Sunday, January 24, 2016

When is it too cold for canines?

Bitter-cold weather has already visited us this winter, and you can bet that more is on the way. One question from dog owners that often crops up is:  How long can my dog be outside when it’s cold?

It’s important to know the answer, because in Illinois, a law took effect on New Year’s Day that makes it a Class A misdemeanor to expose dogs to life-threatening situations for prolonged periods of time in extreme heat or cold. If you disobey this law, you can be fined up to $2,500 and serve up to a year in the slammer!

I can almost hear what you’re thinking:  What constitutes “extreme cold” and “prolonged periods of time”? My friend Mark emailed me the other day with that question.

Mark has two Samoyeds and a golden retriever, whose privileged lives include access to a dog door leading from a heated laundry room to a large yard. They enjoy the freedom of wandering in and out of the house in all weather, even if Mark isn’t home. The arrangement suited both Mark and his buddies beautifully  ̶  until a few days ago.

That’s when a concerned citizen called the police after seeing Mark’s dogs in his yard on a particularly frigid day. After Mark spoke to a couple of police officers, it became apparent to all of them that the law was vague; some guidelines were needed.

Fortunately, the Cummings School of Veterinary Medicine at Tufts University has developed a chart to give us guidance. This is a very handy blueprint, and I used it to do some risk assessment for Mark’s dogs. 

Here’s how they fared, assuming a dry day and a temperature of 10°:

1  Sanibel (47-pound 2-year-old Samoyed):  Because she’s a northern breed and is acclimated to the cold, I subtracted 2 from her score. She’s medium-sized (for our purpose, that’s about 40 to 60 pounds), so I looked in the middle column (note the three dog silhouettes at the top of the chart). Her score at 10° is 3 (unsafe potential).

    Aston (87-pound 6-year-old Samoyed):  Again, he’s a northern breed and acclimated to the cold, so I subtracted 2 from his score. His number in the right hand column at 10° is also 3.

    Bentley (100-pound 6-year-old golden retriever): He’s acclimated to the cold, so he gets 1 point subtracted from a score of 5 in the right-hand column. His score is 4 (dangerous weather; use caution).

Some easy math tells me that at 20°, Aston is in the first category, “no evidence of risk”, while the other two dogs are in the second category, “risk is unlikely, but be careful”.

The chart also takes into account wet weather, which raises the score. What it doesn’t really account for is Mark’s situation; his dogs can go into a warm room any time they want. They are unlikely to suffer any ill effects if their owner is gone for a few hours, even if it’s very cold. I still advised Mark to limit their exposure if the temperature is under 20°, for a couple of reasons. Is it possible that the Samoyeds, a breed that thrives in cold weather, could fall asleep in the sun and suffer hypothermia, or frostbite of the extremities? I’m not sure, but why take a chance? Also, it’s possible that another concerned citizen will notify the police on a future frosty day. A fine could ensue.  

At what temperature, and for how long, is it safe to take Fido for a walk?  A score of 3 shouldn’t keep most dogs from taking their regular walk (although some may need a coat). A 4 score warrants a short walk only. A score of 5 means a super-quick trip to the potty area, donning a thermal doggie coat and booties if your friend is old or frail, has a short coat, is a toy breed, or simply hates the cold and shivers.  

We Midwesterners are made of tough stuff, and we laugh at the cold. But some of our tail-wagging friends may not be as hardy. So when in doubt, use the chart, and let common sense prevail.

Tuesday, January 5, 2016

We’re not finished with the flu

2015 was notable for the usual litany of memorable events: Syria was in crisis, terrorists struck in Paris, deflated footballs made the national news, the United States and Cuba are speaking again. And we’ll remember 2015 as being the year of Bill Cosby, Caitlyn Jenner, and The Donald.

Those of us with dogs will also remember 2015 as the year of a nasty outbreak of canine influenza in Illinois. It took some time to figure out that this wasn’t the familiar H3N8 strain of flu, but rather a new strain -- H3N2 --  so the existing vaccine was not effective.  Routine frolics in the dog park were curtailed, as were vacations, walks in the neighborhood, and visits to the groomer. 

You probably haven’t heard much about the flu lately, but it’s still a viable concern in Lake and surrounding counties; we continue to see small outbreaks in and around Chicago. A disease is classified as endemic when it’s constantly present within a given geographic area over a long period of time. Epidemiologists now consider H3N2 canine influenza to be endemic in our area of the country. For dog owners, that means we have to consider this new flu a continuing threat.

So the bad news is that the flu has not flown. The good news is that there’s a new vaccine against the H3N2 strain that is safe and effective. 

Puppies as young as 8 weeks can be immunized. After the initial dose, another dose is given two to four weeks later, and then boosters are given yearly. Full immunity occurs two weeks after the second vaccine. If you do the math, you’ll see that it takes a minimum of four weeks to full immunity, so now is a good time to protect your dog.

During the clinical trials for the new vaccine, both vaccinated and unvaccinated dogs were challenged with the H3N2 influenza virus. 42% of the unvaccinated group developed severe clinical signs and had to be euthanized.1 None of the vaccinated dogs developed serious symptoms, and the vaccine prevented secondary pneumonia and lung damage. No adverse reactions or swelling at the injection site were noted. However, as with all vaccines, once they are given to thousands of dogs we’re likely to see the occasional vaccination reaction. 

The older H3N8 strain of flu is still alive and kicking, and there’s a good vaccine for that, too. It probably doesn’t provide much, if any, protection against the newer flu strain, so experts advise giving your dog both vaccines. Both contain inactivated viruses and can be given together safely. I’ve learned that several drug companies are working on a vaccine that contains both strains.

Does your four-legged friend need to be protected against the flu? It depends on his or her lifestyle. Dogs that go to doggy day care, boarding kennels, grooming facilities, the dog park, dog shows or agility trials, or that are otherwise in close contact with others of their species, are most at risk.

Another consideration is whether any cases have been reported in your area. The problem with waiting for that to happen, though, is that if there’s a local outbreak, you may have to halt your dog’s visits to the park or groomer. Or you may have to cancel your vacation. 
Most upper respiratory infections we see are caused not by the flu but by Parainfluenza, Bordetella, and Adenovirus Type 2.  Like the flu, they are spread by close contact. At-risk dogs should also get the vaccine for those agents. It’s an intranasal, injectable, or oral vaccine that we offer to all of our clients.

I’m conservative regarding vaccines; there are some that we don’t even have at our hospital. But given the severity of last year’s flu epidemic, I think all healthy dogs in our area that are at risk should be vaccinated. As events develop, the doctors at Vernon Hills Animal Hospital may change this recommendation. But for now, it seems like the prudent thing to do. 

1.    In a natural outbreak of the H3N2 influenza, 100% of exposed dogs will contract the virus. 20% will have no clinical signs (but will still shed the virus and spread the infection). That means 80% will get sick. The mortality rate is less than 10%, which, although not even close to the 42% in the study, is still scary.