What you don't know about heartworm disease can hurt your dog or cat

By Kim Campbell Thornton

You've probably seen a dusty jar of long, spaghettilike worms in your veterinarian's office. They're heartworms (Dirofilaria immitis), and they are deadly to dogs and cats. The internal parasites make themselves at home in the heart and lungs, causing heart failure and lung disease and potentially migrating to the brain, eye and spinal cord. Here are seven things you might not know about heartworm disease:

1. Heartworms are transmitted by more than 70 species of mosquitoes. Some of these mosquitoes don't need standing bodies of water to reproduce. They thrive in small areas, such as downspouts, gutters and flowerpots and adapt well to cold weather.

2. The incidence of heartworm disease is rising. Between 2013 and 2015, the Companion Animal Parasite Council saw a 166 percent increase in reported positive heartworm cases. That's because nationwide, only about 35 percent of dogs are on preventive medication, says C. Thomas Nelson, DVM, who practices in Anniston, Alabama, and is a spokesperson for the American Heartworm Society. On the West Coast, it's only 16 to 18 percent. In the Southeast, where heartworms are especially prevalent, it's about 26 percent.

3. Heartworm disease has been found in pets in all 50 states. "Owners carry their dogs with them a lot," says parasitologist John W. McCall, Ph.D., professor emeritus in the department of infectious diseases at the University of Georgia College of Veterinary Medicine. "They go from the north to the south, and they just don't really think that they're going into an area where there's mosquitoes. Many owners don't even know heartworm is transmitted by mosquitoes."

4. Cats can get heartworm disease. They are not as susceptible as dogs, but the worms can cause more serious problems in cats. Larvae in the lungs lead to what's called heartworm-associated respiratory disease (HARD), which has signs similar to feline asthma. It's worse if worms manage to develop to the adult stage.

"The clinical signs associated with the presence of a couple of adult worms in the cat's pulmonary artery are usually very severe, ranging from acute respiratory distress to sudden death as a result of severe inflammation and pulmonary embolism," says Romain Pariaut, DVM, an internal medicine specialist and associate professor of cardiology at Cornell University College of Veterinary Medicine in Ithaca, New York.

5. Preventive medication is recommended year-round for dogs and cats in all areas. One reason is because mosquitoes are more widespread. Another is that longer bouts of warm weather and shorter bouts of cold weather mean mosquitoes are seen year-round in most areas.

6. Heartworms are becoming resistant to preventive products. Bacteria, viruses and parasites such as heartworms eventually become resistant to drugs used against them, McCall says. The current drugs have been used for almost 30 years.

"We don't really know how much of a problem it is," he says, "but the longer we use the products, the more likely it is to occur."

7. Experts recommend combining preventive with a dog-safe mosquito repellent. Even though preventive medication is highly effective, it's not failproof, especially in areas where heartworms have become resistant. Based on a study McCall did using Vectra 3D, which repels and kills mosquitoes, combining heartworm preventive with the topical parasiticide was 100 percent effective in blocking transmission of microfilariae (immature heartworms) from dogs to mosquitoes -- a necessary part of the heartworm lifecycle -- and more than 95 percent effective in repelling and killing mosquitoes for 28 days after treatment.

"If the dog is treated, the mosquito can't bite the dog and it can't transmit the infective larvae to the dog," McCall says. "It will pretty much keep the dog protected, even when there's a high degree of resistance." The product is not safe for use on cats, but cats who live with dogs who are protected share the benefit.

Q&A

Fever can have

many causes

Q: My dog had her teeth cleaned, and all went well with a couple of extractions. A week or so later, she wouldn't eat, and when we took her to the vet, she had a 104-degree fever. We tried a couple of different antibiotics, which didn't reduce the fever, so we were referred to a specialty hospital. They tested for everything, and she wasn't getting better. The vets kept her overnight and gave her fluids and super antibiotics, but she would not consistently eat and every test came back negative.

Long story short -- and $10,000 later -- my vet took an X-ray of her mouth and discovered an abscess in the jaw. He removed the tooth, cleaned out the abscess, gave her antibiotics and away she went. Why is it so hard to find the cause of a fever like this? -- via email

A: What an ordeal! I really feel for you. I can tell you that it's a real diagnostic puzzle when fever is the only significant sign on examination. My colleague Kenneth R. Harkin, an internal medicine specialist at Kansas State University College of Veterinary Medicine, spoke on this subject in January at the North American Veterinary Conference in Orlando, Florida. He says that figuring out the cause of a fever of unknown origin -- also called a cryptic fever -- becomes challenging when routine diagnostic tests don't pinpoint the problem.

