Shared Flashcard Set

Details

Alterations in body weight or size
asdf
43
Veterinary Medicine
Graduate
02/27/2016

Additional Veterinary Medicine Flashcards

 


 

Cards

Term
Methods of assessing weight
Definition

 

  • By eye: most owners favour this approach and their perception of weight loss is often the reason for calling the vet

  •   Body condition scoring: e.g. method of Carroll and Huntingdon 

     

    e.g. 9 point score
    o poor; very thin; thin; moderately thin; moderate; moderately fleshy; fleshy;

    fat; extremely fat

    weight tape and calculations
    o variety of tapes available

    o based on algorithms calculated from girth and/or other anatomical points weight bridge

    o most accurate but least available o regular calibration required

    •   Note that this can be a touchysubject for owners at both ends of the spectrum

    •   Owners should be encouraged to regularly condition score their horses

    •   Owner perceptions are often faulty therefore good education is required. If you are

      not confident then get a nutritionist involved 

Term
Weight loss and failure to gain weight
Definition

 

    1. Amyriadofdifferentcausesmayleadtoweightlossandfailuretothrive. Thefollowing describes a rational approach to the investigation of this common problem.

      Aetiology and DDx

Management, physiology etc:
o Poor nutrition: amounts and/or types and/or quality
o Increased metabolic demands: exercise; pregnancy; vices o Hierarchy/pecking order
o Inability to access feed
o Old age

Disease:
o Dysphagia (see lecture on Dysphagia)
o Maldigestion & Malabsorption (parasites; IBDz; neoplasia; liver disease) o Increased consumption or loss (parasites; IBDz; neoplasia; ECDz/PPID*;

EGS; renal disease; liver disease; cardiac disease; infections and sepsis;

chronic pain)

 

Term
Approach to diagnosis in the weight loss case
Definition

 

A good history and clinical examination is vital especially if there are no glaringly obvious abnormalities. However as the signs are generally non-specific, this needs to be backed up by a number of diagnostic tests which range from those that are easy to perform on a first examination, to those that require some time, thought and expense.

- age

- history of dental disease/routine floating

- feeding history

- med history

- worm history

- any diarrhea

- any lethargy?

- water intake  

Term
Age
Definition

 

  • Parasitism occurs more often (but not exclusively) in the young and problems like equine proliferative enteropathy (EPE) are only features of weanlings living in relatively crowded conditions. Neoplasia is inevitably more common in older animals. 

Term

 

  • History of dental disease/routine floating 

Definition

 

  • Importantly, this must be by a competent dentist or vet! Many abnormalities such as diastema, caudal hooks may be missed without a proper examination. 

Term
Feeding history
Definition

 

  • Amounts and types. Are they matched nutritionally to the metabolic needs? 

Term

 

  • Medication history:  

Definition

 

  • Is there any history of repeated or continual NSAID use (e.g. chronic laminitis/other orthopaedic disease)? Is the animal currently on a course of antibiotics? 

Term

 

  • Worm history’ 

Definition

 

  • Very important. Best case scenario is to obtain information relating to faecal egg counts (FEC), but remember that these do not reflect encysted cyathostome numbers, only adults. Even though the owner thinks they have a good worming regime, that may not be the case (often depends on the set up e.g. stocking density, whether faeces is picked up from the pasture). Therefore get a good history of what has been used and when, in addition to assessing the husbandry practice. Most important worm with respect to weight loss is likely to be cyathostomes and these are resistant to some anthelmintics and insusceptible to most anthelmintics in the encysted stage. Rule worms out at your folly! 

Term

 

  • Any diarrhoea noted by owner? 

Definition

 

  • : Is it persistent or recurrent? Is the consistency variable or constant? Is it generally watery or cowpat? Diarrhoea generally means large intestinal problem in the horse. 

Term

 

  • Any lethargy/malaise noted by the owner?  

Definition

 

  • It is often difficult for you to assess this feature yourself on a first visit, although it may be obvious that the horse is subdued. 

Term
water intake
Definition
has this been measured by the owner?
Term
Clinical exam
Definition

 

  • Colic/Pain: variable; may be subtle/low grade e.g. teeth grinding.

  •   Rectal temperature: In many cases of weight loss temperature will be within the

    normalrange. Howeverinsomecasese.g.cyathostominosis,peritonitisorneoplasia, there may be mild pyrexia. 

     

    • Signs of ventral oedema: This may be very subtle in some cases, comprising only a thin plaque at the sternum. Take care to look specifically for it, especially in the winter and in thick coated horse and ponies.

