The Spleen: Do Dogs and Cats Really Need One?

August 29, 2011

Some weeks seem to have a medical theme. For me, this week’s theme is the spleen or, more accurately, the absence of one as I wrote earlier this week about the case of Walker. Many of my patients this week have had their spleen surgically removed, a procedure called a splenectomy.

The spleen is a dark red organ which resides in the abdomen and is loosely attached to the border of the stomach by a thin veil of tissue and blood vessels.

Outlined is a very large, but smooth spleen in a cat. This is due to a mast cell tumor.

In most pets, the spleen is about as long as their forearm. It functions as part of the immune system, helping the body to fight off infections and removing aged, non-functioning red blood cells from circulation. Neither dogs nor cats suffer long-term effects from the lack of a spleen, which is different than in humans. Humans without a spleen need to take special precautions to protect themselves from a serious infection.

Veterinarians don’t know the cause, but several different disorders affect the spleen and disturb its normal function. Some disorders require a splenectomy as part of the treatment.

The loose attachment of the spleen to the stomach can sometimes result in the need for an emergency splenectomy in a dog if the spleen twists around itself and blood flow to the organ is blocked. The lack of blood supply makes the dog acutely ill, and on examination the ER veterinarian will feel a very enlarged spleen. The cause of this disorder is unknown, but surgery is curative.

One of the normal functions of a spleen is to remove old red blood cells. In cats with an unusual and as of yet unexplained disease, red blood cells are cleared at a more rapid rate than normal, resulting in anemia and an enormously enlarged spleen. In this disease, known as increased osmotic fragility of erythrocytes, removal of the spleen benefits the cat by improving the anemia.

Outlined is a very large, but irregular spleen in a dog. This is due to hemophagocytic histocytic sarcoma.

Because dogs and cats tolerate removal of their spleens so well, splenectomy is a common treatment for tumors of the spleen. In dogs, the most common tumor of the spleen is hemangiosarcoma.

The x-ray of a dog’s abdomen (shown below) is typical of a dog with a rare splenic tumor called hemophagocytic histocytic sarcoma. The x-ray of a cat’s abdomen shows an enlarged spleen due to mast cell tumor, the most common spleen tumor in the cat.

Although removal of an organ is medically serious, a splenectomy often results in a dramatic improvement in a pet’s quality of life without long-term negative consequences.

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This may also be found in the “Tales from the Pet Clinic” blog on WebMD.com.

For over a century, The Animal Medical Center has been a national leader in animal health care, known for its expertise, innovation and success in providing routine, specialty and emergency medical care for companion animals. Thanks in part to the enduring generosity of donors, The AMC is also known for its outstanding teaching, research and compassionate community funds. Please help us to continue these efforts. Send your contribution to: The Animal Medical Center, 510 East 62nd Street, New York, NY 10065. For more information, visit www.amcny.org. To make an appointment, please call 212.838.7053.


Hemangiosarcoma: A Common Tumor of the Spleen

August 25, 2011

The Animal Medical Center’s ER struggled to save Walker last week. Walker was an apparently healthy, 10-year-old German shepherd. He collapsed at home and was rushed to the ER. Examination by the ER staff was quickly focused on a triad of abnormalities – anemia, abdominal distension and shock. These findings immediately suggested internal hemorrhage from a tumor of the spleen common to German shepherds called hemangiosarcoma.

Hemangiosarcoma is a tumor arising from blood vessels. Unlike lymphoma, which is common in both humans and pets, hemangiosarcoma is not a human cancer. Walker’s tumor developed in his spleen, but the right side of the heart and skin are other common locations for hemangiosarcoma in the dog. Occasionally it develops in an unusual location like the eye, prostate, bone, retroperitoneal space (an area outside the abdomen but inside the body, near the kidneys). Almost any breed of dog can develop hemangiosarcoma. Most large breed dogs are at risk for this deadly tumor, including German shepherds like Walker, Golden retrievers, Labrador retrievers and schnauzers. Cats are affected by hemangiosarcoma, but it typically occurs in the skin and rarely occurs in the spleen. For those with large animals in their lives, horses and sheep also develop hemangiosarcoma.

