Canine Illnesses and Diseases

Heart Disease in Dogs   Top

If you are a dog owner, you will probably agree that your pet holds a special place in your heart. But you must remember that keeping your dog's heart healthy is one of your responsibilities.

"When it comes to heart disease, regular visits to your veterinarian could mean the difference between life and premature death," says Dr. Joanne Bicknese. "Dog owners may not realize that their pets are susceptible to many forms of heart disease. In most cases, heart disease can be successfully managed with early detection and treatment".

What is Heart Disease in Dogs?
Heart disease in dogs, as in people, can be either present at birth or acquired, often developing during middle age. Acquired heart disease is more common, affecting many older dogs.

Are there different types of heart disease in dogs?
Yes, there are two common types of heart disease in dogs:

• In one type, a dog's heart valves lose their ability to close properly, causing abnormal blood flow.
• In the other type, the muscular walls of a dog's heart become thinned and weakened.

Both types develop gradually over time and result in the same serious condition called heart failure.

Heart Failure
A major threat to your dog's health is heart failure. Of the dogs in the United States examined annually by a veterinarian, approximately 3.2 million have some form of acquired heart disease and may be in heart failure. Heart failure results from the heart's inability to pump blood at a rate required to meet the body's needs. While continuing to work harder to pump blood, further heart damage can occur.

What are the signs of heart disease in dogs?
Although some of the early stages of heart failure in dogs have no visible signs, heart failure can be diagnosed through a clinical evaluation by a veterinarian. Dogs with mild to moderate heart failure typically experience heart enlargement, coughing, lethargy and difficulty breathing. Severe heart failure is characterized by difficulty breathing (even at rest), fainting, profound intolerance to exercise, loss of appetite and weight loss.

How can I find out if my dog has heart disease?
Your veterinarian is your dog's healthcare expert. Regular veterinary visits are important for early detection of health problems.

Your veterinarian may ask you for specific information about your dog before performing a thorough physical examination. If indicated, blood and urine tests, X-rays, an EKG or other tests may be ordered. Regular testing is important for early detection of heart disease in dogs.

"Too often, dog owners do not take their dogs to visit the veterinarian until they are displaying severe signs of heart failure, and by then it may be too late," says Dr. Bicknese. "When heart disease is detected in your dog, your veterinarian can recommend a schedule of regular visits and discuss a treatment plan that can help."

Can dogs with heart disease be treated?
Yes. Although there is no cure for most heart disease in dogs, new treatments are available. Success of treatment depends on various factors, but early detection is always best. By following your veterinarian's recommendations, you can help your dog live a longer, more comfortable life.

Keeping Your Dog Healthy
In addition to safeguarding your dog's heart, there's a lot you can do to keep your dog happy and in top shape. Ensure that your dog gets a moderate amount of exercise on a regular basis and has a balanced diet. An obese dog may have a harder time staying healthy.

Avoid the heartbreak of seeing your family's best friend fall ill. Proper care and veterinary supervision can help you watch your dog grow to a "hearty" old age.

The contents of this page are a consumer awareness campaign
co-sponsored by AVMA & Merial

Heartworm Disease   Top

General Information   Top

The life cycle of the heartworm begins when an infected dog, carrying tiny immature heartworms (microfilariae) circulating in its blood, is bitten by a mosquito. The mosquito takes in microfilariae (larvae) when it feeds.

During the next two-three weeks, the larvae develop within the mosquito into the infective stage.

When the mosquito feeds again, it can
transmit infective larvae to the healthy dog. The larvae penetrate the dog's skin and migrate through the tissues and develop over the next few months, eventually reaching the dog's heart.

Once in the dog's heart, the worms can grow to as long as 14 inches and cause significant damage to the heart, lungs and other vital organs. If left untreated, heartworm disease can result in death.

Heartworm FAQs   Top

Can my dog get heartworm disease?
Yes. Your dog can get heartworm disease, whether he's an "outside" dog or even if he stays inside most of the time. Dogs get heartworm disease from mosquitoes. It is the female mosquito that bites and transmits the infection. Female mosquitoes are very tiny and can easily slip through cracks around windows, doors or screens. Every dog can be at risk, indoors or out.

Are some dogs more susceptible than others?
Unfortunately, no dog, or breed of dog, is immune to heartworm disease. The mosquito that bites your dog could be carrying this common and deadly parasite. One bite from an infected mosquito is all it takes for your dog to become infected.

How can I know for sure if my dog already has heartworm?
The only way to know for sure is to have your family veterinarian examine and test your dog. The procedure is quick and easy. But don't delay in calling your veterinarian to arrange for a heartworm test. If your dog gets heartworm disease, treatment can be dangerous for him and expensive for you.

