Conditions of the bovine skin (TV4101, Lecture 24 Notes)

Discuss sampling/testing of skin lesions

Tier 1 - sample multiple animals (accompanied by lesion photographs)

- Biopsy (formalin fixed and fresh)

- Cytology

- Whole blood and serum

- Skin scraping

- Hair pluck

- Superficial ectoparasites, especially maggots (alcohol fixed)

Tier 2

- Cytology

- Bacterial culture

- Fungal culture

List common skin conditions

Discuss dermatophilosis (rain scald)

- Common

- Associated with skin damage/maceration and prolonged wetting with close contact transmission

- Pain-brush hair lesions with raw, non-pruritic erosions

- Impression smear with branching filaments and railroad track appearance

- May self-resolve with drying environment, if severe treat with systemic antibiotics (e.g. penicillin, LA oxytet or TMP-sulpha)

Discuss differential diagnosis of skin lumps

Discuss atypical cutaneous actinobacillosis (woody tongue)

- Associated with penetrating lesion (i.e. opportunistic infection)

- Pyogranulomatous soft-tissue lesions (commonly on the head)

- Administer IV sodium iodine

Discuss Staphylococcal infections

- Superficial pustular dermatitis (especially udder, scrotum and perineum)

- Wash daily with chloramine (0.5%) or povidone iodine (5%)

Discuss udder cleft dermatitis

- Multifactorial disease with opportunistic anaerobe overgrowth

- Erythema/papules/crusts or ulcerative, exudative wounds with necrosis/hemorrhage of the intermammary cleft

- May spontaneously recover or implement rigorous cleaning/debridement

Discuss black spot/pox

- Necrotic lesion at teat orifice with secondary infection (e.g. Staphylococcus aureus and Fusobacterium necrophorum)

- Evaluate milking machine function and routine

- Administer high-emollient teat disinfectants with hypochlorite dips to debride dead tissue

Discuss common fungal skin diseases

Ringworm (Dermatophytosis)

- Common, self-limiting disease

- Due to Trichophyton verrucosum

- Exudation and fungal hyphae produce characteristic dry, crusty lesions

Aspergillosis

- Due to Aspergillus fumigatus

- Fungal placentitis resulting in skin lesions (grey, felt-like or yellow, dry plaques) in the aborted foetus

Discuss common viral skin diseases

- Papillomatosis (warts), due to bovine papillomaviruses

- Bovine papular stomatitis

- Bovine herpes mammillitis (BoHV-2)

- Pseudo lumpy skin disease (BoHV-2)

- Bovine viral diarrhoea (BVDV), with diffuse stomatitis

- Malignant catarrhal fever (MCF), sheep-associated with oral ulcers and erosions

- Foot-and-mouth disease (FMD), excessive salivation with mouth and foot lesions causing lameness

- Lumpy skin disease (Capripoxvirus)

Discuss common external parasites

Typically associated with reduced BCS, milk production and damaged hides;

- Cattle tick

- Buffalo fly, may transmit Stephanofilaria (susceptible to MLs)

- Lice, common during cooler months

- Follicular, burrowing or non-burrowing mites, perform skin scraping (with oil until capillary ooze)

- Chorioptic manage (susceptible to MLs)

- Myiasis/blowfly strike, secondary to open wounds

Discuss common neoplastic skin diseases

- Warts, due to bovine viral papillomatosis

- Squamous cell carcinoma (common), due to UV light exposure

- Cutaneous lymphosarcoma

- Fibroma

- Melanoma

- Cutaneous angiomatosis

Discuss common deficiency skin disorders

Copper deficiency - dry, dull, non-elastic skin with poor growth of scant brittle hairs and subtle coat changes

Cobalt deficiency - poor growth rate and wasting with poor, fragile hair.

Zinc deficiency - deterioration and loss of hair thickened with cracked skin (parakeratosis) of muzzle, neck, lower limbs, perineum and scrotum.

Vitamin A, E or C deficiency

Discuss dermatosparaxis

- Autosomal recessive disease

- Collagen dysplasia causing extensible and fragile skin