GI - bovine GI disease Flashcards
Where is 80% of water reabsorbed in the bovine GI tract?
In the small intestine
Opposite of horses who absorb most in large intestine
What is lost in acute diarrhoea and what is lost in chronic diarrhoea ?
Acute diarrhoea - loss of electrolytes
Chronic diarrhoea - loss of nutrients
How is diarrhoea diagnosed in cattle?
History - age, herd, duration, nutrition
Examine group, individual and faeces
What should you examine in a cow with diarrhoea?
Oral vacity
Perineal region
TPR
BCS
Pain
What is the biggest cause of coccidiosis?
Build up of parasite oocysts in the environment
Indoor house, insufficient bedding
What are the signs of coccidiosis?
Acute to chronic diarrhoea - smelly, greenish, mucoid
Poor weight gain in growing calves
What is the treatment for coccidiosis?
Self limiting usually
Can give diclazuril
What are the most important helminths that cause chronic dairrhoea?
Ostertagia
Liver fluke - fasciola hepatica
What 3 diseases does salmonellosis cause?
Enteritis
Abortion
Septicaemia
What are the 2 salmonella serotypes?
Typhimurium
Dublin
How is salmonella spread?
Faecal-oral
Conjunctival
Respiratory
What is the difference between salmonella typhimurium and salmonella dublin?
Typhimurium - exist in the environment or in different species and spill into cattle - fluctuate
Dublin - endemic, in cattle population at all times, cow host specific
What season is salmonella typhimurium peak incidence?
Autumn - associated with housing
How does salmonella dublin shed? How is it different between carriers?
Active carriers - shed for up to a year
Passive carriers - shed while exposed
Latent carriers - shed when stressed
What is salmonella dublin associated with?
Fasciola hepatica - liver fluke
How long is salmonella typhimurium and salmonella dublin carried for?
Typhimurium - 4 weeks
Dublin - years, with intermittent shedding
How is salmonella diagnosed?
Faecal culture
Histopath
Lesion culture
What is a notifiable disease that causes diarrhoea in animals?
Salmonella heheh got you
Which salmonella serotype is sensitive to most antibiotics?
Salmonella dublin
Salmonella typhimurium is much more resistant
What are the clinical signs of the enteric syndrome of salmonellosis?
Lethargy
Pyrexia
Milk drop
Diarrhoea
Pain, recumbency, death
What is the second most common diagnosed cause of bovine abortion in GB after neospora?
Salmonella
What does salmonella cause in calves?
Diarrhoea
Lethargy
Pyrexia
Inappetence
Sloughed extremities - peripheral gangrene
Death
How do you treat salmonellosis?
Systemic antibiotics - amoxycillin, trimethoprim/siulphonamides
Supportive care - fluids, diet
How can you prevent salmonellosis?
Closed herd
Isolate introductions for 4 weeks
Isolate sick animals
Clean buildings between occupancies
Vaccinate - bovivac S
What is the most important cattle viral disease in the UK?
Bovine viral diarrhoea virus
What is the genus of BVD virus?
Pestivirus
What are the two genotypes of BVD virus?
Classical form - BVDV 1
Severe acute BVD haemorrhagic syndrome - BVDV 2
What are the two biotypes of BVD virus?
Non-cytopathic - 90%
Cytopathic - 10%
How do the different biotypes relate to mucosal disease BVD?
Secondary infection of animals with the non cytopathic virus with the cytopathic virus
What is the key to the survival of the virus in bovine populations?
Naïve adult cattle with subclinical BVD producing persistently infected calves
What symptoms can naive adult cattle get from BVD?
Mild pyrexia
Diarrhoea
Reduced milk yield
Poor fertility, early embryonic death, abortion
What symptoms can naive calves get from BVD?
Immunosuppression - resp disease, diarrhoea, pyrexia
What does BVDV 2 cause?
Acute haemorrhagic enteritis and death
What do persistently infected calves with BVD get?
Poor growth rates
Immunosuppression
Mucosal disease - if they become infected with the cytopathic virus
So what are the two broad syndromes of BVD?
Acute infection followed by immunity
Persistant infection +/- mucosal disease
Why do persistently infected calves react so badly to the cytopathic BVD virus?
Because they gain immunotolerance to BVD in the womb so the body doesnt learn that the virus isnt self so doesnt mount an immune response
How do calves get congenital abnormalities from BVD?
If between 4-9 months there is an immune response in the foetus to the virus
How does the mucosal disease of BVD initially invade a herd?
If the virus mutates from the non cytopathic form to the cytopathic form then spreads through the herd
What are the clinical signs of mucosal disease in BVD cattle?
Oropharynx - ulcers, pain, ptyalism, hyperaemia
Muzzle - ulcers, cracked
Gut - ulcers, profuse homogenous diarrhoea
Feet - ulcers in digital cleft
Eyes - lacrimation, epiphora
Nose - mucopurulent discharge
Rapid loss of condition
How do you diagnose mucosal disease from BVD in cattle?
Clinical signs
PM exam - microvesicles/ulcers in GI tract
Lab testing
What are 3 notifiable diseases that are differential diagnoses for BVD/mucosal disease?
Food and mouth
Bluetongue
Rinderpest
What lab tests do you do for BVD/mucosal disease?
Antibody ELISA - testing for immune response
Antigen PCR - testing for virus
What will be the lab results for mucosal disease?
Positive antigen PCR but negative antibody ELISA - no immune response
What will the lab results be for vaccination against BVD?
Only positive antiBODY ELISA, not antigen PCR - not virus present but immune response
How do you eradicate BVD in the dairy herd?
Test bulk tank for antigens
If positive then test individual cows for antigens
Cull PI animals, vaccinate others
How do you eradicate BVD in youngstock?
Test 9-18month cohort pooled blood for blood antibodies
If positive for antibodies then means there are PI cows in herd infecting others
So if herd positive to antibodies then test individuals for antigens - if positive then cull
How do you monitor for BVD?
Do bulk milk antigen PCR quarterly
Test purchased stock
Annually test unvaccinated youngstock
How do you vaccinate for BVD? When do you do it?
Vaccinate with bovilis BVD from 8 months onwards
Or with bovela from 3months onwards
Must complete first course before first service - to prevent PI calves
When are cows most susceptible to Johne’s disease?
Calves under 6 months - become more resistant when they get older
But dont show clinical signs of infection until they are 2-5 years old - long incubation period
What are the clinical signs of Johne’s disease? What is the first sign?
Drop in milk yield - early sign
Profuse watery diarrhoea
Gluteal muscle wastage
But still bright cow with no anorexia
What is the pathogen that causes Johne’s disease?
Mycobacterium avium paratuberculosis
How is Johne’s disease transmitted?
Faecal-oral
Transplacental
Semen
Milk
How long does Johne’s disease survive in the environment?
Over 1 year in temperate conditions
But usually about 6 months
How do you diagnose Johne’s disease?
ELISA - most widely used
Faecal smear - Zeil-Neilson stain, pink acid fast bacteria
History/clinical signs
PCR
What does Johne’s disease look like on faecal smear?
Bright orange/pink mycobacterium
Appear in clumps inside macrophages - pathognomic
Can be difficult to find
What does the intestinal mucosa look like from Johne’s disease?
Corrugated - cant pull flat, not stretchy
Yellow if wash it - from toxin