Laurie Anne Walden, DVM
Are dogs’ mouths really cleaner than humans’ mouths? Definitely not! You may have read the recent news story of a Wisconsin man who required multiple limb amputations after contracting a bacterial infection from dog saliva. This type of severe infection is extremely rare, but dogs' (and cats’) mouths do harbor quite a variety of bacteria, some of which can make people sick.
The organism responsible for the Wisconsin patient’s infection was Capnocytophaga canimorsus, which is common in dog and cat saliva. Many different Capnocytophaga species normally live in the mouths of healthy dogs, cats, and humans. Up to 74% of dogs and 57% of cats have Capnocytophaga in their mouths. The types of Capnocytophaga that live in human mouths are usually different from those in dogs and cats.
Capnocytophaga canimorsus is one of the bacteria that cause infections in people who are bitten by dogs. Although it is usually spread through bites, it’s possible for a person to contract the infection after being licked by a dog. The Wisconsin man was reportedly licked, not bitten. A case report published in 2016 described an older woman who developed serious illness from Capnocytophaga canimorsus that likely came from contact with her own Italian greyhound. She recovered fully after 2 weeks of intensive care and antibiotics.
The vast majority of people exposed to this bacterium do not become ill. (Think of all the times you’ve been licked by a dog and haven’t gotten sick.) People who have had their spleen removed, use alcohol to excess, or have compromised immunity (from cancer or HIV infection, for example) are at increased risk of Capnocytophaga infection. Infection can cause severe sepsis (blood infection), gangrene, and inflammation of the heart lining, eyes, lymph nodes, and brain membranes. Infection in a pregnant woman can spread to the fetus. A 2015 review article reported a fatality rate of about 26%.
Of course Capnocytophaga are not the only bacteria in our pets’ mouths. Oral cavities—everyone’s, humans included—contain hundreds of different species of bacteria. Most of these bacteria are not zoonotic; that is, they are not spread between animals and people. The ones that do cause illness in people are usually transmitted by bites. However, one study found that several oral bacteria species could potentially be transmitted by close contact between pet dogs and their owners.
For most people, the risk of contracting a severe infection after being licked by a dog is incredibly low. But if your dog has zoonotic parasites like hookworms or roundworms, eats a raw meat diet, or eats feces (including foraging for snacks in the cat’s litter box), it would be a very good idea not to let him lick you in the face.
The Centers for Disease Control and Prevention recommends taking extra precautions around animals if you have an increased risk of infection. And everyone should take steps to prevent dog bites, which are much more likely than doggie kisses to cause an infection.
Photo by James Barker
Laurie Anne Walden, DVM
1. Never leave an animal in a parked car in warm weather.
Pets can die of heat stroke if they’re left for even a short time in a hot car. Heat exhaustion isn’t only a summertime risk. On sunny days, a car interior can become dangerously hot even if it’s pleasantly warm outside. The temperature inside a parked car can increase by nearly 20°F in only 10 minutes. When the outside temperature is 70°F, a car interior may reach 113°F in an hour. If it’s 95°F outdoors, the temperature inside a car can climb to 114°F in 10 minutes. Cracking the windows open has no effect on the temperature inside a parked car.
Signs of heat exhaustion and heat stroke include panting, dark red gums, rapid heart rate, vomiting, and difficulty breathing. Heat stroke can be fatal. Brachycephalic (flat-faced) animals are especially at risk. Read more about heat stroke here.
2. Keep your pet restrained.
Just like children, pets are safest in cars when they’re securely restrained. Seat belt harnesses and crates keep pets from becoming airborne during hard braking or being thrown out of the car in a collision. Pets riding in laps can be crushed by a person’s body or an inflating airbag. Unsecured animals can also injure people in the car if they become projectiles during a crash.
Animals that are loose in cars can also distract the driver, increasing the risk of accidents. Pets may worm their way into a driver’s lap or line of vision, and those that make their way into the footwell interfere with the foot pedals.
Dogs riding in truck beds should be confined in a ventilated crate that is protected from the weather and attached to the truck. Dogs should never ride in a truck bed unrestrained or secured only by a leash; they can be killed or severely injured if they jump or are thrown out.
