Meet the Tripods!

By Beth Guerra, DVM

A while back, I wrote a blog about my three-legged poodle, Matilda. She was brought into ACCES Seattle during my first month of work, around the time I was looking to add a second dog to my household. She had sustained severe injuries to both the skin and bone on her right forelimb, and after consulting with our surgeon about several possible options, I chose amputation of the limb. She was estimated to be six months old at the time, and in the four years since then has flourished. She navigates stairs with ease, jumps on and off the bed more easily than my quadruped dog, and frequently runs 5Ks with me. I don’t think she remembers ever having four legs.

Matilda

This past fall, we added a second tripod to our home. Fiona is a long haired Chihuahua mix that was brought in by the King County Animal Control after she was found as a limping stray. The x-rays showed a fractured left elbow, and the decision was made to amputate the limb. She was about three months old at the time. I came back after some time off to discover her still convalescing in the ICU, and I fell in love with her immediately. Like Matilda, she was up and walking the day after surgery, and hasn’t looked back since. While her stature, combined with a missing leg, does make it hard for her to jump off furniture and climb stairs, she is extremely active, runs at the dog park, and grapples with our other two dogs.

Fiona

I have learned that each of my tripods has adapted to life differently. Each has a unique gait, which I did not expect. Matilda can move at slow speeds and stay balanced, but Fiona is constantly running to her destination and occasionally face-plants. Each dog chooses to present herself differently to new people. Matilda will bat you with her oversized front paw, but Fiona tends to hang back and hide. Each dog is a novelty at the dog park, and stimulates many conversations that revolve around rescuing pets and limb amputations. Although my dogs are small, and small dogs generally adapt better after losing a forelimb, I always tell people that this type of amputation does not necessarily mean a huge change in the quality of life for their pet, especially if it is a large breed dog. As they run full out at the park, my dogs are an ambassador for those pets with disabilities, proof that every dog deserves a chance, and that spirit can overcome a handicap.

For more information on three legged dogs, visit www.tripawds.com

Feline Saddle Thrombus

By Beth Guerra, DVM

Cats can develop a particular type of heart disease, known as hypertrophic cardiomyopathy (HCM). In this type of cardiomyopathy, the left ventricular wall becomes very thickened, or hypertrophied. This differs from the canine type, which is characterized by a dilated heart with thin walled chambers. These changes can lead to a variety of systemic problems, such as abnormal heart rhythms and murmurs, decreased oxygen delivery to heart muscle, and increased blood pressure. There can also be a change in blood flow through the chambers of the heart. Several of these changes together can lead to the formation of thrombi, or clots, within the heart. These clots are sent through circulation and can become lodged in distant arteries, causing an obstruction of blood flow. One of the most common sites for these clots to end up is where the aorta divides into two major arteries supplying the rear limbs. The presence of a clot, known as a ‘saddle thrombus,' is a strong indication that there is underlying heart disease.

Thrombus formation is acute and often the reason for presentation to the ER. Immediate symptoms include vocalization, discomfort, and paralysis of the rear limbs. Upon examination, no pulses in the limbs can be detected, the rectal temperature may be decreased (<97 F), and the rear paws may be cool to the touch or the nail beds bluish in color. Less often, a thrombus can form in one of the forelimbs, leading to similar symptoms of lameness or cold paw pads. Smaller thrombi can also shower the brain, lungs, or kidneys, leading to neurologic signs, respiratory difficult, or kidney failure. Because the saddle thrombus is nearly impossible to diagnose based on imaging techniques such as x-ray, diagnosis is usually made based on physical examination. A history of heart disease, murmur at time of exam, or arrhythmias/hypertension can also help solidify the diagnosis of HCM.

Treatment is multifactorial, as both the thrombus and the underlying heart disease must be addressed. An echocardiogram (ultrasound) of the heart is the best way to confirm HCM. This disease in cats is not reversible; treatment is aimed at trying to prevent further thrombi from forming and can include heparin initially and then aspirin or Plavix. Other drugs may be added based on the severity of heart failure. However, there is no foolproof way to break down the pre-existing saddle thrombus with medications, although it may break up on its own over time. Supportive treatment is indicated during the initial days, and is aimed at nutritional support, pain control, and physical therapy. If circulation cannot be restored within one to two days, necrosis of the limbs can develop, ending in either partial amputation or euthanasia. Although prognosis is generally guarded, it is reasonable to support the cat for a few days with pain medications to see if circulation returns to the limbs. Survival can be up to 10 to 12 months after diagnosis, however, these cats are usually euthanized if the initial clot fails to resolve or if symptoms recur, eve n if the cat is on medication.

