Canine distemper virus (CDV) (sometimes termed footpad disease) is a
viral disease
A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...
that affects a wide variety of mammal families, including domestic and wild species of dogs, coyotes, foxes, pandas, wolves, ferrets, skunks, raccoons, and felines, as well as pinnipeds, some primates, and a variety of other species. CDV does not affect humans.
In canines CDV affects several body systems, including the gastrointestinal and respiratory tracts and the spinal cord and brain. Common symptoms include high fever, eye inflammation and eye/nose discharge, labored breathing and coughing, vomiting and diarrhea, loss of appetite and
lethargy
Lethargy is a state of tiredness, sleepiness, weariness, fatigue, sluggishness or lack of energy. It can be accompanied by depression, decreased motivation, or apathy. Lethargy can be a normal response to inadequate sleep, overexertion, overwo ...
, and hardening of nose and footpads. The viral infection can be accompanied by secondary bacterial infections and can present eventual serious neurological symptoms.
Canine distemper is caused by a single-stranded
RNA virus
An RNA virus is a virusother than a retrovirusthat has ribonucleic acid (RNA) as its genetic material. The nucleic acid is usually single-stranded RNA ( ssRNA) but it may be double-stranded (dsRNA). Notable human diseases caused by RNA viruses ...
of the family ''
Paramyxoviridae
''Paramyxoviridae'' (from Ancient Greek, Greek ''para-'' “by the side of” and ''myxa'' “mucus”) is a family of negative-strand RNA viruses in the order ''Mononegavirales''. Vertebrates serve as natural hosts. Diseases associated with this ...
'' (the same family of the viruses that causes
measles
Measles is a highly contagious infectious disease caused by measles virus. Symptoms usually develop 10–12 days after exposure to an infected person and last 7–10 days. Initial symptoms typically include fever, often greater than , cough, ...
,
mumps
MUMPS ("Massachusetts General Hospital Utility Multi-Programming System"), or M, is an imperative, high-level programming language with an integrated transaction processing key–value database. It was originally developed at Massachusetts Gener ...
, and
bronchiolitis
Bronchiolitis is inflammation of the small airways in the lungs. Acute bronchiolitis is due to a viral infection usually affecting children younger than two years of age. Symptoms may include fever, cough, runny nose, wheezing, and breathing ...
in humans). The disease is highly contagious via inhalation.
Morbidity and mortality may vary greatly among animal species, with up to 100% mortality in unvaccinated populations of ferrets. In domestic dogs, while the acute generalized form of distemper has a high mortality rate, disease duration and severity depends mainly on the animal's age and immune status and virulence of the infecting strain of the virus.
[ Despite extensive vaccination in many regions, it remains a major disease of dogs, and was the leading cause of infectious disease death in dogs, prior to a vaccine becoming available.
]
Etymology
The origin of the word ''distemper'' is from Middle English
Middle English (abbreviated to ME) is a form of the English language that was spoken after the Norman conquest of 1066, until the late 15th century. The English language underwent distinct variations and developments following the Old English p ...
''distemperen'' 'to upset the balance of the humors', which is from Old French
Old French (, , ; Modern French: ) was the language spoken in most of the northern half of France from approximately the 8th to the 14th centuries. Rather than a unified language, Old French was a linkage of Romance dialects, mutually intelligib ...
''destemprer'' 'to disturb', which is from Vulgar Latin
Vulgar Latin, also known as Popular or Colloquial Latin, is the range of non-formal Register (sociolinguistics), registers of Latin spoken from the Crisis of the Roman Republic, Late Roman Republic onward. Through time, Vulgar Latin would evolve ...
''distemperare'' 'to not mix properly'.
History
In Europe, the first report of CDV occurred in Spain in 1761. Edward Jenner
Edward Jenner, (17 May 1749 – 26 January 1823) was a British physician and scientist who pioneered the concept of vaccines, and created the smallpox vaccine, the world's first vaccine. The terms ''vaccine'' and ''vaccination'' are derived f ...
described the disease in 1809, and French veterinarian Henri Carré
Henri is an Estonian, Finnish, French, German and Luxembourgish form of the masculine given name Henry.
People with this given name
; French noblemen
:'' See the 'List of rulers named Henry' for Kings of France named Henri.''
* Henri I de Montm ...
determined that the disease was caused by a virus
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea.
