RUMINANT MEDICINE for Finals Flashcards
an infectious disease that affects sheep, calves, goats, and pigs.
CHLAMYDIAL POLYARTHRITIS
In sheep and goats, stiffness, lameness, hyporexia or anorexia, and ___________________ may occur.
concurrent conjunctivitis
Causative agent of Chlamydial polyarthritis
Chlamydophila (Chlamydia) pecorum (reclassified from Chlamydophila [Chlamydia] psittaci)
Most frequently, one of the causal lesions is present and the transition from the initial lesion to the joint infection is readily apparent. However, when a swollen foot is treated before the cause
has been established, a joint infection may have been ongoing for weeks before the true nature of the condition is diagnosed.
SEPTIC ARTHRITIS OF THE DISTAL INTRAPHALANGEAL JOINT
Infection enters the distal interphalangeal joint via three possible main sites:
1) the dorsal commissure of the interdigital space, via penetrating trauma or complicated footrot (interdigital phlegmon
2) sandcracks;
3) white line disease or retroarticular abscess.
Clinical signs
Increased pain, together with swelling of the anterior region of the coronary band in cases of sandcrack and white line disease, is suggestive of joint infection.
Treatment
Digital amputation is indicated in animals that have a limited life expectancy, eg, old or poor-producing animals. The procedure is
simple, quick, can be perfom1ed in standing animals under regional analgesia, and in most cases, produces rapid relief.
characterized by three soft, fluctuating
swellings between the ligaments of the femorotarsal joint. In some instances, this condition is heritable. It does not cause pain
or lameness. In later life, there may be a predisposition to arthritis.
• diagnosed by depressing the swelling of the
joint capsule at one location and palpating the fluctuation that is seen at another. There is no successful treatment.
SEROUS TARSITIS (BOG SPAVIN)
a worldwide disease of farm animals that results from ingestion of sclerotia of the parasitic fungus Claviceps purpurea, which replaces the grain or seed of rye and other small grains or forage plants, such as the bromes, bluegrasses, fescues, and ryegrasses.
ERGOTISM
___________ the first sign, may appear 2–6 weeks or more after initial ingestion, depending on the concentration of alkaloids in the ergot and the quantity of ergot in the feed. Body temperature and pulse and respiration
rates are increased.
Lameness
Treatment
• Cessation of exposure
• Temperate environment (shade and cooling in hot weather or warmth in cold weather); good bedding for animals with lameness and distal limb lesions
• Supportive treatment, including the use of antimicrobials if the distal limb lesions are infected; adequate and easily accessible food and water
_________________, which resembles ergot toxicosis, is believed to be caused by ergot alkaloids, especially ergovaline, produced by the endophyte fungus Neotyphodium coenophialum in tall
fescue grass (Lolium arundinaceum, formerly Festuca arundinacea).
FESCUE FOOT (FESCUE LAMENESS)
Clinical signs
It begins with lameness in one or both hindfeet and may progress to necrosis of the distal part of the affected limbs. The tail and ears also may be affected independently of the lameness. In addition to gangrene of these extremities, animals may show loss of body mass, an arched back, and a rough coat. Outbreaks have been confirmed in cattle, and similar lesions have been reported in sheep.
a disease complex of ruminants and horses caused by plant poisoning or mineral imbalances and characterized by extensive calcification of soft
tissues.
Enzootic calcinosis
Clinical signs of Enzootic calcinosis
- Stiffness and shifting limb lameness.
- Abnormal straightness of distal joints.
- Stiff, slow gait with short steps.
- Forelimbs primarily affected; some animals graze or walk on their knees.
- Tachycardia (rapid heart rate).
- Audible heart murmurs (if endocardial calcification is present).
- Prominent jugular venous pulse in some cases.
DISORDER OF BONES AND JOINTS
Ankylosing spondylosis
Degenerative Arthropathy
exostoses develop on the ligament of the ventral aspect of the lumbar vertebrae, primarily in older
bulls. Fracture of the exostosis and associated vertebrae causes pressure on the spinal cord, which results in severe ataxia or paralysis. There is no treatment.
Ankylosing spondylosis
This nonspecific condition affecting mainly the hip and stifle is characterized by degeneration of articular cartilage and eburnation of subchondral bone, joint effusion, and fibrosis with calcification of the joint capsule.
