Chapter 15. Biology and Diseases of Ruminants Flashcards
Sheep, cattle, goats - taxonomy
- Order Artiodactyla (animals with cloven hooves)
- Suborder Ruminatia
- Family Bovidae - even number of toes, compartmentalized forestomach, horns; herbivores; derive all glucose from gluconeogenesis
- Subfamily Capra = sheep & goats
- Genus & subgenus Ovis = domestic sheep & wild Asian and European sheep
Domestic sheep
Ovis aries
Domestic goat
Capra hircus
-Originated from western Asian goats
Bovine taxonomy
- Subfamily Bovinae & genus Bos = all domestic and wild cattle, including yak and Banteng (Bali cattle)
- Subgenus Taurus = all today’s domestic cattle; originate from Europe
- Bos taurus - from Europe, no hump
- Bos indicus - Zebu cattle, have hump over withers and drooping ears
Sheep meat breeds
- Common meat breeds in US = Dorset, Columbia, Suffolk, Hampshire
- Smaller meat breeds = Southdown & Border Cheviot
Sheep wool breeds
-Merino, Rambouillet, Lincoln, Romney
Goat breeds
-Dairy, meat, fiber or skin types
Goat dairy breeds
- Alpine, Nubian, Toggenburg, La Mancha (rudimentary ears), Saanen
- All originated in Europe
- Nubian developed from crossbreeding British & stock with Egyptian & Indian doats
Goat fiber breeds
-Angora, Cashmere
Goat meat breeds
-Boer, Kiko, Pygmy
Cattle dairy breeds
-Common in US = Holstein (Holstein-Friesian), Brown Swiss, Jersey, Ayrshire, Guernsey
Cattle meat breeds
-Common in US = Angus, Hereford, Simmental
Ruminant research models
- Agricultural research
- Cardiac transplantation & preclinical models for evaluation of cardiac assist or prosthetic devices (vascular stents, cardiac valves)
- Embryo transfer, AI, control of reproductive system
- Genetic engineering - one proposed use is for production of proteins in milk that can be isolated later
- Sheep & goats - antibody production
- Sheep - basic and applied fetal research; circadian rhythms; olfactory cues and behavior
Natural disease models in sheep
- Congenital hyperbilirubinemia/hepatic organic anion EXCRETORY defect (Dubin-Johnson syndrome) = Corriedale
- Congenital hyperbilirubinemia/hepatic organic anion UPTAKE defect (Gilbert’s syndrome) = Southdown
- Gamma-glutamyl carboxylase deficiency = Rambouillet
- Lysosomal storage diseases, pulmonary adenomatosis (Jaagsiekte) = several breeds
Induced disease models in sheep
- Arteriosclerosis
- Hemorrhagic shock
- Copper poisoning (Wilson’s disease)
- Metabolic toxicosis
- Orthopedic procedures
- Drug discovery
- Implantation research
Goat research models
- Immunology
- Mastitis
- Nutrition
- Parasitology
- Vascular research - large, readily accessible jugular veins
- Inherited caprine myotonia congenita (‘fainting goats’) = model for human myotonia congenita (Thomson’s disease)
- Nubian inbred line = beta-mannosidosis & prenatal therapeutic cell transplantation strategies
- Osteoporosis
Cattle research models
- Ruminal fluid research, teaching, treatment of other cattle - fistula
- Bovine trichomoniasis (Tritrichomonas fetus) - model for human Trichomonas vaginalis
- Holstein - inherited cardiomyopathy; leukocyte adhesion deficiency syndrome
- Ayrshire - lipofuscinosis
- Shorthorn & Brahman - glycogenosis
- Saler - hemochromatosis
- Achrondroplasia in several breeds
SPF sheep, goats, cattle
- SPF sheep & goats housed in biosecure or closed flocks
- SPF cattle NOT typically available
‘Backgrounding’
-Preparation of cattle for research use with appropriate transition diet & vaccination schedule
Health screening program for sheep
-Q fever (Coxiella burnetti), contagious ecthyma, caseous lymphadenitis (Corynebacterium pseudotuberculosis), ovine progressive pneumonia, internal & external parasitism
Health screening program for goats
-Q fever (Coxiella burnetti), caprine arthritis & encephalomyeliis (CAE), brucellosis, TB, Johne’s disease (Mycobacterium paratuberculosis), caseous lymphadenitis, contagious ecthyma, mycoplasma
Minimum vaccinations for small ruminants
- Tetanus toxoid
- Other clostridial diseases
Health screening program for cattle
-Johne’s disease, brucellosis, TB, persistent infx with bovine viral diarrhea virus (BVDV), respiratory diseases, internal & external parasitism, foot condition (hairy heel warts, foot rot), bovine leukosis virus (BLV)
Vaccination recommendations for cattle
- BVDV, infectious bovine rhinotracheitis virus (IBR), bovine respiratory syncytial virus (BRSV), bovine parainfluenza-3 (PI-3), Leptospira spp.