If possible, give your pet time to become familiar with the restraint (harness or carrier) before using it on a road trip. Start with short rides that end in something fun to help your pet build positive associations with the restraint.
3. Don’t let your dog ride with its head out of the window.
A dog sticking its head out of a car window with its ears flapping in the breeze may look cute, but this is not a safe way for dogs to ride. Dogs can sustain eye and head injuries from flying debris. A dog that is able to get its head or other body parts out of a window is also not safely restrained.
4. Manage anxiety and nausea on car trips.
Stress and motion sickness are not as dangerous for pets as heat stroke or being ejected from a moving vehicle, but managing these common problems makes a trip easier for everyone. (And a dog vomiting all over the upholstery is certainly a distraction for the driver.)
Both anxiety and motion sickness can cause vomiting, so discuss your pet’s symptoms with your veterinarian to determine the best treatment approach. Two things you can try are withholding food for a few hours before travel and starting with very short rides. Pets with motion sickness may experience less nausea with an empty stomach—at the very least, cleanup will be easier if they do vomit. Pets with anxiety may need to begin by just sitting with you for a few minutes in the parked car. Over time, with patience and positive reinforcement, you can begin driving them around the block and building up to longer rides. One of my own dogs is much calmer in the car if he’s in the crate that he likes to nap in at home (in this case, the crate is both a restraint and a safe, familiar space).
Antianxiety and antinausea medications help many animals travel more comfortably. The choice of medication depends on the symptoms and the cause of the problem. Talk to your veterinarian if your pet continues to have signs of nausea or stress in the car.
5. If in doubt, leave your pet at home.
Not all pets like to ride in the car, and not all destinations welcome animals. Some trips, like visits to the veterinary clinic, are unavoidable. For other excursions, consider leaving your pets safely at home if they don’t enjoy car rides and don’t have to go with you.
Photo by n-k
Laurie Anne Walden, DVM
Zoonotic diseases, or zoonoses, are infections spread from animals to people (and vice versa). Many zoonotic diseases are transmitted by insects, wildlife, and livestock, and some are carried by pets.
Controlling zoonotic disease is a cornerstone of One Health, the concept that human health, animal health, and the environment are all linked. July 6 is World Zoonoses Day and is also the anniversary of the day Louis Pasteur administered the first successful rabies vaccination to a person (July 6, 1885).
How to reduce your risk
Preventive care for pets helps keep everyone in the family safe. The chance of contracting a zoonotic disease from a dog or cat is low if you take proper precautions. Zoonotic infections are also spread by contaminated food, insects, ticks, farm animals, birds, reptiles, and rodents. Young children, older adults, and people with compromised immune systems are at higher risk than others.
These measures can lower your risk:
Find out more at the Centers for Disease Control and Prevention (CDC) website.
Zoonoses in companion animals
Many zoonotic diseases have been identified, and the CDC estimates that 75% of emerging infectious diseases originated in animals (often insects). Some of the most common zoonotic diseases in companion animals are listed below.
Other infectious agents
For more information:
Zoonotic diseases (CDC)
Zoonotic diseases and pets FAQ (American Veterinary Medical Association)
Photo by Lydia Torrey
Laurie Anne Walden, DVM
There’s something special about living with an older dog or cat. After years in the family, senior pets know the household routine and seem able to read our thoughts. And because of advances in nutrition and veterinary medicine, pets tend to live longer than they once did.
Pets’ needs change as they age, and older pets need extra care. Regular veterinary visits and some household adjustments can help keep dogs and cats healthy and comfortable into their senior years.
How old is old?
The common belief that 1 dog year equals 7 human years isn’t really true. Dogs don’t all age at the same rates; small breeds tend to live longer than large breeds. Cats and small dogs are traditionally thought of as senior at about 7 years old (although since they can live well into their teens, 7 years may actually be middle age). Large dogs enter the geriatric stage a bit sooner. Check out these resources for more information:
What to watch for
Keep an eye out for gradual changes over time. Stiff joints, reduced vision, and picky eating are not necessarily normal effects of aging. They are often symptoms of medical conditions that can be treated.
