Porcine Flashcards
What causes exudative epidermitis (greasy pig disease)?
Staphylococcus hyicus subspecies hyicus or rarely S. chromogenes - exfoliatin toxin-producing strains
S. sciuri and S. aureus (incl. MRSA) causal in some cases
At what age are pigs typically affected by exudative epidermitis?
Less than six weeks old
What is the average mortality rate of exudative epidermitis?
25% (range 5-90%)
In the acute form of exudative epidermitis, where does dark brown, greasy exudate first appear?
Periocularly
Name three differential diagnoses for exudative epidermitis?
Parakeratosis Strep pyoderma Biotin or zinc deficiency Viral infections (e.g. swine pox) Sarcoptic mange Dermatophytosis Pityriasis rosea (pustular psoriaform dermatitis) Dermatosis vegetans of Landrace pigs
Are exudative epidermitis and staph folliculitis pruritic?
No, not usually
What are the differentials for staph folliculitis?
Spirochetosis and necrobacilosis
Strep infections
What are the clinical signs of spirochetosis?
Erythema and oedema followed by necrosis and ulceration with granulomatous nodules (often with central necrosis) and a grey-brown glutinous pus
Is Erysipelothrix rhusiopathiae a: gram positive rod gram negative rod gram positive cocci gram negative cocci
Gram positive pleomorphic rod
What skin lesions do you see with Erysipelas?
Acute
Subacute
Chronic
Acute form: bluish to purple discolouration with pink to red macules and papules (can cause septicaemia/sudden death)
Subacute form: erythematous papules and wheals that form square, rectangular or rhomboid plaques (‘diamonds’) with a purple necrotic centre
Chronic form: necrosis and sloughing of plaques with subsequent ulcers (and arthritis and endocarditis)
Is Erysipelas zoonotic?
Yes
What do you see on histopathology with Erysipelas?
Neutrophilic vasculitis, suppurative hidradenitis and necrotising dermatitis
What are the clinical signs of Actinomyces suis infection?
Firm nodules or tumours with draining yellowish pus with ‘sulphur’ granules
Septicaemic slough is associated with which bacteria?
Salmonella choleraesuis
How common is Dermatophilosis in pigs?
Very rare
Oedematous pinnae, cutaneous cyanosis and meningitis are signs of which infection?
Haemophilus parasuis
Which dermatophyte most commonly affects pigs?
M. nanum
Do pigs get the hyperkeratotic form of sarcoptic mange as well as the hypersensitive form?
Yes - debilitated older animals get the hyperkeratotic form
How long after treatment do sarcoptes antibody titres remain elevated?
9-12 months
Which sucking louse affects pigs?
Haematopinus suis
Which Demodex mite affects pigs and what lesions are seen with mange?
Demodex phylliodes
Skin coloured to erythematous papules that are not painful nor pruritic with thick, white material within them
Which fleas affect pigs?
Pulex irritans
Echidnophaga gallinacea (sticktight flea)
C. felis
Which vectors can spread suipoxvirus?
Haematopinus suis, flies and mosquitoes
Which disease shows clinical signs associated with an immune complex leukocytoclastic and necrotising vasculitis and systemic coagulopathy?
Dermatitis and nephropathy syndrome
What are the differentials for foot and mouth disease in pigs?
Swine vesicular disease Vesicular exanthema Vesicular stomatitis UV light-induced vesiculobullous disease due to eating parsnips or celery infected with Sclerotinia sclerotiorum fungus Parvovirus vesicular disease Chemical burns
Bullous pemphigoid has been reported in which breed of pigs and antibodies target which antigen?
Yucatan minipigs
Collagen XVII in the BMZ
Dermatosis vegetans in Landrace pigs causes which clinical signs?
Cutaneous
Systemic
Cutaneous: symmetrical erythematous maculopapular dermatitis that develops into brown-black papillomatous crusted plaques, coronary band erythema and oedema an hoof ridges/dysplasia
Systemic: Giant cell pneumonia, stunted growth
At what age is juvenile pustular psoriasifom dermatitis seen?
3-14 weeks
On histopathology of juvenile pustular psoriasifom dermatitis, is the hyperkeratosis ortho- or para-keratotic and which inflammatory cells are present in pustules and in a perivascular to interstitial pattern?
Parakeratotic
Neutrophils and eosinophils
Which breeds are reportedly predisposed to melanocytic tumours?
Duroc Sinclair miniature Hormel Hampshire Iberian
What percentage of melanocytic neoplasms in predisposed breeds have spontaneously resolved by one year of age?
Up to 95%
What do you see on histopathology of skin lesions in porcine dermatitis and nephropathy syndrome?