The acute collapse Walker’s owner observed is a common sign of hemangiosarcoma. The tumor bleeds easily resulting in anemia and weakness. Sometimes, if the bleeding is only slight, the signs are more subtle – weakness followed by normal energy or difficulty jumping into the car or onto the sofa. If hemangiosarcoma occurs in the heart, it may block the heart from pumping blood, causing collapse.

Veterinarians do not know what causes hemangiosarcoma. Because we don’t know what causes it, we can only treat the tumor, not prevent its occurrence. The emergency surgeon often handles the first part of treatment, splenectomy.

The spleen is removed to stop the internal hemorrhage and also test the spleen for malignancy. Similarly skin tumors can be removed with surgery, but tumors of the right side of the heart are not so easily removed. In some cases, treatment stops there, but in other cases, dog or cat owners elect follow-up chemotherapy. Chemotherapy has been shown to prolong survival compared to dogs treated with surgery alone, but virtually all dogs relapse.

Walker’s family wanted to give him every chance and he has just gotten his first treatment. I am happy to report he has had no reaction and we will keep our fingers crossed.

Some of you may be wondering what the impact of removal of the spleen will have on Walker. I’ll address your question in my next post.

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This may also be found in the “Tales from the Pet Clinic” blog on WebMD.com.

For over a century, The Animal Medical Center has been a national leader in animal health care, known for its expertise, innovation and success in providing routine, specialty and emergency medical care for companion animals. Thanks in part to the enduring generosity of donors, The AMC is also known for its outstanding teaching, research and compassionate community funds. Please help us to continue these efforts. Send your contribution to: The Animal Medical Center, 510 East 62nd Street, New York, NY 10065. For more information, visit www.amcny.org. To make an appointment, please call 212.838.7053.


Managing your Pet’s Medications: The Importance of Compliance

August 22, 2011

On a daily basis, the veterinarians at The Animal Medical Center prescribe pills, capsules and tablets to cure, control and prevent diseases. We have pockets full of prescribing information, access dosing online and carefully follow guidelines to use medications safely and wisely.

Correct prescribing by the veterinarian is critical to medication success, but the other half, administering medications as prescribed is equally important. Pet owners, upset by the illness of their pet often misunderstand directions or adjust medication dosing without consulting their pet’s veterinary healthcare team. If you think no one would do this, here is summary of this week’s medication conversations.

Becky
Poor Becky had major dental surgery this week, including eight extractions and resulting in a prescription for pain medications. Becky, a dachshund, belongs to an employee of The AMC and I stopped by her office the next day to check on the dog. It just happened to be medication time and Becky’s owner was worried Becky was painful (highly likely given eight extractions) and she though she would give only half the prescribed dose of pain medications. I reassured her the amount prescribed had been carefully calculated for Becky’s size and pain level and that the entire dose should be given.

Montana
Montana is getting chemotherapy and also some antinausea pills. When I reviewed his prescriptions, his owner reported she was giving half a pill twice daily rather than one pill once daily. She thought the antinausea effect would last longer if she gave the pill more often. The problem with this logic is the antinausea medicine stays around a long time, hence the once a day dosing recommended by the manufacturer. By giving half a dose, Montana may not have gotten a high enough level of antinausea medicine in the bloodstream to have a full effect.

Harvey
Finally, there’s Harvey and his chemo pills. He started a new regimen and I called a couple days later to see how it was going. Harvey felt great. I should have listened to my inner doctor voice saying, “Hmm, seems too good to be true.” Turns out his owner made an honest mistake, misread the label and was giving only one pill instead of two. Now he is on the correct dosage and is feeling better than ever since his tumor is shrinking.

Medication Pointers

  • Read the label. Read it again and if you have questions, call your veterinarian’s office.
  • Give the medication as prescribed on the label. Don’t adjust the amount, frequency or duration of administration without talking to your veterinarian.
  • If you are having trouble administering medications, stop by your veterinarian’s office for a lesson in administration.
  • If the medication schedule does not fit with your schedule, ask your veterinarian if there is an alternative drug with a different schedule.
  • If your pet won’t take a pill, ask if the medication comes in a liquid or can be formulated into a liquid to ease administration.
  • If you think your pet is having a bad reaction to the medication, stop the medication and call your veterinarian immediately. For after hours trips to the animal ER, be sure to take all the medications with you and show them to the ER staff.

