approximately when everyone goes home and when they come back in the morning. There is a lot of difference between leaving a pet when the hospital staff leaves at 5PM and returns at 8AM the next morning and when the staff leaves at 11PM and comes back in at 6AM, for instance. I doubt that many, if any, pets are comfortable when left alone for 14 hours in a cage.
Will someone come in to check on the pets or are they monitored in some other way?
Will medications be administered to my pet during the time it is staying at the hospital at night? If not, I think it is reasonable to ask to take the pet home and bring it back in the morning, even if the veterinary hospital usually keeps pets overnight after surgeries or for ongoing medical therapy.
Can I pay someone on the staff to spend the night, if desired? We have had several clients who wished to do this for their pets and we can arrange for a certified technician to stay with a pet when requested. This is an expensive option but it does insure pretty individualized attention for pets who may need that.
Does the veterinary hospital have a working fire alarm system that automatically notifies the police and fire departments of trouble? I don't think that I would want to leave a pet at a hospital that did not have this sort of protection. I know of two veterinary hospital fires in our region alone that have cost the lives of numerous pets who were spending the night at the hospitals. I honestly do not know if either of the hospitals had alarm systems. If so then maybe this doesn't provide enough protection but it is at least worth asking about.
Is it possible for me to provide necessary medications and treatments at home? We have sent home intravenous fluids for pets with catheters in place, seizure control medications for rectal administration, stretchers for moving orthopedic patients and made other accommodations that allowed clients to care for their pets at home.
Do I have the option of transferring my dog to an emergency veterinary hospital or 24 hour care facility? Many emergency clinics also offer hospitalization for pets from surrounding veterinary hospitals. In most cases it is necessary to move the pet to the EVC around 6PM and then pick the pet up at 8AM the next morning but pets are monitored during the night and there is a veterinarian on the premises all night at most EVCs.
There are also some things to consider if your pet is not hospitalized and you will be providing the comfort and perhaps even the nursing care necessary following surgery or for extended medical illnesses. It is vitally important that you know who to contact if there is an emergency and how to contact them. Write down emergency numbers if they are not published in the phone book or some other readily available source. If your pet had surgery that was not routine or has a medical illness it may be best to ask for a copy of the current records to take with you if a trip to an emergency or after-hours care facility is necessary.
Many of our clients ask if it is safe to take a pet home on the same day as surgery. We have sent almost all of our surgical patients home the same day for the entire 22 years that we have owned our practice. We have not had a dehiscence (opening of a surgical wound through all layers) during that entire time from a spay, neuter or other routine surgery. This has happened to us several days after a bladder surgery in one instance, though. We have had other complications associated with surgery that necessitated returning to the clinic to meet the client and see the patient but most of our clients understood that it was best that someone was with the pet to see that complications were occurring.
Know your vet's hospitalization policies and think about how you want to approach hospitalization should it be necessary for your pet. Being prepared will make it easier to make appropriate decisions if you do find yourself in a situation in which you have to choose between hospitalizing your pet or caring for your pet at home. While I truly believe that pets are better off at home or at a continuous care facility, I know that hospitalization is favored by many veterinarians who can not offer round the clock care and feel quite sincerely that it is the best option for many of their patients.

Many of you have noticed that we are currently stating on our online order form that we are no longer answering questions from subscribers. Please check our subscriber area,
www.vetinfo.com/subscriber/subscriber.html, for information on our current policies regarding questions and also for an update on how we intend to deal with the changes in the economic climate of the Internet over the next year or so. We want to provide the best possible veterinary information site and we hope to be able to do that and to provide some individual assistance to subscribers.

If you send us e-mail, remember that Michal Justis receives the e-mail at vetinfo@vetinfo.com. E-mail sent to mervet@inna.net goes to Dr. Michael Richards.

This page was last edited 06/15/04
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This page is authored by
Dr Michael Richards, DVM
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Opinions expressed are those of Dr. Richards.
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