Farm animal 3 Flashcards
What are the possible consequences of a poor/no pre-milking routine in cattle?
- Biphasic milk let down and inefficient harvesting
- Increased unit-on time, development of teat-end hyperkeratosis
- Increased risk of environmental mastitis infections
- Increased bacteria in milk
- Failure to detect clinical mastitis cases
Define puerperal metritis in cattle
Clinical metritis but with acute systemic illness: pyrexia, dullness, reduced yield, inappetance, tachycardia, dehydration
Define clinical metritis in cattle
Uterine disease within 21 days of parturition, most common in first 10 days
Outline the characteristics of clinical metritis in cattle
- Enlarged uterus, watery red-brown fluid to viscous off-white purulent uterine discharge with foetid odour
- +/- pyrexia
- Not as sick as puerperal metritis
Define clinical endometritis in cattle
Clinical disease beyond 3 weeks post partum
Describe the characteristics of clinical endometritis in cattle
- > 3 weeks PP
- Mucopurulent discharge detectable in vagina
- Cervical diameter >7.5cm (i.e. enlarged)
- No systemic signs of illness, generally milk well
Define subclinical endometritis in cattle
Chronic inflammation of the endometrium without clinical signs of uterine disease, but resulting in significant reduction in reproductive performance
Describe the characteristics of subclinical endometritis in cattle
- PMNs >5-18% in samples from flush or cytobrush, +/- bacteria
- No discharge
Define retained placenta in cattle
Failure to pass placenta within 24hours post-partum
Describe the characteristics pyometra in cattle
- (muco)purulent discharge in uterus, distension of uterus, presence of active CL
- Incomplete closure of cervix
- Mixed echodensity on US
- Generally not systemically ill
Outline the key features of treatment for metritis in cattle
- Systemic antibiotics (amoxicillin, procaine penicillin)
- TLC
- Fluids (oral or IV)
- NSAIDs (>1 day, e.g. flunixin)
- +/- lavage - no evidence for benefit
When is treatment for metritis in cattle indicated?
When 2 or more signs of metritis are present i.e. 2 of the following: retained placenta, T > 39.5C, dullness, inappetance, foetid uterine discharge
What is the reason for treating cows with endometritis?
In order to get cows back into calf sooner - are not systemically ill
Outline and explain your treatment approach to a case of clinical/subclinical endometritis in a cow where there is a CL present
- Administer PGF2a
- Luteolysis → increased oestrogen and myometrial contractions
- Stimulates uterine defences
- Want to encourage cycling again to expulse material preventing pregnancy establishment
Outline an explain your treatment approach to a case of clinical/subclinical endometritis in a cow where there is no CL present
- Cephapirin (aka metricure) intrauterine treatment
- Systemic antibiotics not required, but will allow cows to get into calf quicker (depending on economic benefit may be worthwhile)
Discuss the use of oxytetracycline or Lugols iodine in the treatment of endometritis in cows
- Can cause coagulation necrosis of endometrium
- Will get rid of bacteria, but damage to uterus will prevent establishment of pregnancy
Discuss the treatment of pyometra in cattle
- PGF2a, need to lyse the CL
- May not always work esp. if true closed cervix
Explain the effect of uterine infections such as metritis and endometritis on ovarian function in the cow
- Pathogen associated molecules affect release of GnRH, LH and sensitivity of pituitary to LH → cow less likely to ovulate
- Lower oestradiol concentration at time of maximal follicle diameter → less likely to ovulate
- Slower growth of PP dominant follicle
- Lower progesterone concentrations 5-7 days after ovulation (response of luteal cells to cytokines secreted by infected endometrium)
- Prolonged luteal phase
Define retained foetal membranes in the cow
Retention of foetal membranes >24 hours
What are the risk factors for retained foetal membranes in the cow?
- Twins
- Dystocia
- Stillborn calf
- Induced parturition
- Abortion
- HypoCa
- Increased age
- Seasonal effects
- Suboptimal DMI
- High PG and cortisol levels 1 week prior to parturition (i.e. stress)
Describe the pathogenesis of retained foetal membranes in the cow
- Failure of immune system to degrade placentomes (rather than lack of uterine motility)
- Low intracellular calcium affects immune function
- May result from stress, esp. in transition period
What rate of retained foetal membranes would indicate the need to investigate , and what period in particularly should be examined?