- Depending on herd status, endemic diseases, geographic location, may also include: veneral diseases, clostridial diseases, pathogens causing neonatal diarrhea or respiratory disease, Moraxella bovis (pink eye), Fusobacterium necrophorum (foot rot), Staphylococcus aureus (mastitis), Histophilus somni, rabies
Regulations regarding ruminant laboratory management and husbandry
- USDA regulates use for biomedical & nonagricultural research = Code of Federal Regulations (CFR), 1985
- Guide for the Care and Use of Agricultural Animals in Agricultural Research and Teaching (‘FASS Guide’)
- Guide for the Care and Use of Laboratory Animals
- Animal Welfare Act
Common stressors for ruminants
- Standard husbandry practices: weaning, castration, dehorning, vaccinations, deworming or treatment for external parasites
- Shipping w/ assoc feed and water deprivation
- Introduction to new housing environments & novel personnel
- Intercurrent disease
Ventilation in confinement housing
- Proper ventilation is critical - ammonia buildup and other waste gases may induce respiratory problems
- In cold weather, if the ceiling, walls or water pipes condense water vapor, th ventilation should be increased at the expense of lower temps
- Adult goats & young cattle comfortable in colder temps if provided adequate dry dust-free bedding and draft protection
- Sheep, because of wool, tolerant to both hot and cold extremes
- Newborn lambs & recently shorn adults suscetible to hypothermia, hyperthermia, sunburn
Chain link fencing for ruminants
-DANGEROUS - goats & some breeds and ages of sheep like to stand on hind limbs against walls & may get forelimbs caught
Enrichment for ruminants
- Provide for singly housed animals - including regular human contact
- Singly housed or recently weaned calves, in particular, need play objects
Light intensity for ruminant housing
220 lux
Stomach anatomy of ruminants
- Forestomach = rumen, reticulum, omasum
- True stomach = abomasum
Rumen physiology
- Mature rumen functions as anaerobic fermentation chamber in which enzymes, including cellulase, of resident bacteria (10^9-10^10/mL) allow herbivorous diet
- Digestion in rumen aided by microorganism, including protozoa (10^5-10^6/mL) and fungi
- Produce volatile fatty acids (VFA: acetic, propionic, butyric)
- Fermentative digestion and VFA absorption also occur in the large intestines
- Rumen microorganisms synthesize B-complex vitamins & vitamin K & provide protein utilized by animal
- Large amounts of fermentation gases - CO2 and methane - are naturally eructated
Energy sources of ruminants
- Main source: VFA
- Glucose formed from propionic acid (or from amino acids) for metabolism in the CNS, uterus, and mammary gland
- Plasma glucose much lower & regulated differently in ruminants
Passive transfer in ruminant neonates
- Intestinal immunoglobulin absorption is crucial for success of passive transfer
- This transfer mechanism is functional for ~36 hr after birth
- Neonatal ruminants are immunocompetent - advantage utilized when vaccinating calves against common neonatal juvenile diseases when the dams’ colostrum is lacking antibody against those pathogens
Deciduous dental formula (sheep, goats, cattle)
2 (Di 0/3, Dc 0, Dp 3/3) = 30
Permanent dental formula (sheep, goats, cattle)
2 (I 0/3, C 0/1, P 3/3, M 3/3) = 32
MHC classes in ovines
-3 major histocompatibility classes identified: Class I, II, III
Bovine immune system
- Bovine lymphocyte antigen system (BoLA) - ranks after human HLA & murine H-2 systems in terms of depth of knowledge
- Complexity of immunobiology of the bovine mammary gland is being studied b/c mastitis very prevalent
- Several innate immune mechanisms & cellular defenses, and their variation throughout lactation, have been described
Bovine corneal epithelium
-Distinguished from other species by ability to heal without treatment, even when severely infected
Ruminant hematology
- Generally have fewer neutrophils than lymphocytes
- RBCs may become more fragile during rehydration = some hemolysis & hemoglobinuria
- RBCs smaller & more fragile than most other mammals; Hct tend to be overestimated unless blood samples centrifuged for extended periods
- Rouleaux formation: limited in sheep & goats, does NOT occur in cattle
- Normal caprine RBCs lack central pallor b/c flat & lack biconcavity; may exhibit poikilocytosis