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This may also be found in the “Tales from the Pet Clinic” blog on WebMD.com.

For over a century, The Animal Medical Center has been a national leader in animal health care, known for its expertise, innovation and success in providing routine, specialty and emergency medical care for companion animals. Thanks in part to the enduring generosity of donors, The AMC is also known for its outstanding teaching, research and compassionate community funds. Please help us to continue these efforts. Send your contribution to: The Animal Medical Center, 510 East 62nd Street, New York, NY 10065. For more information, visit www.amcny.org. To make an appointment, please call 212.838.7053.


Visionary Leaves His Imprint in Veterinary ICUs

August 18, 2011

Dog in oxygen cage in AMC’s ICU. Plexiglas door provides total visibility for monitoring while maintaining oxygen-rich environment for patient.

The Washington Post has an interesting obituary online. The obituary of Dr. Max Harry Weil credits this physician with helping to invent the intensive care unit (ICU) in human hospitals. I wonder if he would be surprised to know his work is visible in the intensive care unit at The Animal Medical Center and many other large veterinary hospitals as well?

Dr. Weil’s precursor to the ICU we know today was a “shock ward” with four beds in 1958. The AMC’s ICU has 19 “beds” and manages pets in shock from serious trauma, such as automobile accidents, on a daily basis.

Dr. Weil’s vision was for all the necessary equipment and expertise required by seriously ill patients to be housed together in a single location. He coined the term “critical care” to describe both the hospital space and the expertise. To meet the needs of his critically ill patients, he developed the rolling “crash cart” holding the equipment and drugs necessary for managing cardiac arrest. The AMC has multiple crash carts throughout the hospital so one is always near a pet in need.

Contents of just one drawer in an AMC crash cart.

In the AMC’s ICU, there is a small “stat lab” where we measure biological parameters which can change on a minute to minute basis. This stat lab allows the ICU staff to measure blood oxygen levels, red blood cell counts, liver and kidney function, blood sugar and the blood’s ability to clot 24 hours a day, 7 days a week. Ready access to monitoring allows the critical care staff to change treatments in response to changes in the pet’s condition.

Stat lab in AMC’s ICU.

In keeping with Dr. Weil’s vision of critical care, the AMC ICU also includes a highly trained staff specializing in the care of critically ill patients. Veterinarians who are specialists in the management of critically ill patients are board certified by the American College of Veterinary Emergency and Critical Care.

We also have nurses, called licensed veterinary technicians, who are certified by the North American Veterinary Technician Academy in emergency and critical care.

Pets and veterinarians everywhere owe a debt of gratitude to Dr. Max Harry Weil for his vision of critical care, which helps us to take better care of our patients every day.

Photos: Ann Hohenhaus, DVM

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This may also be found in the “Tales from the Pet Clinic” blog on WebMD.com.

For over a century, The Animal Medical Center has been a national leader in animal health care, known for its expertise, innovation and success in providing routine, specialty and emergency medical care for companion animals. Thanks in part to the enduring generosity of donors, The AMC is also known for its outstanding teaching, research and compassionate community funds. Please help us to continue these efforts. Send your contribution to: The Animal Medical Center, 510 East 62nd Street, New York, NY 10065. For more information, visit www.amcny.org. To make an appointment, please call 212.838.7053.


DNA Testing for Your Pet: Not Just for Criminals!

August 15, 2011

DNA testing appears daily in the news. The OJ Simpson trial in 1995 made DNA testing famous and the technology continues to help juries determine innocence or guilt. Veterinarians use DNA testing for both serious medical conditions and to determine dog heritage. One apartment complex in New Hampshire is using DNA testing to identify the dogs and dog owners guilty of violating pooper scooper laws!

