Swine Infectious Diseases: Circulatory, skin, reproductive, vesicular, emerging

What was mycoplasma suis reclassified as?

M. suis has been reclassified from Eperythrozoon suis

Etiology of Eperythrozoon suis?

These are epicellular and membrane-bound

intracellular, round to oval organisms that are found

within or attached to the outer surface of erythrocytes

and free within the plasma (Groebel et al., 2009). They

change size and shape as they mature, which gives the

microscopic appearance of infection by two separate

organisms. They stain well with Giemsa but not with

Gram stain.

What is the reservoir for Eperythrozoo suis?

The reservoir for M. suis is domestic swine

What vector and non vector transmission dynamics transmit Eperythrozoon suis?

Transmission is mechanical by blood-sucking arthropods,

primarily lice, or reuse of blood-contaminated

needles, snares, and surgical or tattoo instruments.

Most common clinical sign of Eperythrozoo suis?

Acute disease is characterized by

anemia

Clinical signs and what age is affected for Eperythrozoo suis?

Acute disease is usually

seen in suckling or newly weaned piglets or other pigs

that have been stressed, and consists of fever of 40–42°C,

anemia, jaundice, pale mucous membranes, cyanosis of

the ears, weakness, and poor weight gain.

Eitiology of Greasy Skin Disease / Exudative dermatitis in pigs?

Staphylococcus hyicus is a gram-positive coccus considered to be normal flora on the skin of pigs. This bacterium is very persistent in the environment.

Pathology of Staph hyicus?

At least six antigenically distinct exfoliative toxins (ExhA, ExhB, ExhC ExhD, ShetA, ShetB). These toxins target the stratum granulosum in the epidermis and are similar to S. aureus toxins.

Classic picture of what skin disease?

Greasy skin disease (Staph Hyicus)

Clinical signs and what age groups for greasy pig disease?

Aged 5 days to 2 months, Lesions progress to an exudative dermatitis characterized by exfoliation and crusting, which

begins in the groin, axillae, behind the ears, and on areas

of damaged skin. Erosions at the coronary band of hooves

and vesicles or ulcers in the mouth and on the tongue

and snout are common findings

Is greasy skin disease itchy?

NO!

DDX for greasy skin disease?

Differential diagnoses should include swine

pox, mange, ringworm, and pityriasis rosea.

Is greasy skin disease treatable?

Treatment with antibiotics is challenging

due to resistance to beta lactams, erythromycin,

streptomycin, tetracycline, and sulfonamide. The choice,

therefore, should be based on sensitivity testing. Topical

Etiology of swine pox

Swine pox virus is the only member of the

genus Suipoxvirus, family Poxviridae. DNA enveloped

Transmission dynamics swine pox

The pig is the only known host of this virus, and although worldwide in distribution, it exists primarily in herds where poor

sanitation is practiced. The reservoir is infected swine, as

the virus is host-restricted. The virus may persist in an

active form in dry skin scabs for up to 1 year. Although

horizontal transmission may occur via nasal and oral

secretions coming in contact with abraded skin, the

primary method of transmission is mechanical via the

pig louse. Flies and mosquitoes can also carry the viral

particles. Once the virus is established within a herd, it

usually persists.

What area of the skin does swine pox replicate in?

The virus replicates in the cells of the stratum spinosum

Clinical progression of swine pox

Maccular form (reddening), followed by 1- to 6-mm-diameter papules (reddening with edema); transient vesicles (flui

within the lesion), then pustules (umbilicated, ischemic),

and finally, crusts (brown to black in color).

How can location of pox on the pig help lead to the transmission cause?

location of the lesions follows the vector

preferences, that is, the pig louse attacks the lower parts

of the body, while flies feed predominantly over the top

of the body.

What is the hallmark pathologic finding of swine pox?

The presence of intracytoplasmic

inclusion bodies along with central nuclear clearing

in affected epithelial cells is a hallmark sign of this disease.

What is the most significant ectoparasite of swine?

Sarcoptes mange, Sarcoptes scabiei var. suis

Common transmission of mange to piglets?

Nursing piglets obtain the mites from

an infected sow through direct contact

What group of pigs are the primary reservoirs for mange?