- D/t high number blood groups in sheep & goats, transfusion reaction rates may be as high as 2-3% = crossmatching recommended - can give 10-20 mL/kg volumes
- Safe blood withdrawal volume - up to 10 mL/kg
Ruminant serum chemistry
- BUN values CANNOT be used to indicate renal function d/t metabolism of urea nitrogen by rumen microflora
- Because of large volume or rumen water, adults can generally go several days without drinking before significant dehydration; but dehydration can occur quickly in pre-ruminant neonates, animals that are ill
- Urine pH alkaline in adults
- AST & LDH not liver specific
- ALT CANNOT be used to evaluate hepatic disease in goats
- Gamma glutamyl transferase (GGT) & ALP are assoc w/ biliary stasis; elevations in GGT assoc w/ hepatic damage
Sheep hemoglobin & coagulation, blood groups
- Sheep have at least 6 different hemoglobins
- Coagulation similar to humans; at least seven blood groups identified in sheep (A, B, C, D, M, R, X)
Blood groups in goats
At least five (B, C, M, R-O, X)
Ruminant concentrate mixtures
Usually contain a protein source (soybean meal, for example), salt & other required macro- and microminerals, Vits A, D, and E
-Good quality pasture meets nutritional requirements for maintenance and growth of ruminants under many circumstances
Concerns with lush spring pastures?
- Especially those containing alfalfa
- Bloat, diarrhea, grass tetany, nitrate poisoning
- Feed good quality hay & slowly introduce to pastures
Ruminant eating habits
- Cattle & sheep = grazers
- Goats = browsers; will also eat seeds, nuts, fruits, woody-stemmed plants; since goats are selective eaters, tend to consume the leafy or more nutritious parts of plants & often don’t need grain supplementation; if goats need supplementation pelleted concentrate preferred otherwise goats will pick out large particles in mixes
Horse feeds
- May be fed to goats
- Should NOT be fed to sheep because sensitive to copper toxicity
Ruminant intake
- Goats: 5-8% of body weight dry matter intake
- Cattle: 4% body weight intake
Urinary calculi in male ruminants
- Assoc w/ rations that contain excessive phosphorus, low Ca:P ratio, elevated Mg
- Forage grasses high in silicates and oxalates
- Roughage sources should be analyzed for nutrient content
‘Flushing’ female ruminants
- Feeding does and ewes 200-400g of concentrate per head per day for several weeks before and after initiation of breeding season
- Thin pregnant does and ewes should receive supplemental grain & ad lib forage during last 6 weeks of gestation
Newborn ruminant nutrition
- All newborns must receive passive immunity from colostrum
- Colostrum contains concentrated maternal antibodies (mostly IgG1), functional leukocytes, cytokines
- Quality of colostrum impacted by vaccination program, dam’s condition & nutrition throughout gestation & at time of parturition
- Reliance on suckling in dairy calves has been assoc w/ failure or passive transfer - frozen or ‘banked’ colostrum may be used
- Holstein calf should receive its first 2-1 meal of colostrum within 4 hr of birth and should consume at least 100g of IgG within first 24 hr of life - in general, this can be met with 4L of good quality colostrum
- After 2-3 days, dairy calves can be fed milk replacer or whole milk; provide additional calories if ambient temps fall below TNZ
Juvenile ruminant nutrition
- Can be offered good quality hay be 1 week of age
- Rumen development in calves is enhanced by supplementation with a concentrate feed
- Commercial ‘starter’ feeds should be fed by 2-3 weeks of age
- Young animals should have access to fresh water at least twice daily if not continually
- Lambs and beef calves typically fed a ‘creep’ supplement to provide additional nutrient & accustom to solid feed prior to weaning
Reproductive physiology - sheep
- Seasonally polyestrus - estrus brought about by decreasing day length; some breeds cycle in both fall and spring
- Induce estrus cycling by maintaining females in 8:16 hr light:dark for 8-10 wees
- Older ewes tend to have multiple lambs; Finn & Dorset especially prolific
- Estrus detection: mild vulvar enlargment, mucus secretion; anxious, isolate from flock; use sterile ram to mark ewes in standing heat
- Can be ‘hand mated’ or ‘group mated’