Since Dmitri Ivanovsky's 1 ...
in 1905. Carré's findings were disputed by researchers in England until 1926, when Patrick Laidlaw
Sir Patrick Playfair Laidlaw (26 September 1881 – 20 March 1940) was a Scottish virologist.
Biography
Laidlaw was born in Glasgow, the son of Robert Laidlaw, M.D., at that time Superintendent of the Glasgow Medical Mission. He was educated a ...
and G.W. Dunkin confirmed that the disease was, in fact, caused by a virus.
The first vaccine against canine distemper was developed by the Italian Vittorio Puntoni. In 1923 and 1924, Puntoni published two articles in which he added formalin
Formaldehyde ( , ) (systematic name methanal) is a naturally occurring organic compound with the formula and structure . The pure compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde (refer to section Fo ...
to brain tissue from infected dogs to create a vaccine which successfully prevented the disease in healthy dogs. A commercial vaccine was developed in 1950, yet owing to limited use, the virus remains prevalent in many populations.
The domestic dog has largely been responsible for introducing canine distemper to previously unexposed wildlife, and now causes a serious conservation threat to many species of carnivores
A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other sof ...
and some species of marsupial
Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a po ...
s. The virus contributed to the near-extinction of the black-footed ferret
The black-footed ferret (''Mustela nigripes''), also known as the American polecatHeptner, V. G. (Vladimir Georgievich); Nasimovich, A. A; Bannikov, Andrei Grigorovich; Hoffmann, Robert S. (2001)''Mammals of the Soviet Union''Volume: v. 2, pt. 1 ...
. It also may have played a considerable role in the extinction of the thylacine
The thylacine ( , or , also ) (''Thylacinus cynocephalus'') is an extinct carnivorous marsupial that was native to the Australian mainland and the islands of Tasmania and New Guinea. The last known live animal was captured in 1930 in Tasman ...
(Tasmanian tiger) and recurrently causes mortality among African wild dogs
The African wild dog (''Lycaon pictus''), also called the painted dog or Cape hunting dog, is a wild canine which is a native species to sub-Saharan Africa. It is the largest wild canine in Africa, and the only extant member of the genus '' Lyc ...
. In 1991, the lion population in Serengeti, Tanzania, experienced a 20% decline as a result of the disease. The disease has also mutated to form phocid distemper virus, which affects seal
Seal may refer to any of the following:
Common uses
* Pinniped, a diverse group of semi-aquatic marine mammals, many of which are commonly called seals, particularly:
** Earless seal, or "true seal"
** Fur seal
* Seal (emblem), a device to impr ...
s.
Clinical signs
In dogs, signs of CDV vary widely from no signs, to mild respiratory signs indistinguishable from kennel cough
Kennel cough, also known as canine infectious respiratory disease, formally canine infectious tracheobronchitis, is an upper respiratory infection affecting dogs. There are multiple causative agents, the most common being the bacterium ''Bordete ...
, to severe pneumonia with vomiting, bloody diarrhea and death.
Commonly observed signs are a runny nose, vomiting and diarrhea, dehydration, excessive salivation, coughing and/or labored breathing, loss of appetite, and weight loss. If neurological signs develop, incontinence may ensue. Central nervous system signs include a localized involuntary twitching of muscles or groups of muscles, seizures with salivation and jaw movements commonly described as "chewing-gum fits", or more appropriately as "distemper myoclonus". As the condition progresses, the seizures worsen and advance to grand mal convulsions followed by death of the animal. The animal may also show signs of sensitivity to light, incoordination, circling, increased sensitivity to sensory stimuli such as pain or touch, and deterioration of motor capabilities. Less commonly, they may lead to blindness and paralysis. The length of the systemic disease may be as short as 10 days, or the start of neurological signs may not occur until several weeks or months later. Those few that survive usually have a small tic or twitch of varying levels of severity. With time, this tic usually diminishes somewhat in its severity.
Lasting signs
A dog that survives distemper continues to have both nonlife-threatening and life-threatening signs throughout its lifespan. The most prevalent nonlife-threatening symptom is hard pad disease, in which the skin on the paw pads and the end of the nose thickens. Another lasting symptom that is common is enamel hypoplasia
Enamel hypoplasia is a defect of the teeth in which the enamel is deficient in quantity, caused by defective enamel matrix formation during enamel development, as a result of inherited and acquired systemic condition(s). It can be identified as m ...