- > 5%
- Transition period i.e. drying off
Discuss the impact of retained foetal membranes in cattle
- Risk factor (endo)metritis
- Placenta itself unlikely to cause a problem
- Majority endometritis (~20-25%)
Outline the treatment for retained foetal membranes in cattle
- No effect immediately post partum with oxytocin, PG or Ca
- If systemic signs of illness, treat as metritis
- If not clinically ill and placenta easy to remove, pull out otherwise leave in place (do not peel apart caruncles and cotyledons)
Discuss the effect of body condition score on post partum uterine inflammation in cattle
- Low BCS → high neutrophil count vs those in good condition
- Older cows, higher BCS → higher neurtophil count
Discuss the role of body condition score and post-partum treatment on cow fertility
- Little effect of treatment if good BCS
- Immunity and general cow health, immune function may be indicated by BCS
- Treatment following calving less important vs. general status of cow
How are uterine infections in cows diagnosed?
- Manual vaginal exam and rectal exam + ultrasound most common in practice
- Observation of odour/discharge
- Fever
- Bacteriological culture
- Biopsy
- Cytology
Discuss the role of uterine cytology in the diagnosis of uterine infection in cattle
- PMN% is a better predictor of reproductive performance than intrauterine bacteriology or gross vaginal inflammation score
- Vaginal exam and transrectal examination alone are not valuable predictors or subsequent reproductive performance
Describe the grading of vaginal mucus in cows
- 0: clear/translucent mucus
- 1: mucus containing flecks of white or off-white pus
- 2: Exudate containing <50% white or off-white mucopurulent material
- 3: exudate containing >50% purulent material, usually white or yellow, occasionally sanguinous
Describe the grading of endometritis in cattle
- Reflects the number of pathogenic and non-pathogenic bacteria isolated from uterus of cattle, presented as CFU from uterine swab
- 0 = no growth
- 1 = <10 CFU
- 2= 10-100 CFU
- 3 = 101-500CFU
- 4 = >500 CFU
- Prognostic for treatment success
What are the main aims of treatment of uterine infection in cattle?
- Reduce bacterial load
- Enhance uterine defence and repair mechanisms
- Halt and reverse inflammatory changes that impair fertility
Outline your treatment of puerperal metritis
- Systemic antibiotics e.g. procaine penicillin, amoxycillin for 3-5 days
- NSAIDs e.g. flunixin
- Supportive treatment: fluids, warm, soft bedding, feed and water
Which pathogen causes the most severe endometrial lesions in cattle with uterine infection?
Trueperella pyogenes (synergistic with anaerobes to enhance likelihood and severity of disease)
Explain why dairy cows are more at risk of uterine infection than beef cattle
- General health, immune function and BCS determine risk of infection
- The transition period if more pronounced in dairy animals with regards to metabolic changes, and puts more pressure on the immune system
What instructions would you give to a farmer before arriving on farm in the case of a uterine prolapse in a cow?
- Protect and support uterus by wrapping in moist towel/sheet
- Restrain cow, keep her calm and comfortable
Outline the preparations you should make prior to replacing a prolapsed uterus
- Epidural
- +/-Sedative
- Ideally replace in frog-position but leave in position currently in, never in lateral
- may need to relieve tympany if bloat has occurred
- Clean perineal area and uterus with clean, warm water
- Tie tail out of the way
- Inspect uterus for lacerations
- Lots of lubricant
- Remove afterbirth if this comes away easily, partial removal if contaminated and difficult to wash clean
In a uterine prolapse in a cow, compare the management of a partial vs. a full thickness uterine tear/laceration
- Partial: only suture if likely to lead to severe haemorrhage and/or almost fully perforated
- If full thickness, suture or advice euthanasia if condition of animal is poor
Outline the method for the replacement of a uterine prolapse in a cow
- Start replacement at vulva generally
- If recent and no oedema, then starting at horn may be easier
- Manually evert horns after replacement using well lubricated arm or extension of arm e.g. bottle
Outline your post-replacement actions in a uterine prolapse in a cow
- Administer oxytocin
- Parenteral antibiotics, NOT intrauterine
- Administer NSAIDs
- Treat hypoCa in multiparous cows, preferably IV and after replacement unless severe signs and immediate tx needed
- Vaginal sutures recommended but limited evidence (Buhner pattern, remove after 4-5 days)
Outline the after care following a uterine prolapse replacement in a cow
- Monitor for straining, recurrence, anorexia, dehydration, discharge for 48 hours
- Follow up visits recommended if replacement was complicated/requested by client
- Farmer to continue treatments as directed by vet
What questions should you ask when a farmer rings regarding a (post)calving problem?
