Livestock dermatology Flashcards
What are common dermatological problems in cattle + sheep?
- Infectious
– Parasitic
– Bacterial
– Fungal
– Viral - Neoplastic
- Nutritional
- Toxic
- Physical
- Congenital
What is general approach to skin condition in livestock?
- Signalment + history =
– Incidence & onset
– Location (soil type etc.)
– Animal(s) affected - Full clinical examination =
– BCS
– TPR
– Rumination
– Lameness etc.
– Skin lesions & lymph nodes - Visual and manual assessment (wear gloves!), Distribution & description (depth & tissues affected) - Diagnosis =
– Differentials
– Sample collection
– Response to treatment - Dermatological signs may be manifestation of systemic disease
– May be sign of underlying issue (nutritional deficiency, immunosuppression etc.) - E.g. poor coat condition
What are physical skin conditions? What do they indicate?
- Rub mark injuries =
-indictive of environment / housing issues
What housing issues can cause skin damage?
- Cubicle design and bedding = Hock, stifle, pelvic, spinal and neck lesions
- Feed barrier = Neck rubbing- reduced DMI?
- Cleanliness = General management, routines, building design, SARA
What are ectoparasites that affect livestock indoor/outdoor?
- Indoors = lice + mites
- Outdoor = flies + ticks
What are the lice in cattle? Where do they effect?
- Sucking = Linognathus vituli + Haematopinus eurysternus - can cause anaemia in calves
- Chewing = Bovicola bovis
- Mainly seen on back + neck = hairloss
What are the mites that affect livestock? What is seen?
- Chorioptes bovis - hairloss of Legs, feet, tail base, caudal surface of udder
- Sarcoptes scabei - hairloss of neck + face
- Psoroptes bovis - hairloss of Legs, feet, tail base, caudal surface of udder
How are mites diagnosed?
- Skin scrapes - edge of lesions
- examine under low power (x100) - liquid paraffin
How are ectoparasites treated?
- Pediculosis & mange = Check underlying health status, management & husbandry
– Mild infestations may not warrant treatment.
– Often self limiting/ winter housing specific
– Check your diagnosis (especially if psoroptic mange suspected)
– Treatments informed by clinical assessment - Psoroptic mange = injectable MLs
- Chorioptic mange = Pour on MLs
- Sarcoptic mange = injectalble or pour on MLs
- Louse =
- chewing = pour-on MLs
- sucking = injectable MLs
What is ringworm of calves? Dx? Tx?
- Trichophyton verrucosum
- Dx = clinical signs, history, Culture + microscopy (hairpluck at edge of lesion)
- Tx = Clean + disinfect housing, UV light + spontaneous resolution
What causes pustular impetigo?
- Staphylococcal infections
- wounds
- udder + perineum
- poorly applied ear tags
What causes abscesses + cellulitis? Tx?
- Actinobacili (Trueperella pyogenes) = oral cavity entry
- lower jaw + popliteal LNs
- Penetrating injuries (dirty needles)
- Non-resolved / infected hygromas + haematomas
- Tx = Open + drain, parenteral Ab (Gram +ve anaerobes)
What causes lumpy jaw + wooden tongue?
- Lumpy jaw = Actinomyces bovis
- Wooden tongus = Actinobacillus lignieresii
What causes Streptothricosis (rain scald)? Tx?
- Dermatophilus congolensis
- wet weather
- Tx = topical disinfectant, oxytet / penicillin + move to dry environment
What causes warts? Tx?
- Bovine viral papillomatosis
- possibly spread by flies
- Can persist in immunocompromised animals
- Usually self-limiting
- Surgical removal sometimes needed (penile / teat warts)
What are other viral skin lesions?
- Stomatitis/ mamillitis & vesicular diseases
– Generally self limiting
– Mild to painful - Bovine papular stomatitis (muzzle and lips)
- Bovine herpes mamillitis (teats & udder)
– May indicate systemic disease =
* Ulceration of mouth and nose =
1. Mucosal disease = PI with cytopathic BVDv
2. Malignant Catharral fever (MCF), IBR etc.
– FMD?
* Pyrexia (>40oC), depression, lameness
* Vesicles on muzzle, tongue, nostrils udder & feet
What causes poor growth rates + brown tinged coat w spectacles?
- Copper deficiency
- Molybdenum toxicity
What causes photosensitisation? What is seen? Tx?
- Primary caused by photodynamic agents in diet = St John’s Wort
- Secondary (hepatogenous) = liver damage + accumulation of phylloerythrin - ragwort
- CS = unpigmented skin affected = sloughing + serous ooze, secondary bacterial infections
- Tx = Symptomatic, house animals away from sunlight
What are physical causes of skin damage in sheep?
- Rubbing – Due to pruritis/irritation
- Wool break – Nutritional/condition/stress, Systemic disease
- Trapping (eg. fence wire)/ fleece grabbing
- Dog attacks – Consider underlying structures (eg. joints, abdomen etc.)
What is Prevention / Tx of scab in sheep?
- Px = Good biosecurity (fences), Adequate quarantine measures
- Tx = Whole flock, OP dip, Injectable MLs, Avoid previous housing + pastures
What are Ddx for scab? what does this indicate?
- Bovicola ovis
- heavy infestation indicates underlying flock health issue =
- investigate health + nutrition + reduce stocking density
- SHEAR / Dip
What is seen with Orf? Tx?
*Affects mouth, feet + teats - hungry lambs, mastitic ewes
* Self limiting - 1-4wks
* Tx = antibiotics for 2ary infections, Scabivax - only if present on farm
What are other skin diseases in sheep?
- Ringworm = lambs, face
- Photosensitisation = non-pigmented skin
- CLA = Corynebacterium pseudotuberculosis - CULL
- Scrapie = Notifiable - intense pruritis + wool break + neuro signs
When are biting / nuisance flies + ticks seen? What is their primary pathology + What diseases can they be a vector for?
- Summer months
- Primary pathology =
- Blood feeding species
- Secondary infections
- Myiasis
- Disease vectors =
- New Forest disease, BVDv, Summer mastitis
- Tick borne disease - babesiosis, Q-fever
- Bluetongue + schmallenberg
What can be done for fly control?
- Regular inspection
- Risk forecasting (NADIS blowfly alert)
- Identify risk areas
– Outdoors- trees & shaded pastures
– Indoors- Good hygiene (e.g. muck out) - Routine topical treatments (SPs, IGRs, 3-MLs)
- Insecticide-impregnated ear tags, tail bands etc.
- Environmental controls
What are external threats outside the UK?
- Aujesky’s disease (“pseudorabies”) = notifiable
– Contagious viral disease, Extreme pruritis & self-injury - Besnoitiosis
– Besnoitia besnoiti (apicomplexan parasite)
– Present in France, Italy, Spain & Portugal
– Cattle are intermediate hosts
– Mechanical transmission = Flies & needles
– Clinical disease = 1-3 weeks acute to chronic progression - Pyrexia, fever-like symptoms and wasting
- Various dermal lesions with lymphadenitis and cyst formation
- Lumpy skin disease = notifiable
– Transmission = Biting flies, ticks, needles, Cattle movement
– Skin nodules, emaciation, lymphadenitis, nasal discharge, mastitis & fever (10-14 days)
– Control with biosecurity (national & local) & vaccination
