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
What is another name for Actinomycosis?
Lumpy jaw
What is the cause of Actinomycosis?
Caused by bacterium Actinomyces bovis
What type of tissue does lumpy jaw affect?
Soft tissue AND bone
What is the occurrence of lumpy jaw?
World-wide
How is lumpy jaw transmitted?
Oral wounds
What are the clinical signs of lumpy jaw?
Bony swelling. Also, can see erosion of bone, honey-comb type pockets. Can lose teeth, jaw can fracture.
How is lumpy jaw treated?
Same treatment as wooden tongue. Usually give antibiotics as well, can be difficult to penetrate bone. May have to go in surgically and scrape material out in conjunction with sodium iodine + antibiotics.
1. Antimicrobials
2. Sodium iodide
3. Surgical debridement
How can lumpy jaw be prevented?
- Isolate infected animals –> When draining fistulas are seen
- Management –> Make sure feed is good; avoid course, stemmy type feed. If there has been any demolition in pasture, pick up metal / nails.
What is the cause of choke?
Obstruction of the esophagus
What are the predisposing factors of chose in cattle, calves, and horses?
- Cattle –> rapid ingestion
- Calves –> boluses
- Horses –> dry grain
What are the clinical signs of choke?
- Bloat
- Extension of head
How is choke diagnosed?
Clinical signs are obvious
1. Palpate
2. Stomach tube
How is bloat secondary to choke treated in cattle and calves?
Relieve bloat (free gas bloat). Pass trocar through lumbar fossa and relieve gas pressure. Often if gas pressure is released, it will pass into rumen. If it doesn’t, need to get more aggressive, could require surgery.
How is choke treated in horses?
Withhold feed and water, sedation + muscle relaxant properties will resolve usually. If not, pass NG tube, sedate, slowly gently flush. Endoscopy, possibly surgery.
What are other names for lactic acidosis?
- Rumen overload
- Toxemia
- Rumenitis
- Grain overload
- Founder
- Laminitis
What is the cause of lactic acidosis?
Feed: high energy rations with grains, rumen microflora not adapted.
What is the pathogenesis of lactic acidosis?
- Ingestion of highly fermentable carbohydrates
- Impaired rumen activity
- Rise in osmotic pressure
- Dehydration
What are the clinical signs of lactic acidosis?
- Anorexia
- Lameness*
- Atonic rumen
- Feces
- Incoordination
How is lactic acidosis treated?
- Rumenotomy –> Severe cases – open rumen and physically remove grain + add healthy rumen material from donor cow. Flushing out rumen will not be enough.
- Adjust rations (roughage) –> Give good quality hay (NO GRAIN). Add grain back SLOWLY so that microbial flora has time to accommodate
How is lactic acidosis prevented?
Avoid sudden changes in ration
What is rumenitis – liver abscess complex?
One step further beyond lactic acidosis. See when put on high energy diet ration. Lactic acid erodes rumen wall. Bacteria escapes to portal vein and go to liver where abscesses occur.
What is the cause and occurrence of rumenitis – liver abscess complex?
- Cattle on finishing rations
- Concentrate : roughage ratio
What is the pathogenesis of rumenitis – liver abscess complex?
- Lactic acid
- Bacteria (Fusobacterium necrophorum and Trueperella pyogenes)
- Abscess
What are the clinical signs of rumenitis – liver abscess complex?
- Depression and intoxication
- Fluid diarrhea
How can rumenitis – liver abscess complex be prevented?
- Adjust ration
- Adaptation
What is ruminal tympany?
Bloat
What is another name for primary ruminal tympany?
Frothy bloat
What is the mechanism of pathogenesis of frothy bloat?
Instead of having a lot of gas, have tiny bubbles of gas in foamy mixture and the bubbles can’t get rid of them. Young plant material pastures. Can see in feedlot but is thought to be more a result of high grain / high energy rations and change to microflora creates biofilm which mixed with gas and causes frothy bloat.
What is frothy bloat caused by?
a. Gas entrapment*
b. Legume pastures
What is another name for secondary ruminal tympany?
Free gas bloat
What causes free gas bloat?
Obstruction of esophagus
What are the clinical signs of bloat in ruminants?
