Clin Med - Food Animal GI

drraythe's version from 2016-03-14 20:58

Anatomy & Fxn

Question Answer
Name the compartments of the stomach of a ruminant in orderRumen
(Where’s the access point of the rumen externally?)Lft paralumbar fossa
Which part of the stomachs is up against the liver?Reticulum
What should you know about the motility of the esophagus in ruminants?Peristalsis in both directions regularly (rumination reqd reverse peristalsis)
What is the pH like when the rumi is fed grass? Grain?Grass: 6.5-7.5
Grain: 5.5-6.5
What 3 main purposes do rumi microflora have?(1) Cellulolytic - To digest fiber & structural CHO (micro have cellulose, rumi doesnt)
(2) Amylolytic - To digest starch/grain & non-structural CHO
*What are the 3 main volatile fatty acids?Butyric acid
Propionic acid
Acetic acid
(there is also Formic acid)
What are the MOST COMMON BACTERIA in the reticulorumen? (2 types)OBLIGATE ANAEROBES & facultative anaerobes (G-& G+, responsible for producing the VFAs)
What 1 specific FACULTATIVE ANEROBE is in the reticulorumen & why do we care about it?Strep. Bovis!!!! It is a G+ Coccus which is responsible for producing LACTATE
What is a methanogen?A methane gas producing microflora
What do the VFAs provided by the microflora do for the ruminants? What other things can the microflora provide for the rumis?The VFAs provide the rumi w/ energy. When the microflora die, they become a protein source for the rumi. Also, the micro. Produce Vitamin B1 (thiamine-important for neuro. fxn) → this is all SYMBIOTIC MUTUALISM
What’s the main fxn of the omasum?Water absorption
Fun fact: Up to _________% of dry weight of feces is composed of microbes50%
Describe how the stomachs of a young ruminant develop as it ages (less than 4 weeks, 5 weeks, 8 weeks, mature) what encourages rumen growth?VFAs encourage rumen growth
Less than 4 weeks there is no fxnal rumen-Abomasum is 50 – 70% of total stomach!
5wk they can use grain & hay
8wk the abomasum is only 30% of total capacity & when mature the abomasum is only 9% of the capacity of the stomach
At birth, what is the % capacity of the rumen & the abomasum? How about at maturity?BIRTH: Rumen is 30% & abomasum is 55%
MATURITY: 80% is rumen & 10% is abomasum
What is the esophageal groove & how does it work?This is a groove that allows milk to bypass the still non-fxning reticulorumen in baby rumis. It is stimulated by suckling
What does renin do & where is it in who?There is an enzyme called renin in the abomasum of calves which clots milk & slows its passage through the GI so the calf has time to digest the milk
**What governs gastrointestinal motility? → NEURAL CONTROLS? (2)(1) VAGAL NERVE (X)
(2) Myenteric plexus
**What governs gastrointestinal motility? → 5 main factors
Neural control
Hormonal influences
Physical factors
**What governs gastrointestinal motility? → 7 things which are INHIBITORY to gastric motility?General anesthesia
Endotoxins (← these affect the gastric center in the medulla oblongata)
Splanchnic pain
Chemoreceptors in rumen for VFAs
**What governs gastrointestinal motility? → 3 things which are EXCITATORY/STIMULATORY to gastric motility?(1)↓ tensile receptors
(2) Buccal receptors in pharanx & mouth = oropharyngeal cues
(3) Abomasal chemoreceptors - pH in abomasum too ↓, needs to ↑ pH, so rumen fluid released to dilute out HCl
(Whats a tip she told us to help stimulate a rumi to eat if it wont?)If it isnt eating, you can scrunch up some grass, put it in the mouth & use your hands to make it "chew" & this will actually stim a little bit of motility

