Parvovirus; Think Outside the Box

By Dr. Beth Guerra

Quite a few years ago, I evaluated a one year old schnauzer for an acute onset of vomiting and diarrhea. He had no known medical problems and had not eaten anything unusual that could have caused his symptoms. The owner allowed me to do a complete workup, including x-rays and bloodwork. There were very few abnormalities except for a very low white blood cell count, which can indicate overwhelming infection or inadequate bone marrow response to infection. I was wracking my brains for a cause that would also explain his symptoms, when I noted in the chart that the owner had acquired him as a very young puppy and that he was not yet neutered.  When I asked why she had not neutered him, she said he had never visited a veterinarian. That set off a bell in my head, and I questioned her about vaccine status. She reported he had never had any vaccines or boosters and that the breeder did not mention that he was given any before she acquired him. I immediately set up a parvo test, and it was a strong positive.

Veterinarians tend to think of parvovirus as a disease of very young puppies, usually under 16 weeks of age. The general public knows of parvo as “the puppy killer” because it is highly contagious and often affects young dogs that are not fully developed and therefore have an immature immune system. What I had failed to think of in this case was that even though this dog was a year old, he had never been vaccinated and therefore was still at risk for contracting the virus. We just had another case present this week with a severe parvo infection who is 4 years old, but again, had not been fully vaccinated.  In our current case, he had a single puppy shot and not the full series needed to produce immunity.

Parvovirus is ubiquitous in the environment and very difficult to kill with normal disinfectants; prolonged contact with a bleach solution is required. It is highly contagious and can remain in the environment for many months. Transmission between animals is via oral exposure to feces containing the virus, however, objects such as bedding and toys can also transmit the virus. Infection can be widespread in environments such as pet stores or breeding facilities due to close contact between animals. Incubation within the body can be up to two weeks and the virus can continue to be shed in the feces after infection has resolved.

The virus targets specialized crypts in the intestinal lining where new cells are rapidly produced. These cells die off and the intestinal lining becomes more permeable, allowing for loss of vital blood proteins and electrolytes and also letting harmful bacteria into the bloodstream from the intestinal tract. 

Symptoms include vomiting, diarrhea (often bloody), inappetance, and abdominal pain. Septic shock or disseminated intravascular coagulation (widespread hemorrhage) can occur in severe cases. The virus can also destroy developing white blood cells. The drop in crucial white cells increases the risk of secondary bacterial infections.

Diagnosis is based on presenting symptoms, vaccine history, and test results, which can include a positive parvo test (fecal test that can be done in house), decreased white blood cell count, or low blood albumin. Some puppies also have intestinal parasites that are found on fecal exam. Therapy is supportive while the virus runs its course. Intravenous fluids, anti-emetics, and broad spectrum antibiotics are utilized to minimize secondary effects of the virus. Some animals receive transfusions of whole blood or plasma. Parvovirus can be rapidly fatal if left untreated and these cases usually require several days of hospitalization on the road to recovery. Puppies that develop severe sepsis or secondary infections, such as pneumonia, may succumb to the disease. However, studies have shown that chance of survival with aggressive treatment is over 90%.

Once infection has cleared, the puppy may have lifelong immunity, however, vaccines are the best prevention. Puppies usually receive a series of “combo” vaccines, which include distemper, parvovirus, adenovirus, and parainfluenza. Vaccines begin around 8 weeks of age and boosters are administered every few weeks until they are 16 weeks of age. Whether you obtain a puppy from a breeder, pet store, or friend, it is important to question them about the vaccination status up to that point. Infection with parvovirus can occur at any time between boosters, so it is important to have your puppy evaluated by a veterinarian and comply with the  FULL vaccine schedule.

Full Moon and the ER

By Dr. Beth Guerra 

There are nights in the ER where I take a moment to reflect upon the phase of the moon. This usually occurs when I have every exam room full of potential patients and multiple critical animals being carried into the ICU on stretchers hemorrhaging, seizuring, or gasping for breath. Every emergency doctor, human or veterinary, cannot shake the conviction that a full moon coincides with a full, and often crazy, emergency room.