When is the right time to get my dog tested?
Mosquitoes, the carriers of heartworm disease, can be found at varying times of the year depending on the climate. Ask your veterinarian when the best time is to have your dog tested.

How can I prevent my dog from getting heartworm disease in the future?
If your veterinarian determines that your dog is free of heartworms, he or she will tell you how easy and convenient prevention can be. It's important to follow your veterinarian's instructions; if you don't, your dog could still be at risk. Remember, the first, most important step is to have your dog tested for heartworms.

Heartworm and Traveling with Your Dog   Top

Dog owners, be aware of the following:
Alex, a Labrador retriever, lives in a heartworm-endemic state. He has heartworms, but his owners don't know it because the disease is not easily detected until its later stages. Alex travels with his owners on vacation to states where there are fewer incidences of heartworm disease like Alaska. While in Alaska, Alex is bitten by a mosquito, which picks up the heartworm larvae from his bloodstream. Later, the same mosquito bites a healthy local dog, infecting him with heartworm. The cycle continues.

A problem can also result if a dog from a low-incidence state like Alaska travels into a state where heartworm disease thrives, is bitten by a mosquito and then brings the disease back home.

What Does This Mean For All Dog Owners?
Now that greater numbers of people are traveling across the country with their dogs, on vacation or visiting friends and relatives, no state is entirely heartworm-free. Heartworm disease continues to pose a threat to dogs across the United States. Because heartworm disease is potentially fatal, owners should visit their family veterinarian to learn how easy and convenient prevention can be.

When Traveling, Help Protect Your Dog from Heartworm Disease

1. Many states require that owners traveling with their dogs obtain an up-to-date health certificate from a licensed veterinarian.
2. As a part of the examination, your veterinarian may check for heartworm disease. If your dog is not infected, the veterinarian can recommend preventive measures. Prevention is the key to protecting a dog both at home and away.
3. Upon returning home from a trip, owners should revisit their family veterinarian for an examination to make sure their dog did not pick up any parasites, either internal (e.g., heartworm, hookworm, roundworm) or external (fleas and ticks).
4. Remember, annual heartworm tests are important whether or not your dog is traveling.

Canine Distemper   Top

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Younger dogs and puppies are the most susceptible to infection. Among puppies, the death rate from distemper often reaches 80%. The disease also strikes older dogs, although much less frequently.

Even if a dog does not die from the disease, its health may be permanently impaired. A bout with canine distemper can leave a dog's nervous system irreparably damaged, along with its sense of smell, hearing or sight. Partial or total paralysis is not uncommon, and other diseases — particularly pneumonia — frequently strike dogs already weakened by a distemper infection.

Cats are not susceptible to canine distemper. The so-called "cat distemper" is a different disease caused by a different virus. Neither disease is transmissible to humans.

What Does Distemper Do?   Top

Canine distemper is a highly contagious disease caused by a virus.

Canine distemper virus is most often transmitted through contact with respiratory secretions. Contact with the urine and fecal material of infected dogs can also result in infection.

The many signs of distemper are not always typical. For this reason, treatment may be delayed or neglected. The disease frequently brings about something like a severe cold. Most infected dogs have a fever and "stuffed up" head. Exposed animals may develop bronchitis, pneumonia and severe inflammation of the stomach and intestines.

The first signs of distemper an owner might notice are squinting, congestion of the eyes, and a discharge of pus from the eyes. Weight loss, coughing, vomiting, nasal discharge, and diarrhea are common. In later stages the virus frequently attacks the nervous system, bringing about partial or complete paralysis as well as "fits" or twitching. Dogs suffering from the disease are usually listless and have poor appetites.

Sometimes the signs may be very mild and perhaps go unrecognized, or the dog may have a slight fever for a couple of weeks. If pneumonia, intestinal inflammation or other problems develop, recovery takes much longer. Nervous problems often last many weeks after the animal has recovered from all other signs of infection. Occasionally the virus causes rapid growth of the tough keratin cells on the footpad, resulting in a hardened pad.

Distemper is so prevalent and the signs so varied that any sick young dog should be taken to a veterinarian for a definite diagnosis.

Prevention and Protection   Top

Dogs that survive a natural infection usually develop sufficient immunity to protect them from distemper the rest of their lives. Many dogs — particularly pups — do not survive a naturally-acquired infection. The safest protection is vaccination.

Puppies born to dogs which are immune to distemper acquire a degree of natural immunity from nursing. This immunity is acquired through substances in the colostrum, which is the milk produced by the mother the first few days after giving birth. The degree of protection a pup receives varies in proportion to the amount of antibody its mother has, but the protection diminishes rapidly.

Your veterinarian can determine the most advantageous time to begin vaccination based upon his or her experience and the general health of your dog. Ask your veterinarian about a recommended vaccination schedule.