- Define the problem
- No. of calves
- Parity (i.e. heifer, second etc.)
- Any other cows affected?
- If calved, status of dam and calf
- Any treatments already administered?
- Location
- Pain, distress, recumbency?
What are the following findings on vaginal exam in a cow indicative of?
Constriction of birth canal, downwards and laterally spiralling folds of vagina
Uterine torsion
In what direction does the uterus usually rotate in cows?
Counterclockwise
Discuss the difficulties with preventing uterine torsion in cows
- Cause largely unknown
- Suggested: anatomy, slipping, butt in flank, movement of foetus, lack of foetal fluids, reduced rumen volum
- Little can be done preventatively as cause unknown
What are the treatment methods available for uterine torsion in a cow?
- Manual detorsion
- Rolling the cow
- Using detorsion rod
- Laparotomy
- Do nothing and emergency slaughter
Discuss manual detorsion for the treatment of uterine torsion in a cow
- Arm all the way in up to shoulder, aim to swing uterus using momentum
- If not working after 5 mins trying, go and get help
Discuss rolling a cow for the treatment of uterine torsion in a cow
- Must be soft-bedded pen, 1-2 helpers
- Roll in SAME direction as torsion i.e. clockwise torsion, roll clockwise
- Keep calf in same position and roll cow around calf
- Arm in cow holding calf in place, roll cow around you OR use plank of wood to keep calf in same place
Discuss the use of detorsion rods for the correction of uterine torsion in a cow
- Metre long rod with bar handle and double prong with eyelets
- Attach each presenting limb to a prong by rope/chain
- Rotate foetus along long axis by rotating handle
- Effective but puts pressure on calf’s legs, rolling of cow not necessary
Discuss the use of laparotomy to correct uterine torsion in a cow
- Only if nothing else works (likely torsion is close to 360 if this is the case)
- Uterus will be very friable: removing calf fine, but suturing closed will be difficult
- Poor prognosis
Discuss the use of epidurals during the management of uterine torsion in cattle
- Aim to perform without where possible
- Abdominal contractions will help delivery of calf
- Use when cow is straining so hard as to prevent hand getting in
Once the uterus has been corrected in a case of uterine torsion, what further management would you consider?
- Wait 2 hours: umbilical cord still normal and in place, rupturing may case more damage
- Cervix likely poorly dilated, if life, pull calf’s head through cervix, if dead, use calf’s head to dilate cervix
- Oxytocin post calving if: unsure if calf will suckle/cow can go into parlour or not, calf is dead
- NSAIDs
- Antibiotics likely not needed if easy to untwist
Discuss the prognosis for a uterine torsion in the cow
- Good if treated early, worse with time and degree of torsion
- Foetal survival ~24%, dam survival 78%
- 50-75% pregnant in next lactation
Discuss the emergency slaughter of a cow with uterine torsion
- Generally worth trying to correct
- Prognosis can be good
What are the most common complications following correction of uterine torsion in the cow?
- Retained foetal membranes
- Metritis
- Reduced conception rate
- Depends on how bad the torsion was
What is the prognosis for a uterine prolapse in a cow?
Generally very good to very poor, depending on duration, sustained injury, internal haemorrhage
Discuss the aetiology of uterine prolapse in the cow
- Mainly dairy cattle
- Pluri > primiparae
- 90% within 24 hours after calving
- Immediately after calving in delivery with heavy traction
- Abdominal straining, gravity, hypoCa (uterine inertia) dystocia
When do most cases of toxic mastitis occur in cattle and why?
- Within 1 week of calving
- Immune function poor in transition and post-calving period, infection more likely to take hold and become severe
Explain the importance of the dry period in the development of mastitis in cows
- Dry period often the origin of infection
- Key period for prevention and cure of mastitis
What are the 3 broad categories on which mastitis prevention in cattle depends?