As dogs and cats get older, their risk for arthritis, cancer, kidney disease, thyroid disease, heart disease, and many other problems increases. Watch for symptoms like these:
Dogs and cats should be examined by a veterinarian at least once a year. Older pets may need to be seen more frequently. Many veterinarians recommend wellness checks every 6 months for senior animals. Think of it this way: if 1 dog year really were the same as 7 human years, then an annual examination for a dog would be the same as an examination every 7 years for you and me.
Some diseases progress for a long time before an animal shows any symptoms. Routine diagnostic testing can turn up evidence of chronic disease early in its course, when treatment is most effective. Your veterinarian may recommend these tests for your senior pet:
Preventive health care includes vaccination. Rabies vaccination is required by law in North Carolina for all dogs, cats, and ferrets over 4 months old (for good reason). Dogs’ and cats’ vaccination needs may change as they age, so talk with your veterinarian about immunizations that make sense for your pet.
Things you can do
Photo by Eric Han
Laurie Anne Walden, DVM
Summer is rapidly approaching, and it’s already hot outside. Even when the weather is moderately warm, the temperature inside a parked car can rise dangerously high. Heat and humidity put dogs at risk of heat stroke, which can be fatal.
Dogs rely mostly on panting to cool themselves (they sweat only a little from their paw pads). But panting isn’t always enough to keep a dog’s body temperature in the normal range, from about 100°F to 103°F. As the body temperature rises above normal, dogs can develop heat exhaustion. Heat stroke (in dogs) is defined as a body temperature over 105.8°F along with central nervous system dysfunction.
Heat stroke is a serious medical emergency and has a reported death rate of about 50% in dogs. It damages the brain, kidneys, heart, intestines, and other internal organs, and it causes blood clotting disorders.
Causes of heat stroke
Heat stroke is caused either by exposure to heat and humidity or by strenuous physical exertion. These are situations that commonly lead to heat stroke in dogs:
Justine Lee, DVM, DACVECC, an emergency veterinary medicine specialist, recommends not exercising with your dog if the temperature (in Fahrenheit) plus the humidity level is over 150. So when the temperature is 80°F and the humidity level is 80%, it’s too hot to take your dog on a run (80 + 80 = 160).
Dogs at risk
Although any dog can develop heat stroke, the risk is higher in dogs with these conditions:
Signs of heat stress
Dogs start showing signs of heat exhaustion before they develop full-blown heat stroke. Watch for the warning signs, which become more severe as heat stroke sets in:
If you see signs of heat exhaustion in your dog, carry him to a cooler place immediately; at least get him into the shade. Wet him down with cool water (ice is not necessary) and give him water if he’s able to drink on his own. Take him to a veterinary clinic right away if he has any of the more severe signs or if you’re not sure whether he’s OK after a few minutes. It’s much better to take in a dog who turns out to be fine than to delay treatment for a dog who has heat stroke.
Preventing heat stroke
Photo by Kasia Koziatek
Laurie Anne Walden, DVM
Dental radiography (x-ray imaging) is an important diagnostic tool for pets, just as it is for people. Animals don’t always show signs of mouth pain, and radiographs may be the only way to know there’s a problem.
Most dental disease in dogs and cats happens under the gumline, where it’s hidden from view. In published studies, radiographs revealed disease in apparently healthy teeth in 27.8% of dogs and 41.7% of cats. Dental radiographs find problems that can’t always be seen on a physical examination:
Radiographs also guide dental procedures in pets. For example, some dog and cat teeth have curved roots, extra roots, or roots that extend very close to the jawbone. It’s best to know about these issues before trying to extract these teeth.
In animals, dental radiography requires general anesthesia or sedation. The radiographs use sensors or small film cassettes placed inside the mouth, and animals can’t wiggle during the procedure. Imagine putting an x-ray sensor between your dog’s teeth and politely asking her to lie still and not chew on it. Now imagine asking your cat the same thing. Dental radiographs are often obtained while a pet is already under anesthesia for a dental procedure.
Dental radiography delivers a very small radiation dose to the patient. The American Veterinary Dental College reports that “the radiation risk to the patient from taking dental radiographs is minimal.”
