Cattle2 Flashcards
How is lepto spread?
Via contact with infected urine or from water/pasture contaminated with urine. products of abortion also source of infection. Venereal transmission possible. not carried by vermin/wildlife. sheep can carry and excrete leptospira.
How is leptospirosis destroyed?
Leptospires do not tolerate drying, exposure to sunlight, ph
What are the risk factors for lepto?
Open heard, shared bulls
Mixed grazing with sheep
Shared grazing/water courses
What are the clinical syndromes seen with leptospira?
Milk drop - 2-7 days after initial infection
Abortion - 3-12 weeks following infection (in last trimester usually)
How is leptospirosis diagnosed?
Microscopic agglutination test - used to detect antibodies to lepto hardjo in serum. also ELISA titre. Leptospires in urine following acute infection using dark field micrsocopy or PCR.
What are the clinical signs of malignant catarrhal fever?
acute onset illness with depression, anorexia, pyrexia, intense scleral congestion with keratitis erosive stomatitis of mucosa and muzzle, mucopurulent discharge, nervous signs hyperaesthesia and incoordination, diarrhoea.
How can MCF be differentiated from other mucosal diseases?
History of sheep and classical clinical signs - central nervous signs are rare with any other mucosal diseases. Differential diagnosis are IBR, BDV, BTV, VSV, FMD. Serological test is available but may not be positive at time of clinical signs, or demonstration of viral genome in blood (PCR).
What is sporadic bovine lymphosarcoma (leukosis)
NOT the same as Enzootic bovine leukosis caused by retrovirus !!
Rare and sporadic - juvenile, thymic and skin forms.
In thymic form characteristic massive enlargement of thymus and local LN, thymic mass acuses jugular engorgement, oedema of brisket extending to submandibular region and chronic bloat due to oesophageal compression.
tumour masses can be found in a wide variety of organs including the heart, abomasum, spleen and CNS.
What type of virus is BvD?
Pestivirus
How is BVD spread?
Nasopharyngeal secretions, urine, aerosol droplets. Faeces not a major source of virus excretion.
How does mucosal disease occuR?
When a PI animal becomes superinfected with cpBVD. the CpBVD virus can arise from genetic assortment of Ncpbvd within the PI animal from transfer of genetic material from a heterologous starin to the NCP BVD strain or can arise as an entirely new strain. most cases occur in 6 month to 2 year age group which may coincide with waning of passive immunity.
What are the signs of mucosal disease caused by BVD?
Acute onset depresison, pyrexia, anorexia, saliva around muzzle, oral nasal erosions/ulcers, nasal discharnge, profuse diarrhoea/dysentry with shreds of gut mucosa/blood present in terminal stages.
How can mucosal disease be diagnosed?
Virus isolation from PM tissues. Normally are antibody negative antigen positive on ELISA test.
How can PI calves be confirmed?
Ear notch or blood for persistent viraemia. Ear notch testing can be done at any age. Serum antigen BVDV test accurate from 1 month in the presence of mternal antiboies.
How is BVDV screened for in a herD?
Bulk milk or first lactation screens
Calf screen - 5 animals between 9-18 months old from each management group.
What did pregsure bvd vaccine cause?
Bovine neonatal pancytopenia
What is necrotic enteritis?
Seen almost exclusively in spring born suckled calves and normally affects calves in 2-4 month old age group. Most cases affected are seen at pasture in june/july.
What are the clinical signs of necrotic enteritis?
Depression, pyrexia, diarrhoea often profuse and haemorrhagic, tenesmus, abdmoinal pain, respiratory signs, pale mucous membranes, oral and nasal ulcers. Non regenerative neutropenia.
What is the cause of winter dysentry?
Bovine coronavirus. Acute highly contagious diarrhoea tht occurs in epizootic fashion in winter housing period. spread by faecal oral route.
How is johnes transmitted?
Ingestion of the organism in faeces from infected animals, contaminating food,water or teats. Infection mainly occurs in neonatal animals up to a few months old but occasionally older animals also become infected.
What cell does johnes multiply within?
Macrophages. It localises in the ileum and gut associated lymph nodes and is phagocytosed by macrophages and may multiply intracellularly.
What are the clinical signs of johnes?
Weight loss, emaciation, sub mandibular oedema, coat depigmentation, fall in milk yield. NO FEVER OR TOXAEMIA. appetite and rumenal activity are good. soft faeces or dairrhoea that is thick pea soup with no blood mucous or debris. Small ruminants usually have faeces which remains firm.
What do johnes cases usually show on clinical pathology?
Hypoalbuminaemia with normal gammaglobulin levels.
What tests are used to diagnose johnes?
Faecal examination for acid fast organisms ZN stain.
Culture of faeces on mycobactin containing media (3 months or more)
PCR to detect quantities of mycobacterial DNA in faeces.
Agar gel immunodiffusion test - not good at detecting subclinical cases.
ELISA - best option though sensitivity still
Which species causes dermatophytosis in cattle?
Trichophyton verrucosum.
What is the treatment of ringworm?
Griseofulvin in feed - not in UK
Sodium idiode - toxicit
Ringvac vaccine
topical enilconazole, iodine/glycerin
What is bovicola bovis?
A biting lice
What is haematopinus eurytsternus, linognathus vituli, solenopotes capillatus?
Sucking lice of catle.
What is chorioptes bovis?
A surface mite. Lives off epidermal debris. Causes papules, pruritis, alopecia, crusts.
Which flies spread summer mastitis?
Hydrotoea irritans.
Which flies cause multiple nodules from bites?
Haematobia species. Open wounds/lesions on the lower abdomen, udder and teats can be caused by bites of flies such as haematobia irritans or feeding of hydrotea irritans.
Stomoxys calcitrans (stable flies)
simulium black flies - can cause painful vesicle, mass attack can cause acute syndrome with haemorrhage and oedema
Tabanid horse flies - painful bite
Which flies cause blowfly strike?
Lucilia sericata or phormia terranovae.
What could be the cause of subcutanoues nodules and cysts along the backs of cattle in spring?
Warble fly larval infestation by hypoderma bovis or h lineatum - notifiable.
What is the cause of infectious bovine keratoconjunctivitis?
Moraxella bovis +/- mycoplasmas, flies, dust, IBR.
What is the treatment for IBK?
topical antibiotics, subconjunctival injection, systemic oxytet, florfenicol or ceftiofur.
What is the cause of ovine infectious keratoconjunctivitis?
Mycoplasma conjunctivae.
What are struvite crystals composed of?
Magnesium ammonium phosphate hexahydrate.
What is the cause of bacillary haemoglobinuria?
Clostridium haemolyticum (clostridium novyi type D)
What is postparturient haemoglobinuria?
A rare condition of intravascular haemolysis, haemoglobinuria, anaemia and jaundice in high producing multiparous cows thought to be related to hypophosphataemia found in affected cows and herdmates.
What BCS should a dairy cow be at calving?
2.5-3