    •   Faecal staining on the tail and perineum: May give some indication as to the presence of diarrhoea and severity. Scalding is more likely with very frequent and very loose faeces.

    •   Other subtle signs that at first may seem irrelevant/puzzling: e.g. increased respiratory rate and skin lesions with cases of MEED (very rare disease but nonetheless does occur).

    •   Any skin lesions?: associated with some IBDs

Term
Further evaluation for a horse losing weight
Definition

a) simple cheap and quick

b) more complex, expensive, time consuming 

Term
Simple , quick and cheap evaluation
Definition

1. rectal exam

2. abdominal paracentesis

3. faecal analysis

4. haematology

5. biochemistry 

Term
Simple, quick and cheap: rectal exam
Definition

 

  • Alwaysworthwhile,notleasttoobtainafreshfaecalsample. Some intra-abdominal changes will be obvious e.g. large masses associated with abdominal neoplasia. With experience, you can pick up changes in bowel wall thickness,increasedmesentericlymphnodesizeetc. Remembertoexaminethe glove carefully as you exit the rectum for cyathostome larvae. 

Term
simple, quick, cheap: abdominal paracentesis
Definition

 

  • Not always that useful, but you would kick yourself if you omitted this very simple technique and missed peritonitis. Rarely, intra-abdominal neoplastic masses will shed cells into the peritoneal fluid. 

Term
Simple, quick, cheap: faecal analysis
Definition

 

  • Ongrossexaminationmaynoteblood,mucus,presenceofsmall redwormlarvae. Someassessmentoffibrelengthmayalsobemade,andmaybean indication of poor mastication. A full standard analysis involves laboratory examination for parasite eggs and larvae. Culturemay be warranted in some cases. 

Term
Simple, quick, cheap: haematology
Definition

 

  • Leukaemia is relatively rare in horses. However more commonly with neoplasia and with other inflammatory disease there may be a significant neutrophilia. Leukaemia is characterised by abnormal white cells in the blood, but is relatively rare in equine lymphosarcoma. As with many chronic diseases, there may be a mild anaemia. Additionally disease such as severe parasitism may contribute directly to anaemia. Other causes of anaemia are rarer. 

Term
Simple, quick, cheap: Biochemistry
Definition

 

  • Initial panel for evaluation of weight loss should include the following:

    •   Proteins (total protein albumin and globulins). Essential. Generally oedema will be

      expected where the albumin is less than 15 g/l, even if the globulins are slightly raised to maintain total protein within the normal range. This is because of its chemical properties and abundance albumin exerts the greatest influence on plasma oncotic pressure.

    •   Fibrinogen/other acute phase protein (e.g. SAA). Provide evidence of inflammation.

    •   Alkaline Phosphatase (ALP). ALP is present in high levels in the intestinal brush

      border and with significant damage will be raised. However non-specific (liver biliary cells and bone also release ALP). Intestinal form of ALP may be measured by some labs.

    •   

      Liver ‘screen’. GLDH and GGT provide information about hepatocytes and biliary tract damage respectively.

    •   Assessment of urea and creatinine for evaluation of urinary function.

    •   Further tests may be required depending on findings. 

Term
More complex, expensive: serum protein electrophoresis
Definition

 

  • May be useful in some instances to demonstrate increases in certain protein components (particularly increased beta globulins for parasites). 

Term
More complex, expensive: oral glucose absorption test
Definition

 

  • 1g/kg glucose as 20% solution. Normal result is doubling (or >85%) of glucose in 2-3h then return to baseline by 4-6h. Less than 15% absorption is strongly suggestive of severe SI pathology. Large grey area (15-85%): ~70% of these horses have an abnormality. 

Term
More complex: rectal biopsy
Definition

 

  • A standard uterine cervical biopsy instrument is suitable. Biopsies should be taken at wrist length from the dorsolateral rectal mucosa. Samples should be placed in formalin (unless for PCR) and sent to a lab experienced in examinin g equine biopsies. 

Term

More complex: 

  • Abdominal ultrasound 

Definition

 

  • A thorough evaluation will involve trans-rectal as well as trans- abdominal ultrasound. Ideally 5-10 MHz (rectal) and 2-5Mhz (trans-abdominal). Look out for increased free fluid, abnormal structures and increased bowel wall thickness. 

Term
More complex: faecal analysis
Definition

 

  • e.g. faecal occult blood. May collect samples for PCR (e.g. Proliferative Enteropathy in weanlings, Salmonella). 

