Large Animal Medicine Salivation Dr. Cebra

Front 1

What are 8 functions of saliva in large animals?

Back 1

1) Lubrication of the upper GI tract
-very important in herbivores
2) Liquefaction of the food bolus
3) Buffering and supporting rumen fermentation (ruminants only)
4) Some digestion by salivary amylase and lipase (probably inconsequential in herbivores)
-hardly worth mentioning
5) Small role in evaporative heat loss
6) Excretion of phosphorus (ruminants)
-microbes need phosphorus to function
7) Excretion of urea (ruminants)
8) Anti-foaming (ruminants)

Front 2

Why is the buffering function of saliva so important in ruminants?

Back 2

***Acids produced by fermentative processes are neutralized by bases in saliva

Front 3

***What is the main route of phosphorus excretion in ruminants?

Back 3

Salivation!!!
-more important than kidney!!!

Front 4

Why is urea present in the saliva of ruminants?

Back 4

microbes use urea for non-protein nitrogen source (for 2-3 days) so urea in the saliva allows urea to be recycled in rumen

Front 5

What are the 3 main sources of saliva in large animals?

Back 5

1) Parotid glands
*Rockstar of salivary glands
2) Mandibular glands
3) Sublingual glands (buccal in some species)

Front 6

Should you be able to the mandibular salivary glands? Parotid salivary glands?

Back 6

Nope, don't feel either of them unless enlarged, but if do feel anything underneath the mandible in cattle it's salivary glands NOT lymph nodes

Front 7

Where do the mandibular salivary ducts drain?

Back 7

Duct goes under tongue so can't feel it, in cows they have one or more papillae under tongue where the mandibular ducts empty out
-not much happens to mandibular duct or papilla

Front 8

Where do sublingual glands drain?

Back 8

Wherever they are, pretty much just ooze (not really secrete)

Front 9

The ______ and ______ glands both empty beneath the tongue.

Back 9

Mandibular
Sublingual

Front 10

Which salivary glands secrete predominantly a mucinous secretion?*

Back 10

Mandibular and sublingual salivary glands

Front 11

**How much saliva is produced by the mandibular and sublingual salivary glands combined in ruminants? How is this affected by eating?

Back 11

Combined: 2 mL/kg/h
-increases about 50% with eating

Front 12

Where do the parotid glands drain?

Back 12

On the buccal side of the cheek

Front 13

What type of secretion is predominately secreted by the parotid salivary gland?

Back 13

Primary aqueous secretions

Front 14

How much saliva is produced by the parotid salivary glands? How is this affected by eating?

Back 14

EACH gland produces about 2 mL/kg/h at rest
-~50% more active during active chewing (eating or ruminating)

Front 15

___% of fluid enter the ruminant stomach is usually salivary.

Back 15

80%

Front 16

How much saliva does a 500 kg ruminant produce when fasted?

Back 16

2 mL/kg/h + 2(2mL/kg/h)= 6 mL/kg/h
6 mL/kg/ h x 500 x 24 h/day= 72 L

Front 17

The parotid saliva of horses is similar to the make-up of ______ and is produced in much more modest amounts.

Back 17

Plasma (minus the protein)

Front 18

**What is the pH of the saliva produced by the parotid salivary gland in ruminants?

Back 18

ALKALINE (pH= 8.0 -8.6)

Front 19

What electrolytes are contained in the saliva produced by the parotid salivary gland in ruminants? (4)

Back 19

1) High bicarbonate (100-150 mEq/L)
2) Phosphorus (18-34 mEq/L)
3) Sodium (148-175 mEq/L)
4) Potassium (6.5-14.0 mEq/L)
-salivary chloride concentration is very low

Front 20

When do bicarbonate concentrations increase in the saliva produced by the parotid gland in ruminants? what is the role of bicarbonate in the saliva?

Back 20

Slight increase in bicarbonate during feeding
-Role is to buffer gastric fermentation

Front 21

What is the function of phosphorus in the saliva (produced by parotid gland) in ruminants? (2)

Back 21

Buffer and supports microbial cellulose digestion

Front 22

Are horses or ruminants more affected by a loss of saliva (and hence its counterparts)?

Back 22

Based on volume and make up this is more important in ruminants. Horses lose small amounts of volume and suffer little electrolytes derangements (more physiologic like sweat)
-horses= smaller volume of saliva

Front 23

Loss of saliva in ruminants results in what 3 things?

Back 23

1) Dehydration
2) Electrolyte depleted
3) Acidemic (bicarb loss)
-*Keep in mind when planning fluid treatments

Front 24

What are the 2 components of the neurologic control of salivation?