Degenerative Arthropathy
the partial or complete break in a bone, caused by
trauma, stress, or pathological conditions such as:
- Falls or slips, particularly on slippery or uneven surfaces.
- Vehicle accidents or being struck by heavy machinery.
- Kicks from other animals or collisions during handling.
FRACTURES
Clinical signs of Fractures
- Swelling, deformity, or abnormal angulation of the limb.
- Open wounds with exposed bone in compound fractures.
- Lameness or inability to bear weight on the affected limb.
- Reluctance to move.
Treatment
- Casting or Splinting: For simple, closed fractures in small ruminants or young animals.
- External Fixation: Using external pins or frames for stable immobilization.
- Internal Fixation: Surgical placement of plates, screws, or intramedullary pins in severe or displaced fractures.
- Amputation: As a last resort in irreparable fractures, especially in small ruminants.
seen in most breeds of cattle. The forms range from the so-called Dexter “bulldog” lethal in which the calf is invariably stillborn, to mildly affected
animals .
- improper development of the growth plate, causing dwarfism (brachycephalic or dolichocephalic).
DYSCHONDROPLASIA (BULLDOG CALF)
- Short faces, bulging foreheads, prognathism, cleft palate, large abdomens, and short legs are characteristic. They are approximately half normal size.
- common in hereford cattle
brachycephalic
- same general body conformation as the brachycephalic dwarf, except that it has a long head and does not have either a bulging forehead or prognathism.
- common in angus cattle
dolichocephalic
a hereditary condition of Jersey cattle, apparently
controlled by a simple lethal autosomal recessive gene. Some affected calves are born dead. Living calves appear normal at birth but are unable to stand because of incompletely formed muscles, ligaments, tendons, and joints. The shoulder and hip joints can be rotated in any direction without apparent discomfort.
Limber leg
a generalized, inherited bone defect in cattle, dogs, and cats, characterized by extreme fragility of
bones and joint laxity attributable to any of a large number of possible mutations of type I collagen.
Osteogenesis imperfecta
Clinical signs
The mechanical properties of the “soft” part of the
collagen/mineral composite in the bone appear to be altered. The long bones are slender and have thin cortices. Calluses and recent fractures may be present. The sclera of the eyes may be bluish. The inheritance is most likely polygenic
a metabolic bone disease characterized by a
systemic increase in skeletal mass. It is a rare disease that appears to be inherited as a simple autosomal recessive trait in Angus, Sinmmental, Dutch Holstein-Freisian and Hereford cattle.
Osteopetrosis
Signs
It is characterized by premature stillbirth 10 days to 1 mo before term, brachygnathia inferior, impacted molar teeth, and easily fractured long bones. Bone marrow cavities are absent and replaced by primary spongiosa. The fetal-like abnormal
intramedullary bone consists of chondroosseous tissue. Foramina of the skull and long bones are hypoplastic or aplastic.
Diagnosis
Diagnosis is confirmed by a longitudinal bisection of long bones revealing the diaphysis filled with a plug of bone instead of marrow.
also known as Hereditary chondrodysplasia, is an inherited, semi-lethal, musculoskeletal disease affecting lambs primarily of Suffolk or Hampshire breeds.
SPIDER LAMB SYNDROME OF SHEEP
The location of the locus causing spider lamb syndrome is ________________. This mutation causes an inactivation of normal fibroblast growth factor receptor 3, which produces skeletal. overgrowth in animals homozygous for the gene.
along the distal end of ovine chromosome 6.
Clinical Signs
Signs
• Limb Deformities:
○ Medial deviation of carpus and hock; bowed radius, ulna, and tibiae; thickened growth plates.
• Spinal & Skull Changes:
○ Kyphosis causing rounded backline; “Roman nose” skull with narrowed occipital condyles.
• Chest Abnormalities:
○ Flattened sternum due to dorsal deviation of sternebrae.
• Muscle Atrophy:
○ Predominant across affected lambs.
Also known as mule foot, is the partial or complete fusion of the digits of one or more feet. Reported in numerous cattle breeds, it
is most prevalent in Holsteins and is inherited as a simple autosomal recessive condition.