As you discovered, the cost of testing (and hospitalization) can skyrocket as veterinarians seek other answers. Inflammation is the most common cause of fevers, Dr. Harkin says. Among the many possible inflammatory or infectious diseases that could cause fever are acute pancreatitis, pyelonephritis, lupus, immune-mediated polyarthritis and leptospirosis. Dogs with a recently discovered heart murmur may have bacterial endocarditis. Certain cancers can cause fever as well, including lymphoma, leukemia and liver cancer. All of these can be easily missed because abnormalities in the lab work can be subtle.

I'm glad your dog's fever was successfully resolved. -- Dr. Marty Becker

Do you have a pet question? Send it to askpetconnection@gmail.com or visit Facebook.com/DrMartyBecker.

THE BUZZ

More retirement

homes permit pets

-- TigerPlace, a retirement community in Columbia, Missouri, is a pet lover's dream. Residents can keep their animals with them and benefit from an animal care staff that helps walk, feed and care for the pets as needed. Allowing pets and providing pet-care services is a growing trend at retirement communities. TigerPlace, with 90 residents, is operated in collaboration with the Sinclair School of Nursing at the University of Missouri. Rebecca Johnson, director of the Research Center for Human-Animal Interaction at MU's College of Veterinary Medicine, says pets encourage people to walk, decrease loneliness and promote social interactions with other people.

-- Prehistoric best friend? Scientists in Siberia are studying the mummified remains -- including skin, hair, internal organs and stomach contents -- of two unusually well-preserved puppies thought to have died in a landslide more than 12,000 years ago. Amazingly, the brain of one is intact, the first-ever completely preserved brain of a Pleistocene canid. DNA tests on the first puppy, found five years ago, confirm dog rather than wolf ancestry, but the genetic makeup of ancient dogs and wolves is similar. The pups' genomes will be further evaluated in the hope of learning more about canine domestication and evolution.

-- A veterinarian at the University of Wisconsin School of Veterinary Medicine is working with physicians to test a new delivery method for a canine melanoma vaccine, according to an article by David Wahlberg in the Wisconsin State Journal. David Vail, DVM, is testing a modified tattoo gun with multiple punctures, which may induce a stronger immune reaction than a single injection. The canine melanoma vaccine, an immunotherapy approach that works to prevent the skin cancer from spreading, was approved in 2010 and is currently injected intramuscularly. If the new approach works in pet dogs, it could also benefit humans. -- Dr. Marty Becker, Kim Campbell Thornton and Mikkel Becker

ABOUT PET CONNECTION

Pet Connection is produced by a team of pet-care experts headed by "The Dr. Oz Show" veterinarian Dr. Marty Becker and award-winning journalist Kim Campbell Thornton. They are affiliated with Vetstreet.com and are the authors of many best-selling pet-care books. Joining them is dog trainer and behavior consultant Mikkel Becker. Dr. Becker can be found at Facebook.com/DrMartyBecker or on Twitter at DrMartyBecker. Kim Campbell Thornton is at Facebook.com/KimCampbellThornton and on Twitter at kkcthornton. Mikkel Becker is at Facebook.com/MikkelBecker and on Twitter at MikkelBecker.

Feline obesity is out of control. Here's how to get your cat back on track to a healthy figure

By Kim Campbell Thornton

When we at Pet Connection say "fat cats," we're not talking Wall Street bankers. The percentage of cats considered to be overweight (10 to 19 percent greater than ideal weight) or obese (20 percent or greater than ideal body weight) has reached a whopping 58 percent, according to a survey by the Association for Pet Obesity Prevention.

That makes excess weight the No. 1 nutritional disorder in cats. Carrying too many pounds is linked to a number of feline health problems. Obese cats are more likely to suffer a liver disease called hepatic lipidosis; feline urinary tract disease; diabetes; lameness; complications from anesthesia; and non-allergenic skin conditions.