Back 24

Autonomic Nervous system so:
1) Parasympathetic
2) Sympathetic

Front 25

How does parasympathetic input affect saliva production?

Back 25

Increases volume and aqueous (parotid) secretion
-increases base a little bit

Front 26

How does sympathetic input affect saliva production?

Back 26

Little change in volume
-Increases protein and mucin content
-get dry mouth w/ fight or flight

Front 27

Why is atropine commonly used during surgery of ruminants?

Back 27

For parasympatholytic effects to decrease salivation

Front 28

What are 3 ways that saliva can be lost out of the mouth?

Back 28

1) Ptyalism/ sialism (overproduction)-rare
2) Pseudoptyalism
3) Abberant path

Front 29

What are 4 causes of ptyalism?

Back 29

1) Irritation of mouth
2) Toxins
3) Fever
4) Infections

Front 30

What are 4 examples of causes of irritation of the mouth that results in ptyalism?

Back 30

1) Dental disease
-teeth that are bumping & annoying mouth
2) Stomatitis
-infection that is an irritant = pretty low grade
3) Glossitis
4) Oropharyngeal foreign bodies
-cow that gets stick rammed through mucosa

Front 31

What are 2 things that commonly cause chemical injury to the tongue, resulting in glossitis?

Back 31

Medications
Blister beetles
-cows will also chomp on batteries--> acid burns

Front 32

What are 2 causes of glossitis?

Back 32

1) Infectious
2) Toxins

Front 33

What are 2 common clinical injuries that result in glossitis and hence ptyalism?

Back 33

1) Medications
2) Blister beetles
-cattle can eat car batteries= acid

Front 34

**What are 3 toxins that cause ptyalism in large animals?

Back 34

1) Slaframine
-'slobber factor'
2) Heavy metals
3) 'Watery mouth' in lambs

Front 35

what is Slaframine?

Back 35

Indolizidine alkaloid produced by fungus that colonizes legumes

Front 36

What legumes are most commonly infected with Slaframine?

Back 36

*Particularly red clover in damp areas and subterranean clover in dry areas

Front 37

How can you tell if red clover is infested with Slaframine?

Back 37

Fungus causes discoloration of the clover known as 'black patch'

Front 38

What large animals are affected by Slaframine?

Back 38

All species of herbivores
-**often get herd outbreaks

Front 39

What is the pathogenesis of slaframine?

Back 39

After ingestion, the toxin is metabolized by the liver to an acetylcholine analog

Front 40

When do the signs of slaframine toxicity appear? How long do they last?

Back 40

-Signs start 3-5 hours after ingestion
-last ~24 hours

Front 41

What are the clinical signs of slaframine toxicity? (9)

Back 41

1) Profuse salivation ('slobbers')*
2) Colic*
3) Lacrimation*
4) Tremors*
5) urination
6) Diarrhea (SLUD signs)
7) bloat*
8) dyspnea*
9) Stiff gait

Front 42

What is the seasonality related to red clover toxicity (slaframine)?

Back 42

Clovers proliferate with more exposure to moisture, so common after rainfall

Front 43

What is a major sign of slaframine toxicity in horses?

Back 43

Coli

Front 44

Why do ruminants with slaframine toxicity get dyspnea?

Back 44

If rumen gets too big then they can't move their diaphragm

Front 45

How do you diagnose slaframine toxicity?

Back 45

-Signs (rule out other signs of colic)
-Finding infected plants (can send clover to lab and get analyzed

Front 46

What is the treatment for slaframine toxicity?

Back 46

1) Wait it out (can go on 1-3 d in severely affect animals)
2) Atropine in severe cases
-remove animals from source

Front 47

Why don't we like to give atropine to horses?

Back 47

can make them colic

Front 48

How should you administer fluids to an animal with slaframine toxicity?

Back 48

orally bc rumen still works

Front 49

What can you do in a cow that has bloat due to slaframine toxicity?

Back 49

Let gas off the rumen

Front 50

What are 5 heavy metals that can cause irritation of the mouth and therefore ptyalism?

Back 50

1) Mercury
2) Iodine
3) Copper
4) lead
5) Arsenic

Front 51

What causes 'Water mouth' in lambs?

Back 51

Coliform cholinergic toxin

Front 52

What age of lambs are affected by the coliform cholinergic toxin?

Back 52

New born lambs
-first 1-2 days of life

Front 53

What do they think the is the pathogenesis of watery mouth in lambs?

Back 53

E. coli makes cholinergic toxin--> stimulates parasympathetic--> saliva & water deposition around mouth, bloat, GI atony
-other name is rattle belly bc can pick up lamb and shake it and hear water sloshing around in gas distended stomach)

Front 54

Why is there a high mortality rate in watery mouth lambs?