- Ultrasound or interrectal Doppler for pregnancy detection - work best beyond 60 days gestation
- Commercial serums test for pregnancy specific protein B can be used beyond 30 days gestation in ewes and goat
Reproductive physiology- goats
- Seasonally polyestrus
- Estrus detection: uneasiness, tail switching/’flagging’, redness & swelling of vulva, clear vaginal discharge that becomes white by end of estrus, vocalization
- Ovulate within 7-10 days after introduction of a buck
- Most ovulate between 24-36 hr after onset of estrus - mate once signs of estrus recognized and every 12 hr until end of estrus
- Pregnancy detection: similar to sheep
- Dairy goats should have 6-8 week dry period for udder to fully involute & prepare for next milking period
Reproductive physiology - cattle
- Usually have singletons; twins can occur - evaluate females of male-female twins for freemartinism
- Estrus detection: standing heat - lasts 6-24 hr (usually 12-16 hr); clear vaginal mucous discharge; teaser animals with marking devices; blood progesterone levels, change in conductivity of cervical mucus, cange in vaginal pH, body temperature, changes in activity level via pedometry - hyperactivity, decreased feed consumption, flehmen, standing behind other cows resting their chins on their backs, licking, sniffing
- Ovulate 12-18 hr after onset of estrus
- Pregnancy detection: presume based on failure to return to estrus; ultrasound starting 28-32 days after insemination - fetal sex can be determined by ~55 days; rectal palpation at 30-40 days post conception; levels of pregnancy-specific protein B in serum or milk
Placentation in sheep, goats, cattle?
Epitheliochorial & cotyledonary
- Placentomes: infolded functional units of placenta; formed as result of fusion of the villi of the fetal cotyledons projecting into the crypts of the maternal caruncles (projections of uterine mucosa)
- Caruncles of sheep & goats = concave
- Caruncles of cows = convex
- Placentomes distributed between the pregnant & nonpregnant horns of the uterus; those in nongravid horn may be smaller
Husbandry considerations for pregnant ruminants
- Proper plane of nutrition (not overnutrition)
- Adequate exercise - confine to small pasture or sanitized maternity pen a few days to hours prior to parturition
- Outdoor parturition = less stress & intensity of pathogens
- Indoor maternity pens should be clean, dry, well bedded, well ventilated, well lit; water troughs/buckets elevated so offspring do not fall into them; sanitize between dams
- Clip & clean perineal area of ewes and does
- Check cow udder to ensure passive transfer to neonate
- Inexperienced heifers may act indifferent or aggressive towards calves
Parturition space requirements for sheep, goats, cows
- Doe & ewe: ~1.4-1.5 m^2 area
- Cow: 9 m^2 area
Parturition in sheep
- Ewes isolate themselves, restless, stamp feet, blat, periodically turn & look at abdomen
- Once contractions begin, lambs usually born quickly
- Most cases of dystocia d/t fetal malpresentation can be corrected via vaginouterine manipulation; occasionally C-section needed
- Cleanliness, sanitation, adequate lubrication very important for all ruminant obstectrical procedures
Parturition in goats
- Does nearing parturition will have obviously swollen udder & red swollen vulva; pelvic ligaments at base of tail relax; restlessness; vocalization; uneasiness; pawing at bedding; mucous discharge & moist tail
- Rectal temp drop ~24 hr prior
- Vaginal exam indicated if labor prolonged beyond 1 hour
- Induce parturition with prostaglandin F2alpha (PGF2α) - give 2.5-5 mg on day 144 of gestation - will deliver within 28-57 hr
Pseudopregnancy in goats
- One of the few ungulate species that commonly exhibit ‘false pregnancy’
- Abdominal distension; may develop hydrometra & ‘deliver’ large volumes of cloudy fluid at expected due dates
- Subsequent pregnancies can be normal
- Tx: prostaglandin
Parturition in cows
- Separate from herd; lift tail & arch back when within a few hours of delivering; most are recumbent during delivery
- Entire birthing process typically takes ~100 min - longer in primiparous animals & those carrying large calves
Postparturition in ruminants
- Monitor for delivery of fetal membranes within 12 hr of birth; if not expelled, monitor dam temp, attitude, appetite
- Do NOT manually remove placenta or give intrauterine boluses
