Nutrition Flashcards
what are the 2 classes of dietary sensitivities?
immunologically mediated
non-immunologically mediated
what are the 2 classes of non-immunologically mediated dietary sensitivities?
repeatable
non-repeatable
what is an example of a non-immunologically mediated, repeatable dietary sensitivity?
food intolerance
what is an example of a non-immunologically mediated, non-repeatable dietary sensitivity?
dietary indescretion (gluttony)
intoxication
contamination (poisoning)
what is an immunologically mediated dietary sensitivity also known as?
food allergy (hypersensitivity)
can you have a non-immunologically mediated food allergy?
no
can food allergies be proven?
often suspected but rarely proven
what is a food allergy?
an immunologically mediated, adverse food reaction to a dietary component
what type of molecule usually triggers adverse food reactions?
proteins
why aren’t AFRs more common than you’d expect for an organ so exposed to foreign antigens?
defence mechanisms are in place to reduce likelihood of an AFR
explain the concept of ‘oral tolerance’
a complex series of signalling and processing events resulting in tolerance of foreign antigens
what happens when ‘oral tolerance’ fails?
adverse food reaction occurs
broadly, why does an adverse food reaction occur?
failure of ‘oral tolerance’ - a response is triggered
which body systems usually display the clinical signs of an AFR?
dermatological and/or gastrointestinal systems
what do adverse food reactions commonly manifest as?
delayed hypersensitivity (type 4)
what are the most common food allergens in dogs?
beef
dairy products
wheat
what are the most common food allergens in cats?
beef
dairy products
fish
which allergen causes canine epileptoid cramping syndrome?
wheat
what are the common cutaneous signs of a food allergy?
pruritus/erythema
what are cutaneous signs of a food allergy often identified as?
atopy and flea allergy
what is atopy?
skin reaction due to external factors e.g mites/fleas
can cutaneous signs present without GI signs?
often
what are the GI signs of a food allergy?
vomiting, diarrhoea
why can it be difficult to diagnose a food allergy from GI signs alone?
non-specific - need to differentiate from other causes
what is the systemic sign of a food allergy?
signs associated with anaphylaxis
what is the common clinical presentation of a patient with a food allergy?
younger pets (any age possible)
large intestinal pattern diarrhoea
other causes of clinical signs have been excluded where appropriate
after what age do we become less suspicious of a food allergy over other causes?
after age 10
what are the main stages of diagnosis/management of a food allergy?
exclusion/limitation
challenge and rescue
provocation and rescue
maintenance
what is involved in the exclusion/limitation stage?
consumption of prescribed foods and water only
what is involved in the challenge and rescue stage?
re-introduction of normal diet
what is involved in the provocation and rescue stage?
addition of 1 new food type at a time and monitoring symptoms
what is involved in the maintenance stage?
maintenance on food which aids symptoms
should blood tests be performed for suspected food allergies?
blood testing for GI manifestations of food allergies/sensitivities has no clinical utility
how long before we would expect to see an improvement in cutaneous signs?
up to 10 weeks
how long before we would expect to see full resolution of GI signs?
~6 weeks
what are chronic inflammatory enteropathies?
group of diseases with chronic (gastro-)intestinal inflammation
what are the symptoms of a CIE?
any of - vomiting, diarrhoea, dysorexia, weight loss
~3 weeks duration
what is dysorexia?
abnormal appetite
what must occur before diagnosis of CIE?
exclusion of other causes of clinical (GI) signs/inflammation first
what extra-GI diseases might cause similar symptoms to CIE?
exocrine pancreatic insufficiency
local abdominal inflammation - pancreatic/hepatic/renal
metabolic causes
which metabolic dysfuctions should be ruled out before CIE diagnosis?
portosystemic shunts
hypoadrenocorticism (addisons)
hyperthyroidism
which tests can we use to rule out other causes before CIE diagnosis?
lab tests - faecal analysis, bloods
imaging - AUS
what are the possible causes of CIE?
food responsive disease
antibiotic responsive disease
idiopathic disease
how can we confirm food-responsive CIE?
