Dog cough

Dog Cough

Coughing can be due to an extremely minor problem - no more than drinking water too fast - or it can be the first sign of serious problems of the lungs or heart.

Some of the questions your veterinarian will ask you:

How long has he been coughing?
How old is your pet?
Is the cough harsh and dry or is it moist and productive?
Does your pet cough most when it is up and active or when it is lying down?
Is your pet listless or more depressed than usual?
Is it having trouble breathing or breathing rapidly?
Does the problem occur this season every year?
Does your pet sneeze too and have a runny nose?
Has the pet been boarded or groomed recently?
Are there any other changes you have noticed in your pet?

Some causes of coughing:

Kennel cough:
High, dry coughs are typical of kennel cough or acute tracheobronchitis. A dog with kennel cough seems to feel fine but has frequent bouts of hacking cough. Cases usually heal in about two weeks. Treatment includes isolation to avoid infection of other family or kennel dogs, monitoring of temperature, rest, and if the coughing is severe, use of a children's over-the-counter cough syrup. A humidifier can help the dog breathe easier and thus reduce coughing and further throat inflammation.

Kennel cough in puppies and toy breeds can be more serious because the throat irritation can be accompanied by thick secretions that can cause pneumonia.

Bordatella vaccine protects dogs from several strains of kennel cough. The intranasal version of the vaccine is more effective than the inoculation. Any dog that is constantly exposed to other dogs away from home should be protected against kennel cough.

Tonsillitis:
Infectious tonsillitis is passed from pet to pet through close contact, coughing and sneezing and through contaminated food, water bowls and other objects. It is most common in toy breeds of dogs and puppies. The two tonsils normally lie in deep crypts or crevices at the far back of the mouth. With certain infections such as kennel cough, the tonsils enlarge, partially obstructing the pet's throat. Usually both tonsils are affected. When enlarged tonsils become inflamed and ulcerated the pet will spend hours trying to cough them up. This is a retching, violent cough that usually ends in a gag producing foam. These pets will sometimes paw at their mouths. Vets will treat this with a two-week course of antibiotics such as trimethoprim/sulfa. If the tonsillitis returns frequently, then it's generally recommended to remove the tonsils.

Tooth and Mouth Infections:
Small breeds of dogs, especially Toy poodles, Yorkshire terriers, Maltese and Pomeranians are very subject to periodontal disease, loose infected teeth and oral inflammation. This is partly due to their genetics but also due to feeding them soft table foods. These oral infections sometimes inflame the rear of the throat causing coughing. Often the problem is magnified by a flabby, narrow trachea or windpipe as well as tonsillitis due to the mouth infection. Many times the infection has migrated to the valves of the heart (mitral valve) damaging that organ as well. These pets need to have all diseased teeth removed. This is not major surgery in these pets because the teeth are already loose, lifeless and no longer used in eating. Many teeth may have already fallen out on their own. Subsequent to dental surgery, dog are put two weeks of antibiotics.

Collapsed Trachea:
Toy breeds of dogs are very prone to a genetic abnormality called tracheal collapse. The trachea is made up of cartilaginous rings in the shape of a C that are fibrous and soft on their innermost side. In collapsing trachea the inner soft portion of the windpipe is sucked into the airway during inspiration, partially occluding it. With time, the membranes lining the trachea become inflamed causing a chronic dry, hacking cough.

The condition is easily diagnosed by massaging the trachea near the dog's chest for a minute or two. Dogs with this problem go into a coughing spell as soon as you finish the massage. When the problem flares up, dogs are given a cough suppressant and an anti-inflammatory drug such as prednisone until the problem resolves. Air humidifiers are also helpful. These dog do well wearing a harness rather than collars and limited exercise until the cough is better. Various surgical techniques are used to attempt to cure this condition. They meet with mixed success.

