Unit 3 Flashcards
What is the digestive tract?
Muscolomembranous tube that extends from the mouth to anus
What is the function of mucous membranes?
Communicate with exterior. Direct communication with the outside of the body.
Where can mucous membranes be found in the body?
Not only line the digestive tract, but line respiratory, urogenital, etc
What are serous membranes?
Very thin, uniform, lining surrounding internal cavities
What is the function of serous membranes?
Covers surfaces closed from exterior
What are the functions of the digestive tract?
- Digestion
- Absorption
- Motility
- Excretion
What is a simple stomach?
Monogastric – vast majority of digestion and absorption is within the small intestine
What animal would be classified as having a simple stomach?
Pig
What animals would be classified as ruminants?
Sheep, cattle, goats, etc
What are the 4 sections of a ruminant stomach?
- Rumen
- Reticulum
- Omasum
- Abomasum
What is a ruminant stomach designed for?
Digestive tract is designed for fermentation (ferments feedstuff, precursor to energy
What is the function of the rumen?
Vast majority of fermentation occurs here. Can hold <40 gallons of feedstuffs + fluid
What is the reticulum?
Anterior portion. Honeycomb lining.
What is the function in the omasum?
Plays role in transporting appropriately sized feed particles
What is the function of the abomasum?
“True stomach.” Similar function to monogastric stomach.
What animal is known to be a hindgut fermenter?
Horse
What does a hindgut fermenter digestive tract consist of?
Large intestine with large diameter
What are the sections of a hindgut fermenter large intestine?
Cecum, colon, rectum
What is the cecum?
Blind sack, where most fermentation occurs
What are signs of disturbances of the digestive system?
- Inability to chew or swallow
- Depraved (bad) appetite
- Vomiting
- Excess salivation
- Bloating
- Fever
- Abnormal feces
- Pain
What is another name for neonatal calf diarrhea?
Calf scours
What are the infectious causes of neonatal calf diarrhea?
- Bacteria (E. coli)
- Viruses (Rotavirus, Coronavirus)
- Cryptosporidium
What are the non-infectious causes of neonatal calf scours?
- Stress
- Nutrition
- Oral antibiotics
What is the occurrence of neonatal calf scours?
Most important disease of neonatal calves
What is the economic significance of neonatal calf diarrhea?
Significant economic loss for producers ($95,000,000). Common cause of mortality, if the calf survives you may still have an animal that doesn’t do well
How is neonatal calf diarrhea transmitted?
- Oral –> contamination (environment / teat)
- Systemic –> umbilicus
What is the pathogenesis of bacterial neonatal calf diarrhea?
E. coli colonize intestinal epithelium. Able to attach to mucosal cells using pili (fimbriae). Then they produce an enterotoxin.
What is the pathogenesis of viral (rotavirus/coronavirus) neonatal calf diarrhea?
Damages intestinal villi. Animal will not be able to absorb nutrients (malabsorptive type diarrhea).
What are the three types of pathogenesis in neonatal calf diarrhea?
- Viral – damage intestinal villi
- Fluid passage
- Bacterial overgrowth
How does E. coli infectious neonatal calf diarrhea cause changes in fluid passage?
Produces enterotoxin, which increases the amount of fluid that are being secreted into lumen in comparison to what is absorbed.
What is the mechanism of fluid passage pathogenesis by a virus in neonatal calf diarrhea?
Fluid secretion is the same, but can’t absorb things anymore. Fluid stays in lumen along with what is being secreted.
What are the pathological changes seen associated with neonatal calf diarrhea?
- Electrolyte loss –> bicarbonate, K, Cl, Na
- Dehydration
- Blood shunting
- Acidosis
- Electrolyte imbalance
What percent of fluid loss in cattle will it be noticeable for producers?
6%
When do clinical signs of E. coli neonatal calf diarrhea occur?
1-7 days
When do clinical signs of Rotavirus neonatal calf diarrhea occur?
3-10 days
When do clinical signs of Coronavirus neonatal calf diarrhea occur?
1-6 weeks
When do clinical signs of Cryptosporidium neonatal calf diarrhea occur?
5-35 days
When do clinical signs of Salmonella neonatal calf diarrhea occur?