Term
More complex: Nuclear scintigraphy
Definition

 

  • Has been used in a few cases, particularly in the investigation of right dorsal colitis and abdominal neoplasia. The most useful technique at present is using radiolabelledwhitebloodcells. However,this has limited usefulness at present in equine medicine. 

Term
More complex: Laparoscopy
Definition

 

  • Can be really useful and minimally invasive. Many owners will favour this above exploratory laparotomy. However this must be offset with the limited visualisation obtained, and limited ability to obtain full thickness biopsies. 

Term
More compleX: ex lap
Definition

 

  • Generally likely to provide the most useful information, allowing areas of bowel/ lymph nodes to be investigated, selected and biopsied. However this must be balanced against the cost and the risk of anaesthesia. If cryostatic examination of biopsy material is available close-by then this can facilitate a quick decision for euthanasia rather than allowing recovery. 

Term
Symptomatic treatment of weight loss
Definition

1. assess weight and set date for re-evaluation

2. Dietary change

3. Stop/start any long term medication

4. Anthelmintic therapy 

Term
Dietary change
Definition

 

Ad lib good quality grass, hay, haylage
o High Energy feed e.g. sugar beet, youngstock mix, veteran diets, add oil to ration 

Term
Stop/start any long term medication
Definition

 

  • For example phenylbutazone may

    be a potential cause of colitis or protein loss. Alternatively chronically lame horses will lose weight due to chronic pain and/or impaired eating habits. In this scenario, some analgesia may improve weight gain. 

Term
Anthelmintic therapy
Definition

 

  • It is probably always worth giving larvicidal doses of anthelmintics, despite the apparent adequacy of an anthelmintic regime. In cases where there is a high suspicion of cyathostome infestation, then using either a single dose of moxidectin or the older regimen of a repeating regime of 5 day fenbendazole followedbyivermectinonthesixthdaymaybeused. Thisregimeisrepeatedatten day intervals for three treatments (moxidectin can also be used in this regimen, but it is only used twice on days 6 and 36). This repeating regimen is not licensed, but is followedbymanypractitioners. Itmaybeprudenttoadministersteroids(1mg/kg prednisolone) concurrently to minimise inflammation associated with any worm death/emergence, and encourage further worm emergence and therefore susceptibility to the anthelmintics. 

Term
What is the equine metabolic syndrome?
Definition

 

  •   Term currently used to describe and explain obese horses or ponies prone to laminitis.

  •   Also known (older terms) as peripheral Cushing’s disease and obesity dependant

    laminitis.

  •   The term Equine Metabolic Syndrome (EMS) was proposed due to similarities in

    pathophysiology between horses at risk of laminitis and humans afflicted with the Metabolic Syndrome, at risk of cardiovascular diseases such as myocardial infarction and cerebrovascular stroke.

Insulin resistance may be a key factor: 

Term
How do we recognise the EMS and obesity?
Definition

 

If an animal is obese and suffers recurrent bouts of laminitis then it probably has underlying metabolic predisposition to the obesity and the laminitis. Similarly any horse or pony with unexplained laminitis (e.g. no underlying colic, metritis etc) should be considered as metabolically at risk and therefore potentially included in the syndrome EMS. Examples would include those animals that develop laminitis post vaccination or following exogenous steroid administration. 

Term
MEasures of insulin sensitivity and glycaemic status
Definition

 

Insulin resisitance is thought to play a major role in EMS. Avarietyoftestsmaybeusedto examine insulin and glycaemic status and in individuals. 

Term

 

Fasting glucose and insulin: 

Definition

 

This may be carried out in conjunction with tests to rule out ECD. Starve of concentrates for 12 hours prior to test. Water and grass hay may still be fed up until the sampling without invalidating the test. Increased levels of insulin provide evidence of insulin resistance, while increased glucose levels in a non-stressed individual suggest severe IR/type 2 DM (usually ECD!) 

Term
Oral glucose tolerance test
Definition

 

  • Horse or pony is starved of concentrates for 12 hours before test. Water is removed 1 hour prior to test.

  •   1g/kg glucose is administered as a 20% solution.

  •   Blood glucose and insulin levels are tested prior to administration and at 30, 60, 90,

EXOG. STEROIDS STRESS

[image] [image] [image] [image]

120, 150, 180, 240 minutes. 