- Sudden death
- Rapid onset
- Dyspnea –> Difficulty breathing (head extended, trying to breathe)
How can free gas bloat be diagnosed in a postmortem exam?
Bloat line on esophagus; pressure in thorax from bloat. Not being able to be profuse with blood, causes constriction of esophagus. Hemorrhagic type response on outside.
How can free gas bloat be treated?
- Rumenotomy
- Stomach tube / Trocar
- Resolve choke
How can frothy bloat be treated? Gas can’t be released with trocar
- Introduce antifoaming agent into trocar in rumen (surfactant + oil – changes surface tension)
- Stomach tube
How can bloat be controlled?
- Ration
a. Add good quality hay (1/3 diet)
b. Wait until legume is more mature - Antifoaming agents
a. Introduce ionophores into diet which help to prevent bloat
What are other names for traumatic gastritis?
Traumatic reticuloperitonitis, hardware disease
What is the cause of traumatic gastritis?
Perforation of the reticulum wall.
What are the predisposing factors of traumatic gastritis?
- Cow eating habits
- Late gestation –> Uterus is taking up space of abdomen, more likely to push material through membranes during contractions.
- Grazing conditions
What is the pathogenesis of traumatic gastritis?
- Metallic object swallowed
- Penetration
- Perforation of reticulum
- Peritonitis
What is peritonitis secondary to traumatic gastritis?
Infection / fibrous material around heart + abdomen, adhesions.
What are the clinical signs of traumatic gastritis?
Easier to diagnose earlier than later. Initially will see decrease in rumen / reticulum activity (contraction). Rectal temperature and HR may be slightly increased. Careful about gait if they move just right it will poke.
1. Decreased milk production
2. Resistant to movement
How is traumatic gastritis diagnosed?
- History
- Clinical signs –> Clinical signs more prominent early with initial penetration + peritonitis
How is traumatic gastritis treated?
- Surgery
a. Get rid of metal material (surgery –> rumenotomy)
b. Drain abscess - Antibiotics
How is traumatic gastritis prevented?
- Magnets –> Pass magnet over feed. Bar magnets administered orally at about 1 year of age)
- Management
What are abomasal disorders caused by?
Abnormal anatomy / movement of the abomasum.
What is abnormal anatomy that results in abomasal disorders caused by?
Multifactorial causes such as abomasal atony or gas production. Usually, a result of hypomotility.
What are the clinical signs of abomasal disorders?
Anorexia, decreased milk production
How are abomasal disorders diagnosed?
Evaluate for displacement, use stethoscope to listen for ping sound. Also, can diagnose based on history.
What is the treatment for abomasal disorders?
- Surgery –> Incision on paralumbar fossa, take tube attach to needle and let air be released. Pull abomasum back to where it belongs +/- tack in place
- Cast –> Put animal down on side, hold on back. Should go back to normal ventral side of animal
How can abomasal disorders be prevented?
Adjust rations (good dry matter rations, maintain 3.5 BCS during calving, good quality and quantity of forage)
What Is the cause and pathogenesis of abomasal ulcers?
Poorly understood (ulcers can be result of going off feed after giving birth, changes pH, etc)
What is the occurrence of abomasal ulcers?
- High producing cow
- Hand fed calves
- Suckling calves
What are the clinical signs of abomasal ulcers?
- Anorexia
- Blood in feces
- Abdominal pain
- Death
How are abomasal ulcers diagnosed?
Feces with blood (caused by peritonitis)
How are abomasal ulcers treated?
Ration management (Want them to eat again. Food acts as good buffer in abomasum, helps stabilize pH).
How can abomasal ulcers be prevented?
Management and ration adjustments (withholding / decreasing concentrates, adequate roughage, increase concentrate particle size)
What is another name for paratuberculosis?
Johne’s disease
What is the cause of paratuberculosis / Johne’s disease?
Mycobacterium paratuberculosis
What is the occurrence of paratuberculosis / Johne’s disease?
Worldwide
How is paratuberculosis / Johne’s disease transmitted?
- Oral fecal route
- Carriers –> usually introduced into carrier animal b/c it has long incubation period
- Milk
What is the incubation period of paratuberculosis / Johne’s disease?