- Cows & sheep occasionally eat placenta - may subsequently obstruct rumen outflow = remove delivered membranes to prevent
Management of ruminant neonates
- Identification: ear tag or ear notch
- Need high-quality colostrum within first 12-24 hr of birth
- Kids & lambs may need supplemental heat in cold weather
- To control transmission of infectious diseases (CAE, Johne’s) may remove immediately and hand feed heat-treated colostrum
- First feeding may be up to 125 mL colostrum (lamb, kid) or up to 4 L (calf)
- Dehorn & castrate kids within first few days of life- CAUTION with electric or butane dehorners b/c thin calvarium & small frontal sinus
- Calf dehorning occurs when hornbuds appear at 3-6 weeks & castration at 2-9 weeks
Freemartinism in cows
-Genetic female born as a twin to a male - results in anastomoses between blood-forming cells & germ cells - results in XX/XY chimera
-Occurs in 85-90% of phenotypic bovine femals born twin to males
-Female will often have abnormal vulva & clitoris & vagina is a blind end lacking cervix
-Singleton freemartins can occur if male fetus lost after 30 days gestation
(Twinning is common in goats - freemartinism in about 6%; intersexes seen in some goat breeds & when polled goats are mated; freemartinism rare in sheep)
Weaning in ruminants
- Lambs: offer grain & later roughage well in advance of weaning; can wean when consuming 0.6-0.8 kg per day creep feed; 6-8 weeks old most common, sometimes as early as 4 weeks
- Kids: offer forages within 1st week of life because naturally curious; reduced hand fed milk by 4 weeks; wean when 6-10 weeks or 18-25 lbs
- Dairy calves: wean at 4-7 weeks
- Avoid stressful procedures like castration, dehorning, vaccination in the week prior to & week following weaning
Passive immunity in ruminants
- Wanes gradually until young are about 6 months old
- Duration varies considerable in calves
- Calves can mount B & T cell responses to vaccination even in presence of colostral antibody = can start vaccinating at 4 months of age, or as young as 1-2 months of age & continue to booster until 7 months old & passive immunity is gone
Artificial insemination in ruminants
- More difficult in sheep than in cattles
- Laparoscopic AI: surgical AI into uterus via small abdominal opening - as high as 70% pregnancy rate with frozen semen but technical & expensive
- Cervical AI
- Transcervical AI: penetration through the cervix into uterus; up to 75% success in ewes
Synchronization of breeding in goats
- Goats in luteal phase of estrus - days 4-16 - are sensitive to PGF2α (2.5–5 mg IM) and will show estrus in 36–60 h post injection
- Induce ovulation via introduction of a buck (pheromones) - does ovulate within 6-10 days
- Vaginal pessaries of fluorogestone acetate left in place for 21 days in the doe followed by injection of pregnant mare serum gonadotropin (PMSG) at the time of pessary removal can be successful
Synchronization of breeding in cattle
-PGF2α or one of its analogs to induce luteolysis; vaginal suppository progestogens
-Sychronize ovulation via OvSynch: scheduled delivery
of PGF2α followed by gonadotropin-releasing hormone
-Estrus may be suppressed in beef heifers in a feedlot by feeding melengestrol acetate (synthetic progestogen)
Synchronization of breeding in sheep
- Expose ewes to vasectomized rams prior to beginning of normal fall mating period - pheromones released by males will stimulate female cycling
- Artificial or natural progesterones in feed, via parenteral injection, SC implant, vaginal pessaries
Embryo transfer in ruminants
- Removal embryos from superovulated donor & transfer to synchronized recipient
- Donor animal superovulated with gonadotropins & inseminated
- In sheep, remove embryos surgically about 1 week after breeding
- In cattle, nonsurgical transcervical flush
- About 75% of expected embryos can be recovered
- Pregnancy rates are ~70%
- Can also freeze embryos
- Disease screening for all animals involved important b/c several pathogens can be transmitted directly or indirectly - BVDV, bluetongue virus, infecitous bovine rhinotracheitis virus, mycoplasma
Castration of ruminants
- Sheep & goats: elastrator in animals less than 1 week old; crushing spermatic cord with emasculatome; surgical castration; debated topic