Canine Parvovirus   Top

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CPV infection is spread by dog-to-dog contact and has been diagnosed wherever dogs congregate, including dog shows, obedience trials, breeding and boarding kennels, pet shops, humane shelters, parks and playgrounds.

A dog that is confined to a house or yard and is rarely in contact with other dogs is far less likely to be exposed to the virus. CPV infection can only be transmitted to dogs and other canids, not to other types of animals or people, but animals and people can carry it to your dog.

The source of infection is fecal waste from infected dogs. Large amounts of the virus may be present in fecal material of infected dogs. The virus is resistant to extremes in environmental conditions and can survive for long periods. It is readily transmitted from place to place on the hair or feet of infected dogs or by contaminated cages, shoes, or other objects. Definitive information on other means of transmission, if any, is lacking.

How Can You Tell If A Dog Has CPV Infection?   Top

The first signs of CPV infection are depression, loss of appetite, vomiting, and severe diarrhea. Rectal temperatures may be raised. These signs will most often appear 5-7 days after the dog is exposed to the virus. At the onset of illness, the feces will generally be light gray or yellow-gray. Sometimes, the first sign will be fluid feces streaked with blood.

Dogs may dehydrate rapidly due to vomiting and diarrhea. Some dogs may vomit repeatedly and have projectile and bloody diarrhea until they die. Others may have loose feces and recover without complications.

Most deaths occur within 48-72 hours following the onset of clinical signs. Pups suffer most with shock-like deaths, occurring as early as two days after the onset of illness. In the past, a high percentage of pups less than five months old and 2-3% of older dogs died from this disease. Now, due to widespread vaccination, these percentages have decreased dramatically.

Puppies, between weaning and six months of age are at increased risk of acquiring the disease. There appears to be a higher risk of severe disease in certain breeds (e.g. Rottweiller and Doberman Pinscher).

How Is CPV Infection Diagnosed and Treated?   Top

A veterinarian will make the initial diagnosis based on clinical signs but only after considering other causes of vomiting and diarrhea. Evidence of rapid spread in a group of dogs is strongly suggestive of CPV infection and may be confirmed by testing feces for the virus. Some tests may be available in your veterinarian's office. Your veterinarian may choose to send samples to an outside laboratory, however. There are no specific drugs that kill the virus in infected dogs.

Treatment of CPV infection, which should be started immediately, consists primarily of efforts to combat dehydration by replacing electrolyte and fluid losses, controlling vomiting and diarrhea, and preventing secondary infections with antibiotics.

Sick dogs should be kept warm and be provided good nursing care.

Prevention and Protection   Top

With a few exceptions, dogs of any age should be vaccinated to prevent CPV infection. Unless the actual immune status of a pup or litter is known, it is recommended that a series of vaccinations be given to provide adequate protection. Ask your veterinarian about a recommended vaccination schedule.

Proper cleaning and disinfection of kennels and other areas where dogs are housed is essential to control spread of the virus. Remember, the virus is capable of existing in the environment for many months unless the area is thoroughly cleaned. Sodium hypochlorite solution, such as one-quarter cup household bleach in 1 gallon of water, is an effective disinfectant.

An owner should not allow a dog to come in contact with fecal waste of other dogs when walking in a park or playground or along city streets. This is especially true until six months of age. Prompt and proper disposal of waste material is always advisable. Check lawns, sidewalks, and street gutters for fecal waste from neighborhood dogs, and urge friends to do the same.

If you are unsure whether this disease is affecting dogs in your community, check with a veterinarian. The risk of exposure can be reduced if you prevent your dog from contacting other dogs in areas where the incidence of CPV infection is alarmingly high.

Canine Bordetellosis (Kennel Cough)   Top

Bordetellosis is caused by bacterium Bordetella bronchiseptica which is present in the respiratory tracts of many animals. It is a primary cause of tracheobronchitis (kennel cough) which results in a severe chronic cough. In addition to the cough, some dogs develop a nasal discharge. Transmission most frequently occurs by contact with the nasal secretions of infected dogs.

Vaccination is usually accomplished by the use of a nasal spray. There are several effective schedules and methods for administering the vaccine. Your veterinarian will establish a schedule that is best for your dog.

Canine Parainfluenza   Top

Parainfluenza is caused by a virus which produces a mild respiratory tract infection. It is often associated with other respiratory tract viruses. In combination these viruses are usually transmitted by contact with the nasal secretions of infected dogs. The vaccine to protect against this disease may be combined with other vaccines to offer broader protection.

Canine Leptospirosis   Top



Leptospirosis is a bacterial disease that impairs renal (kidney) function and may result in kidney failure. Clinical signs include vomiting, impaired vision, and convulsions. The disease is transmitted by contact with the urine of infected animals or by contact with objects that have been contaminated with the urine of infected animals.