Up to 2 years
What are the clinical signs of paratuberculosis / Johne’s disease?
- Cattle over 2 years
- Diarrhea
- Decreased milk production
- Emaciation
What will postmortem examination look like for animals that have paratuberculosis / Johne’s disease?
Look at distal small intestine region. SI will be thick, rough. Not necessarily ulcers. Minimal clinical signs and intestinal tract can look horrible. Other sever dz can have S.I. that isn’t that bad. No direct correlation btwn clinical signs and severity of infection.
How is paratuberculosis / Johne’s disease prevented and controlled?
- Management –> To control / limit – as soon as animals are born, move away from mom, feed pasteurized colostrum / milk, -rear in isolated area
- Eradication –> can be eradicated but takes a lot of testing & won’t happen overnight. Pay attention to replacements that come in – quarantine + test appropriately
What is BVDV?
Bovine Viral Diarrhea Virus
What is Bovine Viral Diarrhea Virus caused by?
Genus Pestivirus, Family Flaviviridae
What are the biotypes of BVDV?
- Cytopathic –> When cells get infected, virus kills cells
- Noncytopathic –> Cells get infected with virus, live in harmony. Infecting fetuses that are persistently infected
How many species / genotypes of BVDV are there? Are they similar?
Type one and type two. Antigenically diverse.
What is the occurrence of BVDV?
Worldwide
How is BVDV transmitted?
Contact (direct or across placenta)
What is the morbidity and mortality of BVDV?
Highly variable. Some strains are severe and will kill adult cow, some are very mild.
What is the pathogenesis of BVDV and mucosal disease (MD)?
- Predilection of virus for lymphoid organs
- Persistent infections
- Immunotolerance
- Immunosuppression
How does BVDV / MD cause immunotolerance?
Does not mount immune response to BVDC in persistently infected calves
How does BVDV / MD cause immunosuppression?
Does not mount immune response to other pathogens (animal has increase susceptibility to other bacteria / virus)
What systems are affected by BVDV?
All systems within body can be affected (digestive, respiratory, immune, reproductive)
What are the clinical signs of BVDV / MD?
- Diarrhea
- Respiratory tract signs
- Unthrifty
- Reproductive failure
- Fetal anomalies
- Persistent carriers
What is the pathogenesis of fetal infection of BVDV?
- Oronasal passages
Initial replication – tonsils, epithelium - Phagocytic cells
Lymphoid tissues - Viremia
Fetus
What age of animals are persistent carriers of BVDV?
Fetal infections
What biotype of BVDV do persistent carriers have?
Noncytopathic BVDV
When do fetuses become susceptible to being persistent carriers of BVDV?
First 1/3 of gestation, before they are immunocompetent / have developed immune response.
How long are persistent carriers of BVDV?
Carrier status = lifetime
What will necropsy of BVDV animals show?
Postmortem examinations will show lesions that are erosions of the GI tract and lymphoid organs
What is mucosal disease (MD) and how is it related to BVDV?
Sequel to persistently infected animals. When they have both biotypes – sets them up for MD and severe erosions + ulcerations
How is BVDV / MD diagnosed?
- History –> tentative diagnosis from history, clinical signs, gross / microscopic lesions
- Necropsy findings
- Lab tests –> viral antigens, ear notch as minimally invasive technique
What are the differential diagnoses of BVDV / MD?
- Vesicular stomatitis, bluetongue –> ulcerations
- Johne’s disease, winter dysentery –> diarrhea, GI upset
How can BVDV / MD be controlled?
Management (biosecurity, avoid PI carriers)
What management practices can be done to avoid PI carriers of BVDV?
Test animals, focus on calves, quarantine / test replacement animals
How can BVDV / MD be prevented?
Vaccination
What is winter dysentery caused by?
Bacteria and/or virus
What bacteria causes winter dysentery?
Campylobacter jejuni
What virus causes winter dysentery?
Bovine coronavirus
What animals does winter dysentery occur in?
Adult dairy cattle
How is winter dysentery transmitted?
Fecal-oral route
What are the clinical signs of winter dysentery?
Diarrhea. The cows may go off feed, may be depressed, significant drop in milk production.
What is the mortality of winter dysentery?
Mortality tends to be low (usually recover)