Like people, pets benefit from having full-mouth dental radiography from time to time to be sure no problems are lurking under the surface. Oral imaging may also be indicated in pets with these conditions:
Photo by muhannad alatawi
Laurie Anne Walden, DVM
It’s snake season in North Carolina. Snakes are most active in the early spring through fall, and dogs that accidentally disturb snakes sometimes get bitten. Although a bite from a venomous snake is a medical emergency, try not to panic if it happens to your dog.
North Carolina snakes
North Carolina is home to about 37 snake species. Most are nonvenomous. Don’t run for the hoe if you see a snake in your yard; chances are it’s a nonvenomous snake that’s helping control the rodent population.
Six venomous snake species live in North Carolina: copperheads, cottonmouths, 3 rattlesnake species, and coral snakes. Copperheads are by far the most common. In our state, venomous snakebites are usually from copperheads. Rattlesnakes and possibly cottonmouths can also be found in the Piedmont. Coral snakes are rare and live in the southeastern part of the state.
See photos of NC snakes here: http://herpsofnc.org/snakes/.
Symptoms of snakebite
Nonvenomous bites: Nonvenomous snakes may bite if they are provoked. These bites may look like small abrasions or punctures in the shape of a horseshoe (if they’re visible at all). Venomous snakes sometimes bite without injecting any venom. Nonvenomous bites typically don’t require medical attention unless they become infected.
Venomous bites: Venomous bites are easy to diagnose if you see a snake bite your dog. Diagnosis is a little trickier if the bite isn’t witnessed. Fractures, abscesses, and insect bites can cause symptoms similar to those of snakebite.
Copperheads, rattlesnakes, and cottonmouths are all pit vipers belonging to the family Crotalidae. These snakes inject venom through 2 long fangs. The puncture wounds might or might not be visible through a dog’s fur.
Crotalid venom causes significant tissue damage at the bite site. Copperhead venom is typically less toxic than rattlesnake and cottonmouth venom. The severity of symptoms depends on the size of the dog, the amount of venom delivered, and the location of the bite (for example, bites to the face or neck can cause swelling that obstructs breathing). Symptoms that usually appear right away include the following:
Crotalid venom can also interfere with blood clotting. The venom of some rattlesnake species (not native to North Carolina) damages the nervous system.
Coral snakes are in the family Elapidae, like cobras and mambas. Elapid venom targets the nervous system and can paralyze the muscles of breathing. Bites from coral snakes are serious medical emergencies but luckily are very rare.
If your dog is bitten by a snake
Stay as calm as possible; this will help your dog stay calm too. Limit your dog’s movement by carrying him to your car (if possible) instead of having him walk. Snakebites can be extremely painful, so you may need to muzzle your dog before handling him to prevent him from biting in response to pain. Take your dog to a veterinary hospital without delay. Treatment of crotalid bites depends on the severity of symptoms, and your dog will probably need to be hospitalized. Copperhead bites do not necessarily require antivenin. The decision to use antivenin depends on the individual case and the severity of symptoms.
Do not try first aid techniques that you might have read about. These can worsen the tissue damage caused by crotalid venom and delay transport to a veterinarian.
Don’t try to kill or capture the snake. You risk being bitten yourself if you do. Snake identification is not necessary for treatment. Nearly all venomous snakebites in Mecklenburg County are from copperheads, but the treatment is similar for all pit viper bites. Crotalid antivenin is polyvalent, meaning the same antivenin treats copperhead, rattlesnake, and cottonmouth bites.
The best way to avoid being bitten is to leave snakes alone. Copperheads are not aggressive and do not typically bite except in defense. Dogs may stumble upon snakes by accident, though, so take the following measures to reduce the risk:
For more information, check out the Snakes of North Carolina section of the NC Cooperative Extension website and the Carolinas Poison Center website.
Image credit: CDC/James Gathany
Laurie Anne Walden, DVM
Do you have unused or expired prescription medications in the house? Keeping these drugs around is risky because of the possibility of accidental exposure, overdose, or intentional misuse, says the Drug Enforcement Administration (DEA). Disposing of medications safely also protects the environment.