For more information, visit  http://mysite.verizon.net/jachinitz/hcm or http://www.ncbi.nlm.nih.gov/pubmed/12564730

(Note: Cardiologist Dr. Anthony Tobias referenced in above source article is joining the ACCES specialty team on February 20, 2012.)

The Subtle Signs of Pericardial Effusion

By Dr. Beth Guerra

Occasionally, as a veterinarian I must chase down a diagnosis with not much to go on. An animal presents with very vague symptoms but both the owner and I know that something is amiss. Through experience, I have learned to think outside the box in some situations and look for the ‘zebra’ diagnosis when symptoms just don’t add up.

One of these elusive diagnoses is pericardial effusion. The heart is contained within a mostly rigid sac, called the pericardium. When fluid or blood accumulates in this space, the heart is compressed and cannot expand efficiently. Because of this, blood flow through the heart is decreased, leading to compromised peripheral circulation. To compensate, the heart beats faster to try and make up for the deficit. This compression of the heart by fluid is known as cardiac tamponade. Blood pressure drops, oxygenation is low, and the animal may experience collapsing episodes. Sometimes they have pale mucus membranes, or muffled heart sounds from the fluid that has built up. Diagnosis is based on x-ray, where a large, globoid heart silhouette is seen, or more easily with ultrasound, where fluid around the heart is directly visualized.  Sometimes the ECG will show characteristic changes in the tracing.

In a textbook situation, all of the above symptoms occur. More often, I have animals that present with subtle symptoms, such as slow, deep breathing, mild weakness when walking, or apparent abdominal pain (hunched posture, groaning). Physical exam reveals none of the classic symptoms of pericardial effusion. The history is inconclusive. Yet something tells me to look for the ‘zebra’, to systematically evaluate every body system to try and explain the symptoms. Since I have access to a portable ultrasound, in these cases I will often do a quick scan of the heart to see if there is any pericardial fluid. It is a relief when I find it, because I have a diagnosis. However, the presence of this fluid usually indicates a poor prognosis.

Fairly frequently, animals with pericardial effusion are in distress. The quickest way to stabilize such a patient is to remove the fluid with a needle, known as pericardiocentesis. This also allows the doctor to examine the fluid to try and determine an underlying cause. The fluid is often blood, which can indicate a heart base tumor that has ruptured. Occasionally, the fluid is clear or has very little blood, which may also indicate a tumor but may also be idiopathic (unknown cause). Diagnosing tumors in this area can be extremely difficult, as they can be too small to detect on thoracic ultrasound. A CT may be recommended, especially if surgical intervention is being considered. Some owners choose to treat palliatively, draining the fluid as needed, although this does present its own risks. If a tumor is found, the overall long term prognosis is poor.  In the rare instance of idiopathic effusion, some animals may do well with a surgery to remove the heart sac.

ACCES is lucky to have a veterinary cardiologist joining our staff to help with these difficult cases.  Anthony Tobias, DVM DACVIM (Cardiology) will be joining ACCES February 20, 2012.

Marijuana Toxicity in Pets

By Dr. Beth Guerra

At the emergency clinic, we commonly treat pets that have gotten into household medications, even those considered to be hidden or out of reach. For example, we often see a range of medication ingestions, from vitamin supplements to heart medications.

However, in the last few months, we are seeing a greater number of pets who have gotten into owners medicinal or recreational marijuana. The active compound, THC, interacts with neurotransmitters in the brain and can cause a variety of symptoms. The amount of THC varies greatly (i.e., dried product vs. oil), as does a pet’s individual response to the drug. According to the ASPCA Poison Control Database, research has shown that ingestion of 3-9g/kg of body weight can cause symptoms. Death from ingestion can occur, but is rare. A majority of cases (97%) are dogs.