What's the skinny on the increase in tubby tabbies? It may be as simple as a lack of recognition of what a healthy cat looks and feels like. A study published in the Journal of Feline Medicine and Surgery in 2010 found that nearly 34 percent of owners underestimated their cats' body condition score.

Body condition scores rank cats on a 5-point scale, with 1 being emaciated, 2 thin, 3 ideal, 4 heavy and 5 grossly obese. In a hands-on test, it should be easy to feel a cat's ribs and other prominent bones using light pressure. If your cat falls into category 4 or 5, it's time to institute a kitty weight loss plan to help him regain a slim, trim figure.

Start with a veterinary exam to rule out medical problems that might be causing the weight gain. A weigh-in establishes current weight so a goal weight can be determined.

Your first thought might be to cut back on the amount of food you give, but that just leads to a cat who is hungry and unhappy. A different food may be a better option.

Feeding a diet that swaps out carbohydrates for proteins appears to be useful for weight loss, says Margie Scherk, DVM, speaking on feline weight management at the World Feline Veterinary Conference in San Diego, California, last October. And be aware that even 10 extra pieces a day of kibble formulated for normal weight maintenance can cause a cat to gain a pound in a year. Measure food and give it at regular mealtimes instead of free feeding.

Diet is a big part of helping cats lose weight, but getting them moving is important, too. You might not be able to take your cat jogging or get him to walk on a treadmill, but there are plenty of creative ways to add exercise to your pet's life and at the same time provide a more stimulating environment.

An easy way to keep him moving while you're gone during the day is to divide the amount of food he receives daily into six or seven portions. Place each portion in a small container, and hide them throughout the house. Mix up your hiding places so he has to work to find his food each day.

Interactive play is also important. Use toys to encourage him to walk and run around the house. Your cat is a predator, so focus on his love of stalking and chasing. Cats have short attention spans, so playtime of two to five minutes a few times a day is plenty. Since cats are nocturnal, you may find that he is more interested in being active after the sun goes down.

Introduce exercise gently and gradually. Cats who are overweight or obese can injure their joints if they do too much too quickly.

Most important, remember that prevention is best when it comes to obesity. Weight gain is more likely after cats turn 2 years old, so don't let them become sedentary as they mature. That's a heck of a lot easier than trying to change their eating habits or food after they have put on too many pounds.

Q&A

Dog won't stop

humping mom

Q: We have a 4 1/2-year-old neutered English springer spaniel who humps my mother. There are two other adults in the house, but he humps only her. Any ideas as to why this would be? -- via email

A: This is one of those embarrassing and common dog behaviors that none of us enjoys. The first thing to know is that humping is normal dog behavior. Dogs hump for three main reasons: to get attention, in play and in response to stress and anxiety.

Your dog may be seeking attention from your mother, he may be excited that she's visiting (if she doesn't live there) or she may have never let him know that it's not acceptable behavior. You need to let him know that his behavior is unacceptable, and teach him an alternative behavior for which he can be rewarded.

Dogs who hump a leg or climb on an arm to hump are often seeking attention. When people laugh, look at them or even tell them to stop, they've gotten a response for their behavior.

If this is how your dog behaves toward your mother, the best thing she can do is to remove her attention altogether. Look the other way, stand up and walk away. You can also remove him yourself. Don't yell, but in a neutral manner take him away and give him a brief timeout of one to three minutes.

The lesson for your dog is that humping puts an end to any attention he might receive. Teach him instead to sit, shake or perform some other activity in her presence. Then she can reward him for acceptable behavior. Even better, pay attention so you can distract him and ask him to perform a command or trick before he begins this unwanted behavior. -- Mikkel Becker

Do you have a pet question? Send it to askpetconnection@gmail.com or visit Facebook.com/DrMartyBecker.

THE BUZZ

Cats don't thrive

on veggie diet

-- Can cats be vegetarian or vegan? That depends on how long you want to have a cat, says Kristi Krause, DVM, a board-certified specialist in feline medicine. Cats, with their claws and teeth made for taking down and eating meat, are obligate carnivores, meaning they require certain proteins that can be obtained only from meat. Supplements don't contain enough of the essential amino acids cats need to thrive and survive. Cats who eat a diet that's not meat-based can develop vitamin and mineral deficiencies that affect bone and muscle development; an enlarged heart from lack of taurine; and vision problems.

