Definition
An acute, enteric, viral infection of cats characterized by sudden onset, depression, vomiting and diarrhea, severe dehydration, and a high mortality.
Pathophysiology
The causative virus, feline parvovirus, infects only mitotic cells, causing acute cell cytolysis of rapidly dividing cells.
Systems Affected
- Gastrointestinal-intestinal crypt cells of the jejunum and ileum destroyed; acute enteritis with vomiting and diarrhea; shortened blunt villi with poor absorption of nutrients, dehydration, and secondary bacteremia.
- Hemic/Lymphatic/Immune-severe panleukopenia; atrophy of the thymus.
- Nervous and Ophthalmic-in neonatal kittens rapidly dividing granular cells of the cerebellum and retinal cells of the eye destroyed; cerebellar hypoplasia with ataxia and retinal dysplasia.
- Reproductive-in utero infection in non-immune queens leading to fetal death, fetal resorption, abortion, stillbirth, or fetal mummification.
Genetics
N/A
Incidence/Prevalence
- Unvaccinated populations-the most severe and important feline infectious disease.
- Routine vaccination-almost total control of this disease.
- Extremely contagious.
- Extremely stable virus, surviving for years on contaminated premises.
Geographic Distribution
Worldwide in unvaccinated populations
Signalment
Species
- Felidae-all, domestic and exotic.
- Canidae-susceptible to the closely related canine parvovirus; some exotic canids may be susceptible to FPV infection.
- Mustelidae-especially mink; may be susceptible.
- Procyonidae-raccoon and coatimundi; susceptible.
Breed Predilections
None
Mean Age and Range
- Unvaccinated and previously unexposed cats of any age can become infected once passively transferred maternal immunity has been lost.
- Kittens 2–6 months of age-most susceptible to develop severe disease.
- Adults-often mild or subclinical infection.
Predominant Sex
N/A
Signs
Historical Findings
- History of recent exposure (e.g., adoption shelter).
- Newly acquired kitten.
- Kitten 2–4 months old from a premises with a history of FP.
- No vaccination history or last vaccinated when <16 weeks of age.
- Sudden onset, with vomiting, diarrhea, depression, and complete anorexia.
- Owner may suspect poisoning.
- Cat may have disappeared or hid for 1 day or more before being found.
- Owner may report cat hangs head over water bowl or food dish but does not eat or drink.
Physical Examination Findings
- Depression-may be mild to severe.
- Typical “panleukopenia posture”-sternum and chin resting on floor, feet tucked under body, and top of scapulae elevated above the back.
- Dehydration-appears rapidly; may be severe.
- Vomiting and diarrhea may occur.
- Body temperature-usually mild to moderately elevated or depressed in the early stages of disease; becomes severely subnormal as affected cat becomes moribund.
- Abdominal pain-may be elicited on palpation.
- Small intestine-either turgid and hose-like or flaccid.
- Subclinical or mild infections with few or no clinical signs common, especially in adults.
- Ataxia from cerebellar hypoplasia-kittens infected in utero or neonatally; signs evident at 10–14 days of age and persist for life: hypermetria; dysmetria; incoordination with a base-wide stance and an elevated “rudder” tail; alert, afebrile, and otherwise normal; retinal dysplasia sometimes seen.
Causes
Feline Parvovirus
- Small, single-stranded DNA virus.
- Single antigenic serotype.
- Considerable antigenic cross-reactivity with canine parvovirus Type 2 and mink enteritis virus.
- Extremely stable against environmental factors, temperature, and most disinfectants.
- Requires a mitotic cell for replication.
Canine Parvovirus Types 2a, 2b, and 2c
- CPV-2a, CPV-2b, and CPV-2c can produce FP in domestic and/or exotic cats.
- Properties of CPV like those for FPV.
Risk Factors
- Anything that increases the mitotic activity of the small intestinal crypt cells-intestinal parasites; pathogenic bacteria.
- Secondary or co-infections-viral upper respiratory infections.
- Age-kittens 2–6 months of age tend to be more severely affected.