This Saturday, April 28, is National Prescription Drug Take-Back Day. From 10 a.m. to 2 p.m., you can take prescription medications you no longer need (whether they were prescribed for animals or for people) to collection sites for safe disposal. To find a site near you, go to the DEA Take Back Day website.
Don’t dispose of medications by flushing them down the toilet or pouring them down the drain. Drugs discarded this way enter the waterways, where they can harm wildlife and damage the environment. Drug residues can even enter the drinking water supply.
The safest way to dispose of medications is to take them to an authorized collection site. These sites are usually located in police stations or pharmacies and are available throughout the year, not only on Prescription Drug Take Back Day. To find a location, check one of these resources:
Some prescription drugs have disposal instructions in the package insert. If your medication came with disposal instructions, follow those directions. If disposal instructions aren't included and you don't have access to a collection site, follow these steps:
A few prescription medications are so harmful if they're accidentally ingested that the US Food and Drug Administration (FDA) does not recommend throwing them in the trash. For more information about these drugs or about drug disposal in general, see Disposal of Unused Medicines: What You Should Know on the FDA website.
Photo by Joshua Coleman
Laurie Anne Walden, DVM
April is Heartworm Awareness Month. How much do you know about this infection? Check out the questions, then scroll down for the answers.
1. How are heartworms transmitted?
a. By mosquitoes
b. By eating raw meat
c. Through the feces of infected animals
d. By vampires
2. About how many dogs tested positive for heartworm in North Carolina in 2017?
3. Adult heartworms grow to what length in a dog’s heart?
a. 3 inches
b. 6 inches
c. 9 inches
d. 12 inches
4. In addition to dogs, which animals can get heartworms?
5. True or false: Dogs should receive heartworm preventives through the winter.
6. You forgot your dog’s monthly heartworm pill and now it’s a month overdue. What should you do?
a. Have your dog tested for heartworms before giving the pill.
b. Give your dog the pill now.
c. Give your dog a double dose.
7. True or false: Heartworm preventives sold over the counter at pet stores work just as well as the prescription versions.
c. Unfair trick question
8. Which state is free of heartworms?
d. None of the above
1. a. By mosquitoes
Mosquitoes pick up tiny heartworm larvae, called microfilariae, when they take a blood meal from an animal infected with adult heartworms. When the mosquito bites another animal, it injects these larvae into the new host. The larvae mature into adult heartworms in the new host in about 6 months.
2. c. 9000
According to the Companion Animal Parasite Council, 9457 dogs tested positive for heartworms in 2017 in North Carolina. This number has been increasing each year. To see more parasite statistics, see the Parasite Prevalence Maps on the Pets & Parasites website.
3. d. 12 inches
Adult heartworms grow about 12 inches long in dogs. Infected dogs typically have 14 to 20 of these foot-long worms in their heart and lungs.
4. c. Both
Both cats and ferrets get heartworm disease. In cats, heartworms do not grow as large as they do in dogs and are usually fewer in number. However, heartworm infection can be devastating in cats, potentially causing severe respiratory disease or sudden death. In ferrets, even a single worm can cause serious illness because ferrets’ hearts are so small. Medical options for heartworm removal (like those used in dogs) cannot be used in cats and ferrets. Heartworm preventives are available for cats and ferrets.
5. a. True
For best protection, the American Heartworm Society recommends year-round heartworm prevention for all dogs, not just for dogs in southern states. Also, think of this: for several days this past February, the temperature in Charlotte was 75°F or higher. Do you want to risk your pet’s health by guessing what the mosquitoes here consider “winter”?
6. b. Give your dog the pill now.
But do not give a double dose! Have your dog tested 6 months after missing a pill. The test detects adult heartworms, not larvae, so the test result will not be positive until the larvae have had time to mature.
7. b or c. False; unfair trick question
All heartworm preventives approved by the Food and Drug Administration for use in dogs and cats are available only by prescription. Deworming medications that are available over the counter (without a prescription) either don’t prevent heartworms or are not approved by the Food and Drug Administration for use in dogs and cats.