Migrating Hook and Roundworm Larva:
Canine hookworms and roundworms can also cause a cough, which is called a verminous cough. This problem is primarily a concern in young dogs, and puppies. When a dog accidentally eats a hookworm or roundworm larva or egg, the larva burrows through pet's stomach or intestine into the blood stream. When it reaches the lungs it is coughed up, re-swallowed and then matures in the pet's intestine. If the pet becomes infested with large numbers of larva due to an unsanitary environment the owners will notice the cough.

Preventing verminous coughs is a mater of sanitation. Dog feces need to be collected and disposed of properly.
Hookworm larva thrives in damp shaded soil. One of the best ways to prevent this problem is to keep all your pets on a monthly heartworm medication, which contains pyrantel pamoate.

Allergies and Irritants:
Some dogs, like people, experience throat and nasal irritation due to chemicals in perfumes, cigarette smoke, new bedding, carpeting, etc. Dust mite allergy is said to occasionally cause coughing, however these cases are fairly uncommon. Coughing can be a multifaceted problem and it is quite likely that allergies and irritants can make a cough worse.

Heartworm Disease:

Heartworms are transmitted to dogs and cats by mosquitoes. The disease is common in dogs. Mosquitoes that bite an infected dog, ingests microscopic heartworm larva or microfilaria. When they next bite a dog these larva migrate through the new host's body and lodge in the upper right side of the heart. Depending on the number of heartworms present and the length of time they are there, the heart is slowly damaged and enlarges.

The presence of heartworms also causes inflammatory changes in the lungs. In dogs, these changes, along with pressure from the enlarged heart on the windpipe cause a dry to moderately moist cough. By the time a cough is present the disease is quite advanced and some of the changes to the heart and lungs are irreversible.

Dogs with heartworm coughs are noticeably ill. They are thin and their hair coat is dry and musty. They have a worn-out look about them and are often prematurely grey around their muzzle and toes. They are usually pot bellied due to an enlarged liver and excess fluid in their abdomens and are positive on a heartworm antigen test.

Their cough is worse when the dog is lies down. The pet's history includes the fact that they are not receiving heartworm preventative.

After assessing the degree of damage to the body, dogs are put on Immiticide, an arsenic-containing medication that kills the adult parasites. If the dog's liver, heart and kidneys are strong enough to withstand the side effects of this powerful medication, then they can have the standard two injections at twenty-four hour intervals. If the disease has caused marked damage to the liver and heart the vet will try to stabilize and improve the pet's health before the injections. If that cannot be done, then the vet can give a single injection and then place the dog on monthly heartworm preventative or just place them on the monthly preventative. Recent studies have shown that dogs placed on monthly Ivermectin are free of adult heartworms within a year. Coughs can take up to six months to resolve.

Congestive Heart Disease

Coughing is one of the most consistent signs of heart disease. The most common form of heart disease in dogs begins with damage to the mitral valve on the left side of the heart. When the vet will listen to the heart with his stethoscope, he can detect abnormal sounds on the left upper quadrant of the heart - the area where this valve is located. X-rays of the pet's heart show a typical globular, enlarged heart shape with elevation of the trachea.

Pressure on the trachea and fluid in the lungs are the primary causes of the cough. The pets' gums are often bluish (cyanotic) and slow to return to normal color when the vet's fingers blanch them. The livers of these pets are enlarged with pooled blood and they may have fluid in their abdomens. Mitral valve insufficiency is the most common heart disease in older dogs. It affects over one-third of the dogs that are older than ten.

Early in this disease placing the pet on the diuretic Furosemide eliminates the cough and improves the function of a weakened heart. These dogs do well when placed on a sodium-restricted diet. As the disease progresses, the pet will need other medications. One of the most effective medications is the ACE inhibitor, Enalapril Maleate.

Dilated Cardiomyopathy

Cardiomyopathy is a form of heart disease that affects larger breeds of dogs. Doberman Pinchers and Boxers have a high incidence of this condition. Most recently, Taurine deficiencies due to feeding lamb and rice diets have been shown to cause the disease in dogs. It is very rare in dogs that weigh less than 28 pounds.

