Name:________________________________ Date:____________ Period:___
Canine distemper blamed in skunk deaths1
Published 12:00 am PDT Saturday, May 17, 2008
DAVIS – Researchers at the University of California, Davis, said canine distemper is
responsible for the death of dozens of skunks and other wildlife near Redding.
Davis researchers had ruled out distemper last month based on early molecular tests, but
necropsies showed tissue damage associated with a contagious virus that causes distemper.
Canine distemper causes inflammation in the nervous and respiratory systems.
Since February, 83 skunks, 13 foxes and 12 raccoons were reported to have died from
mysterious causes in Shasta County. Based on two necropsies and spatial analysis that found
a "clustering of deaths," researchers linked the deaths to the distemper virus.
Owners should vaccinate their pets and keep them away from wild animals. The virus is not a
threat to humans.
People who find a dead or dying animal should not touch it, but report it to Fish and Game
officials in Redding at (530) 225-2300.
– Ngoc Nguyen
Canine Distemper2
Overview,Transmission, Symptoms
Overview
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).
Incidence
Canine distemper occurs worldwide, and once was the leading cause of death in unvaccinated
puppies. Widespread vaccination programs have dramatically reduced its incidence.
CDV occurs among domestic dogs and many other carnivores, including raccoons, skunks,
and foxes. CDV is fairly common in wildlife. The development of a vaccine in the early 1960s
led to a dramatic reduction in the number of infected domestic dogs. It tends to occur now
only as sporadic outbreaks.
Young puppies between 3 and 6 months old are most susceptible to infection and disease
and are more likely to die than infected adults. Nonimmunized older dogs are also highly
susceptible to infection and disease. Nonimmunized dogs that have contact with other
nonimmunized dogs, or with wild carnivores have a greater risk of developing canine
distemper.
Transmission
Infected dogs shed the virus through bodily secretions and excretions, especially respiratory
secretions. The primary mode of transmission is airborne viral particles that dogs breathe
in. Dogs in recovery may continue to shed the virus for several weeks after symptoms
disappear, but they no longer shed the virus once they are fully recovered. It is possible for
humans to contract an asymptomatic (subclinical) CDV infection. Anyone who has been
immunized against measles (a related virus) is protected against CDV as well.
This article is protected by copyright and should not be printed or distributed for anything except personal use. Story appeared
in METRO section, Page B2. The Sacramento Bee, 2100 Q St., P.O. Box 15779, Sacramento, CA 95852 Phone: (916) 321-1000
2
Original source: www.animalhealthchannel.com Veterinarian developed and monitored.
Original Date of Publication: 01 Mar 2001
1
Symptoms
Macrophages (cells that ingest foreign disease-carrying organisms, like viruses and bacteria)
carry the inhaled virus to nearby lymph nodes where it begins replicating (reproducing). It
spreads rapidly through the lymphatic tissue and infects all the lymphoid organs within 2 to
5 days. By days six to nine, the virus spreads to the blood (viremia). It then spreads to the
surface epithelium (lining) of the respiratory, gastrointestinal, urogenital, and central nervous
systems, where it begins doing the damage that causes the symptoms.
Early symptoms include fever, loss of appetite, and mild eye inflammation that may only last
a day or two. Symptoms become more serious and noticeable as the disease progresses.
The initial symptom is fever (103°F to 106°F), which usually peaks 3 to 6 days after
infection. The fever often goes unnoticed and may peak again a few days later. Dogs may
experience eye and nose discharge, depression, and loss of appetite (anorexia). After the
fever, symptoms vary considerably, depending on the strain of the virus and the dog's
immunity.
Many dogs experience gastrointestinal and respiratory symptoms, such as:
 Conjunctivitis (discharge from the eye)
 Rhinitis (runny nose)
 Diarrhea
 Vomiting
 Fever (usually present but unnoticed)
 Pneumonia (cough, labored breathing)
These symptoms are often exacerbated by secondary bacterial infections. Dogs almost always
develop encephalomyelitis (an inflammation of the brain and spinal cord), the symptoms of
which are variable and progressive. Most dogs that die from distemper die from neurological
complications such as the following:
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Ataxia (muscle incoordination)
Depression
Hyperesthesia (increased sensitivity to sensory stimuli, such as pain or touch)
Myoclonus (muscle twitching or spasm), which can become disabling
Paralysis
Paresis (partial or incomplete paralysis)
Progressive deterioration of mental abilities
Progressive deterioration of motor skills
Seizures that can affect any part of the body (One type of seizure that affects the head,
and is unique to distemper, is sometimes referred to as a "chewing gum fit" because
the dog appears to be chewing gum.)
Many dogs experience symptoms of the eye:
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Inflammation of the eye (either keratoconjunctivitis, inflammation of the cornea and
conjunctiva, or chorioretinitis, inflammation of the choroid and retina)
Lesions on the retina (the innermost layer of the eye)
Optic neuritis (inflammation of the optic nerve which leads to blindness)
Two relatively minor conditions that often become chronic, even in dogs that recover are:
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Enamel hypoplasia (unenameled teeth that erode quickly in puppies whose permanent
teeth haven't erupted yet—the virus kills all the cells that make teeth enamel)
Hyperkeratosis (hardening of the foot pads and nose)
In utero infection of fetuses is rare, but can happen. This can lead to spontaneous abortion,
persistent infection in newborn puppies, or the birth of normal looking puppies that rapidly
develop symptoms and die within 4 to 6 weeks.
Comprehension
1. What does CDV stand for?
2. What kinds of animals can be infected with the virus?
3. Can humans become infected with CDV?
4. Have you been vaccinated against measles?
5. How is the virus transmitted (spread from animal to animal)?
6. What are some of the symptoms that relate to the immune system?
7. What are some of the symptoms that relate to the nervous system?
8. What are some of the symptoms that relate to the gastrointestinal system?
9. What are some of the symptoms that relate to the respiratory system?
10. Is the virus curable?
11. What does In utero mean?
Extra Credit
If you have a dog as a family pet determine if it has been vaccinated. Explain how you
could determine that any pet was vaccinated against canine distemper virus.