Wednesday, June 20, 2012

The Great Lyme Debate

Last fall I attended DC Academy; a continuing education meeting held monthly for local veterinarians. The speaker was Dr. Goldstein, an Internist from Cornell Veterinary School, who discussed his latest findings and recommendations related to Lyme disease.  What he said about Lyme disease completely challenged what I had thought about vaccinating against this all too common disease.

I have said in previous posts that I hate Lyme disease, this did not change during my day at DC Academy.  In fact the issue became even more confused and it took the last few months for me to research the issue and come up with an opinion.  Ultimately I have changed my view of the vaccine and now recommend it for specific at risk dogs. 

I have always recommended against vaccinating for Lyme, concerned that the vaccine is not effective and reportedly causes more vaccine reactions than the other vaccines we give.  Besides, we have so many dogs test positive for Lyme that never develop any clinical signs, it doesn’t seem like a disease that causes many problems – until you consider Lyme nephritis which terrifies me.

Lyme nephritis is a syndrome characterized by acute kidney failure that almost always results in death.  It occurs most frequently in younger adult dogs and there may be a higher incidence in Labrador and golden retrievers.  Clinical signs come on suddenly and include increased thirst, increased urination, lethargy, decreased appetite and vomiting.  Despite aggressive treatment dogs that develop Lyme nephritis rarely survive.

The topic of vaccination for Lyme is such a hotly debated issue in veterinary medicine that even the members of the American College of Veterinary Internal Medicine (ACVIM) Lyme Disease Task Force could not come to a consensus.  Dr. Littman of the University of Pennsylvania College of Veterinary Medicine does not believe in vaccinating for Lyme.  She argues that the vaccine has not been proven to prevent Lyme nephritis and in fact may predispose dogs that have been infected with Lyme disease to developing Lyme nephritis.

After processing all this information I now feel that the best way to protect your dog against Lyme nephritis is with a combination of a monthly topical tick preventive and vaccination.  Owners should be applying preventives once a month every single month.  After attending a lecture at NAVC I now have an even greater repulsion for ticks, their resilience and their disease carrying capacity.  Keep in mind that ticks transmit countless other disease that are equally as nasty, if not more so than Lyme disease.  Therefore keeping ticks off you, children, dogs and cats is vitally important.

I am not advocating that we vaccinate all dogs against Lyme disease, only those that are at increased risk.  This group includes dogs that frequent dogs parks, Rock Creek Park and any other wooded area that they would be likely to come into contact with ticks.  I would also strongly consider vaccinating all Labs and goldens given their tendency to contract Lyme nephritis.  The final caveat with vaccination is I would think very hard about vaccinating a dog that is already positive for the disease given that we really don’t know if the vaccine contributes to Lyme nephritis.

Since Frank and Poppy are retriever crosses and negative for Lyme I vaccinated them using the Recombitek Lyme vaccine by Meriel.  This is the only Lyme vaccine I would consider giving as the other ones on the market have a greater reported incidence of vaccine associated reactions.  I have also switched my dogs from Frontline Plus to a newer product called Parastar Plus.  If you have cats in your house please discuss the risk of using Parastar Plus with your veterinarian.

I still feel Frontline Plus works very well but Parastar Plus is reported to kill ticks within one hour, which theoretically prevents transmission of any disease.  We used to believe that the tick had to be attached an feeding for more than 24 hours to transmit disease but current research suggests they may transmit disease in as little as 4-6 hours.

So there you have it, my updated opinion on Lyme disease and the best way to prevent it.  In the end there is no one right answer, even veterinarians can’t come to a conclusion.  Whether or not to vaccinate is a personal decision that you need to make for your dog based on the risk of disease and the risks associated with the vaccine.

Monday, June 4, 2012

Summer heat advisory for dogs

Summer is my favorite time of the year but many summertime activities can be dangerous to your pet’s health.  By far the most common threat is the risk of overheating. At Friendship we see so many cases of heat stroke every summer I feel it is necessary to revisit my annual hot weather warning.

Dogs are much more susceptible to heatstroke than their human companions are. As if wearing thick fur coats weren’t enough of a challenge, dogs have only two ways of dissipating heat: by panting, and through their paw pads.  When the temperature rises, neither of these cool-down tricks works too well: Panting becomes much less effective when the weather is hot and humid. And when your dog walks on a scorching sidewalk his paws stay too hot to help him cool down.

If you’re out on a walk with your dog and he suddenly lies down, collapses or becomes unresponsive, seek veterinary care immediately. DO NOT try to cool down your dog on your own. Instead, get to a vet as quickly as possible.

All dogs can be affected but the “Smushy-faced” (“brachycephalic” is the technical term!) dogs like bulldogs and pugs are especially susceptible to heat-related illness. This is because breed characteristics such as narrow nostrils and elongated soft palates decrease their ability to effectively cool themselves.  Please keep this in mind if you have a brachycephalic breed at home.

Photo credit: Robert Cole

If for some reason you can’t make it to a veterinary hospital immediately there are a few cooling measures you can begin.  Fist take your dog’s temperature rectally with a digital thermometer, normal is 100-102.  You can then soak a towel in tepid (not cold) water, place it over your dog, and aim a fan at him.  Continue to closely monitor his temperature and once it hits 103 degrees discontinue cooling.  Even if your dog seems fine you should take him to a veterinarian as soon as he is more stable.

What makes heat stroke potentially fatal is that the patient can develop a condition called disseminated intravascular coagulation or DIC that causes massive and widespread damage to the blood vessels.  This quickly results in multiple organ failure and the patient loses the ability to clot his blood.  Treatment consists of aggressive supportive care and plasma transfusions, both of which are very expensive and not guaranteed to prevent death. 

When it comes to heat stroke, the best treatment is prevention.  Here are some commonsense tips to help keep your dog cool and comfortable:

1. Avoid taking your dog out during the hottest times of the day.  (Quick rule of thumb: If it is too hot for you, then it is definitely too hot for your dog!)

·      Keep an eye out for unusual behavior: If you are out in the hot weather with your dog and he slows down, lies down or acts reluctant to keep walking, you should let him rest, offer him cool water and head inside immediately.

·      Make sure your dog has cool, fresh water available at all times. 

·      Never leave a dog (or any other pet) in a parked car when it is even slightly warm out.  The temperature in the car can rise amazingly quickly and before you know it you have an overheated animal.

·       Don’t take your dog running. (I am never a fan of running with your dog—check out this article to see why--but in this weather it is an especially bad idea).

Poppy and Sparkle enjoying some beach time