- Preventative treatments
- Cow, farm, herd management
- Cow immunity
Outline antibiotic dry cow therapy for mastitis
- Target therapy towards G-ve bacteria
- Ubro-red: Framycetin Sulfate, Procaine Penicillin
- Prevents infection during dry period, reducing mastitis after calving
Outline non-antibiotic dry cow therapy for mastitis
- Teat sealants: Bismuth subnitrate
- Uninfected cows
- No antimicrobial activity, must infuse aseptically
- Reduces new infections caused by E coli, all enterobaceriaeceae and all major pathogens
What is meant by selective dry cow therapy and why is it important?
Select some cows to receive ABs at drying off, others just use teat sealants, in order to reduce use of antibiotics
List the risk factors for mastitis
- Individual cow susceptibility
- Previous lactation
- Bacterial interactions
- Unclean environment
- Early/late dry period management
What must be done when administering dry cow treatments?
Surgical spirit cleaning of teat ends before administration using cotton swab
Discuss the indoor environmental hygiene measures that should be taken for mastitis prevention
- Ensure good drainage
- Clean and bed cubicles daily
- Scrape feed and loafing areas daily
- Ensure bedding materials are dry in storage
Discuss the space requirements for dry cows
- 1.25m^2 per 1000L annual mean milk production e.g. 8000L needs ~10-12m^2
- Dry cows need more space than previously though
How should dry cow grazing area be managed for the prevention of mastitis?
Graze an area for 2 weeks then rest the area for 4 weeks
Discuss the calving period management for the prevention of mastitis
- Calves not allowed access to suckle other cows
- Calving pens cleaned out daily
Give an example of an area of research into the prevention of mastitis in cattle
Immune function of cows, as well as microbiome and vaccines
Outline the epidemiology of bovine herpes mammillitis
- BHV II or IV
- Sporadic outbreaks
- Often late summer in UK
- Spread by contact (e.g. calves suckling various dams) and fomites e.g. people, milking units
- Most common in first lactation
Describe the clinical signs of bovine herpes mammillitis
- Mild, small plaques of oedema to severe ulceration
- Variable early signs
- Vesicles develop and rupture
- Painful teats
Outline the treatment and control of bovine herpes mammillitis
- Supportive care only (iodophore teat dips with added emollients may help inactivate virus)
- Isolate cows
- Separate milking units, clean gloves for milking personnel
Describe the epidemiology of bovine papillomavirus affecting the teats
- BPV 1, 4, 6, 9
- Spread by direct or indirect contact
- Isolated in blood, milk, urine, other bodily fluids
Outline the diagnosis, treatment and control of bovine papillomavirus affecting the teats
- Diagnosis: presumptive based on clinical signs and exclusion of other causes
- Treatment: often not necessary, unless frond-like lesions
- Control: autogenous vaccines and virucidal dips in herd outbreaks
Describe the clinical signs of bovine papillomavirus affecting the teats
- Variable appearance
- May be pale, smooth, raised lesions that may persist without causing problems
- Or filamentous/frond-like lesions at teat orifice that interfere with milking
What pathogen is implicated in blackspot in cows?
F necrophorum
Outline the epidemiology of blackspot in cows
- Poor milking machine leads to damage to teat orifice which is then colonised by f necrophorum
- Spread by miking equipment and personnel
- Major risk factor for intramammary infection
Outline the treatment of blackspot in cows
- Teat disinfectants
- May contain emollients that help promote skin healing
Describe the lesions and consequence of cow pox on the teat of cows
- Lesions develop from erythematous lesion to pustule that ruptures then suppurates
- Heals centripetally and usually uncomplicated, takes up to 3 weeks
- Pain may prevent milking
- Life long immunity occurs
Outline the epidemiology of vesicular stomatitis affecting the teat of cattle
- Never seen in UK, notifiable
- Spread by biting insects
- Mortality moderate to low
- Can cause flu like symptoms in people, occasionally mucocutaneous vesicles and erosions
Describe the appearance and importance of vesicular stomatitis of the teat in cattle
- Notifiable, possibly zoonotic
- Clinical signs resemble FMDV, although usually unilateral
- Need to rule out FMDV in lab
Discuss FMDV of the teats in cattle
- Notifiable
- Spread by vesicular fluid, saliva, milk faeces, contaminated fomites, airborne
- Causes profuse salivation, nasal discharge as well as skin lesions