Term
Interpretation of oral glucose tolerance test
Definition

 

Blood glucose should double within two hours and reduce to normal levels within 6 hours. Increased peak in glucose (>11.1mmol/l) or delay to return to normal levels (i.e. longer than 6 hours) is indicative of relative insulin resistance. Be aware of other conditions which could affect this test e.g GIT function. Evaluating the insulin levels as well as glucose gives more information. It has been suggested that an I:G at 90 minutes may be a convenientparametertotestforinsensitivity. I:G>0.3-0.5maysuggestrelativeinsulin resistance. Total insulin secretion is also raised with insulin resistance. Note when also looking at insulin, that animals with type 2 DM will have low/normal insulin and high resting glucose and glucose responses. 

Term
Other tests used for EMS
Definition

 

  • Intravenous Glucose Tolerance Test (IVGTT)

  •   Insulin Tolerance Test

  •   Combined Intravenous Glucose and Insulin Tolerance Test (CGIT)

o Currently recommended as the most suitable dynamic test in clinical practice

  •   Proxies based on resting insulin and glucose e.g. 1/square root insulin

  •   Hyperinsulinaemic/Euglycaemic Clamp 

Term
How do we treat/manage EMS
Definition

 

  • Control of calorific intake combined with...

  •   Judicious exercise in those individuals where this is possible.

  •   If there is an identifiable underlying cause, then this should be treated appropriately.

    ForexamplethoseanimalswithECDshouldbetreatedwithpergolide. Howeverin many cases, animals will be negative clinically and following tests for ECD. 

Term
Feeding for EMS
Definition

 

  • Feeds with a low glycaemic index should be chosen.

  •   Complete starvation should be avoided (promotes a survival mode of increased insulin

    resistance,thuspotentiallyworseningthesituation). Alsocarereriskof hyperlipaemia.

    • Rich grass should be avoided in these animals as sugar content can be unacceptably high, particularly at some times of the year.

    •   The restricted grazing practice must be balanced with the need for exercise, therefore use of grass muzzles or night grazing may be advantageous

    •   Grass hay is generally good but may be variable in soluble carbohydrate/sugar content therefore best practice is to encourage owners to have it analysed for non structural carbohydrate (NSC i.e sugar content).

    •   Soaking hay (12 hours optimal) may also reduce soluble CHO as it gets trapped in the water.

    •   If further feeding is required then use other low GI foods. For example sugar beet (mustbeunmollassed)hasaverylowGI. Alfalfachaffissimilarlyagoodextraration, and for older ponies with bad dentition, the short chopped alfalfa feeds can be very useful. Alternatively there are now some good compounded feeds specially designed for laminitics (e.g. Safe and Sound, Dodson and Horrell)

    •   There is some evidence to suggest that antioxidant therapies aid dysfunction in human diabetics and others at risk of cardiovascular diseases. Based on this, and as it is unlikely to do harm, it may be sensible to advise supplementation with antioxidant vitamins e.g. Vit E, Vit C. Owners generally like supplementation! Note however that the compounded feeds generally have added micronutrients.

    •   It is worth considering consulting a nutritionist. At the very least, you can encourage the owner to contact e.g. Dodson and Horrell for forage advice. They will analyse hay for ~£5 and give some idea of the nutrition content of the hay 

     

Term
Exercise
Definition

 

  • May improve insulin sensitivity

  •   Can be difficult if active laminitis

  •   Placing an animal out to grass in theory is beneficial, but can be difficult at the high-

    risk times of year (anytime but the deep of winter!). However devices like grazing muzzles are freely available in most tack shops. Remember that fructans and other sugars are highest in the grass during the daytime therefore night grazing may be an option. Owners can be averse to this idea, as they feel that their ponies should be locked up at night when they are, but it represents a good compromise! 

Term
MEdications for EMS
Definition

 

  • Humans with obesity and type II diabetes are often treated with oral hypoglycaemic agents e.g. Metformin, which enhances glucose uptake by cells, but unlike some other drugs used for human DM, will not cause hypoglycaemia. Trials in horses are underway but results equivocal.

  •   Thyroid supplementation has erroneously been administered to many obese laminitics in the belief that the animals were suffering from hypothyroidism. This is unlikely to be the case in the majority of animals. Nevertheless it may be that thyroid supplements could be an aid in the short term to help lose weight.

  •   Steroidogenic inhibitors?/thiazolidones...under evaluation in humans. 

Term
Prevention of EMS
Definition

 

  1. As with all animals, exercise combined with a diet appropriate to that level of exercise is optimal for a healthy individual. Despite this, animals will still get laminitis but measures such as these throughout the equine population as a whole should lead to an overall decrease in incidence of laminitis. One should always be aware of at risk individuals and manage appropriately. Itremainstobeseenwhetherepidemiologicalstudiescouldshowfamilial associations, however this would make sense from human work. 

Supporting users have an ad free experience!