Histologically, the skin lesions showed haemorrhagic dermatitis associated with necrotizing vasculitis in the superficial dermis and fibrinoid necrosis of arterioles in the deeper dermal layers and sometimes the subcutis
Name diseases associated with cutaneous vasculitis in pigs
- Erysipelothrix rhusiopathiae
- Pestivirus (Classical swine fever)
- Porcine Circovirus-2-3-4 (Porcine Dermatitis and Nephropathy Syndrome)
- Actinobacillus suis (in case of septicaemia it can lead to erysipelas like skin lesions)
- Salmomella cholerasuis (in case of septicaemia can cause blue-purple discoloration due to endotoxin induced venous thrombosis)
- Pasteurella multocida
- Hemolytic E.coli (Edema disease, can cause fibrinoid necrosis)
- Shiga toxin 2e (damages endothelium of vessels)
What are the histopathological findings of exudative epidermitis?
- Subcorneal cleft formation at the level of the stratum granulosum with formation of vesicles and pustules that evolve into crusts
- The degree of acantholysis varies from mild to moderate in severity.
- Gram-positive cocci are usually visible in the pustules and crusts using special stains.
- Superficial neutrophilic folliculitis may be a feature in some animals.
Name the exfoliatin toxins produced by exudative epidermitis-causing strains of Staphyloccus hyicus
ExhA ExhB ExhC ExhD SHETA SHETB
In the study by Joshi et al. (2021), which cytokines were found to be significantly elevated in pigs with sarcoptic mange compared to healthy controls?
IL-1
TNF-alpha
What was the immune response in pigs with crusted/Norwegian scabies?
In early infestation, genes relating to inflammation, immune recognition and cell migration were potently suppressed in pigs with crusted scabies. In later infestation, the large numbers of mites triggered a strong inflammatory response (Th2 and Th17) leading to severe skin pathology.
Which isoxazoline has been used to treat sarcoptic mange in pigs?
Afoxolaner at 2.5 mg/kg
What causes sarctopic mange in pigs?
Sarcoptes scabiei var. suis
The Exh toxins in greasy pig disease have been shown to digest __________ in the epidermis of porcine skin
Desmoglein-1
What are the clinical signs of greasy pig disease (EE)
- Reddish then coppery coloured skin
- Thin scales in the intertrigenous areas of the axillae and groin;
- Lesions can progress to cover the whole body with a greasy brown exudate
- Ulcers may be observed in the mouth, and there may be erosions of the coronary band and heel areas
Which other disease can be associated with S. hyicus infection in piglets in the absence of skin lesions?
Septic arthritis
What are the histopathological findings in greasy pig disease (EE)?
An intraepidermal subcorneal vesicular and pustular dermatitis, together with neutrophils, bacteria and acantholytic keratinocytes.
The other histopathological changes frequently include acanthosis, crusting, exfoliation and exocytosis.
How do you treat greasy pig disease (EE)?
Piglets with skin lesions can be treated topically and systemically.
Address farm hygiene and management of the piglet accommodation.
How are the piglets exposed to S. hyicus?
During parturition (vagina is site of S. hyicus carriage)
Which is the most commonly reported strain of MRSA isolated from farm animals (cows, pigs, chickens)? Why is it of concern both for humans and animals?
ST398
Increasing prevalence of this strain as a community-acquired MRSA - would suggest that it is relatively nonspecific with respect to host colonization and that it can spread easily
Name a virulence factor of Erysipelothrix rhusiopathiae
- Neuraminidase - plays a significant role in bacterial attachment and subsequent invasion into host cells
- A heat labile capsule - resistance to phagocytosis
How do you treat Erysipelothrix rhusiopathiae?
Penicillin
Which wildlife can spread Erysipelothrix rhusiopathiae?
Wild birds and rodents
Is there a vaccine for Erysipelothrix rhusiopathiae?
Yes
What are the clinical signs of suipoxvirus infection?
- Erythematous macules that become papular, vesicular, and pustular
- Pustules become umbilicated (depressed center) and have a peripheral red, raised border (these lesions are the classic “pocks”)
- Lesion distribution represents vector feeding sites
Is swinepox (suipoxvirus) zoonotic?
No
What are the clinical signs of dermatitis and nephropathy syndrome?
- Erythematous to reddish‐purple macules and papules evolve into patches/plaques.
- Larger papules and plaques often develop a central black area of necrosis and become covered with crusts
Porcine circovirus type ___, an emerging porcine circovirus, is considered the cause of porcine dermatitis and nephropathy syndrome (PDNS)-like clinical signs
3 (PCV3)