- Cattle: castrate no later than 3 months of age; if maximum hormone responsive muscle production important, may castrate older animals with sedation & analgesia
Management of male animals
- Rams may be housed together for most of the year; bucks are penned separately
- Ewes exhibit only a limited number of estrous cycles before becoming reproductively quiescent = critical that male can successfully breed & efficiently
- Breeding bulls in dairy operations should be monitored for excessive weight gain, lameness due to laminitis (d/t energy dense diets); immunize for venereal diseases, campylobacteriosis, trichomoniasis
Tail docking in cattle
- Relatively recent practice
- Believed it will minimize bacterial contamination of the udder & therefore milk
- Tails typically docked to ~10 inch length
- Published research to date does NOT support tail docking in cattle to improve cow cleanliness or milk quality
- Tail docking is common practice in sheep
Bruxism
Teeth grinding - associated with discomfort or pain
Ruminant behavior
- All ruminants are social animals = every effort should be made to allow contact among individuals in terms of either direct contact, sound, smell, or sight
- Cattle & sheep can hear at higher frequencies than humans and may react to sounds not perceived by handlers
- Movement of animals is simplified by proper facility design; ruminants have wide-angle visual field; movement often disrupted by contrasts such as light and shadows
Ruminant flight zone
- Minimum zone of comfort - will scatter when flight zone is penetrated
- Minimal flight distance can be modified by increasing handling of the animals & by working at the edge of the flight zone
- Always consider minimal flight distances when working with animals in chutes, pens, or other confined areas
Unique goat behaviors
- Browsers & orally investigative
- Inquisitive, restless, agile jumpers & climbers, mischievous
- Strong, high fences are essential
- Need adequate space for exercise, or boulders & rock piles for hoof maintenance and climbing
- Goats more tolerant of isolation than sheep & cattle, but goats are still social
Unique cattle behaviors
- Known for non-nutritive suckling, bar licking, tongue rolling
- Non-nutritive suckling greater in hungry calves & also immediately after milk meal = provide nipples & other clean noninjurious materials for animals to suck
- Non-nutritive suckling can transmit diseases - esp mastitis; hairball formation; behavior diminishes as animals weaned onto solid food
- Play activity and vocalization of calves mimic adult dominance behaviors; play more common in males, can be rough, often triggered by a change in environment
Social hierarchies in cattle
- Determined by dominance behavior, presence of horns, increasing age and body size
- Aggression most common among intact adult males
Food Animal Residue Avoidance Databank (FARAD)
- A food safety project of the USDA
- Information resource to prevent drug and pesticide residues in food animals and animal products
- Approved & off-label drug uses in ruminants, incl withholding times prior to slaughter, formularies, related information
Animal Medicinal Drug Use Clarification Act of 1994 (AMDUCA)
-Defines Extra-label drug use as: “Actual use or intended use of a drug in an animal in a manner that is not in accordance with the approved labeling. This includes, but is not limited to, use in species
not listed in the labeling, use for indications (diseases
and other conditions) not listed in the labeling, use
at dosage levels, frequencies, or routes of administration other than those stated in the labeling, and deviation from labeled withdrawal time based on these different uses”
-FDA under the provisions of AMDUCA recognizes the professional judgment of veterinarians and allows use of extra-label drugs by veterinarians within the context of a valid veterinarian-client relationship
-Extra-label use limited to circumstances when health of an animal is threatened or suffering or death may result from failure to treat
-FDA can prohibit extra-label use of a new animal drug if no sufficient analytical method exists for detection of residues and/or if drug poses a risk to human health
Extra-label drug use conditions
i. There is no approved new animal drug that is
labeled for the intended use that contains the
same active ingredient in the required dosage
form and concentration.
