VMS3010 Approach to Skin Conditions of Farm Animals PDF

APPROACH TO SKIN CONDITIONS OF PRODUCTION ANIMALS LUISA SOARES LMV, FHEA, MRCVS LECTURER IN PRODUCTION ANIMAL MEDICINE  LEARNING OBJECTIVES By the end of this lecture should be able to 1. Recognise common integument lesions and describe their causes and pathogenesis. 2. Reco...

APPROACH TO SKIN CONDITIONS OF PRODUCTION ANIMALS LUISA SOARES LMV, FHEA, MRCVS LECTURER IN PRODUCTION ANIMAL MEDICINE  LEARNING OBJECTIVES By the end of this lecture should be able to 1. Recognise common integument lesions and describe their causes and pathogenesis. 2. Recognise the major clinical signs of notifiable diseases in the skin and hoof. 3. Describe how liver disease can cause skin disease. 2 DIFFERENTIAL DIAGNOSES Ectoparasites Bacterial Mites+ Dermatophilus Lice Digital dermatitis and other treponeme Ticks infections Flies+ Erysipelas Pyoderma Viral Bovine Herpes Virus Others Photosensitisation BVD mucosal disease Malignant catarrhal fever Ringworm Papillomavirus Scrapie* Squamous Cell Carcinoma Vesicular stomatitis* FMD* LSD* Bluetongue* * Notifiable disease + Some species are notifiable 3 GENERAL APPROACH TO SKIN DISEASE History Physical exam Examine lesions – gross pathology Diagnostics: Skin scrapes Hair plucks Biopsy Swabs Treatment – symptomatic: Pain relief – steroidals or non-steroidals Antiparasitics E C T O PA R A S I T E S Mites+ Lice Ticks Flies+ Good resources: SCOPS - https://www.scops.org.uk/external-parasites/ COWS - https://www.cattleparasites.org.uk/app/uploads/2020/12/ect oparasites-111220.pdf 5  MITES (SHEEP) https://www.scops.org.uk/workspace/pdfs/best-practice-use-of-injectable-scab-treatments_1_1.pdf https://www.scops.org.uk/workspace/pdfs/scab-product-options-table-updated.pdf Psoroptes ovis – sheep scab (notifiable - Scotland) Chorioptes bovis – Rams (scrotum, lower limbs, poll) Sarcoptes scabiei Demodex (pruritus is not a feature) – very rare in UK Full fleeced Clinical signs Pruritus, loss of fleece Multiple animals affected Diagnosis: Skin scrapes and microscopy Serology for AB sheep scab Hair plucks for Demodex Treatment: (even unaffected animals) Injectable – macrocyclic lactones (e.g. doramectin) – difficult for Chorioptes! Sheep- Plunge dipping in organophosphates (although environmentally hazardous) Prevention: Biosecurity – closed flock, quarantine treatments, fencing 6 In NADIS MITES (SHEEP) https://www.scops.org.uk/workspace/pdfs/best-practice-use-of-injectable-scab-treatments_1_1.pdf https://www.scops.org.uk/workspace/pdfs/scab-product-options-table-updated.pdf 7  M I T E S ( C AT T L E ) Chorioptes bovis – feet, legs, base of tail and udder Psoroptes – dorsum, shoulders and tail head (uncommon in UK but more severe that Chorioptes) Sarcoptes scabiei – neck, face and tail head Demodex (pruritus is not a feature) – very rare in UK Winter/ Housed Clinical signs Pruritus, loss of hair Pustular, crusted, scally skin Multiple animals affected Diagnosis: Skin scrapes and microscopy Hair plucks for Demodex Treatment: (even unaffected animals) Pour-on Permethrin, Macrocyclic lactones (e.g. Ivermectin, eprinomectin) Injectable – macrocyclic lactones (less effective for Chorioptes) Move animals to “clean” housing (no animals for 3 weeks) Prevention: Biosecurity – closed herd, quarantine treatments, fencing https://www.cattleparasites.org.uk/app/uploads/2020/12/ectoparasites-111220.pdf 8 L I C E ( C AT T L E ) Bovicola (Damalinia) bovis (common) – Chewing - Treatment: head, neck, shoulders, back, tail Pour-on/Spot-on pyrethroids (e.g. Deltamethrin) or Lignonathus vituli – Sucking – head, neck, dewlap macrocyclic lactones brisket Injectable macrocyclic lactones will target sucking Haematopinus eurysternus – Sucking lice only (less effective) Solenopates capillatus– Sucking Repeat tx? Eggs! Common in winter/ indoors Prevention: Transmission direct physical contact Routine anti-ectoparasite treatments? Resistance? Biosecurity (same as mites) Clinical signs: Pruritus and loss of hair Rough skin > bruises > wounds > sec. infection Anemia Diagnosis: Visible parasites on skin surface Skin scrapes and