-- Until recently, neuroscientists believed that neurons such as the eye's photoreceptor cells did not regenerate after being damaged. But new findings from researchers at the University of Pennsylvania School of Veterinary Medicine showed that in certain forms of early canine blindness, photoreceptor cells in the retina continued to divide when puppies were between 7 and 14 weeks old. Further research will focus on genes involved in turning cells on to divide, in the hope of developing a therapy to interfere with cell death and retinal degeneration. It could eventually help not only dogs, but also people with similar disorders.

-- Rabbits are an age-old symbol of fertility, and for good reason. The furry breeding machines can produce six or more litters a year, with each litter containing five to eight kits (what baby rabbits are called). Do the math: That's at least 30 to 48 baby bunnies per year. During their breeding season, which runs from February to September, female rabbits are constantly pregnant. They can become pregnant again within 24 hours of giving birth. To prevent unwanted pregnancies, spay or neuter rabbits ASAP; they reach sexual maturity between 3 and 6 months of age. -- Dr. Marty Becker, Kim Campbell Thornton and Mikkel Becker

ABOUT PET CONNECTION

Pet Connection is produced by a team of pet-care experts headed by "The Dr. Oz Show" veterinarian Dr. Marty Becker and award-winning journalist Kim Campbell Thornton. They are affiliated with Vetstreet.com and are the authors of many best-selling pet-care books. Joining them is dog trainer and behavior consultant Mikkel Becker. Dr. Becker can be found at Facebook.com/DrMartyBecker or on Twitter at DrMartyBecker. Kim Campbell Thornton is at Facebook.com/KimCampbellThornton and on Twitter at kkcthornton. Mikkel Becker is at Facebook.com/MikkelBecker and on Twitter at MikkelBecker.

Pulling a cart or wagon is bred in the bone for some breeds, but almost any dog can learn

By Kim Campbell Thornton

You've probably seen vintage photos of dogs pulling carts or wagons loaded with milk cans, large cheeses and other goods to market for farmers. Certain breeds specialized in this work, among them Bernese mountain dogs, bouviers des Flandres, great Pyrenees, greater Swiss mountain dogs, Leonbergers, Newfoundlands, Rottweilers and Saint Bernards. Dogs were less expensive to purchase and care for than horses and were sometimes referred to as "the poor farmer's horse."

Some modern dog owners, inspired by their breeds' heritage, are eager to teach their dogs to perform their traditional work. They've taken up drafting, also known as carting.

Laura Bullock of Charlotte, North Carolina, has had greater Swiss mountain dogs for nine years. "I really wanted to do all of the things that my breed is meant to do," she says. "It's something that is interesting and different and definitely challenging. It may look easy, but it's not."

Dogs who can pull a cart or wagon are popular for lots of reasons. They are crowd pleasers in parades, give rides to neighborhood kids, haul recycling bins out to the street, help bring home groceries and work as gardening assistants, pulling wagons loaded with potting soil, bark and trays of plants around the yard.

A framework of training and trust between dog and owner is necessary to be successful. Before a dog starts training for carting, he should know and respond readily to basic obedience commands, especially "stay" and "come."

Before a dog is ever put into a harness or attached to a cart, he becomes accustomed to having a cart brought behind him and learns how it feels to have the shafts of the cart touching his shoulders. Experiencing that sensation is important because as the cart turns, the shafts will touch the dog's body, so it's something he needs to be prepared for.

More advanced lessons involve learning to go in circles, back up, pull uphill, control the speed of a cart going downhill and walk across different surfaces. In a draft test, to earn a title, a dog may have to pull his cart over dirt, grass or gravel, as well as over a bridge or through a gate. He needs to learn how it feels and sounds to cross those surfaces and how to make his way through narrow spaces. As he learns, he is rewarded with toys, treats and praise.

Dogs can become accustomed to wearing a harness and being hitched to a cart at any age -- the earlier, the better -- but depending on the breed, they must be 18 months to 2 years old before they can enter a draft test to earn a title. That's to ensure that the dog's bones and joints are fully developed.

Drafting isn't limited to large breeds. Any dog of any size can learn to pull for fun, exercise or utility, although a smaller dog's loads are limited. Breeds and mixes that have learned to pull include papillons, cockapoos, Shetland sheepdogs and collies.

Before getting started, take your dog to the veterinarian. He shouldn't have any physical problems that could be made worse by the activity.