8. d. None of the above
Heartworms have been diagnosed in all 50 states.
For more information, see the American Heartworm Society website.
Laurie Anne Walden, DVM
Brachycephalic (flat-faced) dogs and cats are popular, but those cute squashed noses can cause some serious health problems. If you have a brachycephalic pet, watch for breathing trouble (snoring and grunting are not normal). These pets are also prone to heat stress, especially if they’re overweight.
Brachycephalic means “short-headed.” Brachycephalic animals have short noses, round heads, and large, low-set eyes. Examples are English and French bulldogs, pugs, Boston terriers, shih tzus, and Persian cats. If you think these pets are adorable, you're not alone. Studies have shown that many people are attracted to facial features in animals that are similar to those of human infants.
Unlike dog breeds that were developed for tasks like hunting, brachycephalic dogs have been bred over time for looks. Unfortunately, breeding for form over function has compromised the health of many of these dogs.
Earlier this year the British Veterinary Association released a policy position on the welfare of brachycephalic dogs. Their aims are to improve the health of future generations of these dogs and to increase awareness of the problems caused by breeding for extreme brachycephaly. The association highlighted 5 of the most common medical concerns: respiratory, eye, reproductive, skin, and dental problems.
Many brachycephalic animals cannot breathe normally. Although the bones of the face are shortened, the soft tissues are not, leaving excess tissue that can block the airway. Signs of impaired breathing include snoring, snorting, and exercise intolerance. Brachycephalic animals are at risk for heat stroke, respiratory distress, and collapse. Long-term labored breathing can also cause digestive tract problems like gagging and vomiting. Obesity makes all of these problems worse.
Brachycephalic obstructive airway syndrome includes 3 main anatomic abnormalities: narrow nostrils, elongated soft palate (excess tissue at the roof of the mouth), and everted laryngeal saccules (tissue that blocks airflow through the trachea, or windpipe). Some animals require surgery to correct these problems. Brachycephalic animals may also have an abnormally narrow trachea, which gives the effect of constantly breathing through a small straw.
Brachycephalic animals have shallow eye sockets and large eyelid openings, so their eyes are not as well protected as those of other animals. Many also have impaired tear production (dry eye), reducing their defense against eye irritants. Skin folds at the top of the nose may cause hair to rub against the eyes. These problems can cause eye ulcers and eventual blindness.
Some brachycephalic breeds have trouble giving birth naturally because the puppies’ heads are too large to fit through the mother’s pelvis. One study found that over 80% of English bulldog, French bulldog, and Boston terrier litters born in the United Kingdom were delivered by cesarean section.
Skin and dental disease
Folds of loose skin give bacteria and yeast a handy place to grow, so brachycephalic animals are prone to skin fold infections. Because of their shortened upper jaw, they often have crowded or maloccluded teeth.
If you have a brachycephalic pet:
If you are thinking of getting a brachycephalic pet:
1. Archer J, Monton S. Preferences for infant facial features in pet dogs and cats. Ethology. 2011;117(3):217-226.
2. Health and welfare of brachycephalic dogs. British Veterinary Association website. https://www.bva.co.uk/news-campaigns-and-policy/policy/companion-animals/brachycephalic-dogs/. Accessed March 27, 2018.
3. Packer RM, Hendricks A, Tivers MS, Burn CC. Impact of facial conformation on canine health: brachycephalic obstructive airway syndrome. PLoS One. 2015;10(10):e0137496.
4. Brachycephalic syndrome. American College of Veterinary Surgeons website. https://www.acvs.org/small-animal/brachycephalic-syndrome. Accessed March 27, 2018.
5. McNabb NT. Top 5 threats to vision in the brachycephalic dog. Paper presented at: North American Veterinary Conference 2017; February 6, 2017; Orlando, FL.
6. Evans KM, Adams VJ. Proportion of litters of purebred dogs born by caesarean section. J Small Animal Pract. 2010;51(2):113-118.
7. Caring for brachycephalic dogs. MSPCA Angell website. https://www.mspca.org/angell_services/caring-for-brachycephalic-dogs/. Accessed March 27, 2018.
Laurie Anne Walden, DVM