Back 54

GI tract shuts down

Front 55

What can you use to treat watery mouth in lambs?

Back 55

Atropine in severe cases
Fluids

Front 56

What are 3 infections that can result in ptyalism? How do each of them result in ptyalism?

Back 56

1) Rabies
-directly irritates salivary glands
2) Bacteria
-irritates mouth, tongue or salivary glands
3) Awns & other foreign bodies

Front 57

What causes pseudoptyalism?

Back 57

Lack of swallowing
-much more common than ptyalism
-this has no increased production
-can have combo of the 2

Front 58

What are 2 general causes of pseudoptyalism?

Back 58

1) Obstruction***biggest reason
-anywhere from mouth to stomach
2) Neuromuscular dysfunction

Front 59

What are 4 examples of obstruction that can result in pseudoptyalism?

Back 59

1) Choke
-esophageal obstruction
2) Oropharyngeal foreign body
-not quite esophageal
-just has to impede flow, not completely occlude
3) Retropharyngeal abscess
-impinge on esophagus or pharynx from outside and decreases size of pharynx
4) Tumor
-big retropharyngeal lnn.: lymphoma, metastatic tumors

Front 60

What are 6 causes of neuromuscular dysfunction that result in pseudoptyalism?

Back 60

1) Cranial nerve damage
-peripheral lesions
-brainstem lesions
2) Botulism
3) Megaesophagus
4) African Horse Sickness
5) Glossitis
6) White muscle disease
-long list of other muscle diseases

Front 61

What are 2 causes (locations) of peripheral lesions of the cranial nerves that result in pseudoptyalism?

Back 61

1) guttural pouch
2) Pharyngeal trauma

Front 62

How do horses most commonly get cranial nerve damage? Cattle?

Back 62

Horses: more common in horses bc cranial nerves go through guttural pouch
Cattle: usually from middle ear damage, less common

Front 63

What are 3 causes of brainstem lesions that can result in pseudoptyalism?

Back 63

1) Rabies
2) Listeria
3) Focal symmetric encephalomalacia (think caused by clostridium toxin)

Front 64

How does botulism cause pseudoptyalism?

Back 64

Causes generalized muscular weakness so animals don't swallow well and then they hang their head--> saliva flows forward and out of mouth

Front 65

Why does megaesophagus cause pseudoptyalism?

Back 65

Combination of obstruction and functional issue (if truly obstructed= choke), causes poor swallowing and maybe some regurgitation

Front 66

What is an example of glossitis resulting from a neuromuscular dysfunction (and therefore causes pseudotyalism)?

Back 66

Wooden tongue
-he's referring more to swelling of tongue with regards to pseudoptyalism; can't swallow

Front 67

What age of animals definitely tend to get pseudotyalism with white muscle disease?

Back 67

Neonates

Front 68

What is the treatment for white muscle disease?

Back 68

Selenium/ Vitamin E
-caused by deficiency

Front 69

What are 3 examples of aberrant paths that result in pseudoptyalism? How do they cause pseudoptyalism?

Back 69

1) Cleft palate
-saliva comes upward through nasal passage and out nose instead of being swallowed
2) Laceration of the parotid duct
-laceration in mouth
3) Malformed pharynx/larynx
-animals can have parotid gland too far forward in mouth
-too small of lower jaw

Front 70

What are 2 general causes of a lack of salivation?

Back 70

1) Obstruction
2) Dehydration/shock

Front 71

What are 5 examples of obstructions that can cause a lack of salivation?

Back 71

1) Trauma to ducts
-salivary mucocele/sialocele
2) Infection
3) Sialoliths
4) Tumors
5) Abscesses

Front 72

How does trauma to ducts cause a salivary mucocele?

Back 72

Get laceration and then scar heals it and strictures the salivary duct
-usually causes dry mouth when bilateral

Front 73

What is the most common infection that causes a lack of salivation in horses? Cattle?

Back 73

Horses: strep
Cattle: Actinobacillus

Front 74

How do you diagnose strep in horses or actinobacillus in cattle as a cause of decrease salivary production?

Back 74

Feel for enlarged nodules and culture discharge or aspirate

Front 75

How do sialoliths usually form?

Back 75

Starts with oral foreign body that lodges in the parotid duct
-secondary obstruction or infection common

Front 76

How do you diagnose a sialolith? What's the treatment?

Back 76

Feel lith in cheek or find on radiographs
-remove surgically

Front 77

What are 3 examples of tumors that cause a lack of salivation in large animals?

Back 77

1) Melanoma
-older grey horses
-can sometimes ameliorate w/ cimetidine
2) Lymphoma
3) Salivary adenoma/ adenocarcinoma