To learn more, contact a local Bernese mountain dog breed club. They often have drafting demonstrations and clinics at fun days or specialty shows so people can learn about the sport.

The benefits of carting go beyond earning titles or even doing work with it, says Kathe Vasquez, co-chair of the draft committee for the Bernese Mountain Dog Club of Southern California.

"It forms a really special bond between you and your dog. When you have that partnership, that teamwork, it's really a beautiful thing."

Q&A

Excess thirst, urine

signal health problems

Q: My cat seems to be drinking a lot more water than usual. She's even started having accidents outside the litter box. I think she can't get there in time. What could be causing this? -- via Facebook

A: In vet speak, what's going on is called polydipsia and polyuria -- excessive thirst and urination. The problem is that these signs can be symptomatic of any number of diseases. It can be really frustrating for veterinarians and owners to try to figure out the cause. Diseases that cause these signs include diabetes, kidney failure and hyperthyroidism, to name just a few.

The differential diagnosis -- a term you may know from medical detective shows such as "House M.D." -- involves a good history first. The veterinarian will want to know how long your cat has been drinking lots of water and whether you've noticed if she's urinating more frequently (pollakiuria) or going a normal number of times but producing greater amounts of urine (polyuria). Other questions may include what you feed your cat, whether you've noticed any changes in eating habits or unusual weight loss and whether you're giving her any medications or supplements.

A physical exam and lab tests are also part of the search for answers. A complete blood count, urinalysis and thyroid test are among the lab work your veterinarian may order. They can help to check such things as kidney and liver values, thyroid hormone levels, abnormal electrolyte levels and excess sugar in the urine. Again, there are many potential causes of these signs, so a veterinary visit is a must. -- Dr. Marty Becker

Do you have a pet question? Send it to askpetconnection@gmail.com or visit Facebook.com/DrMartyBecker.

THE BUZZ

Best workplaces

for pet lovers

-- We've all heard of the Fortune 500 -- the 500 most profitable U.S. companies. Well, here's a more important ranking for pet lovers: the pet-friendly 12, a dozen companies that offer perks to pet-loving employees. They run the gamut: allowing owners to bring dogs to work and providing pet insurance, discounts for doggie daycare, pet supplies, financial assistance for pet adoptions and free pet health screening days. The "purr-ty" dozen are Genentech, Kimpton, Atlantic Health, VMWare, Salesforce, Mars, Google, Build-A-Bear Workshop, Autodesk, GoDaddy, Workday and Activision Blizzard.

-- Thanks to social media, we're seeing lots more photos and videos of cats getting baths or playing in water. You were probably under the impression that cats did a perfectly fine job of grooming themselves, but there are times when a bath can be beneficial. If someone in your family is allergic to cats, a weekly bath (for the cat) can help to keep dander levels low, reducing the person's reaction. Cats also need baths if they get into something sticky or that would be toxic for them to lick off themselves.

-- "Who rescued whom?" The popular bumper sticker is seen on numerous cars, but for Eric O'Grey, it's more than an expression. When his doctor told him he would be dead in five years if he didn't lose weight, he consulted a nutritionist and took her advice to adopt a shelter dog. He chose a middle-aged, overweight dog named Peety, and the two started walking. Within a year, O'Grey had lost 140 pounds and Peety 25. Their story was turned into a video, the kickoff for a contest called the Mutual Rescue initiative, in which people can share stories of how a shelter animal changed their lives. Contact the Humane Society of Silicon Valley for more information. Entry deadline is April 30. -- Dr. Marty Becker, Kim Campbell Thornton and Mikkel Becker

ABOUT PET CONNECTION

Pet Connection is produced by a team of pet-care experts headed by "The Dr. Oz Show" veterinarian Dr. Marty Becker and award-winning journalist Kim Campbell Thornton. They are affiliated with Vetstreet.com and are the authors of many best-selling pet-care books. Joining them is dog trainer and behavior consultant Mikkel Becker. Dr. Becker can be found at Facebook.com/DrMartyBecker or on Twitter at DrMartyBecker. Kim Campbell Thornton is at Facebook.com/KimCampbellThornton and on Twitter at kkcthornton. Mikkel Becker is at Facebook.com/MikkelBecker and on Twitter at MikkelBecker.