Breeding sows with hyperkeratotic encrustations in their ears are the primary reservoirs of mites.

Is mange itchy?

YES!!!

Clinical signs of mange?

acute pruritic or allergic hypersensitive form affects younger, growing pigs. This is characterized by an intensely pruritic, erythematous papular dermatitis on the ventral abdomen, flank, and rump.

chronic or hyperkeratotic form is typically found

in mature sows and boars. Thick, crusty scabs begin on

the pinnae and spread to the neck and head. The papules are manifestations of the hypersensitivity reaction, contain eosinophils, mast cells, and lymphocytes, and have an associated eosinophilic perivasculitis.

What is the only species of louse that affects pigs?

Haematopinus suis, sucking lice and are the only species of louse that affects swine

Transmission of Haematopinus suis?

this louse is host-specific and will not survive very long (less than 2–3 days) off the host.

What is Haematopinus suis a vector for in swine?

It is considered a vector for swine pox and M. suis

Clinical signs of Haematopinus suis in young pigs?

Young pigs may show pruritus, poor growth, and anemia.

What areas do Haematopinus suis preference in swine?

have a predilection for the skin on the flank area, neck, axilla, groin, and the inner ears.

Brucellosis etiology in pigs, which serovar is most common?

Brucella suis, particularly biovars 1, 2, and

3, is the only species of Brucella that causes systemic

infection and clinical disease, including infertility, in

swine. Biovar 3 is currently the most common cause

of this disease in swine. Morphologically

What are potential reservoirs for B. suis and what serovars have been eradicated?

Domestic swine populations are the primary sources for B. suis.

Feral pigs are also reservoirs in areas where

contact with domestic swine can occur. In the US, B. suis biovars 1 and 3 have been eradicated.

B. suis is present in semen of infected boars and can be spread by

natural breeding or artificial insemination.

Pathogenesis of Brucella suis?

After mucosal exposure to organisms,

they enter through follicle-associated epithelial cells (M

cells) or by phagocytosis, travel to the local lymph nodes,

gain entrance to macrophages and neutrophils, and multiply.

Clinical signs of brucella suis?

The clinical signs of B. suis

infection vary with the herd and range from no obvious

disease to the classical signs, which include abortion, infertility,

metritis, orchitis, lameness, spondylitis, and posterior

paralysis. Clinical disease in piglets of weaning age usually

consists of spondylitis and posterior paralysis

Microscopic and histopathologic lesions of brucella suis?

Microscopic lesions consist of granulomatous inflammation in the endometrium, uterine glands, and placenta. Abscesses in the kidneys, spleen, ovaries, lungs, brain, and other tissues may be seen

What BSL should brucella be?

BSL 3. No longer reportable as of NOV 2024

What species of leptospirosis affect pigs?

Leptospira interrogans and L. borgpetersenii

Etiology of leptospirosis and what serovar is most commonly clinical in pigs?

gram negative, motile aerobic spirochetes. The serovar Pomona

is the most common cause of clinical leptospirosis in

swine,

Transmission of leptospirosis in pigs?

Leptospires are shed from carrier animals in urine and genital fluids into the environment.

Venereal transmission is thought to be the mode of

spread for serovar Bratislava because sows and boars

harbor it in the reproductive tract

Clinical signs of leptospirosis in pigs

The acute form is characterized

by a mild transient anorexia, listlessness,

diarrhea, and pyrexia that resolves within a week and

usually goes unrecognized.

The acute form is characterized by a mild transient anorexia, listlessness, diarrhea, and pyrexia that resolves within a week and

usually goes unrecognized.

Infertility of the sow is seen following infections due to serovar

Bratislava;

Necropsy findings of leptospirosis in chronic forms

In chronic disease,

lesions are confined to the kidneys and consist of small

gray lesions on the renal cortex.

Etiology of porcine parvovirus?

PPV is a disease of swine characterized by embryonic

and fetal infection which is manifest as stillbirths, mummification,

embryonic death, and infertility (SMEDI)

when susceptible sows and gilts are exposed to the

virus between 6 and 70 days of gestation. DNA Nonenveloped

Porcine parvovirus is one of the major infectious causes

of embryonic and fetal death

Transmission of parvovirus in pigs

It is ubiquitous

Gilts are most commonly infected oronasally and prenatal pigs are infected transplacentally.

