How Do Dogs’ Noses Work?

April 30, 2014
dog nose

Photo: Mark Watson

Dog noses have been in the news lately. Not just because dogs can sniff out a cracker crumb between the sofa cushions or because dogs smell the new bag of bacon strips through the closed pantry door, but because dog noses are being put to work in a very serious way.

For hundreds of years, dogs, like the Bloodhound, have been employed as search and rescue workers to find missing people after being given a whiff of the missing person’s clothing. Now medical sniffer dogs are being trained to diagnose cancer, detect low blood sugar and predict an epileptic seizure. Several features of dogs’ noses make their sense of smell better than our own.

Bigger is Better
CT scan of a dog's noseCompared to the size of their face, dogs have big noses – well most of them do. And, a bigger nose means they have more area for smell receptors. Inside the nasal passages, the dog has ruffles of tissue called turbinates which increase the surface area that accommodates their smell receptors. Compared to our 5 million, dogs have 300 million receptors on their nasal turbinates. The CT scan on the right shows the ruffles of tissue inside a dog’s nasal passages, and if you watch our video, you can see what turbinates actually look like when a rhinoscopy (nasal endoscopy) is performed.

Bidirectional Smelling
Take a look at your dog’s nose. Notice the nostrils have slits on the sides and the openings are a bit more to the side than directly out front. These features give your dog’s sense of smell directionality. New smells come in from the front and old smells go out through the side slits with exhalation, allowing new smells to constantly bathe the smell receptors.

More Brain Power
Because dogs’ sense of smell is their most highly developed sense, they devote an enormous amount of brain power to the act of smelling. Compared to our rudimentary sense of smell, there is 40 times more canine brain power dedicated to smelling, which allows dogs to differentiate 30,000 to 100,000 different smells. Our repertoire of smells is only 4,000 to 10,000 different smells.

For more about these scent-sitive dogs, watch my interview on Fox5 News with Liz Dahlem.


How to Recognize a Sick Cat

October 2, 2013
Abyssinian cat

Abyssinian cat

Cats are the masters of disguise. Here we see a beautiful Abyssinian cat decoratively perched on a pedestal and disguised as a piece of sculpture- that is until she changes her mind and becomes something else!

Although cats in disguise bring enormous enjoyment to our lives, many cat owners are frustrated with their favorite fur person’s Academy Award-winning ability to masquerade as a healthy cat until hospitalization and intensive care are required. Sick cats commonly hide under the bed or in the closet; however, many cat owners mistakenly believe this behavior is simply their cat expressing its feline independence rather than a potential sign of serious illness. Another sick cat behavior frequently mistaken for bad cat behavior is a loss of litter box training.

Common illnesses, common signs
According to Best Pets Insurance, the top five medical claims for insured cats include: chronic kidney diseasehyperthyroidism, allergies, cancer and diabetesThese five diseases make up one-third of all feline claims to Best Pets Insurance. I don’t want to minimize the important impact allergies have on your cat’s quality of life but, in general, allergies are not life threatening and because they manifest on the outside of your cat, allergies are easy to detect. This blog will focus on how to recognize the big four: chronic kidney disease, hyperthyroidism, cancer and diabetes.

Weight loss in all
Many cat diseases look the same, which is one reason it is difficult for cat owners to identify that their cat may be ill. In fact, weight loss is a common clinical sign in cats with chronic kidney disease, hyperthyroidism, cancer and diabetes.

Increased water drinking in most
When I talk to cat owners at an annual physical examination, I ask about water consumption. Increased drinking can result from chronic kidney disease, hyperthyroidism or diabetes. Only occasionally, does cancer cause cats to drink more water.

Hungry all the time in a few
Hyperthyroidism causes metabolic rate to soar. Hyperthyroid cats are hungry all the time to compensate for their increased metabolic rate. Diabetic cats lack insulin, which allows nutrients to enter the cells. Diabetic cats are hungry because their bodies cannot utilize the food they eat. Cats with cancer and kidney disease usually have poor appetites.

Early recognition

  • An annual physical examination by your veterinarian will go a long way to detecting weight loss, which is a common feature of the big four.
  • Collect a urine sample and take it to your cat’s annual physical exam, since abnormalities like sugar in the urine will help diagnose diabetes early.
  • If your pet is showing any of these signs, discuss blood testing with your veterinarian to help identify your cat’s medical condition.

