4. Diagnostics, therapy and prevention of gastro-intestinal diseases

Question 1

What are some upper GIT diseases (oral cavity and esophagus?

Answer 1

• Congenital oronasal fistula
• Occlusal anomalies
• Tongue anomalies
• Teeth anomalies
• Persistent right aortic arch
• Stomatitis, pharyngitis, laryngitis, esophagitis
• Actinobacillosis - Wooden tongue
• Actinomycosis - Lumpy Jaw

Question 2

Describe Actinobacillosis

Answer 2

= Wooden tongue.
Caused by - Actinobacillus lignieresii (part of normal flora - becomes pathogenic when enter mucosa through wounds).
* Cattle primary host

CS: Granulomatous abscesses, tongue becomes hard and swollen (Wooden tongue), can spread (head, neck, limbs)

Dx: Culture and biopsy

Tx:
* Sodium Iodine IV (1-2x/day 7-10days interval)
*ATB
* Surgical debulking in severe cases
* Avoid food that may cause wounds in oral cavity.

Question 3

Describe Actinomycosis

Answer 3

= Lumpy jaw
Caused by - Actinomycosis bovis (part of normal flora - becomes pathogenic when enter mucosa through wounds.
* Cattle is primary host

CS: Chronic, localized, pyogranulomatous osteomyelitis of mandible, maxilla and facial bones.

Dx: Cytology, biopsy and x-ray.

Tx: Same and prevention as for Actinobacillus

Question 4

What are some lower GIT diseases (intestines)

Answer 4

• Atresia ani
• Hernia
• Diarrheic syndrome
• Bovine viral diarrhea virus
• Bovine rotavirus/coronavirus
• Paratuberculosis (John’s disease)
• Salmonellosis
• Clostridium
• Eimeria
• Crypstosporidium

Question 5

Briefly Atresia ani

Answer 5

Rectum doesn’t open into anus but ends blindly.

No defecation.

Euthanasia.

Question 6

Briefly Hernia

Answer 6

Umbilical/Inguinal/Ventral/Diaphragmatic/Perineal.

Can be congenital or acquired.

Dx: CS and USG

Tx: Surgery and truss/bandage/belt.

Question 7

Describe Diarrheic syndrome

Answer 7

An acute and fatal syndrome in calves less than 3 weeks of age.

Non-infectious causes:
* Colostrum - too much/high/low temperature
* Composition/quality of feedstuff/hygiene

Infectious causes:
* Bacteria: E. coli, Salmonella, Clostridium
* Virus: Rotavirus, Coronavirus
* Protozoa: Cryptosporidium, Eimeria

CS: depend on underlying cause
* E. coli (enterotoxemic form) –> rapid dehydration, watery diarrhea, rapid death from 4th day of life
* Salmonella dublin –> diarrhea from 2nd week of life, fever, apathy, stinky feces - mucous/blood/pseudomembranes in feces, septicaemia.
* Rota and coronavirus –> Diarrhea at day 5-21 of life
- Both: Fecal oral transmission
- Rota destroys enterocytes of SI (osmotic diarrhea, mucous/bloody diarrhea possible)
- Corona cause calf enteritis or winter dysentery in adults cattle (heavy diarrhea, decreased milk production in adult.
* Cryptosporidium –> Subclinical, watery diarrhea, WL (Eimeria causes bloody diarrhea)

General CS: recumbency, emaciation, pale/yellow feces, not drinking, enopthalmos, dehydration, lethargy

Dx:
* Grading system for diarrheic syndrome (posture, behaviour, dehydration status, BCS, suckling reflex, enophtalmos, temperature, color/consistency/odor of diarrhea)
* Blood (High PCV - dehydration 33-44%. Low pH). D-lactate levels to check for metabolic acidosis. Creatinine and BUN levels.
* Ig or TP in blood (see if calf had enough colostrum) - should be over 5g/dl
* SNAP test (available for rotavirus, coronavirus, e.coli and cryptosporidium)
* Fecal flotation - parasites

Tx:
* Restore homeostasis - 2l of rehydration solution (NaCl, NaHCO3, KCl, 20g glucose / 1L of water) + 2L of milk (if suckling is good)
* Probiotics
* ATB for bacteria
* Halofuginone for Crypto
* Colostrum if TP is low
* 500ml HCO3 IV (jugular) for calves with no suckling reflex.