The onset of this disease is very rapid. Pets begin to cough and show general weakness and exercise intolerance all within a matter of weeks. Their heart rate is very fast and weak, and can be very irregular. The usual lack of heart murmurs distinguishes this condition from congestive heart failure. X-rays of these animals chest show a huge heart - often with an enlarged left upper chamber (atrium) and the lungs often filled with fluid.

This condition is treated similar to congestive heart failure. Unfortunately, dogs with Dilated Cardiomyopathy do not live long.

Tumors in the Lungs:

Hacking coughs in old dogs are also common when tumors of the lungs are present. These are always sad cases to deal with. When lung tumors are advance, pets may cough up blood as well as phlegm. Primary lung tumors are exceedingly rare dogs. They are generally secondary tumors that have moved to the lungs from another location. Sometimes, if the disease is advanced, abnormal lung sounds or silent areas are present.

X-rays of these animals' lungs often show a shower of small tumors throughout the lung fields. The most common tumor type is adenocarcinomas. Sometimes the dog's vet will refer these pets on to a veterinary oncologist, but there is really no effective chemotherapy for dog with lung tumors. Veterinarians will try to make their remaining life as pleasant as possible with cough suppressants, steroids and bronchodilators such as theophylline.

Laryngeal Paralysis:

This is a relatively rare condition in which the structures of the throat (larynx) become paralyzed allowing food and water to enter the lungs causing pneumonia. Large breeds of dogs (particularly Labrador Retrievers, Irish Setters and Springer Spaniels) are affected. These dogs loose the ability to bark. They have reduced exercise tolerance and occasional fainting spells. They produce a roaring sound when they inhale.

Mild cases can be managed with corticosteroids and cough suppressants such as Butorphanol or Codeine. The dogs need to be kept cool in the summer. Severe cases require surgery to widen the pet's airway.

Distemper:

Canine distemper is a contagious, incurable, often fatal, multisystemic viral disease that affects the respiratory, gastrointestinal, and central nervous systems. Distemper is caused by the canine distemper virus (CDV). Canine distemper occurs worldwide, and once was the leading cause of death in unvaccinated puppies. Widespread vaccination programs have dramatically reduced its incidence.
The first sign of distemper is eye discharge that may appear watery to pus-like. Subsequently, dogs develop fever, nasal discharge, coughing, lethargy, reduced appetite, vomiting, and diarrhea. In later stages, the virus may attack the nervous system, bringing about seizures, twitching, or partial or complete paralysis. Occasionally, the virus may cause footpads to harden. Distemper is often fatal. Even if a dog does not die from the disease, canine distemper virus can cause irreparable damage to a dog's nervous system. Distemper is so serious and the signs so varied that any sick dog should be taken to a veterinarian for an examination and diagnosis

Veterinarians diagnose canine distemper on the basis of clinical appearance and laboratory tests.

No specific drug is available that will kill the virus in infected dogs. Treatment consists primarily of efforts to prevent secondary infections; control vomiting, diarrhea, or neurological symptoms; and combat dehydration through administration of fluids. Ill dogs should be kept warm, receive good nursing care, and be separated from other dogs. Distemper is preventable by vaccination.

Lungworms:

The chief signs of lungworm infections in dogs are coughing and a rise in the number of white blood cells called eosinophiles. Adults of these parasites live in nodules in the windpipe where they pass living larva, which are coughed up. Some are spit out and others reswallowed and pass out in the stool. Pups become infected by eating the saliva or feces of an infected dog. These worms are treated with fenbendazole (Panacur) at 25mg/pound body weight daily for 7-14 days. Most are also given prednisolone to decrease inflammation and coughing.

Reverse Sneeze-or-Cough (Paroxysmal Respiration):

Reverse sneezing is a forceful bizarre noise that sounds like the honking noise a goose makes. The dog makes a lot of noise and his sneeze sounds a little like a cough and a sneeze. Reverse sneeze syndrome is characterized by a series of rapid, loud, forced inhalations through the nostrils, lasting anywhere from 10 seconds to 2 minutes. Attacks occur on a sporadic, unpredictable basis. Dogs usually have the head extended forward and stand still during the episode with elbows turned out and sometimes with the back arched.