microscopy 9 M I T E S A N D L I C E ( C AT T L E ) https://www.noahcompendium.co.uk/datasheets https://www.cattleparasites.org.uk/app/uploads/2020/12/ectoparasites-111220.pdf 10 LICE (SHEEP) Bovicola ovis (Chewing) Common in winter/ indoors Shearing reduces lice pop Clinical signs: (similar to scab) Pruritus and loss of fleece/damage to hide ‘cockle’ hide – nodular skin defect due to immune response Diagnosis: Visible parasites on skin surface Skin scrapes and microscopy Treatment: Pour-on/Spot-on pyrethroids – less effective in full fleeced sheep Plunge dipping in organophosphates (although environmentally hazardous) Prevention: Routine anti-ectoparasite treatments Biosecurity (same as mites) 11  LICE (SHEEP) https://www.scops.org.uk/workspace/pdfs/product-options-table_1.pdf 12 B L O W F LY S T R I K E / C U TA N E O U S M Y I A S I S larvae of: Lucilia sericata (greenbottle flies) Phormia terraenovae (blackbottle flies) Calliphora erythrocephala (bluebottle flies) Summer Clinical signs: Isolation from the flock, disturbed grazing Discoloured wool Agitation and kicking or nibbling at the affected area Maggots Pustular, foul smelling pyoderma – secondary bacterial infection Typically affects the perineum, flank, or between the digits (associated with foot rot) Pyrexia Toxaemia Recumbency and Death Diagnosis: Clinical signs History (not been sheared, faecal staining due to endoparasites) 13 B L O W F LY S T R I K E / C U TA N E O U S M Y I A S I S Treatment Isolate ewe Trim fleece Remove visible maggots and debride necrotic tissue Pain relief Systemic broad-spectrum antibiotics Apply insecticide to affected area Topical antibiotics Consider euthanasia Prevention Severe welfare concern Client education – importance of shearing Fly treatment – Pour-on/Spot-on pyrethroids every 4-8 weeks during the grazing season (persistence of action?) Endoparasite control to reduce diarrhoea Address wounds and lameness ASAP 14 B L O W F LY S T R I K E / C U TA N E O U S M Y I A S I S 15 https://www.scops.org.uk/workspace/pdfs/blowfly-product-options-table_1.pdf W A R B L E F LY – H Y P O D E R M A ( C AT T L E ) Notifiable in Scotland Eradicated 1990 but risk of importing infected animals Clinical signs: 3mm soft painful swellings on the back of the animal Diagnosis: Warble fly larvae Treatment: Ivermectin injection Prevention: Biosecurity Anti-ectoparasite control – pyrethroids spot- on/pour-on 16 TICKS Ixodes ricinus Clinical signs: Swelling over tick bites Vector for secondary diseases: Babesia “redwater” – anaemia, haemaglobinuria Theileria – anaemia, haemagolbinuria Anaplasma – pyrexia, anaemia, abortion Lyme disease – milk drop, swollen joints, pyrexia Louping ill – neurological signs, pyrexia Diagnosis: Finding a tick Treatment: Permethrin spot-on? (off licence in cattle…) Prevention: Avoid grazing pastures with known tick burdens Improve pastures (long term) Anti-parasitic spot-ons 17  FOOT AND MOUTH DISEASE Notifiable Clinical signs: Pathognomonic lesions Pyrexia Diagnosis: Swab lesions and PCR Diagnosis confirmed: Immediate movement restrictions Strict biosecurity Cull whole herd/flock Vaccination possible in endemic countries 18 V E S I C U L A R S T O M AT I T I S Notifiable Clinical signs: Hypersalivation Similar in appearance to FMD but only affecting mouth and sometimes teats Vesicles, ulcers, erosions, crusting Diagnosis: Virus isolation Serology 19 BLUETONGUE Notifiable Vector- midges Culicoides Clinical signs: >sheep Oedema muzzle, tongue and coronary bands Crusted muzzle Sialorrhea and nasal discharge Skin erythema Diagnosis: Virus isolation Serology Image courtesy of Phil Scott, NADIS PME https://www.gov.uk/government/collections/bluetongue-information-and-guidance-for- livestock-keepers 20 LUMPY SKIN DISEASE Notifiable Spread by insect vectors Clinical signs: Milk drop Malaise, fever Multiple skin nodules Diagnosis: Swab lesions and PCR Prevention: Vaccination possible in endemic countries Vector control Movement control Image courtesy of Phil Scott, NADIS 21 BVDV – MUCOSAL DISEASE Clinical signs: Ulcerated, erythematous lesions over mucosal surfaces Diarrhoea