National Pet Cancer Awareness Month

November 21, 2012

November is a busy month. Not only is it National Diabetes Month, but it is also National Pet Cancer Awareness Month.

Cancer and diabetes are two important diseases the veterinarians at The Animal Medical Center treat every day.

According to VPI, a pet insurance company, their top ten insurance claims for pet cancer treatment include tumors we veterinary oncologists commonly treat.

  1. Lymphoma or lymphosarcoma
  2. Malignant skin cancer
  3. Splenic cancer
  4. Bone or joint cancer
  5. Liver caner
  6. Chest cancer
  7. Bladder cancer
  8. Brain of spinal cord cancer
  9. Mouth cancer
  10. Cancer of the cells lining the inside of the chest and abdomen

Surgery and cancer

Surgery is often the first procedure for a cancer patient and is commonly performed to get a biopsy of a lump which leads to the diagnosis of cancer. For one or two of the tumors on the top ten list, surgical excision might be the only treatment needed to control the tumor. If surgical excision isn’t enough to control the tumor, we often recommend chemotherapy.

Chemotherapy concerns

The tumors listed in the top ten insurance claims also include tumors veterinary oncologists manage with chemotherapy treatments. Chemotherapy helps us control the spread of some tumors and shrink others, improving both the length and quality of a pet’s life.

Many pet owners express concern over the potential side effects of chemotherapy treatment on their pet. Scientific research has proven their concerns unfounded. Carboplatin, a chemotherapy drug used to treat bone tumors called osteosarcoma and other tumors in dogs and cats, receives high marks for improving quality of life.

A combination of chemotherapy drugs for the treatment of feline lymphoma also improved the quality of life of cats suffering from this common tumor.

Setting expectations

Veterinary oncologists successfully give chemotherapy to dogs and cats on a daily basis. Because we have been treating pets with cancer for decades, we know what doses are safe and what additional therapies to administer to limit adverse reactions. In my experience, dogs tolerate chemotherapy better than people and cats tolerate it even better than dogs. I think psychology plays a role in chemotherapy reactions. Humans know what chemotherapy can do. My patients, smart as they are, have no clue about chemotherapy. The typical pet receiving chemotherapy has one or two off days following treatment and then their appetite and energy rebound. We obsess over every patient’s white blood cell count and send them home without treatment if the count is too low for safe administration. Every one of our patients has at least two people helping with chemotherapy administration: someone who holds the pet on a soft, comfortable mat, and a nurse specially trained in administration of chemotherapy drugs.

What can a pet owner do about cancer?

Take an active role in screening your pet for cancer using the Veterinary Cancer Society’s Ten Common Signs of Cancer in Pets.

Investigate pet insurance to see if it is right for your family. If you already have a policy, find out if cancer treatment is covered.


Top 5 Health Issues Facing American Pets Today

March 19, 2012

1. Pets are becoming medically underserved

Data shows the pet population in the U.S. is climbing, but visits to veterinarians are declining. On an annual basis in 2007, dogs saw a veterinarian 2.6 times per year and cats only 1.7 times, indicating cats are affected more than dogs. This number has continued to decline in the aftermath of the Great Recession of 2008. Taking your cat or dog to the veterinarian allows early detection and intervention before medical problems like obesity cause serious disease.

2. Obesity in pets, like in humans, is skyrocketing

Veterinarians know pets are getting fatter, but research has shown pet owners are not likely to recognize obesity in their pets, perhaps because they themselves are overweight. In dogs, obesity is linked to an increased body mass index (BMI) in their owners. If you love your pet and want it to live a long, healthy life, keep its weight down. Obese pets have a shorter lifespan and increased risk of cancer, heart disease, respiratory problems, bladder disease, and, like humans, diabetes.

3. Diabetes is increasing in both cats and dogs

Banfield State of Pet Health reports a 32% increase in diabetes in dogs and 16% increase in cats, comparing 2006 to 2010. This is likely tied to the obesity epidemic in pets. Diabetes can be treated in dogs and cats, but it involves someone in the family injecting insulin once or twice daily under the skin and monitoring response to treatment. Preventing diabetes by maintaining an ideal body weight is simply easier for everyone.