Px: VACCINATION - before calving for rota, coronavirus and e. coli (1st shot 2m before parturition and 2nd 1m before)

Question 8

What is a common consequence of Diarrheic syndrome?

Answer 8

Leading to metabolic acidosis as HCO3 is lost through feces, fluids are lost by diarrhea –> hypovolemia, retention acidosis of kidneys and lactate is produced by bacteria in gut

Question 9

Describe Bovine viral diarrhea virus

Answer 9

Pestivirus, Flaviviridae. BVDV-1 and BVDV-2.
Two biotypes –> cytopathogenic and non-cytopathogenic.
* Affect all ages of cattle, mostly young (up to 18m) + sheep

1) Postnatal infection, young or adult non-pregnant animals –> May cause respiratory signs (nasal discharge, cough), diarrhea, high fever, anorexia, and weight loss
Common lab findings: lymphopenia, thrombocytopenia, possibly leading to hemorrhagic syndrome and death in severe cases

2) Infection of pregnant animals –> embryonal death before day 40. Btw 40-120 fetus becomes persistenly infected if they survive. 120-180 - > cerebellar hypoplasia, ocular anomalies

3) Persistent infection and mucosal disease –> A calf infected with non-cytopathic BVDV in utero between 40–120 days may become persistently infected (PI) and shed the virus for life. If the virus later mutates to a cytopathic form or the calf is superinfected with a matching cytopathic strain, it can develop fatal mucosal disease characterized by severe water diarrhea, ulcers, and rapid death.

Dx:
* By health status on farm
* CS
* Samples from nares/conjunctiva/rectum/feces/semen/serum
* RT-PCR, ELISA
* Serum - Lymphopenia, thrombocytopenia

*** PI animals are w/o Ab.

Tx: Supportive, ATB for bacterial pneumonia that develops secondary.

Px: Eradication program + vaccination but controversial

Question 10

Describe Paratuberculosis

Answer 10

= John’s disease

Mycobacterium avium subsp. paratuberculosis
* All Ru and free-ranging wildlife are hosts
* Risk factors = stress, poor nutrition, transport and parturition.

CS: IP can be >2y, only 2-5% of affected animals show CS.
- Cattle: severe diarrhea, intermandibular edema (bottle jaw), dehydration, progressive wasting
- Sheep/goats: Chronic wasting, diarrhea.

Dx: cultivation, PCR, histopathology (Ziehl-Neelsen), ELISA, AGID - sample from feces/tissue

Tx: Only symptomatic

Px: Isolation of calves after birth, identify sick animals, proper hygiene, prevent stress factors.

Question 11

Important points to Eimeria

Answer 11

Eimeria
- Large Ru: E. zuernii/bovis/ellipsoidalis/aubernensis
- sRu: E. parva/ovina/intricate/crandallis.
Fecal-oral - ingestion of oocyst

Pg/CS: Invade enterocytes –> bloody diarrhea, fever, dehydration, WL

Dx: Fecal flotation

Tx: Toltrazuril (Baycox), Sulphonamides.

Px: Medicated feed and water

Question 12

Important points to Cryptosporidium

Answer 12

Cryptosporidium parvum, C. bovis
*Fecal-oral transmission - Ingestion of sporulated oocyst, often autoinfection from endogenous sporogony (20%)

Pg/CS: in SI causes villous atrophy, catarrhal enteritis, watery diarrhea, dehydration, death.

Dx: Snap test, fecal smear with staining, ELISA, PCR

Tx: Halofuginone and symptomatic.