Nursing pigs absorb protective PPV antibody from

colostrum.

The major reservoir for PPV is environmental. The

virus is thermostable and resistant to many disinfec

tants.

Virus replicated first in the tonsils

What is the crown rump size of the mumified fetuses infected with parvovirus?

Most of the infected fetuses have a crown–rump length of 17 cm

or less because those infected after day 70 are able to

respond to the viral assault and survive

Control of parvovirus in the USA

Vaccines are used extensively in the US. They are administered

several weeks before conception

necropsy findings of pig parvovirus

Gross lesions are confined to the placenta,

which may be edematous and have white, mineralized

deposits and stunted fetuses with prominent blood vessels

on their surfaces, petechial hemorrhages, edema,

enlarged dark liver and kidneys, serosanguinous flui

in body cavities, and mummificatio

Etiology of porcine reproductive and respiratory syndrome?

The causative agent is a single-stranded

RNA virus classified in the order Nidovirales, family

Arteriviridae, and genus Arterivirus. This agent shares

structural and functional organization with others in the

genus, including lactate dehydrogenase-elevating virus,

equine arteritis virus, and simian hemorrhagic fever

virus. These viruses in general are known to have high

rates of mutation.

Hallmark signs include reproductive disorders,

high piglet mortality, and respiratory disease seen in a

wide age range of animals.

What are the two important serotypes of porcine reproductive and respiratory syndrome?

1 (Lelystad) found primarily in the EU and Type 2 (VR-

2332), found primarily in the US

Transmission dynamics porcine reproductive and respiratory syndrome?

This virus is spread predominantly through direct contact between

infected and naive pigs, although the route of fetal PRRSV

infection has not been identified. Once infected, pigs

become persistently infected.

The virus establishes a foothold by infecting macrophages

located within mucosal surfaces. The virus is believed to

be limited to domestic swine. The disease does persist

in infected swine in a transmissible, viable state, often

without stimulating antibody production, thereby making

serologic screening for the disease inaccurate.

The virus has been found in serum, oropharyngeal fluids, semen, feces, and urine, and animals are susceptible via intranasal, intramuscular, oral, intrauterine and vaginal exposure

Pathogenesis of Porcine repro and resp syndrome?

The virus has been shown to enter via

the nasal epithelium, bronchial epithelium, and tonsilar

and pulmonary macrophages, followed by replication in

alveolar macrophages, with a subsequent viremia and

spread to lymphoid organs and lungs.

Late gestational abortions typically occur when animals are infected during the third trimester and can occur sporadically or sweep throughout the population of animals

Clinical signs of PRRS?

Clinical signs

in infected females vary from none to anorexia, fever,

pneumonia, agalactia, red/blue discoloration of ears

and vulva, subcutaneous edema, and a delayed return

to estrus.

Clinical signs in PRRSV-infected newborn pigs also

vary in frequency and severity. Dyspnea and tachypnea

are the most characteristic clinical signs, with other signs

including periocular and eyelid edema, conjunctivitis,

blue discoloration of the ears, diarrhea, and CNS signs.

Mortality can reach 100%.

As the pigs reach postweaning

age, the clinical signs shift to include fever, pneumonia,

failure to thrive, and significant mortality caused

by otherwise non-life-threatening concurrent bacterial

infections

Necropsy findings of PRRS?

Gross lesions in young piglets include mottled lungs with tan foci of consolidation; lymphadenopathy of the mesenteric and middle

iliac nodes, which are tan and may contain cysts, moderately

enlarged and rounded hearts, and clear fluid in

the pericardial space and abdominal cavity.

Etiology foot and mouth disease?

Foot-and-mouth disease virus (FMDV) is

in the family Picornaviridae, genus Aphthovirus. RNA Nonenveloped

Transmission dynamics of Food and mouth disease? What family of animals does it most commonly affect?

FMDV affects members of the order

Arteriodactyla. All secretions

and excretions from infected animals contain infectious

virus. FMDV can remain infectious within the

environment for extended periods.