Pets that have ingested marijuana can exhibit a variety of symptoms. The most common are walking off balance (ataxia), not reacting normally, acting depressed, hypersalivating, and dribbling urine. Pets may also have dilated pupils, can seizure, and may have a fast heart rate. Occasionally, agitation may occur. If the product has been baked into goods containing chocolate, the pet must be monitored and treated for those symptoms as well. Treatment of marijuana toxicity is focused on decontamination and supportive care. Often, vomiting is induced, especially within several hours of suspected ingestion. Several doses of activated charcoal may be given to prevent further absorption from the GI tract. In severely affected animals (i.e., overly sedate), IV fluid support and hospitalization for monitoring may be recommended until the pet is more responsive. Symptoms usually resolve within 24 hours with no lasting effects.

Pet owners are often reluctant to admit that exposure to marijuana is a possibility. However, it is crucial to inform your veterinarian of any possible exposure to this or other drugs. We are not required to contact the authorities about drug ingestions and only use the information to best treat your pet. Signs of marijuana toxicity can be similar to other types of issues. If we don’t know about the exposure, we may need to run tests to rule out other diseases. If we know of the exposure, we can often provide supportive care and be fairly sure of a good outcome.

New Year's Resolutions for Your Pet!

By Dr. Beth Guerra

With the New Year comes the inevitable resolutions. While you are making your own list, consider making one for your pet as well. Whether it’s as simple as learning to trim your pets nails, or focusing on finally getting that extra weight off your beloved companion, remember that you are your pet’s advocate and change starts with you.

Yearly physical exams are important for all pets. In the past, pets usually received a yearly physical when vaccines were due. Because vaccines are not needed as often (every three years is now recommended for adult animals), yearly physicals have sometimes been skipped. Even if your pet has never had an illness, these exams are important to establish a good health baseline and can also be crucial in detecting emerging disease. A thorough exam combined with an extensive history can often aid in disease prevention or help establish a diagnostic and treatment plan early in the progression of a disease. For example, if kidney disease is caught early, a simple diet change can often prolong life for many years.

Obesity has become a major problem in household pets. This may be due to inappropriate diet, lack of exercise, injury, or metabolic disease. If you notice your pet has packed on a few pounds, or seems lethargic, schedule an exam with your veterinarian to discuss weight loss. It may be as simple as reducing the amount of food, switching to a lower calorie/higher fiber or high protein diet, or increasing activity. It is also important for your pet to have an exam to make sure there isn’t another reason for the weight gain, such as hypothyroidism. Consistent weigh-ins with your vet can help chart progress and identify any setbacks.

Dental hygiene is also extremely important. Frequent dental cleanings are recommended for both cats and dogs. Some pet owners may be reluctant due to cost and the need for general anesthesia, but the benefits often outweigh the cost. Dental cleanings focus on removing the tartar visible on teeth and can improve the health of gingiva. Problems with teeth, such as erosions, fractures, or tooth root abscesses can be detected and treated appropriately. The mouth is examined for ulcers or masses that are often not observed by the owner. And, your pet will most likely have fresher breath!

For older pets on medications, a yearly exam is an important part of the monitoring process. Anti-inflammatories for arthritis, thyroid supplements, seizure medications, and insulin are some examples of medications that need to be closely monitored. Bloodwork, such as a complete blood count and serum chemistry, is often an integral part of the monitoring process and may be recommended yearly as well. This also helps to establish a baseline and can provide useful information for comparison if your pet becomes ill.

For 2012, take some time to establish goals for you and your pet. Prevention is the best medicine, and it may keep your pet from having to visit the emergency clinic!

Is it Okay for My Cat to be an Outside Pet?

By Patrick Miles, DVM

One of the questions we ask when a cat presents to the hospital is whether they are indoor only, outdoor only or both. A few clients over the years have become defensive or felt guilty over this issue. The simple answer to the above question is yes. Your cat is your pet and your responsibility. There is not one lifestyle that is perfect for every home. Some cats are not good indoor companions due to behavior issues, allergies, house soiling, etc. There are situations in which owners felt pressured to keep their cats indoor by friends, family, adoption agencies, and veterinary professionals. We will often recommend a cat that has been ill or recovering from a surgery become an indoor pet during recovery to reduce complications risks.  However, it still is an owner’s choice to allow their cat to live an outdoor life once healed.