I have several friends that are human ER physicians, and we all swear by this phenomenon. Reflecting back on my years in the ER, I can recall with difficulty the full moon shifts where I wasn’t up to my elbows in critical patients, no matter what clinic I was working at during that time. I even psych myself out driving to work when I happen to glance up and notice the moon is waxing full.

Multiple studies have been done about this correlation, in both human and veterinary medicine, and the bottom line is, there is no correlation. Separate statistical analyses have failed to show any link between a full moon and the caseload in the ER clinic.

One study from the Indian Journal of Medical Science (2004) failed to show any positive relation between full moon days and variables such as number of trauma patients, assaults, or attempted suicides. Another retrospective study in Resuscitation (2003) analyzed ER caseloads for six years and did not find a correlation between the number of ER visits, the phases of the moon, or the signs of the zodiac. A similar study in Journal of Veterinary Emergency and Critical Care (2007) found no correlation between case load and the phase of the moon (or Friday the 13^th), but did note that weekends and holidays were consistently the busiest days of the year.

A literature search revealed that this phenomenon has been studied extensively since the late 1960s and has even delved into variables like number of births, dog bites, drug overdoses, suicide attempts, surgical complications, and cardiac arrest. In each instance, no relationship has been established that can be linked to a full moon.

Even with all this evidence to the contrary, I still approach my full moon shifts with a certain amount of trepidation. I make sure to get as much sleep as possible and eat before I get to work; as every emergency shift worker knows, you may not get another chance. I take a deep breath as I walk in the door and remind myself that it’s just another day, and that no matter how out of control things get, I can’t blame it on the moon.

SEPTEMBER- Healthy Aging Month

By Jennifer Waldrop, DVM DACVECC

What does “healthy aging” mean for your pet? Is it the same as for you? Basically, the answer is yes, with one glaring difference. Your pet cannot be trusted to tell you when something is starting to go wrong. Subtle warning signs of a problem may resemble age-related changes. For example, increased sleeping might be a headache or blurred vision. Difficulty rising could be arthritis, but could also be weakness related to low blood pressure, altered electrolytes, bone pain, or dizziness. We humans also tend to rationalize and “anthropomorphize” our pet’s issues, which can sadly delay diagnosis of many treatable diseases. Then it seems surprising when our pets are really sick and we hear of the degree or chronicity of the problem.

Given the rapidity of animal aging and their short life span, the only way to reliably monitor aging is by frequent visits to the veterinarian with an examination and geriatric lab work including a Complete Blood Count, Chemistry Panel and a Urinalysis. Chronic kidney disease is one of top three diseases of geriatric pets and kidney failure is only reliably diagnosed by checking a urine sample for concentrating ability (urine specific gravity.)  Ideally, this should be every six months for a dog over nine to 10 years (over seven years for Giant Breeds like Great Danes) and every year for cats over 10 years of age. For exotic pets, these recommendations will vary depending on the size and type of pet. This can become expensive and makes a good argument for pet insurance to cover some of the ongoing costs. When choosing a pet insurance, take care to check for geriatric exclusion clauses given that many pet insurance companies are also aware that aging pets require more care.

What else can we do to fend off some of the preventable changes of aging? Just as in humans, a healthy diet and exercise are crucial. Most commercial and many alternative diets are complete, but when in doubt, your veterinarian or a veterinary nutritionist will be able to consult on the appropriateness of the diet. Most “senior” diets do not have significant changes in ingredients or electrolytes that make them better than regular diets. Supplements like fish oil may have a place in treatment of canine osteoarthritis, but their role in prevention of other diseases such as heart disease or dementia is unknown. I still recommend them if there is no fish in the pet’s diet. There are instances when fish oil supplements are discouraged, specifically in some human cancers during chemotherapy.

Exercise of the body and mind are both important to provide your aging pet. Exercising with your dog has been found to improve health for the human in multiple research studies, and the reverse is likely true as well. The cardiovascular and muscular strength that moderate exercise provides is important to keep both healthy, but also serves as a reserve when you are sick. This reserve strength will improve recovery after accidents, surgery or other health issues. Outdoor exercise is also a mental boost for our dogs with input into all their senses. Time spent with their owner is also important for mental health, so part of a moderate exercise program should include an interactive component.

