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832.e2 Pseudorabies

Pseudorabies Client Education
Sheet
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PHYSICAL EXAM FINDINGS
BASIC INFORMATION
ally limited to the brainstem and include
• Pruritus with swelling, erythema, excoriation, Histopathologic abnormalities are gener-
Definition or ulceration of the skin occurs secondary perivascular cuffing, multifocal gliosis,
Disease is caused by infection with pseudorabies to self-mutilation, especially of the face and neuronal degeneration, and weak eosinophilic
virus (PRV); the alpha-herpesvirus is also head. Intense scratching may include rubbing inclusions in the nuclei of glial cells and
known as suid herpesvirus type 1 (SuHV-1). the head against floors or walls. neurons.
An economically important disease of swine, • Altered mentation • Immunohistochemical techniques can be
pseudorabies is capable of causing subclinical, • Ptyalism used for identifying viral antigen in fixed
neurologic, or respiratory disease in pigs and • Cranial nerve deficits indicate a brainstem tissue sections (brain, tonsils).
cause a rare but severe and almost inevitably lesion(s). • Alternatively, inoculation of cell cultures
fatal central nervous system (CNS) disease in • Dyspnea secondary to severe pulmonary with brain homogenate for virus isolation
dogs and cats as well as other domestic and edema can be performed. Cultures are observed for
wild mammals. • Seizures cytologic changes characteristic of herpesvirus
• Anisocoria and a hoarse voice are highly infection, and immunofluorescent techniques
Synonyms consistent signs in cats. can be applied to the cultures to identify
Aujeszky’s disease, mad itch, bulbar paralysis pseudorabies virus.
Etiology and Pathophysiology
Epidemiology • After infection with pseudorabies virus has
SPECIES, AGE, SEX occurred, the virus travels retrograde along TREATMENT
Dogs and cats are sporadically affected with peripheral nerves from the site of inoculation Treatment Overview
pseudorabies (uncommon). Pigs are the primary to the CNS. With few exceptions, the treatment of pseu-
reservoir of the virus because they have become ○ The incubation period for pseudorabies dorabies in dogs and cats is futile due to an
well adapted to the virus and are often only in dogs and cats is 3-6 days. almost universally fatal outcome. If treatment
subclinically affected. • Damage to brain parenchyma results from is initiated, it is aimed at controlling the major
inflammation and interference of normal clinical signs and providing supportive care until
RISK FACTORS neuronal function by the virus. the animal recovers (rare) or dies.
• Pets living in areas where pseudorabies virus • Microscopic lesions are located almost
is enzootic in the swine population exclusively in the brainstem. Acute General Treatment
• Feeding raw pork from endemic areas to • Heavy sedation or anesthesia as required for
dogs and cats DIAGNOSIS control of self-mutilation and/or seizures
• Dogs used for hunting feral hogs • IV fluids if needed and patient not showing
Diagnostic Overview dyspnea
CONTAGION AND ZOONOSIS Diagnosis is suspected in dogs with a history • Dyspnea due to pulmonary edema is
• Pseudorabies virus may be found in porcine of exposure to pigs or raw pork products. discussed on p. 836.
respiratory secretions, saliva, blood, CNS, Dogs present with severe, acute pruritus of • Euthanasia is often the best option if the
and tonsillar tissues. Dogs and cats are the head and neck. Confirmation requires diagnosis is strongly suspected. If rabies is a
commonly infected by the oral route after histopathologic evaluation of the brainstem. realistic differential, this can facilitate rapid
ingesting contaminated porcine or infected postmortem testing.
wildlife tissue. Pseudorabies has also report- Differential Diagnosis
edly been transmitted to a dog by biting or • Rabies PROGNOSIS & OUTCOME
being bitten by an infected pig. • Canine distemper
• Pseudorabies is not considered a zoonotic • Neurotoxicoses Grave prognosis; despite treatment, death
disease. • Sarcoptic mange usually occurs within 2-3 days of the onset
• Pruritus (p. 830) of clinical signs.
GEOGRAPHY AND SEASONALITY
Pseudorabies can be found in most countries Initial Database PEARLS & CONSIDERATIONS
of the world except Australia. • A provisional diagnosis of pseudorabies is
usually made on clinical suspicion of the Comments
Clinical Presentation disease. Confirmatory testing (CNS histo- Vaccination of dogs and cats against pseudo-
HISTORY, CHIEF COMPLAINT logic evaluation) is required for definitive rabies virus (in endemic areas) is possible but
Acute onset and rapid progression of neurologic diagnosis. of questionable efficacy in the prevention of
signs are noted until death occurs (usually • There are no characteristic hematologic or disease.
within 48 hours of disease onset). Initial signs biochemical abnormalities associated with
may include lethargy, depression, restless- pseudorabies, and antemortem testing Prevention
ness, ataxia, vocalization or aggression, and methods have not been reported. Preventing contact with infected pigs or
occasionally vomiting and diarrhea. Ptyalism contaminated pork products is paramount
and anorexia are the most common clinical Advanced or Confirmatory Testing to the prevention of pseudorabies in dogs
signs. Intense pruritus, usually of the head, • Cerebrospinal fluid analysis (pp. 1080 and and cats.
is probably the most clinically striking sign 1323) may show increased protein and
of pseudorabies. Animals frequently excoriate mononuclear pleocytosis. Technician Tips
the skin of the face and ears due to violent • Definitive diagnosis of pseudorabies Discuss the risks of feeding raw foods with
scratching. has classically been made postmortem. pet owners.

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