. Puppies, especially, have damage to the enamel of teeth that are not completely formed or those that have not yet grown through the gums. This is a result of the virus killing the cells responsible for manufacturing the tooth enamel. These affected teeth tend to erode quickly.
Life-threatening signs usually include those due to the degeneration of the nervous system. Dogs that have been infected with distemper tend to suffer a progressive deterioration of mental abilities and motor skills. With time, the dog can develop more severe seizures, paralysis, reduction in sight, and incoordination. These dogs are usually humanely euthanized because of the immense pain and suffering they face.
Virology
Distemper is caused by a single-stranded RNA virus
An RNA virus is a virusother than a retrovirusthat has ribonucleic acid (RNA) as its genetic material. The nucleic acid is usually single-stranded RNA ( ssRNA) but it may be double-stranded (dsRNA). Notable human diseases caused by RNA viruses ...
of the family ''Paramyxoviridae
''Paramyxoviridae'' (from Ancient Greek, Greek ''para-'' “by the side of” and ''myxa'' “mucus”) is a family of negative-strand RNA viruses in the order ''Mononegavirales''. Vertebrates serve as natural hosts. Diseases associated with this ...
'', which is a close relative of the viruses that cause measles
Measles is a highly contagious infectious disease caused by measles virus. Symptoms usually develop 10–12 days after exposure to an infected person and last 7–10 days. Initial symptoms typically include fever, often greater than , cough, ...
in humans and rinderpest
Rinderpest (also cattle plague or steppe murrain) was an infectious viral disease of cattle, domestic buffalo, and many other species of even-toed ungulates, including gaurs, buffaloes, large antelope, deer, giraffes, wildebeests, and warthogs ...
in animals.[Kate E. Creevy, 2013, ''Overview of Canine Distemper'', in The Merck Veterinary Manual (online): Veterinary Professionals: Generalized Conditions: Canine Distemper, see , accessed 15 December 2014.]
Genetic diversity
Geographically distinct lineages of the canine distemper virus are genetically diverse. This diversity arises from mutation
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mi ...
, and when two genetically distinct viruses infect the same cell, from homologous recombination
Homologous recombination is a type of genetic recombination in which genetic information is exchanged between two similar or identical molecules of double-stranded or single-stranded nucleic acids (usually DNA as in cellular organisms but may ...
Host range
Distemper, or hardpad disease in canines,[Otto M. Radostits, David A. Ashford, Craig E. Greene, Ian Tizard, et al., 2011, ''Canine Distemper (Hardpad Disease)'', in The Merck Manual for Pet Health (online): Pet Owners: Dog Disorders and Diseases: Disorders Affecting Multiple Body Systems of Dogs, see , accessed 15 December 2014.] affects animals in the following animal families and species:
* Ailuridae
Ailuridae is a family in the mammal order Carnivora. The family consists of the red panda (the sole living representative) and its extinct relatives.
Georges Cuvier first described ''Ailurus'' as belonging to the raccoon family in 1825; this cl ...
(red panda)
* Canidae
Canidae (; from Latin, ''canis'', "dog") is a biological family of dog-like carnivorans, colloquially referred to as dogs, and constitutes a clade. A member of this family is also called a canid (). There are three subfamilies found within th ...
(dog, fox, wolf, Chinese raccoon dog)
* Elephantidae
Elephantidae is a family (biology), family of large, herbivorous proboscidean mammals collectively called elephants and mammoths. These are terrestrial animal, terrestrial large mammals with a snout modified into a Elephant#Trunk, trunk and teeth ...
(Asian elephant)
* Felidae
Felidae () is the family of mammals in the order Carnivora colloquially referred to as cats, and constitutes a clade. A member of this family is also called a felid (). The term "cat" refers both to felids in general and specifically to the ...
(large cats,[ though not ]domestic cats
The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members of t ...
.)
* Hyaenidae (hyena)
* Mustelidae
The Mustelidae (; from Latin ''mustela'', weasel) are a family of carnivorous mammals, including weasels, badgers, otters, ferrets, martens, minks and wolverines, among others. Mustelids () are a diverse group and form the largest family in ...
(ferret, mink, skunk, wolverine, marten, badger, otter)[
* ]Pinnipedia
Pinnipeds (pronounced ), commonly known as seals, are a widely distributed and diverse clade of carnivorous, fin-footed, semiaquatic, mostly marine mammals. They comprise the extant families Odobenidae (whose only living member is the wal ...