Usually in a poor doing animal Known BVD infected herd/unknown status Diagnosis: Isolation of cytopathic BVD on swabs Treatment None Prevention Vaccination BVD eradication – remove persistently infected animals 22 M A L I G N A N T C ATA R R H A L F E V E R Ovine Herpes-Virus Clinical signs: Extreme pyrexia (40.5-42.0⁰C) Depression, inappetence Painful crusting over the muzzle Similar appearance to BVD mucosal disease Corneal oedema Diagnosis: Rule out cytopathic BVD Viral PCR Antibody ELISA Treatment: none Prevention: Avoid co-grazing with sheep Image courtesy of Phil Scott, NADIS 23 PA P I L O M AV I R U S Clinical signs: Warts commonly over teats, penis, neck Diagnosis: Characteristic lesions Treatment: Usually self-limiting Disinfect at milking Surgical excision if causing irritation or impairing function (e.g. penis) Prevention: None Image courtesy of Phil Scott, NADIS 24  BOVINE HERPES MAMMILLITIS Bovine Herpes II Clinical signs: Ulcerative lesions on teats Mostly in 1st parity heifers (immunity?) Diagnosis: PCR for virus Treatment: Symptomatic Stop milking Disinfect to prevent secondary pyoderma Prevention: Parlour hygiene to minimise contagious spread 25 C O N TA G I O U S P U S T U L A R D E R M AT I T I S - ORF Clinical signs: Skin lesions over the nose and mouth of lambs Similar lesions on the teats of ewes Zoonotic Diagnosis: Classic lesions PCR or electron microscopy Treatment: None Symptomatic Isolation Prevention: Vaccination Minimise mis-mothering Clean bottles between use Hygiene 26 D I G I TA L D E R M AT I T I S Caused by spirochete bacteria Treponema spp Aetiology: Spread from lesion to slurry to foot Bacteria doesn’t survive well in the environment Hoof knives have been implicated Clinical signs: 50% are lame on mobility score Treatment: Topical antimicrobial (antibiotic or non-antibiotic) Prevention: Footbathing Biosecurity Slurry management Breeding? 27 OTHER SPIROCHETE INFECTIONS Digital dermatitis type lesions have been found in other areas, with treponemes cultured Toe Necrosis Hock lesions Ischaemic Teat Necrosis Udder Cleft Dermatitis Limited evidence for aetiopathogenesis, treatment and prevention 28 E R Y S I P E L A S R H U S I O PAT H I A E Skin disease and lameness with swollen joints Most commonly affects pigs but can affect cattle Diagnosis: Culture from infected joints Characteristic ‘diamond’ skin lesions Treatment: Systemic penicillin/amoxicillin Pain relief – meloxicam 29 R A I N S C A L D – D E R M AT O P H I L U S Dermatophilus congolensis Lesions affect the dorsum, following prolonged wet weather Rarely clinically relevant Symptomatic treatment Image courtesy of Phil Scott, NADIS 30 ABSCESSES Cattle wall off infections well Skin abscesses are a common condition Associated with Fusobacterium necorphorum and Trueperella pyogenes Diagnosis: FNA ultrasound to rule out haematoma/seroma Treatment: Drain and flush No need for systemic therapy unless systemically unwell 31 RINGWORM Trichophyton verrucosum Zoonotic Clinical signs: Pathognomonic lesions – eyesore Variable pruritus Treatment: Limited evidence for treatment efficacy Antifungals – topical itraconazole, enilconazole Sunlight Image courtesy of Phil Scott, NADIS 32 SCRAPIE Scrapie is caused by prion protein It primarily affects the brain but can also affect the skin causing pruritus Clinical signs: Loss of fleece Neurological signs – stargazing, recumbency, depression Notifiable disease – report based on clinical signs 33 P H O T O S E N S I T I S AT I O N Two forms: Primary – ingestion of a photodynamic agent Secondary – hepatic dysfunction Clinical signs: Erythema over non-pigmented areas of the face and dorsum Diagnosis: Secondary – liver biochemistry Primary – by excluding liver pathology Difficult to rule out photodynamic plant Treatment: Remove from sunlight for 2-4 weeks Corticosteroids Treat underlying liver disease (often euthanasia) Images courtesy of Phil Scott, NADIS 34 SQUAMOUS CELL CARCINOMA Neoplasia, affecting non-pigmented areas of skin Common sites: Eyes Teats Treatment: Surgical excision Images courtesy of Phil Scott, NADIS 35 #universityofsurrey 36