As a veterinarian, the lifestyle of a cat can play an important role in addressing an illness. If a cat lives indoors, it can be much easier to develop a diagnostic and therapeutic plan simply because the possibilities causing an illness tend to be more limited. For instance, patients that present sick that live outside may not be able to answer whether there has been any trauma, vomiting, diarrhea, cough, straining to urinate, blood in stools, etc.  Problems that arise with indoor cats tend to be found earlier simply because of the more intimate proximity, i.e. it’s easy to know if your cat has been vomiting when you accidently step in it or find it on the couch.

Risks for outdoor cats can be extensive. The risk for trauma from vehicles, dogs, other cats, raccoons and other wildlife tend to be more obvious. Infectious diseases are more common due to exposure to other cats.  Feline leukemia and Feline AIDS are more common due to bite wounds from infected cats. They may ingest unknown toxins, things that can cause vomiting and diarrhea, etc. The list of risks can be extensive. Subjectively, outdoor cats tend to have a shorter lifespan than indoor cats.

When we ask this question, it is not to judge your decision on your pet’s lifestyle. It is to help develop and focus the approach to an illness. We may advise additional diagnostic testing for a specific problem based on the lifestyle, thus increasing the financial obligation. The issue is really one of understanding and accepting the increased risk of illness or trauma.

When Repeating Diagnostics Makes Sense

By Beth Davidow, DVM DACVECC 

Many times clients will ask why we are repeating a test.  It does seem that if you have just had blood work done recently, things shouldn’t be that different.  However, when an animal is sick, things can change dramatically over a period of hours.  The following case is a good example.

A seven and a half-year-old pointer was referred to our ICU for care of a suspected reaction to a chemotherapy drug.  A review of his case showed that the dog had a skin lump that turned out to be an atypical form of a cancer called lymphoma.  (Lymphoma is a cancer of lymph nodes and lymphatics and doesn’t usually show up as a skin nodule.)  Initial screening showed no evidence of the cancer anywhere else.  The dog had been given a chemotherapy drug three weeks prior to presentation.  The tumor shrank dramatically in size and he seemed to feel well.  Many chemotherapy drugs can suppress the body’s infection fighting cells, the white blood cells, and this did happen seven days after the drug was given.  The dog was put on antibiotics and seemed to be fine.  However, three weeks after the drug was given, the dog acutely started having vomiting, diarrhea and was severely weak.  He had a fever and a borderline low white blood cell count.  Bloodwork, radiographs and ultrasound were done and no evidence was seen of any new cancer.  It was assumed that he had an infection secondary to having the low white blood cell count.

When the dog arrived at ACCES, he was dehydrated, weak and had a fever.  He had been started on IV fluids, antibiotics and anti-nausea medications at the regular veterinarian and those treatments were continued.  However, at 10:00 pm he was still febrile and now couldn’t stand up.  A blood glucose (blood sugar) was rechecked and had fallen to a dangerously low level. He was given IV glucose and was much brighter.

Why did the blood glucose fall in only 12 hours?  Normally dogs can maintain their blood sugar in a normal range even if they aren’t eating.  In the face of overwhelming infection, sometimes the bacteria are “stealing” the glucose and blood values will fall quickly.  Sometimes, if the body’s normal stress mechanisms aren’t working, it can also fall.  Sometimes, tumors can also “steal’ glucose but we hadn’t found any new cancer.  Our working hypothesis was that we still weren’t on top of the infection.  We started an additional antibiotic.

Over the next 24 hours, the glucose stayed normal and the fever resolved but the dog was still very depressed and wouldn’t eat.  The next morning, 48 hours after the initial illness started, small pinpoint bruises were noted on the skin.  This can be a sign that the clotting system isn’t working.  We checked the clotting blood values and found that the platelets, small particles in the blood that make the initial clot, were now very low, even though they had been OK the day before.  A full complete blood count was sent to the lab.  A falling platelet count can also be a sign of infection or emerging cancer but the fever was under control.  What was happening?

In the afternoon, we had our answer.  The complete blood count, which had only normal blood cells 48 hours before, now showed cancer cells in the blood.  The cancer, despite being gone from the skin, had lodged in the bone marrow and in a 48 hour period and multiplied fast enough to be found in the blood stream.  The dropping glucose and platelets were not from a chemotherapy reaction or from infection but from the emerging cancer we couldn’t yet see.

Thus, repeating the same tests several times allowed us to diagnose the reemerging cancer quickly.  It was a lesson of how rapidly things can change in the body.