Syndactyly
a genetic defect of cattle, sheep, pigs, and
occasionally horses. In its most common form, the second digit is developed but the medial dewclaw is missing. The toes may be fused to give rise to polysyndactyly.
Polydactyly
twisted throughout its length in a configuration that displaces the abaxial wall by up to 360°. One or both lateral hind claws may be affected in cows >4 yr old.
CORKSCREW CLAW
Pathogenesis/Cause of corkscrew
Bone molding is seen in the distal phalanx, but it is not known whether this is a matter of cause or effect. Periarticular exostoses develop around the distal interphalangeal joint,
possibly resulting from strain of the distal abaxial collateral ligament. Pressure from the exostosis on the dermis of the wall probably accounts for the excessive growth of the abaxial wall
Treatment
• correctly trimming the hoof.
• however, it does not cure the animal but it helps animal get around for a while
• culling is recommended
named for its alleged likeness to a Persian
slipper. The claw is flat and curled upward to forn a square end. The horn is heavily ridged and has lost its shine, and the coronary band is rougher and darker than normal. Although there is no objective evidence to support the theory, the slipper foot is probably synonymous with chronic laminitis and may be a sequela of either acute or subclinical laminitis. Treatment is always disappointing. The claw can be shaped to approximate normal, but invariably it collapses and serious sequelae follow. Animals with slipper foot should be culled as soon as economically appropriate.
SLIPPER FOOT
occurs outside North America and consists of subcutaneous and intramuscular parasites
causing bleeding.
PARAFILARIA BOVICOLA/PARAFILARIA INFECTION
- ________________ nematode causing
parafilariosis in cattle - Transmitted by ________ (Musca autumnalis)
- Flies ingest _________ from infected animals
- Infective larvae passed to cattle via feeding
on _________
Parafilaria bovicola;
face flies;
larvae;
wounds or mucus
Clinical signs
• Intermittent skin bleeding, especially around
the collar, scapular region, and thorax
• Lesions resemble bruises and may ooze
blood for hours
• Inflammation, myiasis, and secondary
infections
• Severe cases can cause extensive tissue
damage, leading to carcass condemnation
at slaughter
___________________identification of clinical signs and blood microfilariae
___________________can show parasite eggs and microfilariae.
___________________ detect P. bovicola DNA in skin biopsies and exudates for more accurate diagnosis
Traditional methods; Examination of blood; Newer techniques (PCR assays)
- _____________________ - administered as a single injection.
- _____________________ - given in two doses at three-day intervals.
- Ivermectin (Virbamec LA);
- Nitroxynil (Wirecide F)
a small, filarial parasite that causes a circumscribed dermatitis along the ventral
midline of cattle.
STEPHANOFILARIASIS
- Stephanofilariasis caused by _______________
- Transmitted by __________________
- ___________ in dermis; __________ in skin
lesions - Flies ingest ____________ and transmit infective
larvae to cattle during feeding
Stephanofilaria stilesi;
horn fly bites
Adult worms, Microfilariae
microfilariae
manifested by pruritus and dermal irritation,
resulting in scratching, rubbing, and biting of infested areas.
Pediculosis
Different types of mange in cattle
- Chorioptic
- Sarcoptic
- Psoroptic
- Demodectic
transmitted by direct contact, survives off-host for 3 week
Chorioptes bovis
affects young, weak cattle
Demodex species
Mild lesions, hair loss, and moderate itching, is a clinical sign of?
Chorioptic
Severe itching, hair loss, and crusting, are a clinical sign of?
Sarcoptic
Intense itching, crusting, and rapid spread, are a clinical sign of?
Psoroptic
Chronic inflammation and no itching is the clinical sign of?
Demodectic
MANGE IN SHEEP AND GOATS
Sarcoptes scabiei
Chorioptes bovis
Psoroptes ovis
Demodex ovis
Psorobia ovis
Causes intense itching (sarcoptic mange)
Sarcoptes scabiei
Affects legs (chorioptic mange)
Chorioptes bovis
Causes severe lesions in sheep (psoroptic mange)
Psoroptes ovis
Caused by UV light, common in breeds with non-pigmented skin, like Herefords and Holstein
Squamous Cell Carcinoma
Caused by bovine leukosis virus (BLV), more common in dairy herds like Holsteins
Lymphosarcoma