Affected dogs appear completely normal before and after the attack. There is no loss of consciousness or collapse, though some times the appearance of the dog and the noise is upsetting to owners. You might think he has something caught in his nose. Many dogs have these attacks throughout their lives.

A reverse sneeze is associated with noisy inspiratory and expiratory events without the big expiratory burst. Some dogs with nasopharyngeal disease may cough, sneeze and reverse-sneeze, as well as gag or retch, making it challenging for the veterinarian to figure out exactly what the problem is. The exact cause of reverse sneezing is unknown, but it may be associated with sinusitis, incomplete closure of naso-pharynx, and other upper respiratory disorders. Whatever, the cause, the condition is usually not serious.

Treatment is not necessary when episodes occur infrequently or on a random basis. To help your dog you may wish to try any of the following ideas: holding off both nostrils so the dog takes a breath through the mouth, blowing in the nose, or massaging the throat.
All of these techniques are designed to stimulate a swallow reflex, which will help to stop the episode.

You should notify the doctor if the severity or frequency of the attack changes, a nasal discharge or cough develops, or the general health of your pet changes.

Tuberculosis:

Although uncommon, tuberculosis does affect dogs and can cause upper respiratory symptoms. The cough associated with this bacterial infection is moist and productive; dogs may hack up bloody sputum, and suffer from labored breathing. Diagnosis is by x-ray of the lungs. Dogs and humans can infect each other with tuberculosis.

Breed Characteristics:

Dogs with flat faces that snore often have elongated soft pallets in the rear of their mouths, and this can cause coughing. Pekingese, Pugs, Bulldogs, Lhasa Apsos, Shiz Tzu's fall into this category. When flare-ups occur, vets will put these dogs on a short course of corticosteroid and antibiotic treatment. Occasionally the problem is so severe that the pet does not get enough air. When this is the case, the vet will surgically remove a portion of the soft palate, being very cautious when performing this surgery, because if too much tissue is removed coughing will become worse and the pet may inspire food and water into its lungs.

The Bottom Line:

The causes of cough are many and varied, but most can be traced to some stimulation or irritation of sensory nerves in the throat, windpipe or smaller airways. The character of the cough may help to localize the problem to a specific area of the respiratory tree or cardiovascular system and to suggest its potential severity. The duration of the cough is an important part of the history, as well as vaccination and heartworm status, travel or boarding history, pre-existing health problems, concurrent medications, and any prior history of cough.

Coughs are triggered by irritants in the air passages and can be characterized as dry and hacking; moist and bubbly; gagging; wheezy; harsh; or weak. It can be frequent, chronic, or intermittent, and is often self-perpetuating as it dries the throat and leads to further irritation.

Dogs cough for a variety of reasons, some of which can be serious in themselves and others that are signs of an underlying problem. Some common causes of coughing and gagging include foreign objects in the airway, bronchitis, bacterial pneumonia, heart disease, laryngeal paralysis, fungal infections, reflux esophagitis (similar to heartburn in people), food allergies, parasites, tumors, and other diseases. Environmental factors such as exposure to cigarette smoke, new perfumes, or new bedding or carpeting can also aggravate coughing. There could be some abnormality of the trachea, or possibly heart problems.

Some dogs will cough and gag whenever they drink water but never do it any other time. When dogs drink they actually throw the water toward the back of the throat with a neat trick of the tongue. If the dog drinks fast some water contacts the sensitive tissues within the larynx which triggers a cough response. If your dog can run, play, pant and breathe without a chronic cough and only does it when drinking, then it's nothing serious and you can ignore it.

For mild episodes, massaging your dog's throat may help lessen the symptoms.

Coughing may not sound like a serious problem, but sometimes it is a sign of a significant disease. Since there are so many possible causes of coughing in a canine, it's important for you to be patient as your veterinarian tries to get to the bottom of it all. Many of the diseases associated with various types of coughing can be managed if they're caught early on.