(seals, walrus, sea lion, etc.)[
* Primate (some) (e.g., Japanese monkey)][
* ]Procyonidae
Procyonidae is a New World family of the order Carnivora. It comprises the raccoons, ringtails, cacomistles, coatis, kinkajous, olingos, and olinguitos. Procyonids inhabit a wide range of environments and are generally omnivorous.
Character ...
(raccoon, coati)
* Ursidae
Bears are carnivoran mammals of the family Ursidae. They are classified as caniforms, or doglike carnivorans. Although only eight species of bears are extant, they are widespread, appearing in a wide variety of habitats throughout the Nort ...
(bear)
* Viverridae
Viverridae is a family of small to medium-sized, feliform mammals. The viverrids () comprise 33 species placed in 14 genera. This family was named and first described by John Edward Gray in 1821. Viverrids occur all over Africa, southern Europe, ...
(raccoon-like South Asian binturong, palm civet),[
Animals in the family Felidae, including many species of large cat as well as domestic cats, were long believed to be resistant to canine distemper, until some researchers reported the prevalence of canine distemper virus (CDV) infection in large felids.] Both large and domestic cats are now known to be capable of infection, usually through close housing with dogs or possibly blood transfusion from infected cats,[ but such infections appear to be self-limiting and largely without symptoms.][
In a captive population of ]giant pandas
The giant panda (''Ailuropoda melanoleuca''), also known as the panda bear (or simply the panda), is a bear species endemic to China. It is characterised by its bold black-and-white coat and rotund body. The name "giant panda" is sometimes use ...
in China (Shanxi Rare Wild Animal Rescue and Research Center), six of 22 captive pandas were infected by CDV. All but one infected panda died; the survivor had previously been vaccinated.
Mechanism
Canine distemper virus affects nearly all body systems. Puppies from 3–6 months old are particularly susceptible.[, accessed 15 December 2014.] CDV spreads through aerosol droplets and through contact with infected bodily fluids, including nasal and ocular secretions, feces
Feces ( or faeces), known colloquially and in slang as poo and poop, are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the large intestine. Feces contain a relati ...
, and urine
Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excretion, excreted from the body through the urethra.
Cel ...
, 6 to 22 days after exposure. It can also be spread by food and water contaminated with these fluids. The time between infection and disease is 14 to 18 days, although a fever can appear from 3 to 6 days after infection.
Canine distemper virus tends to orient its infection towards the lymphoid
The lymphatic system, or lymphoid system, is an organ system in vertebrates that is part of the immune system, and complementary to the circulatory system. It consists of a large network of lymphatic vessels, lymph nodes, lymphatic or lymphoid o ...
, epithelial
Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellula ...
, and nervous tissues. The virus initially replicates in the lymphatic tissue of the respiratory tract. The virus then enters the blood stream and infects the respiratory
The respiratory system (also respiratory apparatus, ventilatory system) is a biological system consisting of specific organs and structures used for gas exchange in animals and plants. The anatomy and physiology that make this happen varies grea ...
, gastrointestinal
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans and ...
, urogenital
The genitourinary system, or urogenital system, are the organs of the reproductive system and the urinary system. These are grouped together because of their proximity to each other, their common embryological origin and the use of common pathwa ...
, epithelial, and central nervous system
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all par ...
s, and optic nerve
In neuroanatomy, the optic nerve, also known as the second cranial nerve, cranial nerve II, or simply CN II, is a paired cranial nerve that transmits visual system, visual information from the retina to the brain. In humans, the optic nerve i ...
s.[ Therefore, the typical pathologic features of canine distemper include lymphoid depletion (causing ]immunosuppression
Immunosuppression is a reduction of the activation or efficacy of the immune system. Some portions of the immune system itself have immunosuppressive effects on other parts of the immune system, and immunosuppression may occur as an adverse react ...
and leading to secondary infections), interstitial pneumonia
Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severity ...
, encephalitis
Encephalitis is inflammation of the brain. The severity can be variable with symptoms including reduction or alteration in consciousness, headache, fever, confusion, a stiff neck, and vomiting. Complications may include seizures, hallucinations, ...
with demyelination
A demyelinating disease is any disease of the nervous system in which the myelin sheath of neurons is damaged. This damage impairs the conduction of signals in the affected nerves. In turn, the reduction in conduction ability causes deficiency i ...
