Unit 3 - Swine Reproductive Diseases Flashcards
What diseases/agents can result in decreased reproductive performance?
Brucellosis Leptospirosis Pseudorabies Influenza Parvovirus SMEDI (old term) EMC Eperythrozoonosis Arcobacter HEV Blue eye Chlamydia PRRS PCV2 Mycotoxins Streps
What is pseudorabies?
A disease of reproductive failure in breeding swine, CNS disease in suckling pigs or respiratory disease in older swine
What type of virus causes pseudorabies?
An alpha herpesvirus
What seems to be the most important for induction of immunity to pseudorabies?
Glycoproteins - GII, GIII, gp50
What is the primary means of transmission of pseudorabies?
Through introduction of actively shedding or latently infected pigs
What improves survivability of pseudorabies?
Cold, moist conditions - up to a month
What animals are dead end hosts but can play a role in transmission of pseudorabies?
Dogs, cats, rodents, and raccoons
Once in a herd, how does pseudorabies spread?
Direct contact, inhalation, ingestion, breeding, and transplacentally
What clinical signs does pseudorabies cause in neonatal pigs?
High fever, CNS signs (trembling, incoordination, dog-sitting due to posterior paralysis, head tilt, ataxia, paddling, etc.) and sometimes vomiting and diarrhea
Mortality is usually ____% in pseudorabies affected neonates.
100%
What clinical signs does pseudorabies cause in weaners?
Respiratory signs primarily in the older pigs in this age group
CNS signs primarily in the younger pigs in this age group
Marked depression and sneezing
Nasal discharge and coughing
Stunted growth
What clinical signs does pseudorabies cause in grow-finishers?
Predominantly respiratory signs
Temps of 105-107 F
May take a week or two longer to reach finishing weight
What clinical signs does pseudorabies cause in sows?
1st trimester - abortion and return to estrus
2nd or 3rd trimester - Abortion, stillborn, or weakborn pigs
USUALLY NO MUMMIES
What other species are affected by pseudorabies?
Cows - intense pruritus and die
Sheep
Dogs - self mutilation
How is pseudorabies diagnosed?
Clinical signs and herd history FA test Virus isolation - older swine Serodiagnosis - ELISA \+/- Lesions Histopath - formalin fixed
What lesions are associated with pseudorabies?
Note: These are not consistently present
Serous to fibrinonecrotic rhinitis and
tracheitis, necrotic tonsillitis, swollen and hemorrhagic lymph nodes of the oral cavity
and upper respiratory tract
Lower respiratory tract lesions may range from scattered
“blotchy” hemorrhages to areas of necrosis.
Keratoconjunctivitis
Focal necrosis of the liver and spleen
How is pseudorabies prevented?
Vaccination - very controversial
Gene deletion vaccines
T/F: Pseudorabies is no longer found in Iowa.
True
T/F: Reproductive problems are the only clinical manifestations of parvovirus infection in
swine.
True
Where does parvovirus reproduce?
in the intestine
How is parvovirus transmitted?
Boar semen
Transplacentally
Reproductive failure occurs when an infection of parvovirus happens when?
Following conception and before development of immunocompetence in the fetus
If dams are infected with parvovirus between 0 and 30-35 days of gestation what can happen?
Repeat breeders
pseudopregnancies
Small litters
If dams are infected with parvovirus between 30-35 and 65-70 days of gestation, what can happen?
Mummies
Increased stillborns
If dams are infected with parvovirus between 65-70 days of gestation and parturition what can happen as a result?
Normal litters
How is parvovirus diagnosed?
Clinical signs - highly suggestive
IHC or FA test
Serology - when fetuses are not available
How is parvovirus prevented?
Natural infection prior to breeding
Vaccination - killed products
Teschen and Taflan disease (both cause polioencephalomyelitis) are caused by what?
Teshoviruses which are picornaviruses
What is Teschen disease characterized by?
CNS disease and a high mortality
What is Talfan disease characterized by?
Benign enzootic paresis and rarely progresses to paralysis
How is polioencephalomyelitis diagnosed?
Based on isolation of the virus or demonstration of the viral antigen in pigs showing early nervous signs
What is SMEDI?
An old term that was coined to describe a group of enteroviruses implicated in stillbirth, mummification, embryonic death, and infertility
How is SMEDI diagnosed?
Finding viral antigen in fetus
What is the major etiologic agent of leptospirosis in swine?
Leptospira interrogans servoar pomona
What are the only Leptospira serovars that produce clinical disease in swine?
pomona and sejroe
What is the most common Leptospira serovar found in swine?
L. bratislava
How does leptospira transmission occur?
Through breaks in the skin, direct penetration of mucous membranes or through conjunctiva
Where do Leptospira organisms survive? Shed?