ii. A veterinarian has made a careful diagnosis and
evaluation of the condition.
iii. The veterinarian has established an extended
withdrawal period prior to marketing.
iv. The identity of the treated animal is assured and
maintained.
v. Ensure that no illegal drug residues occur in any
food-producing animal subjected to extra-label
treatment.
vi. The prescribed or dispensed extra-label drug must
bear labeling information which is adequate to
assure the safe and proper use of the product.
Extra-label use is PROHIBITED for which drugs?
- Chloramphenicol;
- Clenbuterol;
- Diethylstilbestrol (DES);
- Dimetridazole;
- Ipronidazole;
- Other nitroimidazoles;
- Furazolidone;
- Nitrofurazone;
- Sulfonamide drugs in lactating dairy cattle
(except approved use of sulfadimethoxine,
sulfabromomethazine, and sulfaethoxypyridazine); - Fluoroquinolones;
- Glycopeptides;
- Phenylbutazone in female dairy cattle 20 months of
age or older; - Cephalosporin (excluding cephapirin) use in cattle,
swine, chickens, and turkeys:
Using cephalosporin drugs at unapproved
dose levels, frequencies, durations, or routes of
administration is prohibited;
Using cephalosporin drugs in cattle, swine,
chickens, or turkeys that are not approved for
use in that species (e.g., cephalosporin drugs
intended for humans or companion animals);
Using cephalosporin drugs for disease
prevention.
Which classes of drugs are PROHIBITED for extra-label drug use in chickens, turkeys, and ducks (because they are approved for treating or preventing influenza A in humans)?
- Adamantanes;
2. Neuraminidase inhibitors
Actinobacillosis (‘wooden tongue’)
- Actinobacllius lignieresii: aerobic, nonmotile, nonspore forming, G(-) coccobacilli
- Widespread in soil & manure & normal flora of respiratory and upper GI tract of ruminants
- In sheep & cattle, causes sporadic, noncontagious, potentially chronic disease with diffuse abscess and granuloma formation in tissues of head and occasionally other body organs
- NOT DOCUMENT IN GOATS
- Clin signs: skin lesions - abscesses of tongue (cattle), lip lesions (sheep); soft tissue or LN swelling; draining tracts; swollen tongue protruding from mouth - difficulty prehending food, anorexia, excessive salivation
- Transmission: organism penetrates wounds of the skin, mouth, nose, GI tract, testicles, mammary gland; rough feed material and FBs may play role in causing abrasions
- Necropsy: purulent discharges of white-green exudate containing small white-gray granules drain from tracts
- DDx: Contagious ecthyma, caseous lymphadenitis and Actinomyces bovis (lumpy jaw) are the primary differentials, but rabies should also be considered
- Dx: cytology of discharge smears, biopsy
- Tx: IV sodium iodide; oral potassium iodide; clinical response within 48 hr of IV treatment starting; systemic ceftiofur, ampicillin, or florfenicol; surgical debridement & flush with iodine
- Prevent: Avoid poor quality, coarse feed; isolate or dispose of animals with disease
