Encephalitis in Dogs

The term encephalitis refers to an inflammation of the brain. However, it also may be accompanied by the inflammation of spinal cord (myelitis), and/or the inflammation of the meninges (meningitis), membranes which cover the brain and spinal cord.

German short-haired pointers, Maltese, and Yorkshire terriers are all found to be predisposed to encephalitis.

Symptoms of Encephalitis

Although symptoms may vary depending on the portion of brain affected, they typically appear suddenly and are rapidly progressive. Such symptoms include:

Fever
Seizures
Behavioral changes (e.g., depression)
Decreased responsiveness
Head tilt to either side
Paralysis of face
Uncoordinated movements or circling
Unequal size of pupils (anisocoria)
Smaller sized pinpoint pupils
Decreased consciousness, which may worsen as disease progresses

Causes of Encephalitis

Idiopathic (unknown cause)
Immune-mediated disorders
Post-vaccination complications
Viral infections (e.g., canine distemper, rabies, parvovirus)
Bacterial infections (anaerobic and aerobic)
Fungal infections (e.g., aspergillosis, histoplasmosis, blastomycosis)
Parasitic infections (e.g., Rocky Mountain spotted fever, ehrlichiosis)
Foreign bodies

Diagnosis of Encephalitis

You will need to give your veterinarian a thorough history of your dog’s health, including the onset and nature of the symptoms, and possible incidents that might have precipitated the unusual behaviors or complications. Your veterinarian may then perform a complete physical examination as well as a biochemistry profile, urinalysis, and complete blood count (the results of which will depend on the underlying cause of the encephalitis).

If your dog has an infection, the complete blood count may show an increased number of white blood cells. Viral infections, meanwhile, may decrease the number of lymphocytes, a type of white cells (also known as lymphopenia). And abnormal reduction in platelets (small cells used in blood clotting) is a good indicator of thrombocytopenia.

To confirm lung involvement and related complications, your veterinarian may require chest X-rays, while MRIs and CT-scans are used to evaluate the brain involvement in detail. Your veterinarian may also collect a sample of cerebrospinal fluid (CSF), which is then sent to a laboratory for cultures. This is necessary for definitive diagnosis and to determine the severity of the problem. If culture assays are unsuccessful, a brain tissue sample may be necessary to confirm the diagnosis, but this is an expensive procedure.

Treatment of Encephalitis

Your veterinarian will focus on reducing the severity of the symptoms, such as brain edema and seizures, and halt the progression of the disease. Severe forms of encephalitis require immediate hospitalization and intensive care. For instance, those suspected of having bacterial infections will be given broad spectrum antibiotics, which can reach the brain and spinal cord.

Living and Management

With proper treatment and care, symptoms gradually improve within two to eight weeks; however, the overall prognosis depends on the underlying cause of the condition. For example, in some dogs, symptoms may reappear once treatment is discontinued. In such instances, a second round of treatment (or long-term treatment) may be required to save the dog's life.

Your veterinarian will schedule regular follow-up exams to evaluate the effectiveness of the treatment and the dog's state of health. Your vet may even recommend a new diet for the dog, especially if it is frequently vomiting or severely depressed.

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What is Kennel Cough?

Just as human colds may be caused by many different viruses, kennel cough itself can have multiple causes. One of the most common culprits is a bacterium called Bordetella bronchiseptica m— which is why kennel cough is often called Bordetella. Most dogs that become infected with Bordetella are infected with a virus at the same time. These viruses, which are known to make dogs more susceptible to contracting Bordetella infection, include canine adenovirus, canine distemper virus, canine herpes virus, parainfluenza virus and canine reovirus.

Dogs "catch" kennel cough when they inhale bacteria or virus particles into their respiratory tract. This tract is normally lined with a coating of mucus that traps infectious particles, but there are a number of factors that can weaken this protection and make dogs prone to kennel cough infection, which results in inflammation of the larynx (voice box) and trachea (windpipe).

These factors include:

Exposure to crowded and/or poorly ventilated conditions, such as are found in many kennels and shelters

Cold temperatures

Exposure to dust or cigarette smoke

Travel-induced stress

Symptoms of Kennel Cough

The classic symptom of kennel cough is a persistent, forceful cough. It often sounds like a goose honk. This is distinct from a cough-like sound made by some dogs, especially little ones, which is called a reverse sneeze. Reverse sneezes can be normal in certain dogs and breeds, and usually only indicates the presence of post-nasal drip or a slight irritation of the throat.

Some dogs with kennel cough may show other symptoms of illness, including sneezing, a runny nose, or eye discharge.

If your dog has kennel cough, they are not likely to lose their appetite or have a decreased energy level.

Treating and Preventing Kennel Cough

Kennel cough is contagious. If you think your dog might have the condition, you should keep them away from other animals and contact your veterinarian.

Although most cases of kennel cough will resolve without treatment, medications may speed recovery or minimize symptoms during the course of infection. These include antibiotics that target Bordetella bacteria and cough medicines.

You may also find that keeping your dog in a well-humidified area and using a harness instead of a collar, especially for dogs that strain against a leash, will minimize the coughing.

Most dogs with kennel cough recover completely within three weeks, though it can take up to six weeks in older dogs or those with other medical conditions. Because serious, ongoing kennel cough infection can lead to pneumonia, be sure to follow up with your veterinarian if your dog doesn't improve within the expected amount of time. Also, if your dog at any time has symptoms of rapid breathing, not eating, or listlessness, contact your vet right away, as these could be signs of more serious conditions.

There are three forms of vaccine for kennel cough: one that is injected, one that is delivered as a nasal mist, and one that can be given by mouth. It is important to realize that neither form of the kennel cough vaccination will treat active infections.

The intranasal and oral kennel cough vaccinations are typically given to dogs once a year, but sometimes are recommended every six months for dogs at high risk for kennel cough. These forms of the vaccine tend to provide dogs protection against kennel cough sooner than the injected product.

Encephalitis: Brain Inflammation in Dogs