Usually not <14 days
When do clinical signs of Clostridium perfringens neonatal calf diarrhea occur?
Few days of age, vigorous calves
What is the treatment for neonatal calf diarrhea?
- TLC
a. Warm, dry, clean environment - Fluid therapy
a. Replace what they are losing + maintenance - Oral fluid therapy –>
a. 6-8% dehydration – difference between giving oral fluid replacement vs IV fluid replacement. It is always better if we can give it orally - Parental fluid therapy
Why is withholding milk controversial in treating neonatal calf diarrhea?
With fluid replacements, calves not getting a lot of energy with this. Milk sometimes is withheld but should be for >24 hours. If they are suckling, can still be giving milk even when treating for calf scours.
What does the amount of parental fluid therapy administered depend on when treating for neonatal calf diarrhea?
The amount of fluids to administer depends on clinical signs estimating the % of fluid lost.
How do you calculate how much parental fluid therapy should be given in treating neonatal calf diarrhea (assume 100 lb calf + 6% dehydration)?
100 lb. calf
6% dehydration = 6 lbs.
6 lbs. / 2 = 3 quarts (to correct dehydration)
+
10% maintenance = 10 lb.
10 lbs. / 2 = 5 quarts (milk)
Should antibiotics be given for treating neonatal calf diarrhea?
If we give antibiotics, we are messing up microflora of GI tract, which is already upset. Only reserved and administered if showing systemic signs of infection (bacterial pneumonia, swollen joints). Infection MUST be bacterial, won’t work on viral infection. If not showing systemic signs, hold off on giving antibiotics.
How can neonatal calf diarrhea be prevented and controlled?
NO specific management recommendation that can apply to every situation (differences in herd sizes, facilities, land, labor). It is unrealistic to expect total control of neonatal calf scours
a. Sanitation
b. Nutrition
c. Colostrum
d. Umbilicus
What are the 3 main principles to prevention and control of neonatal calf diarrhea?
- Reduce exposure to infectious agents
- Maximize non-specific resistance by providing good nutrition + colostrum
- Increase specific resistance by vaccinating dam and newborn when appropriate
What can the aftereffects of recovering from neonatal calf diarrhea?
a. Pneumonia
b. Unthrifty
c. Arthritis
d. Abomasa ulcers
What is vesicular stomatitis?
This is a viral disease of livestock. We see it sporadically in the United States. Primarily effects horses and cattle.
What is the cause of vesicular stomatitis?
Caused by family Rhabdoviridae genus Vesiculovirus
What animals is vesicular stomatitis seen in?
Cattle and horses most commonly. Also, swine, sheep, llama, goats
How is vesicular stomatitis transmitted?
- Arthropods –> insect vectors
- Direct contact
What are the clinical signs of vesicular stomatitis?
- Oral vesicles
- Excessive salivation
- Anorexia
- Teat lesions
How is vesicular stomatitis diagnosed?
Reportable and quarantinable disease until officially diagnose because lesions look identical to foot and mouth disease.
1. History
2. Clinical signs
3. Lab tests
How can vesicular stomatitis be controlled?
- Regulatory agency
- Management
- Control arthropods
What is another name for Actinobacillosis?
Wooden tongue
What is the cause of Actinobacillosis?
Caused by bacterium Actinobacillus lignieresii
What is the occurrence of wooden tongue?
Widespread
How is wooden tongue transmitted?
Infected discharges
What is the pathogenesis of Actinobacillus lignieresii causing wooden tongue?
Part of the normal flora of the oral cavity / pharynx region. Gains access to SQ tissue by trauma (eating course material, puncturing mucosa with nail or wire). This allows bacteria to get into area that it normally doesn’t have access to, and it spreads.
What are the clinical signs of wooden tongue?
- Swelling*
- Excessive salivation
- Inability to chew
How is wooden tongue diagnosed?
Clinical signs. Definitive diagnosis is lab exam (biopsy + culture organism).
How is wooden tongue treated?
Sodium iodine. Given IV. Give one dose and 7-10 later, repeat as needed.
What needs to be considered with using sodium iodine to treat wooden tongue?
Can be toxic to the animal, need to monitor for signs of iodine toxicity. Decrease dose or increase time in between doses