diet trial
how can we confirm antibiotic-responsive CIE?
only considered in certain breeds e.g. GSD
how can we confirm idiopathic CIE?
endoscopy to diagnose/confirm and exclude other microscopic/structural disease
how does idiopathic CIE usually occur?
usually immune-mediated
what were idiopathic CIEs originally referred to as?
inflammatory bowel disease
what causes the symptoms of idiopathic CIEs?
loss of tolerance to the mucosal flora in the intestinal tract
what type of disorder is an idiopathic CIE?
immunological
what can we see on endoscopic biopsy which confirms idiopathic CIE?
inflammation - various types
architectural changes - villi atrophy
what are the route options for intestinal biopsy?
laparotomy or endoscopy
what are the advantages of taking biopsies via laparotomy?
enables multiple full-thickness biopsies
enables full exploration of other organs
what are the disadvantages of taking biopsies via laparotomy?
surgical risk of dehiscence (~10%)
risk of peritonitis, sepsis
what are the advantages of taking biopsies endoscopically?
minimally invasive, small mucosal biopsies
what are the disadvantages of taking biopsies endoscopically?
may not reflect jejunal disease (can’t access via endoscope)
what are the consequences/complications of CIEs?
dehydration
protein malabsorption (protein losing enteropathy)
hypocobalaminaemia
GI haemorrhage +/- anaemia
GI perforation (rare)
what can protein losing enteropathy result in?
hypoalbuminaemia
what are the clinical signs f hypoalbuminaemia?
effusions - pleural and peritoneal
oedema
thromboembolitic events
what can GI perforation lead to?
septic peritonitis - life-threatening
what are the types of supportive/standard therapies for CIEs?
fluid balance
nutritional management
anti-emetics/appetite stimulants as required
immunosuppression
what might nutritional management of CIEs look like?
dietary modification, exclusion diet
tube feeding initially in severely affected patients, considering dietary suitability
what is typically used for immunosuppression in idiopathic CIE patients?
prednisolone - minimum effective dose
what other drugs might be given as part of management of idiopathic CIEs?
fenbendazole
metronidazole
vitamin B12
anti-platelet drugs
what are the general principles for dietary trials?
feed exclusively with water min 3-10 weeks
don’t confuse with ‘sensitive’ GI diets
why might other disease response to dietary trials?
started feeding highly digestible, high quality diet may result in resolution of other symtoms
what are the main options of food intolerance/sensitivity trials?
novel protein/carbohydrate
hydrolysed protein
can homemade diets be used for food intolerance/sensitivity trials?
most are not fit for purpose
what are our main nursing considerations for patients with food sensitivities/intolerances?
hydration status
management of inappetence/nausea
nutrition/malnutrition status
abdo discomfort
hypoproteinaemia
diarrhoea/faecal scold - patient hygiene
how can we monitor patient nutrition while hospitalised?
record food intake - hospital charts
monitor body condition/weight, consider effect of fluid balance
when should we consider nutritional support for hospitalised patients?
<80% RER voluntary intake (over 2-3 days)
> 10% BW loss (after fluid balance)
> 3 days hyporexia
severe underlying disease e.g. trauma, sepsis, severe burns
how much BW change is possible day to day due to weight loss?
only 1% per day - rest is fluid balance
how else can we manipulate the diet/feeding to help patients with food sensitivities/intolerances?
feeding frequency/posture - consider raised feeding
low fat
supplemented fibre in large bowel/colonic disease
why might a low fat diet be advantageous for these patients?
facilitates gastric emptying
good for reflux/regurgitation
why might patients with sensitivities/intolerances experience abdominal discomfort?