, and hyperkeratosis
Hyperkeratosis is thickening of the stratum corneum (the outermost layer of the epidermis, or skin), often associated with the presence of an abnormal quantity of keratin,Kumar, Vinay; Fausto, Nelso; Abbas, Abul (2004) ''Robbins & Cotran Patholo ...
of the nose and foot pads.
The virus first appears in bronchial lymph nodes and tonsils 2 days after exposure. The virus then enters the bloodstream on the second or third day. A first round of acute fever tends to begin around 3–8 days after infection, which is often accompanied by a low white blood cell count, especially of lymphocytes
A lymphocyte is a type of white blood cell (leukocyte) in the immune system of most vertebrates. Lymphocytes include natural killer cells (which function in cell-mediated, cytotoxic innate immunity), T cells (for cell-mediated, cytotoxic adap ...
, as well as low platelet count. These signs may or may not be accompanied by anorexia
Anorexia nervosa, often referred to simply as anorexia, is an eating disorder characterized by low weight, food restriction, body image disturbance, fear of gaining weight, and an overpowering desire to be thin. ''Anorexia'' is a term of Gre ...
, a runny nose, and discharge from the eye. This first round of fever typically recedes rapidly within 96 hours, and then a second round of fever begins around the 11th or 12th day and lasts at least a week. Gastrointestinal and respiratory problems tend to follow, which may become complicated with secondary bacterial infections. Inflammation of the brain and spinal cord, otherwise known as encephalomyelitis
Encephalomyelitis is inflammation of the brain and spinal cord. Various types of encephalomyelitis include:
* ''Acute disseminated encephalomyelitis'' or ''postinfectious encephalomyelitis'', a demyelinating disease of the brain and spinal cord, p ...
, either is associated with this, subsequently follows, or comes completely independent of these problems. A thickening of the footpads sometimes develops, and vesicular pustular lesions on the abdomen usually develop. Neurological signs typically are found in the animals with thickened footpads from the virus. About half of sufferers experience meningoencephalitis
Meningoencephalitis (; from ; ; and the medical suffix ''-itis'', "inflammation"), also known as herpes meningoencephalitis, is a medical condition that simultaneously resembles both meningitis, which is an infection or inflammation of the menin ...
. Less than 50% of the adult dogs that contract the disease die from it. Among puppies, the death rate often reaches 80%.
Diagnosis
The above signs, especially fever, respiratory signs, neurological signs, and thickened footpads, occurring in unvaccinated dogs strongly indicate CDV. However, several febrile diseases match many of the signs of the disease and only recently has distinguishing between canine hepatitis
Hepatitis is inflammation of the liver tissue. Some people or animals with hepatitis have no symptoms, whereas others develop yellow discoloration of the skin and whites of the eyes (jaundice), poor appetite, vomiting, tiredness, abdominal pa ...
, herpes
Herpes simplex is a viral infection caused by the herpes simplex virus. Infections are categorized based on the part of the body infected.
Oral herpes involves the face or mouth. It may result in small blisters in groups often called cold s ...
virus, parainfluenza
Human parainfluenza viruses (HPIVs) are the viruses that cause human parainfluenza. HPIVs are a paraphyletic group of four distinct single-stranded RNA viruses belonging to the ''Paramyxoviridae'' family. These viruses are closely associated with ...
, and leptospirosis
Leptospirosis is a blood infection caused by the bacteria ''Leptospira''. Signs and symptoms can range from none to mild (headaches, muscle pains, and fevers) to severe ( bleeding in the lungs or meningitis). Weil's disease, the acute, severe ...
been possible. Thus, finding the virus by various methods in the dog's conjunctival cells or foot pads gives a definitive diagnosis. In older dogs that develop distemper encephalomyelitis, diagnosis may be more difficult, since many of these dogs have an adequate vaccination history.
An additional test to confirm distemper is a brush border
A brush border (striated border or brush border membrane) is the microvilli-covered surface of simple cuboidal and simple columnar epithelium found in different parts of the body. Microvilli are approximately 100 nanometers in diameter and the ...
slide of the bladder transitional epithelium of the inside lining from the bladder, stained with Diff-Quik
Diff-Quik is a commercial Romanowsky stain variant used to rapidly stain and differentiate a variety of pathology specimens. It is most frequently used for blood films and cytopathological smears, including fine needle aspirates. The Diff-Quik p ...
. These infected cells have inclusions which stain a carmine red color, found in the paranuclear cytoplasm
In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. The ...
. About 90% of the bladder cells will be positive for inclusions in the early stages of distemper.