Exercising a cat or exotic pet can be a little more difficult, to say the least, but is extremely important given the high rate of obesity in our pets. Cats may enjoy chasing a toy on a wand or chase toys or balled up socks, but sadly some cats are not interested in chasing. For these cats, a companion cat or dog may provide some impetus for moving around even if it’s just to get away from the other animal. (Conflict can provide good stimulation ;) A younger cat could keep the older cat more active both physically and cognitively. The same is likely true for birds and small mammals.

At home, grooming and petting your cat or dog provides both with the benefits of companionship. Having friends and relationships is as important for our pets as for us. Studies in humans have shown increased longevity and mental health for those people who actively continue human interaction and relationships. Sometimes a pet and their human can become isolated from the rest of the world and this is not healthy for either individual. One of the least judgmental places for dog owners is the dog park where dogs of all sizes, temperaments and interests congregate with their humans of the same variability. For indoor-only cats, frequent household visitors and companionship with other housecats should provide good stimulation.

The best part of living with a pet is having a good friend who lives every day to its fullest. We can follow their example while we age as well and continue to fully enjoy each moment.

Men do not quit playing because they grow old; they grow old because they quit playing.

~Oliver Wendell Holmes  

Gastrointestinal Foreign Bodies

By Beth Guerra, DVM  

In my eleven years as a veterinarian, I have amassed quite a list of objects I have removed from the GI tract of dogs and cats. We veterinarians all have that one item we have pulled from the stomach or intestine that seems unique. I am constantly amazed at the ability of our furry friends to actually swallow these objects. I have seen some spectacular objects pass through with no problem, like straight pins and acorns, but I more frequently deal with patients where the offending object has caused an obstruction. Objects that make it into the stomach have two options; either they will be vomited up or try to leave the stomach through the pylorus. If the object is too big to advance into the intestine, it will remain in the body of the stomach and usually causes intermittent vomiting. Objects that advance into the small bowel will either pass without incident or cause a bowel obstruction.

Patients with GI foreign bodies can have a variety of symptoms, including vomiting, inappetance, or abdominal pain. Some pets will still want to eat but will vomit partially digested stomach contents shortly afterwards. In smaller dogs or cats, the foreign object can often be felt on abdominal palpation. Diagnosis is usually based on x-rays. Some objects, such as rocks or metal, show up easily on an x-ray, but others like cloth can be difficult to visualize, so a diagnosis of obstruction is made based on the appearance of the intestines and gas patterns. Abdominal ultrasound is used in those cases where the x-ray is inconclusive.

A rapid diagnosis and treatment of GI obstructions is ideal, especially when objects are obstructing the small bowel. The longer an object remains in the bowel, the greater the concern for complications such devitalized bowel or intestinal perforation. There can be pressure necrosis, or death of the tissue, over the object. This pressure necrosis can cause the tissue to tear and lead to leakage of intestinal contents into the abdominal cavity. In severe cases, the compromised bowel may need to be resected. If perforation has occurred, the resulting infection in the abdomen, called peritonitis, can be fatal.

Obstructing foreign bodies often need surgery. In some cases where a small, smooth object is in the stomach, the veterinarian may induce vomiting to see if the object can be retrieved. Alternatively, endoscopy can be attempted to pull the object out through the esophagus. If the object is sharp, very large or no longer in the stomach, surgery is indicated. The patient is usually started on aggressive fluid therapy to combat dehydration from vomiting, and in rare cases, this can encourage an object to pass. If the duration of symptoms is more than several days, or if there is concern for bowel perforation, surgery should not be delayed. With prompt treatment, pets often recover uneventfully from these surgeries.

Ingestion of foreign bodies can be prevented by providing your pet with toys that are adequately sized for the breed of dog to prevent accidental swallowing. You should also consider supervising your dog when offering treats such as large rawhides or greenies to make sure the treat is chewed slowly and not gulped down in large chunks. If you suspect that your pet has ingested something inappropriate or is showing clinical symptoms, a veterinary exam is recommended sooner rather than later.