Epidemiology of EQ colic

What is the expected incidence of colic in a population and how common are surgical & medical colics?

• 3-10% overall incidence/ year

• Most episodes undiagnosed / spasmodic

• Only 7-9% surgical

What is colic?

Clin sign of abdo pain —> usually related to GIT

Important to differentiate from non-GI causes (“false colic”)

Why is knowledge of epidemiology of colic important?

• Diagnosis & early surgical management if needed

• Prevention of colic & its recurrence

How is colic classified (broadly)?

• Horse level risk factors

• Management level risk factors

List some of the horse level risk factors for colic in general

• No clear age, breed or sex predilection overall

  • Specific types have specific risk factors

• Crib-biting/ wind sucking behaviour identified for Epiploic foramen entrapment (EFE), Simple Colonic Obstruction and Distension (SCOD), Recurrent colic

• Weaving for recurrent colic

List some of the managment level risk factors for colic in general

• Inc in certain geographical locations for specific types:

  • Sand colic

  • Enteroliths

  • Grass sickness

  • Idiopathic Focal Eosinophilic Enteritis (IFEE)

• Seasonal patterns —> most decr. in summer months

• Feed types/ feeding practices (incr. conc., change, specific feed types)

• Stabling & access to pastures —> incr stabling/ decr pasture turnout → risk factor for:

  • colic in general

  • SCOD, large colon volvulus (LCV), EFE

  • large colon impaction

• Dental care

  • SCOD ass. w/ horses with less freq checked teeth

  • LCV risk incr. in horses w/ known dental problem

  • known dental problem more @ risk of recurrent colic

  • Donkeys w/ dental dx @ incr. risk of LC impactions

• Parasites & anthelmintic admin

• Access to water, transport, exercise, owner/carer

Which types of colic are ass. w/ anoplocephala perfoliata?

• Spasmodic colic

• Ileal impaction

• Caecal intussuseption

What are the risk factors for recurrence of colic?

• Known dental problem

• Crib biting /windsucking

• Weaving —> swaying head from side to side and shifting weight back & forth between FLs

• Time @ pasture

Explain the epidemiology & risk factors of pendunculated lipoma strangulation

• Older horses & ponies >8yo

• Ponies > horses

• Geldings > mares

• Welsh breed ponies

• Prior laminitis & incr. stabling

• SI most common

  • Occ. small colon & other sites

Explain the epidemiology & risk factors of large colon volvulus (LCV)

• Mares post foaling

• Larger horses

• Incr stabling

• Dental dx

• Feed, esp. changes

Explain the epidemiology and risk factors of large colon impaction

• Change in management —> stabling

• Autumn / winter

• Box rest —> motility & water balance

• Straw bedding

• Good prog

  • poss worse in donkeys & older animals

Explain the epidemiology and risk factors of epiploic foramen entrapement (EFE)

• Seasonal —> Dec, Jan, Feb

  • Incr. stabling

  • Other factors —> feed, turnout etc.

• Crib biting / wind sucking behaviour

What are the risk factors for mortality in colic?

• Resection length

• PCV

• Duration of surgery

• Post operative complications

  • Ileus, surgical site infection, jugular thrombosis, reflux, post operative colic, duration of AMs following surgery

  • Risk incr. w/ incr. HR or PCV on admission

What is equine grass sickness (dysautonomia)?

Polyneuropathy affecting central & periph NS of horses —> clin signs related to neuronal degen in autonomic & enteric NS

Varying degrees of severity —> extent of neuronal degen

How is equine grass sickness diagnosed?

• Clinical signs

• Histo

  • Ileal biopsy (surgery)

  • PM exam

How does acute / subacute grass sickness present clinically?

• Colic

• Reflux

• Tachycardia

• SI distension

• Sweating

• Salivation

• Difficulty swallowing

• Ptosis

How does chronic grass sickness present clinically?

• Weight loss

• Dysphagia

• Tachycardia

• Patchy sweating

• Muscle fasciculation

• Rhinitis sicca

• ‘Elephant on a barrel’ stance / ‘greyhound’ like

Explain the epidemiology of grass sickness

• 2.1 episodes per 100 horse years at risk

• Prev. outbreaks on premises incr. risk

• Young horses 2-7 years old

• @ pasture

At what time of year does grass sickness more commonly occur?

• Spring —> esp. April / May

• Also peak in Autumn in certain year

NB—> regional → more common in North & Scotland

What are the management risk factors of grass sickness?

• Access to grass —> longer time @ pasture

• Recent change in pasture

• Pasture disturbance (e.g. mechanical removal of droppings)

• Element levels in soil

What is the aetiological theory of the cause for grass sickness?

Toxico-infection with C. botunilum type C or present in GI tract & risk factors trigger toxin