Physical Exam + Some Critical Thinking

Question Answer
Whats Deglutition?Act of swallowing
Since the GI is mostly a serious of tubes, always keep in mind that problems can be... (3 types)Extraluminal
What are some other types of diagnostics which you can use to investigate the rumis GI system, aside from your regular PE?OBSERVE THE MOUTH!
Diagnostic imaging
Orogastric intubation
You can give Ddx diagnoses in broad a basic categories, like: (4)Hx
Body systems
DAMNIT-V (Degenerative/Developmental, Anomalous, Metabolic, Nutritional, Inflammatory, Traumatic, Vasculogenic)
High-pitched ping versus a low-pitched pongBloat is a pong
Ping is probably something like a displaced abomasum/small intestines which are trapped & distended
Think about what this might be → a really dirty cow comes into your clinic covered in loose fresh fecesGI system, most likely sm/lg int or cecum, maybe animal is in really filthy conditions, musculoskeletal-they just aren't getting up. Diarrhea w/ liver PTxs
Think about what this might be → cow w/ empty sunken rumenOral cavity, obstruction caudal to rumen, MS system (cant get up to get food)
Think about what this might be → a cow w/ a mildly distended abdomen & a clear ↑ pitched ping in the L upper abdomenCould be bloat...but bloat is often a low-pitched sound (more of a pong than a ping). Anatomical change? (Displaced abomasum, small intestine thats trapped & distended)
Think about what this might be → a cow w/ green nasal discharge, distressed & coughing occasionallyResp. system, choking, maybe esophagus cant swallow or eructate
Think about what this might be → cow w/ profuse PtyalismChoking, Nervous system (Rabies)
Think about what this might be → neonate less than 24h old, w/ a distended abdomen, rolling & vocalizingGI (could be rumen, rumen milk drinker), less than 24hr so could have atresia coli/recti. Maybe meconium stuck
Think about what this might be → neonate at 10 days of age, w/ a distended abdomen, rolling & vocalizingWont be atresia’s bc already made it to 10 days
When you are looking at the body, why do you care about symmetry?Abdominal asymmetry might indicate bloat!

Critical Thinking Cases

Question Answer
If a ruminant has PROJECTILE VOMITING, how common is this? What if it also has neuro signs like ataxia/trembling/convulsions? & bradycardia? What are you thinking?VERY RARE for rumi to vomit! Only a few things cz this. w/ Rhododendron toxicity there is Gryanotoxins
What are the CS of gryanotoxicity?Depression
Fall in milk production
Intense abdominal pain
Teeth grinding
Hyper salivation
Nasal discharge
Elevated rectal temp
Weak thready pulses
Cool extremities
What does the hematology of gryanotoxicity look like?Leukocytosis w/ neutrophilia & lymphopenia (stress leuko) & elevated PCV
What does the chemistry results of gryanotoxicity look like?HYPERglycemia
Hyperproteinemia w/ hyperalbuminemia
Azotemia characterized by elevated CREA & BUN
Explain how Rhododendron toxicity w/ the gryanotoxins affects the nervous system (mechanism not CS)Makes the Na+ pumps in excitable tissues more permeable, maintains a state of depol bc of it, Na exchanged for Ca, change in NT release & mm cell fxn
How do you treat Rhododendron toxicity?Remove from the diet (duh). Flush rumen-maybe a rumenotomy? Charcoal, oil? Atropine, supportive care
What’s a good way to pick out a sick cow from a herd, just by looking out at the field?It puts itself away from the herd if it's worried about dying
What are some CS of bloat?Bloat
Resp distress
Not eating or drinking
Separated from herd
njected conjunctiva/MMs
Explain how acidosis & absorption of VFAs relateThe acidosis of the rumen actually encourages FAST ABSORPTION of the VFAs (bc they disassociate bc theyre buffering compared to the super strong acid of lactic acid) & dissociated move faster across cell membranes
How do VFAs & rumen motility relate?VFA receptors in the rumen slow it down (slow motility = slow production of the VFAs bc to acidic already)
How does a SMALL particle feed affect the rumen & digestion?Less saliva, less motility, ↓ digestion/fermentation
How does pH affect the amylase enzyme?Actually IMPROVES fxn of amylase enzyme
How does bloat affect blood pressure/volume?The ↑ oncotic pressure of the VFAs in the rumen will draw water into the rumen & cz HYPOVOLEMIA!!
How can hypovolemia lead to systemic acidosis?There is poor perfusion →↓O2 → acetate production from anaerobic resp → acidosis
How does the↓pH affect the rumen lining?ULCERS
What is SARA?Subacute ruminal acidosis → this doesnt present w/ acute onset & bloat. Usually a problem w/ feedlot cattle & such
What are some diagnostics/Txs you can do for bloat?Orogastric intubation (relief), response to therabloat, trochar & cannular (relief), celiotomy, rumenotomy
What kinda things will you test or look for in rumen fluid?pH
Microbial population diversity
Microbial motility