Clinical signs foot and mouth disease pigs?

Pigs display fever and

formation of vesicles in and around the mouth and feet

(Fig. 16.26). Lesions on the feet are often interdigital,

with the coronary band being especially predisposed

due to the vascularity. Lesions on the feet result in the

animal being lame and often ‘dog-sitting’.

Oral lesions most commonly affect the tongue, and

foot lesions are most often interdigital, at the heel bulb,

and coronary bands.

Etiology of swine vesicular disease?

Swine vesicular disease virus is an

Enterovirus in the family Picornaviridae. RNA nonenveloped

Clinical signs of Swine vesicular disease?

Clinically, pigs have mild

fever with rare lameness.

Why is swine vesicular disease reportable?

Indistinguishable from Foot and Mouth disease

Etiology vesicular xanthema

Vesicular exanthema of swine (VES) is caused by the

vesicular exanthema of swine virus, genus Vesivirus in

the Caliciviridae family. RNA nonenveloped. Indistinguishable from foot and mouth disease

Eitiology of vesicular stomatitis virus?

Vesicular stomatitis (VS) infection in pigs is indistinguishable

from FMD, and therefore is classified a notifiable

disease (Health, 2013a). Vesicular stomatitis virus

is in the genus Vesiculovirus and family Rhabdoviridae. RNA Envelped. Also a zoonotic disease.

Eitiology of classical swine fever?

Etiology Classical swine fever (CSF) virus is in the

family Flavivirus, genus Pestivirus. It is also known as

hog cholera in the literature. RNA enveloped.

Clinical signs of classical swine fever

Animals with CSF have

pyrexia, anorexia, lethargy, conjunctivitis, respiratory

signs, and constipation followed by diarrhea

Necropsy findings classical swine fever

hemorrhage of the peripheral lymph

nodes and renal petechiae and ecchymoses are present,

Etiology nipah virus?

Nipah virus is a single-stranded negative

sense enveloped RNA virus in the family Paramyxovirus, genus

Henipavirus. There are strain differences between isolates

from different geographic regions

Transmission of nipah virus?

Initially identified in Malaysia in 1999, the virus has since emerged in Bangladesh and India. Pigs are an amplifying host; however,

bats are the reservoir host and secrete virus in urine

where pigs may ingest items containing infectious viral

particles and become infected (Williamson and Torres-

Velez, 2010). Close contact is required for transmission

Clinical signs of nipah virus?

Pigs are asymptomatic or have acute

febrile disease with respiratory/CNS signs

What is the BSL for nipah and is it zoonotic?

Highly zoonotic and BSL 4

Etiology of Porcine lymphotrophic herpesvirus (PLHV)?

DNA Enveloped, porcine lymphotropic disease with high mortality, similar to that of human post-transplantation lymphoproliferative disease,

What herpesvirus is a risk to humans from xenotransplantation?

There is also concern that pig–human xenotransplantation may result in human disease from this virus

PLHV infects which cells?

B cells

Clinical signs of PLHV?

Clinical signs included lethargy, fever, anorexia, and enlarged lymph nodes

Ovine herpesvirus 2 etiology?

A naturally occurring disease similar to malignant

catarrhal fever (MCF) has been reported in pigs, although

rare and poorly documented. Pigs becoming ill

after having contact with sheep.

Clinical signs for ovine herpes virus in pigs?

Pigs with MCF display high persistent fever, anorexia, depression, recumbency, foul-smelling nasal discharge, ocular discharge, bilateral corneal edema, keratoconjunctivitis, ataxia, tremors, and possible convulsions

Hepatitis E etiology and clinical signs in pigs?

Infection in pigs is primarily without clinical signs.

Can pigs get ebola?

Yes

Japanese encephalitis etiology and clinical signs in pigs?

Japanese encephalitis virus (JEV) is a member of the

family Flaviviridae, genus Flavivirus. While mosquitos

transmit the agent, the pig is a natural reservoir of JEV

(Grand, 2012). Clinical signs in pigs include testicular

degeneration, infertility, mummified fetuses, and piglets

with birth defects, reproductive failure