Prevention
A number of vaccine
A vaccine is a biological Dosage form, preparation that provides active acquired immunity to a particular infectious disease, infectious or cancer, malignant disease. The safety and effectiveness of vaccines has been widely studied and verifie ...
s against CDV exist for dog
The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is derived from the extinct Pleistocene wolf, and the modern wolf is the dog's nearest living relative. Do ...
s (ATCvet
The Anatomical Therapeutic Chemical (ATC) Classification System is a drug classification system that classifies the active ingredients of drugs according to the organ or system on which they act and their therapeutic, pharmacological and chemical p ...
code: and combinations) and domestic ferrets (), which in many jurisdictions are mandatory for pets. Infected animals should be quarantine
A quarantine is a restriction on the movement of people, animals and goods which is intended to prevent the spread of disease or pests. It is often used in connection to disease and illness, preventing the movement of those who may have been ...
d from other dogs for several months owing to the length of time the animal may shed the virus.[ The virus is destroyed in the environment by routine cleaning with disinfectants, detergents, or drying. It does not survive in the environment for more than a few hours at room temperature (20–25 °C), but can survive for a few weeks in shady environments at temperatures slightly above freezing.] It, along with other labile viruses, can also persist longer in serum and tissue debris.
Despite extensive vaccination in many regions, it remains a major disease of dogs.
To prevent canine distemper, puppies should begin vaccination at 6–8 weeks of age and then continue getting the “booster shot” every 2–4 weeks until they are 16 weeks of age. Without the full series of shots, the vaccination does not provide protection against the virus. Since puppies are typically sold at the age of 8–10 weeks, they typically receive the first shot while still with their breeder, but the new owner often does not finish the series. These dogs are not protected against the virus, so are susceptible to canine distemper infection, continuing the downward spiral that leads to outbreaks throughout the world.
Treatment
No specific treatment for the CDV is known. As with measles, the treatment is symptomatic and supportive.[ Care is geared towards treating fluid/electrolyte imbalances, neurological symptoms, and preventing any secondary bacterial infections. Examples include administering fluids, electrolyte solutions, analgesics, anticonvulsants, broad-spectrum antibiotics, antipyretics, parenteral nutrition, and nursing care.
]
Outcome
The mortality rate of CDV largely depends on the immune status of the infected dogs. Puppies experience the highest mortality rate, where complications such as pneumonia
Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severity ...
and encephalitis
Encephalitis is inflammation of the brain. The severity can be variable with symptoms including reduction or alteration in consciousness, headache, fever, confusion, a stiff neck, and vomiting. Complications may include seizures, hallucinations, ...
are more common. In older dogs that develop distemper, encephalomyelitis
Encephalomyelitis is inflammation of the brain and spinal cord. Various types of encephalomyelitis include:
* ''Acute disseminated encephalomyelitis'' or ''postinfectious encephalomyelitis'', a demyelinating disease of the brain and spinal cord, p ...
and vestibular disease
The vestibular system, in vertebrates, is a sensory system that creates the sense of balance and spatial orientation for the purpose of coordinating movement with balance. Together with the cochlea, a part of the auditory system, it constitutes ...
may be present. Around 15% of canine inflammatory central nervous system diseases are a result of CDV.
Epidemiology
The prevalence of canine distemper in the community has decreased dramatically due to the availability of vaccinations. However, the disease continues to spread among unvaccinated populations, such as those in animal shelters and pet stores. This provides a great threat to both the rural and urban communities throughout the United States, affecting both shelter and domestic canines. Despite the effectiveness of the vaccination, outbreaks of this disease continue to occur nationally. In April 2011, the Arizona Humane Society released a valley-wide pet health alert throughout Phoenix, Arizona.
Outbreaks of canine distemper continue to occur throughout the United States and elsewhere and are caused by many factors, including proximity to wild animals and lack of vaccinated animals. This problem is even greater within areas such as Arizona, owing to the vast amount of rural land. An unaccountable number of strays that lack vaccinations reside in these areas, so they are more susceptible to diseases such as canine distemper. These strays act as a reservoir for the virus, spreading it throughout the surrounding area, including urban areas. Puppies and dogs that have not received their shots can then be infected in a place where many dogs interact, such as a dog park.
References
Further reading
*
{{DEFAULTSORT:Canine distemper
Distemper
Animal viral diseases
Carnivoran diseases
Paramyxoviridae