4. Cancer: a major illness in both cats and dogs

According to the Morris Animal Foundation, 1 in 4 dogs dies from cancer and cancer is the leading cause of death in dogs over 2 years of age.

In dogs, breed is strongly associated with specific types of cancer. Golden retrievers commonly develop lymphoma, German shepherds a splenic tumor called hemangiosarcoma, and Pugs a skin tumor known as a mast cell tumor. Cats get cancer too, most commonly lymphoma. Annual examinations and blood tests by your family veterinarian will help to detect tumors while they are still easily treatable.

5. Dental disease is on the rise

Reluctant is the descriptor for many pet owners when it comes to dental procedures in their pets. I understand their concern for the required general anesthesia, but I am concerned their reluctance is compromising their pet’s health. Periodontal disease is very prevalent in cats and in one study, all cats had evidence of periodontal disease. Over 10% were severely affected and nearly all had bone loss in the jaw as determined by dental x-rays.

Having periodontal disease may cause collateral damage in other parts of your pet’s body. In dogs, periodontal disease was associated with increases in markers of systemic inflammation and indicators of failing kidney function, and was also associated with endocarditis and heart muscle problems.

For more information on healthcare issues facing American pets today, watch my video interview with Yahoo! Animal Nation.

Photo: iStockphoto
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This may also be found in the Tales from the Pet Clinic blog on WebMD.com.

For over a century, The Animal Medical Center has been a national leader in animal health care, known for its expertise, innovation and success in providing routine, specialty and emergency medical care for companion animals. Thanks in part to the enduring generosity of donors, The AMC is also known for its outstanding teaching, research and compassionate community funds. Please help us to continue these efforts. Send your contribution to: The Animal Medical Center, 510 East 62nd Street, New York, NY 10065. For more information, visit www.amcny.org. To make an appointment, please call 212.838.7053.

 


Urine Dribbling: Plugging the Leaking Dog

December 14, 2011

Willa came to The AMC today. Her owner was worried she might have diabetes because the dog bed was smelly and soaked with urine the last couple of mornings. Dogs with diabetes (and cats too!) will drink and urinate excessively, often having accidents in the house. When I questioned Willa’s owner, the “accidents” only happened when the dog was sleeping and there was no increase in water consumption or urinations. A quick test of the urine the owner brought with her dog determined diabetes was not the problem.

Causes of Urine Dribbling
Simple and complex disorders can lead to urination abnormalities in dogs. Infections, bladder stones and hormone problems are common causes of urine leakage and can readily be identified with routine blood tests, analysis of urine and x-rays. The x-ray to the right shows a dog with four large stones in its bladder. In some cases, a special diet will dissolve bladder stones. In this case, surgical removal of the stones resolved the urine dribbling.

In Willa’s case, testing showed no urinary tract infection, no stones and no blood test abnormalities. Because she is an older spayed female dog, I thought she might have “urethral incompetence.” Large breed, older, spayed female dogs are at risk for developing this condition, which may be related to a lack of estrogen in spayed female dogs and occasionally neutered males.

Treatments for Urine Dribbling
Commonly it is treated with medications including drugs to tighten the urethra (known as α-blockers), such as phenylpropanolamine, ephedrine or pseudoephedrine, or with estrogen replacement therapy using diethylstilbestrol. Recently, the Food and Drug Administration approved estriol for use in dogs.

If your dog resists taking medications, specialists at The Animal Medical Center can inject collagen into the urethral wall using special noninvasive endoscopic equipment to help narrow the urethral lumen and prevent urine dribbling. For refractory cases, AMC specialists also use a hydraulic urethral occluder.

Willa quickly responded to treatment with estrogen and once again has a dry bed in the morning. With all these options available to plug the leak, no dog should have to suffer with a stinky, wet bed.

________________________________________________________

This may also be found in the “Tales from the Pet Clinic” blog on WebMD.com.

For over a century, The Animal Medical Center has been a national leader in animal health care, known for its expertise, innovation and success in providing routine, specialty and emergency medical care for companion animals. Thanks in part to the enduring generosity of donors, The AMC is also known for its outstanding teaching, research and compassionate community funds. Please help us to continue these efforts. Send your contribution to: The Animal Medical Center, 510 East 62nd Street, New York, NY 10065. For more information, visit http://www.amcny.org. To make an appointment, please call 212.838.7053.


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