Ruminant Medicine – Key Disorders (Dr. Conchada, MEDI106A)

A comprehensive set of 50 Q&A flashcards covering causative agents, pathophysiology, lesions, and treatments of major ruminant diseases discussed in the lecture notes.

What is another common name for Bloat in cattle?

Ruminal tympany

Which type of pasture is most commonly associated with primary (frothy) ruminal tympany?

Legume-dominated pastures or legume vegetable crops

What is the principal antifoaming agent naturally present in saliva that decreases with succulent forages?

Salivary mucin

Name one emergency procedure used to rapidly relieve life-threatening bloat.

Trocarization (trocar or cannula insertion into the rumen)

Grain overload in cattle is more accurately called __.

Lactic acidosis (carbohydrate engorgement, rumenitis)

Which rumen pH indicates severe lactic acidosis?

≤ 5.0

Why are cattle with acute grain overload often seen gorging on water 24–48 h later?

High rumen osmolality pulls fluid into the rumen, creating intense thirst

What is the first therapeutic step for severe lactic acidosis if salvage slaughter is not chosen?

Rumenotomy with removal and replacement of ruminal contents

Which virus causes Bovine Respiratory Syncytial Virus infection?

Bovine respiratory syncytial virus (BRSV)

BRSV typically produces which gross lung pattern?

Diffuse interstitial pneumonia with subpleural emphysema

What class of drugs is given to control secondary bacterial pneumonia in BRSV cases?

Long-acting antimicrobials (e.g., tulathromycin, tilmicosin, florfenicol, enrofloxacin)

Enzootic pneumonia of calves is most frequently associated with which three bacterial pathogens?

Pasteurella multocida, Mannheimia haemolytica, Mycoplasma bovis

What is the characteristic lung lesion of Mannheimia haemolytica infection in calves?

Severe acute hemorrhagic fibrinonecrotic bronchopneumonia of the cranioventral lung

Spider Lamb Syndrome is caused by a mutation in which gene region?

Distal end of ovine chromosome 6 affecting fibroblast growth factor receptor 3

Give two classic skeletal deformities seen in Spider Lamb Syndrome.

Long bent “spider-like” limbs and kyphosis (hunched back)

What is the recommended management for lambs affected with Spider Lamb Syndrome?

Euthanasia due to severe, non-correctable deformities

Perosomus elumbis results from failure of development of which embryonic structure?

Notochord and associated caudal neural tube / paraxial mesoderm

Which spinal regions are typically absent in calves with Perosomus elumbis?

Lumbar, sacral, and coccygeal vertebrae

What tick species transmits East Coast Fever to cattle?

Rhipicephalus appendiculatus

Which antitheilerial drugs are highly effective when East Coast Fever is treated early?

Parvaquone and buparvaquone

At what altitude does Bovine High Mountain Disease (brisket disease) usually occur?

5,000–6,000 ft (1,500–1,800 m)

What cardiac chamber is characteristically hypertrophied in brisket disease?

Right ventricle

Name the plant genus containing swainsonine that exacerbates brisket disease.

Oxytropis or Astragalus (locoweed)

What is the etiologic agent of Bovine Spongiform Encephalopathy?

A prion (misfolded host prion protein)

Where does prion replication first occur after oral exposure in BSE?

Peyer’s patches of the ileum

Which clinical sign is especially suggestive of BSE in a dairy cow?

Hyperaesthesia and nervousness when handled

Louping ill virus belongs to which viral family?

Flaviviridae

What neuropathologic lesion is typical of louping ill in sheep?

Nonsuppurative polioencephalomyelitis in the brainstem

Congenital photosensitization in Southdown sheep is due to failure to excrete which photodynamic pigment?

Phylloerythrin

What gross renal change is observed in Southdown sheep with congenital photosensitization?

Radial fibrous bands in the medulla with numerous cystic tubules

What virus causes Goatpox?

Capripoxvirus

Describe the typical skin lesion progression in Goatpox.

Erythematous macules → raised plaques → necrosis with hard scab → star-shaped scar

Parturient paresis (milk fever) usually develops within how many hours of calving?

Within 72 h postpartum

Which intravenous compound is the treatment of choice for stage II milk fever?

Calcium gluconate solution

Prolonged inappetence and multiple isoflupredone injections predispose adult cattle to which electrolyte disturbance?

Hypokalemia

What is the preferred route for potassium supplementation in hypokalemic adult cattle?

Oral potassium mixed with feed

Which bacterial genus is the most common contagious cause of mastitis in dairy cattle?

Streptococcus or Staphylococcus spp. (either acceptable)

Name two non-steroidal anti-inflammatory drugs (NSAIDs) used to reduce mammary swelling in mastitis.

Flunixin meglumine and ketoprofen (others: flurbiprofen, carprofen, ibuprofen)

Brucellosis in cattle is most commonly caused by .

Brucella abortus

What is the most obvious clinical manifestation of brucellosis in pregnant cows?

Late-term abortion with retained placenta

Why is treatment of bovine brucellosis rarely attempted?

No practical or reliable therapy exists; control relies on prevention and culling

Which Brucella species primarily causes abortion and orchitis in goats and is highly pathogenic to humans?

Brucella melitensis

What is the classic lesion of Brucella ovis infection in rams?

Epididymal enlargement with spermatoceles containing inspissated sperm

Identify one screening chart used to detect early respiratory disease in dairy calves.

Calf Respiratory Scoring Chart

What management change is essential to aid recovery from enzootic pneumonia of calves?

Improve air quality and ventilation

Why is uterine prolapse a common sequela of parturient paresis?

Hypocalcemia weakens smooth-muscle tone, impairing uterine contraction and involution

What is the hallmark necropsy finding called the “bloat line” and where is it located?

Sharp demarcation of congested proximal esophagus and pale thoracic esophagus in bloat cases

Which pulmonary lesion is frequently seen in brisket disease due to pulmonary arterial thrombosis?

Atelectasis, interstitial emphysema, and edema with thrombi in pulmonary arteries