Survive - proximal convoluted tubule
Shed - in urine
T/F: Leptospira spp. are not very hardy and only survive in the environment for a few hours
false - they hardy AF
What clinical signs are associated with leptospirosis?
Most show no signs
Last half of gestation - abortions, stillbirths, neonatal deaths
Premature births and short survival
Fetal infection
When do abortions and stillbirths usually occur in relation to dam Leptospira infection?
1-4 weeks post infection
How is leptospirosis diagnosed?
Culture
Serology - MAT (1:100 titer or greater)
PCR
RFLP patterns
How is leptospirosis prevented and controlled?
Maintain a clean environment without standing water
Segregate infected animals
Immunization (gilts 2 doses prior to breeding)
Keep other animals away
How is leptospirosis treated?
Tetracyclines and tylocin
In the US, swine brucellosis is essentially confined where?
In the states that have feral swine
What is the etiologic agent of brucellosis in the US?
Brucella suis biovars 1 and 3
How is B. suis transmited?
Venereally - can be readily transmitted by ingestion
In what conditions does B. suis survive?
Frozen conditions - 2 years
It is killed by sunlight and disinfectants
What clinical signs are associated with brucellosis?
The majority of herds may have no clinical signs
Boars may have orchitis
Infertility can result.
Suckling and weaning pigs may develop spondylitis and become paralyzed or lame.
Lameness and vertebral osteomyelitis can occasionally occur in older swine.
How is brucellosis diagnosed?
Culture: most accurate
Serology: Must be used on a herd basis.
How is brucellosis prevented and controlled?
The most successful method of eliminating the disease is to depopulate known infected herds, clean up the facilities, and then repopulate with non-infected swine.
The cooperative state-federal-industry program utilizes routine monitoring of sows and boars
that go to slaughter
Tuberculosis in swine can be caused by any of what three main species?
Mycobacteria: M. avium, M. tuberculosis and M. bovis.
The majority of infections in the past in the U.S. have been associated with contact with
infected ______.
poultry
How is tuberculosis transmitted?
Infection is almost always by ingestion
When M. tuberculosis is found, one needs to consider ______ as the most likely source.
humans
Swine can be skin tested for tuberculosis where?
on the ear or vulva
What gross lesions are associated with tuberculosis?
Lymph nodes are almost always cervical or mesenteric nodes. The lesions are usually caseous and yellowish white and vary from a few millimeters in size to
involvement of the whole node
M. bovis and M. tuberculosis cause more calcified and encapsulated lesions
What are the four main categories or dispositions swine with tuberculosis can fall into?
No lesions
Lesions attributable to TB - not disseminated, passed for consumption
Passed for cooking - disseminated lesions but no emaciation
Disseminated lesions with emaciated carcass - condemned
How is tuberculosis diagnosed?
Gross lesions are suggestive.
Histopathologic exam plus staining for acid fast bacteria
Bacteriologic culture
Tuberculin skin test
How is tuberculosis prevented?
Elimination of contact between swine and poultry and wild birds.
Thorough disinfection of premises that have had swine with tuberculosis.
No dirt floors
Thorough cooking of garbage or meat byproducts that go into swine feed.
What is the etiologic agent of pyelonephritis/cystitis in swine?
Actinobaculum suis
T/F: Actinobaculum suis is normal porcine microflora.
True
The disease is more common in sows housed in _____________.
gestation stalls - greater likelihood of spread due to reduced activity, water intake, and urination
T/F: A. suis is carried in the semen of the boar.
False - prepuce
What clinical signs are associated with cystitis?
Sudden death to acute or chronic renal failure
Acute - hematuria and pyuria, be reluctant to get up and appear lame in the rear; high mortality
What gross lesions are associated with cystitis?
Thickened bladder wall with a hemorrhagic epithelium
+/- purulent exudate and deposits of sand-like material in the bladder
How is cystitis diagnosed?
Bacterial culture
How is cystitis treated?
Ampicillin is best
How is cystitis prevented and controlled?
Management - maximize water consumption, increase salt in ration, general cleanliness, and good ventilation
Cull affected animals or isolate
What is the etiologic agent of eperythrozoonosis?
Mycoplasma suis
How is M. suis transmitted?
Needles and equipment
In-utero
Oral
What clinical signs are associated with M. suis in pigs under 5 days of age?
Anemia and icterus
General unthrifitiness
What clinical signs are associated with M. suis in feeder pigs?
Clinical signs are rarely observed
What clinical signs are associated with M. suis in sows?
High fever Anorexia 1-3 days Chronic - anemia, icterus, unthriftiness \+/- debilitation and death due to secondary infections Decreased conception rates
How is eperythrozoonosis diagnosed?
Blood smears - acute cases
PCR
IHA subclinical
How is eperythrozoonosis treated?
Tetracyclines
Iron dextran to piglets
Control other diseases
How is eperythrozoonosis prevented?
Nothing - there are no vaccines
