By Dr. Becker
Canine distemper, which is also known as Carre’s disease and was once called hard pad disease, is a highly contagious virus that primarily affects young dogs, both domesticated and wild, between the ages of 2 and 6 months. Canine distemper can be fatal, especially in puppies and wildlife.
The disease is caused by a type of Morbillivirus and is closely related to the measles virus that affects humans. It’s referred to as the canine distemper virus or CDV.
How CDV Is Transmitted
Non-immunized dogs that come in contact with an infected animal carry a high risk of contracting distemper, as do puppies born to an infected mother, and young dogs under extreme stress or who are immunocompromised. Dogs exposed to wildlife may also have a heightened risk of contracting the disease.
Bacterial infections, especially of the respiratory or gastrointestinal (GI) tract may also make dogs more susceptible to the virus. On rare occasions, improperly attenuated CDV vaccines have also been implicated as a cause.
Most dogs are exposed to the virus that causes canine distemper when they inhale the respiratory secretions of an infected animal, or come in direct contact with infected feces, urine or saliva.
CDV can also be spread through direct or indirect contact with the bedding, bowls or other items belonging to an infected dog.
In susceptible dogs, the virus first reproduces in the respiratory tract and then moves on to the lymph nodes and the lymph and blood circulatory systems throughout the body. CDV can also infect a dog’s skin, GI and urogenital tracts, central nervous system and other areas of the body.
Infected dogs can shed the virus for several months after infection, even when they are not showing clinical signs of illness.
Canine Distemper Symptoms
The canine distemper virus typically attacks a dog’s tonsils and lymph nodes first, and then after about a week, it attacks the respiratory, urogenital, GI and nervous systems.
In the initial stages of the disease, symptoms include a high fever (103.5 degrees F or higher), red eyes and a runny nose and eyes. Infected dogs become tired and lethargic. Often they lose their appetite and begin to drop weight. They can also develop a persistent cough, as well as vomiting and diarrhea.
In the later stages of disease, the virus begins to attack other body systems, particularly the nervous system, which can trigger seizures and paralysis. Certain strains of CDV can cause an abnormal enlargement or thickening of the pads of the feet, which is why distemper was sometimes called hard pad disease.
Affected dogs are also susceptible to developing secondary opportunistic bacterial infections.
In dogs with weak or compromised immune systems, death can result in two to five weeks after initial infection, and sadly, this occurs about 50 to 75 percent of the time. Very young and elderly dogs have the highest rate of death from distemper.
Dogs who recover from the canine distemper virus can suffer permanent vision and neurologic damage. Puppies who recover can have severe tooth enamel problems as well.
Diagnosing CDV
Veterinarians typically run a complete blood count (CBC) and serum biochemistry profile on dogs suspected of having contracted distemper. These tests provide a lot of information about the infection, organ function and the dog’s overall health.
A urinalysis is also performed, since viral antigens can be found in urine sediment. Advanced blood tests can reveal positive antibodies for the virus; however, these tests can’t determine the difference between antibodies resulting from vaccination or antibodies resulting from exposure to CDV.
X-rays are really only necessary if pneumonia is suspected, and a CT scan or an MRI may be performed to look for brain lesions, which are common.
The best way to definitively diagnose canine distemper in a living dog is a fluorescent antibody test that can be performed on blood, respiratory or tonsil samples, cerebral spinal fluid, bone marrow or urine.
If the disease is in the very early stages, samples from the conjunctiva (the corners of the eye) can also be tested for antibodies. A polymerase chain reaction (PCR) test is also available that detects distemper virus in blood samples, and is considered very reliable.
Treatment Options
Unfortunately, there is no specific conventional therapy for canine distemper, so treatment focuses on managing symptoms and making the patient as comfortable as possible. The disease can be fatal, and the most important factor influencing a dog’s outcome is whether the virus has affected the central nervous system, and if so, to what extent.
Dogs diagnosed with CDV must be hospitalized and isolated from other animals. Conventional treatment includes antibiotics to address pneumonia if it’s present, cough medications, IV fluids, medications to reduce nausea and diarrhea, anti-seizure medications if necessary and pain management.
Integrative veterinarians will add intensive immune support during this time, including Kyosenex (a purified thymus extract), IV vitamin C, hyperbaric oxygen therapy and ozone therapy as well. Many veterinarians find homeopathic distemper nosodes very beneficial for reducing the duration of infection and minimizing the severity of symptoms and disease progression, especially if they’re used early on.
Since dogs can continue to shed the virus for weeks to months after recovery from distemper, they should be kept away from other dogs during this time. All surfaces, bedding and any object the sick dog has been in contact with should be cleaned and disinfected, or thrown away. The virus is sensitive to ultraviolet light, heat and drying, and tends to linger in cold environments more so than in warm climates.
Preventing Canine Distemper
Vaccine specialist Dr. Ron Schultz believes one well-timed canine distemper vaccine is the best prevention against this highly contagious disease. Additional annual distemper shots should be unnecessary if a titer test completed four weeks after the vaccination shows the puppy was successfully immunized.
Dr. Richard Pitcairn, a homeopathic veterinarian, advocates the use of distemper nosodes prophylactically for puppies. In addition, creating a strong and vibrant immune system by making excellent species-appropriate diet choices early on in a puppy’s life will also bolster your dog’s innate defenses against this and other infectious diseases.