- Must notify APHA
Outline the epidemiology of teat skin Staphylococcus aureus infection
- Ubiquitous on skin
- Colonise any lesions readily
- Major risk factor for mastitis
Describe the clinical signs and prevention of Staphylococcus aureus teat skin infection
- may be purulent presenting as pustules or impetigo
- May be necrotising
- Prevention: disinfection of teats after milking
Give examples of environmentally induced teat lesions that may occur in cattle
- Chaps
- Chemical damage
- Hyperkeratosis
- Milking machine induced changes e.g. reddening, oedema, ringing, constriction at mouth piece
- Photosensitivities and allergies
- Sores/abrasions
- Lacerations
List the methods than can be used to anaesthetise cow teats for surgery
- Teat cistern infusion
- Ring blocks
- Inverted V block
- Intravenous regional anaesthesia
- Others: line block, topical splash block, paravertebral anaesthesia, lumbosacral epidural
Discuss the local anaesthetics that can be used in cattle
- Procaine: licensed, includes adrenaline, 0 withdrawal meat or milk
- Lidocaine: licensed in horse (not cattle) but can be used under cascade
Briefly outline the method of teat cistern infusion for local anaesthesia of the teat in a cow (use, structures anaesthetised, method)
- Best performed before other methods
- Anaesthetises mucous membrane lining of cistern
- Infuse 10ml local anaesthetic via teat cannula or syringe into teat cistern
- Can be used for teat polyp removal or to open sphincters
Briefly outline the ring block for anaesthesia of the teat in cattle
- 10-20ml of local into full thickness of teat in 4-6 sites around teat base
- +/- tourniquet
- Care to avoid entering teat canal and circumferential vessels
- Blocks mucosa and connective tissue
Briefly outline the inverted V block for anaesthesia of the teat in cattle
- Full thickness line block over and adjacent to affected tissue/proposed incision site
- Instil local anaesthetic in small quantities 0.5-1cm apart to provide required block
Briefly outline intravenous regional anaesthesia of the teat in cattle
- Tourniquet around teat, inject any superficial vessel with 5-7ml LA
- Analegesia occurs in 5 mins, lasts until tourniquet removed
What are the key advantages and disadvantages of a line block for the anaesthesia of the teat in cattle?
- Mulitple subcut infiltrative injections of LA 0.5-1cm apart
- Risk of oedema and haemorrhage delaying wound healing
- Can be quick and easy to perform
Briefly outline topical (splash) blocks of the teat in cattle
- Drip/splash onto site, allow 20 mins to take effect
- Useful before infiltration in fractious animals
What region of the udder is desensitised y a paraverterbral block in cattle?
Cranial udder and teats, allowing standing surgery
Discuss the use of a lumbosacral epidural for teat surgery in cattle
- Anaesthesia of the caudal abdominal wall to level of umbilicus
- Temporary dysfunction of HLs so need sedation
- Will be recumbent
Outline the aftercare following teat surgery in cattle
- Intramammary antibiotics using lactating cow tubes
- Duration of treatment depending on degree of infection risk
- Self-retaining cannula allows passive milk let down for ~7-10 days
- Or milk catheter to allow milk let down as needed
- Suture removal after 1 days
- Return to milking machine asap after surgery
- Dry off affected quarter if large amount of swelling, or animal resents milking machine
Outline the management of deep teat lacerations in cattle
- Emergency
- Best treated within 4 hours, worse prognosis thereafter, poor after 12 hours
- Clean and suture or bandage asap to reduce contamination
Outline the management of superficial teat lacerations in cattle
- Skin only, or skin and shallow muscle lacerations
- Diagnose on appearance: no milk leaking from teat canal
- Treat with bandage only after cleaning and drying wound
Outline the aftercare for teat lacerations in cattle
- Systemic and intramammary antibiotics
- Machine milking following surgery where possible, if welling not too severe
Outline the surgical technique for the management of deep teat lacerations in cattle
- Debride unhealthy tissue
- Use scissors or scalpel blade until fresh bleednig surface exposed
- Assess blood supply of flaps, remove if compromised
- If teat canal involved, requires suturing
- Mucosal layer: continuous pattern, 4-0/5-0 vicryl
- Submucosal layer: incl. connective tissue and muscle, continuous pattern using 4-0 vicryl
- Skin layer: simple interrupted or horizontal mattress, 2-0/3-0 prolene