GI pain - dilation, ulceration
reflux pain
which medications might be given to help patients with GI pain?
omeprazole
sucralfate
how can we help patients with reflux pain?
manage oesophagitis
postural feeding
why should opioids be avoided in patients with CIEs?
they slow peristalsis - may exacerbate/cause ileus
how can we help avoid diarrhoea scalding?
keep behind as clean and dry as possible
topical barriers e.g. cavilon spray
avoid patient grooming
tail bandages
absorbent bedding (not vetbed-scratchy)
what are the monitoring considerations for patients with food sensitivities/intolerances?
weight and appetite
demeanour
vomiting/diarrhoea - record nature and quantity
hydration/volaemic status
HR/RR
comfort levels
blood/electrolytes
why is clinical nutrition important?
vital for good patient management
reduces morbidity and mortality rates
reduces length of hospitalisation and complications
how would you assess for malnutrition in a patient?
muscle condition
body condition score
unexplained weight loss >10% BW
poor coat condition
what are the risk factors for malnutrition?
severe underlying disease
large protein loss
burns
head trauma
what happens during simple starvation?
normal metabolic adaptations-
utilisation of glycogen stores
conservation of protein
fat usage increased
what happens in the body during stress starvation?
hypermetabolism
breakdown of protein/muscle wastage - catabolism
less time to state of malnutrition
cachexia
what is cachexia?
muscle loss in the presence of disease
what does stress starvation ultimately result in?
poorer prognosis for recovery, particularly if not managed quickly
what should be managed first with malnutrition, before short-term aims are addressed?
address hydration, electrolytes and acid-base balance, manage pain
why is it important to manage pain when providing supportive clinical nutrition?
pain slows gut motility
what are the short-term aims of supportive clinical nutrition?
provide for any ongoing nutritional requirements
prevent/correct ant nutritional deficiencies/imbalances
minimise metabolic derangements
prevent further catabolism of lean body mass
what should long-term nutritional aims for supportive clinical nutrition include?
restoration of optimal body condition
provision of required nutrients to the animal within its own environment
what are the 4 main type of assisted enteral feeding tubes?
naso-oesophageal/gastric - short term
oesophagostomy
gastrostomy
jejunostomy
how long should an NO/gastric tube be in place?
no longer than 5-7 days
can an RVN place an NO/gastric feeding tube?
yes (under instruction)
what factors influence choice of assisted enteral feeding technique?
patient - tolerance, anaesthesia risk, duration required
technical - clinician experience, risk of complications, type of diet
owner - cost, ability to use at home if required
what is re-feeding syndrome?
complex metabolic derangements that occur when enteral/parenteral nutrition is fed to severely malnourished patients, or those following a period of prolonged starvation
why is it important to consider re-feeding syndrome?
patient needs time to adjust to food again - changing from catabolic to anabolic state
potentially fatal complication
what metabolic changes occur due to sudden increased insulin?
severe hypophosphataemia
hypokalaemia
hyponatraemia
hyperglycaemia
hypocalcaemia
what are the clinical signs of re-feeding syndrome?
cardiac failure
respiratory failure
neurological dysfunction
peripheral oedema
haemolytic anaemia
why do clinical signs associated with re-feeding syndrome occur?
due to metabolic derangements
how can we minimise risk of re-feeding syndrome?
only commence feeding once patient is haemodynamically stable (fix fluid/electrolyte defects)
risk assessment regarding malnutrition
gradual introduction - micro-enteral nutrition
tube feed until patient voluntarily eating >85% of calculated energy requirements daily
what is micro-enteral nutrition?
delivery of small amounts of water/electrolytes/readily absorbed nutrients directly into the GI tract
using oral rehydration fluid (oralade/lectade)
how long should it take to get to feeding full RER if patient has been anorexic <3 days?
3 days
day 1 = 1/3rd RER
day 2 = 2/3rds RER
day 3 = full RER
how long should it take to get to feeding full RER if patient has been anorexic >3 days?
