Block 6

Question 1

Pseudocowpox definition

Answer 1

Pseudocowpox is a viral skin disease that causes mild sores on the teats and udders of cattle.
This virus can also infect humans and the condition is commonly referred to as milker’s nodule.

Question 2

Milker’s Nodule

Answer 2

The skin disease that Pseudocowpox causes in humans

Question 3

Etiology of Pseudocowpox

Answer 3

Member of the genus Parapoxvirus

Question 4

Epidemiology of Pseudocowpox

Answer 4

Reported from most countries

Question 5

Transmission of Pseudocowpox

Answer 5

• Source of infection is the infected cattle
• Contaminated milker’s hands, teat cups
• Biting insects may transmit the virus
• Calves get infected during sucking infected teats
• Semen of bulls

Question 6

Pseudocowpox pathogenesis

Answer 6

Lesions are characterized by hyperplasia of squamous epithelium

Question 7

Pseudocowpox Clinical Signs

Answer 7

Infections are generally mild

Question 8

Pseudocowpox acute lesions

Answer 8

Erythema –> Papules –> Vesicle or Pustule –> Rupture –> Thick scab
The thick scab is 0.5 to 25 cm in diameter, becomes elevated due to the accumulation of granulation tissue. After 7-10 days, the scab drops off, leaving a horse-shoe shaped ring of small scabs surrounding a small wart-like granuloma.

Question 9

Pseudocowpox chronic lesions

Answer 9

• Commences as erythema
• Yellow-gray, soft scurfy scabs which are rubbed off during milking
• Skin is corrugated
• No pain
• Lesions may persist for months

Question 10

Pseudocowpox diagnosis

Answer 10

• Horseshoe shaped ring like lesion are pathognomonic for the disease
• Isolation and detection of the virus by various diagnostic laboratory methods from vesicular fluid or from teat skin

Question 11

Pseudocowpox differential diagnosis (6)

Answer 11

• Cowpox virus
• Bovine herpesvirus ulcerative mammilitis
• Vesicular stomatitis
• Udder impetigo (bacterial dermatitis characterized by the development of small pustules on the skin of the udder and teats)
• Teat chaps and frostbite
• Black spot (a form of hyperkeratosis)

Question 12

Pseudocowpox treatment (4)

Answer 12

1) Removal of scabs
2) Burn the scabs to prevent environmental contamination
3) Application of an emollient ointment before milking
4) Application of astringent preparation after milking

Question 13

Pseudocowpox prevention (3)

Answer 13

1) Disinfection, use iodophor teat dip
2) Isolation and treatment of infected cows
3) Reduce teat trauma, as injuries to skin of teat predisposes to infection

Question 14

Pseudocowpox in Humans (The Milker’s Nodule)

Answer 14

Causes a mild skin lesion known as Milker’s Nodule.
Lesions on the hands of dairy farmers milking teats or vets treating infected cows.
Lesions may vary from multiple vesicles to a single, indurated nodule.

Question 15

Contagious Ecthyma etiology

Answer 15

Orf virus, Genus Parapoxvirus

Question 16

Contagious Ecthyma hosts

Answer 16

Sheep and goats, primarily in lambs and goat kids

Question 17

Contagious Ecthyma distribution

Answer 17

Worldwide