Animal Medical Center veterinarians use DNA testing to diagnose a variety of diseases. Take veterinary internal medicine specialists for example. Some members of the Cavalier King Charles spaniel breed have a lower platelet count than most other dogs. Platelets are little blood clotting cells, but even with a lower number than usual, the Cavis do not have excessive bleeding. However, the number of platelets in these dogs is low enough to make the veterinarian think a diagnostic investigation is necessary. Since the low platelet count is inherited in this breed, veterinary researchers at Auburn University developed a DNA test to identify this abnormality and avoid the need for a costly medical evaluation of a low platelet count.

Veterinarians also use DNA testing to diagnose infectious diseases. Polymerase chain reaction (PCR) amplifies a minute piece of DNA from an infectious agent present in the bloodstream to confirm the presence of the organism as the cause of an illness. After treatment, PCR can be used to confirm eradication of the infectious agent.

Oncologists use DNA testing to confirm a cancer diagnosis when the biopsy result is unclear. Veterinary researchers have identified genetic abnormalities in several types of canine and feline cancers. Testing for the presence of these abnormalities can help oncologists identify the tumor type and also help them choose the best treatment for your pet.

A fun use of DNA testing is to determine the genetic heritage of your mixed breed dog. Several companies offer this test.

The tests vary as to the required sample for testing — some require a blood sample obtained by your veterinarian; other tests use cells from the inside of the cheek collected with a special swab. Just like humans are interested in their family background, dog owners are interested in their dog’s background.

There may also be medical applications. If you know your dog is a high percentage of a particular breed of dog, you may monitor for diseases known to affect that breed. Knowing you dog’s heritage may help explain the behavior traits he exhibits, like the excellent swimming skills of a Labrador retriever or herding behaviors typical in Border collies.

So don’t worry if your veterinarian recommends a DNA test for your pet. It is not likely for an episode of CSI.

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This may also be found in the “Tales from the Pet Clinic” blog on WebMD.com.

For over a century, The Animal Medical Center has been a national leader in animal health care, known for its expertise, innovation and success in providing routine, specialty and emergency medical care for companion animals. Thanks in part to the enduring generosity of donors, The AMC is also known for its outstanding teaching, research and compassionate community funds. Please help us to continue these efforts. Send your contribution to: The Animal Medical Center, 510 East 62nd Street, New York, NY 10065. For more information, visit www.amcny.org. To make an appointment, please call 212.838.7053.


On the Road Again: Safety Restraints for Car-Traveling Pets

August 11, 2011

According to the American Automobile Association, 30.9 million Americans will drive to their vacation destinations this summer. Sixty-one percent of pet owners take their pets on vacation. If you do the math, that equals nearly 19 million car-traveling pets. No wonder pet seat belts for dogs were the topic of a recent article in the Wall Street Journal.

Proper restraint of your pet while riding the in the car is an important safety consideration for both you and your pet. The National Highway Traffic Safety Administration (NHTSA) lists unrestrained pets as a driving distraction. Proper restraint keeps your mind focused on the road, keeps the pet from becoming an injury-causing projectile or from becoming injured in the case of an accident. Keeping your pet restrained while you are traveling also keeps your pet inside the car when you roll down the windows to pay a toll or ask for directions.

If you travel in the car with your cat, a carrier will keep your cat from roaming about, distracting you from driving. You should put a seat belt though the handle or straps to keep the carrier immobile during an accident. The cat carrier will only keep your cat safe if you can get the cat into the carrier. The minute a cat spies the carrier coming up from the basement or out of the closet they make a beeline underneath the middle of your king-sized bed. Once you flush them out of their hiding place, the most placid pussy cat becomes a man-eating lion. The folks at the Catalyst Council Channel on YouTube offer several videos to help cat owners train their cat to like getting into its carrier and traveling in the car.

When you buy a car or a child safety seat, you rely on data from crash tests to evaluate the quality of the product you intend to buy. The NHTSA website does not have information about pet restraint systems and I could not find any guidelines for evaluation of pet safety restraints. IMMI designs, tests and manufacturers vehicle safety systems. Their dog product is manufactured using seatbelt materials and they have video showing how it functions during crash testing using a doggie crash test dummy.