5 days
day 1 = 1/4 RER
day 2 = 1/2rd RER
day 3 = 2/3rds RER
day 4 = 3/4 RER
day 5 = RER
what is parenteral nutrition?
provision of nutrition via the IV route when enteral nutrition is not possible
why is parenteral nutrition rarely used?
it is a highly skilled practice with multiple possible complications
human evidence shows may worsen outcomes if not managed appropriately
only suitable for selected patients
what is the first line of nutritional support?
supported enteral nutrition
what are the solution components for TPN?
lipid
amino acids
carbohydrate (dextrose or glycerol)
how should TPN lines be managed?
peripheral lines must only deliver the PN solution
monitor twice daily for phlebitis/infection at cannula site
manage PN mixtures to avoid separation of solution
what complications should be monitored for during TPN?
metabolic complications (most common)
mechanical e.g. occlusion of dislodgement, patient interference
septic - maintain aseptic techniques
what grams/ratios should be in TPN mixture?
calculate for RER
dogs: 4-5g protein per 100kcal then 50:50 lipid:dextrose
cats: 6g protein per 100kcal then 50:50 lipid:dextrose
which conditions have decreased requirements for TPN?
hepatic/renal failure
which conditions have increased requirements for TPN?
protein-losing conditions
sepsis, buns, head trauma
what preventative measures should be put in place to avoid complications during TPN?
experienced personnel involved with all aspects of the process
clear protocols and procedures in place for staff to follow
aseptic techniques
prevent patient interference
regular monitoring and recording
why might owner choose raw/vegetarian/vegan diets for their pets?
personal opinions/beliefs
‘cheaper’
social media influence
allergies/sensitivities
closer to ‘natural’ diet of wolf
more natural, less processed
looks more appealing
human-animal bond
mistrust of food companies
what does BARF stand for?
bone and raw food/biologically-appropriate raw food
why is raw feeding found to be growing in popularity in the UK?
perceived to be ‘healthier’
avoids ‘problematic’ ingredients
health benefit claims
value of time spent preparing food
distrust of pet food industry and ‘processed’ foods
why is a ‘wild diet’ not appropriate for domestic dogs?
domestic dog is genetically altered from wild counterparts
have increased capacity for starch digestion
greater longevity
what are the risks of feeding a RAW diet?
imprecise nutritional measurements
risk of GI perforation, bone impaction in GI tract
low vitamin and mineral content
microbiological infection
issues with sources - e.g. gullet tissue hyperthyroidism
what are the microbiological infection risks involved in raw feeding?
salmonella commonly investigated
listeria, toxoplasma, crypto, mycobacterium bovis
toxicara larvae - humans are paratenic hosts
does the WSAVA recommend raw feeding?
currently no properly documented evidence of health benefits for raw feeding, but there are well-documented risks
recommends against
does the BSAVA recommend raw feeding?
claims important to consider pros and cons
says raw diets can be safely fed provided assurance of nutritional adequacy is confirmed and sufficiently high levels of hygiene are met
what is the Raw Feeding Veterinary Society’s stance on raw feeding?
claims health benefits have been researched and documented
outdated studies on microbiological risks
lack of evidence to support risk of ingested bones
refutes claim of nutritional inadequacy
what does RMBD stand for?
raw meaty bone diet
what are the key considerations for discussions with owners wanting to feed alternative diets?
why do they want to feed an alternative diet? - dispel misconceptions, understand their perspective
discuss importance of risk management with them
how can we discuss risk management for raw diets with owners?
individual assessment of patient
assessment of home environment/children/immunocompromised
appropriate sourcing/preparation
monitoring
what advice can we give owners about source selection for raw feeding?
irradiated diets to remove some pathogens
not ground meat - more risk of surface bacteria, more processing
cook food prior to consumption
scrupulous hygiene
regular antithelmintic therapy
home freezing not effective against bacteria
what temperature is sufficient to kill bacteria in raw food?
74 C
why are vegetarian diets not usually appropriate for domestic animals?
cats and dogs have increased protein requirements compared to people
limited essential amino acids in vegetable protein
essential feline dietary nutrients - generally have animal source
why are commercially available vegetarian/vegan diet still inappropriate?
vast majority nutritionally inadequate
tend to have decreased palatability, digestibility and biological value
how can we consider the clients perspective in conversations around raw feeding?
inappropriate to simply dismiss clients wishes - need to ensure supportive conversation
educate owner of risks and how to manage - individual tailoring with professional advice
what general considerations should we have during conversations around alternative diets?
consult with professional peers in practice
consider practice position
individualised advice and support for owners - show empathy, respect, without judgement
make sure always taking an evidence-based approach