Since there appears not to be criteria for pet seat belts, here is what I would look for:

  1. Device has metal hooks, latches and loops Plastic will not be strong enough if you and your pet are in an accident.
  2. Device attaches to the car’s seat belt or the child safety restraint anchor located in the junction between the back and seat cushions. A device that attaches to the hooks for hanging clothes is not strong enough to hold up during a crash.
  3. Device fits your pet — not too tight and not too loose. Most systems I looked at online came in various sizes.
  4. Device keeps your pet in the back seat where they are safer.

Additional car travel resources include:

  • The American Automobile Association offers tips, product reviews and a pet travel book to its members.
  • Bark BuckleUp offers a free pet safety kit on their website to serve as a reminder to first responders about a possible pet in your car.

Click here for additional information about driving with pets.

________________________________________________________

This may also be found in the “Tales from the Pet Clinic” blog on WebMD.com.

For over a century, The Animal Medical Center has been a national leader in animal health care, known for its expertise, innovation and success in providing routine, specialty and emergency medical care for companion animals. Thanks in part to the enduring generosity of donors, The AMC is also known for its outstanding teaching, research and compassionate community funds. Please help us to continue these efforts. Send your contribution to: The Animal Medical Center, 510 East 62nd Street, New York, NY 10065. For more information, visit www.amcny.org. To make an appointment, please call 212.838.7053.


Will that be One Lump or Two? A Guide to Lumps on Your Dog

August 4, 2011

My telephone and email have been ringing and pinging this week with questions about lumps on dogs.

Lump near the tail base of a standard poodle.

The subject line of the first email said “Lump on Rump” which sounded like a line from an oncology book written by Dr. Seuss. When I examined the dog, I found a firm mass below the skin just to the right of the tail. Since this was a standard poodle, I suspected a sebaceous cyst, a common lump in this breed. But since you can never determine a benign or malignant lump by observation, I performed a fine needle aspiration using the same size needle I would use to administer a vaccination. Within 24 hours the laboratory confirmed my diagnosis. The worried owners were relieved, especially since no surgery was required for this benign lesion.

Small pea sized lump on the shoulder of a dog

The second call was from an AMC colleague who has just adopted a foster dog. He’s been vaccinated, groomed and has a spiffy new collar. His owner was petting him and found a lump over his right shoulder. The combination of the recent vaccination and the location of the lump (right where he would have been vaccinated for distemper/parvovirus) made me think it was a small-localized vaccine reaction. Since this dog comes to AMC most days, we carefully measured it on the first day and again a week later and it was already getting smaller. I will continue to monitor this lump but suspect it will go away in another couple of weeks.

The third call was from a friend of mine who is a veterinarian. She had found a lump on her own dog and performed an aspiration which diagnosed a mast cell tumor.

Because these tumors sometimes require specialist level care, she wanted input from the AMC about how best to approach this tumor surgically and input from me regarding an potential chemotherapy.

If you have a lumpy dog, have each lump evaluated by your veterinarian. I keep a line drawing of a dog’s body in each dog’s medical record. On the drawing I sketch the lump, record the size based on measurements and indicate the date aspiration cytology was performed. This process makes short work of determining if this is a new lump or not.

If your veterinarian recommends aspiration cytology or a biopsy, go for it. Without additional information, it is impossible for me or any veterinarian, to give an owner bad news or good news about the lump on their dog.

Don’t hesitate to seek the opinion of a specialist. A dog with a lump in a difficult location may need a advanced imaging to define the tumor location, a specially trained surgeon to successful remove a lump or a cancer specialist to provide follow up chemotherapy.

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This may also be found in the “Tales from the Pet Clinic” blog on WebMD.com.

For over a century, The Animal Medical Center has been a national leader in animal health care, known for its expertise, innovation and success in providing routine, specialty and emergency medical care for companion animals. Thanks in part to the enduring generosity of donors, The AMC is also known for its outstanding teaching, research and compassionate community funds. Please help us to continue these efforts. Send your contribution to: The Animal Medical Center, 510 East 62nd Street, New York, NY 10065. For more information, visit www.amcny.org. To make an appointment, please call 212.838.7053.


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