1. Clinical Bacterial Mastitis
Most common agent if herd is free of mycoplasma. Easily spread by hand milking or milking machine or if injury or infection of skin of teat. Treatment, even during dry period, often unsuccessful, so culling advised. Subclinical to gangrenous mastitis.
nonhemolytic, coagulase negative staphylococci
Some strains pathogenic, others cause no decrease in milk production or increase in somatic cell count.
Very commonly isolated from apparently normal goats.
Pasteurella (now Mannheimia) haemolytica
Chronic mastitis with abscess formation or acute gangrenous mastitis. May spread to teat from mouth of nursing lamb or kid with pneumonia if poor colostrum program or poor stall ventilation.
Can cause purulent mastitis or just abscessation of supramammary lymph nodes. Refer to lecture of 3.7.00. Organism grows on blood agar in 48 hours, is catalase positive.
Chronic mastitis, often from contaminated wash water or teat dip. Best to cull.
Brucella melitensis = Malta fever,
Especially in goats. May be subclinical or cause firm foci in the parenchyma, changes in the milk, and enlarged supramammary lymph nodes. Suspect if abortions in herd or humans infected. Reportable, slaughter.
Swelling, heat, firmness in udder. Maybe enlarged supramammary lymph nodes.
Lameness or starving lamb/kid often first sign noticed in nursing animal.
Abscesses or scar tissue palpated prebreeding if mastitis occurred after weaning.
Black plate (strip plate) allows comparison of milk from 2 halves for flakes, clots, watery secretion.
Drop in milk production or abnormal flavor to the milk.
California mastitis test detects DNA from increase in cells in milk, but normal goats in late lactation have cell counts above 1 million/ml. Is valid to compare the CMT of the 2 udder halves. Sheep and goats have apocrine milk secretion, with many cytoplasmic particles in the milk - some bovine cell counting methods give double the correct cell count when used in small ruminants.
Culture - include mycoplasma culture if herd outbreak, bilateral mastitis, etc.
Gangrenous mastitis - skin of udder half (and maybe ventral abdominal wall) cool and edematous, secretion red and watery.
Milk with 5 units oxytocin. Intrammary infusion and systemic administration of antibiotics. Fluid therapy and anti-inflammatory/analgesic drugs. Penicillin or oxytetracycline, cephapirin.
Cull to remove source of infection for others, select for resistance to mastitis.
d. Treatment of Gangrenous Mastitis
Penicillin or oxytetracycline, supportive care
Udder amputation under general anesthesia or epidural - can remove one or both halves.
Or, infuse 60 ml of 5% formalin into udder half to stop absorption of toxins.
Allow natural demarcation of dead tissue from udder and abdominal wall, debride after several weeks.
Control fly maggots.
2. CAE and Maedi-Visna (OPP) Interstitial Mastitis
Udder is firm at parturition. Very little milk can be expressed, but this milk is grossly normal, normal cell count, negative culture (and infective to kid/lamb). Round cells accumulate around ducts, eventually fibrosis. See lecture of 3.7.00
3. Mycoplasma Mastitis - special culture methods required. Ear mites can transmit a variety of mycoplasmas.
a. Mycoplasma agalactiae = Contagious Agalactia
Common in Mediterranean countries and Middle East, South Africa but not seen in USA. Septicemic stage (inappetent, depressed, unwilling to follow herd) followed by purulent mastitis and agalactia. Keratoconjunctivitis or arthritis may also occur in the herd. Apparently recovered animals continue to shed the organism.
b. Mycoplasma mycoides subsp mycoides Large Colony type
A common cause of pneumonia (pleuropneumonia) in goat kids in California dairies.
This agent is shed in the colostrum and milk of apparently healthy goats but can also cause mastitis. Control includes pasteurization of all milk to be fed to kids.
c. Mycoplasma putrefaciens
Has caused mastitis, agalactia, arthritis, and abortion in California goats. In addition to the classic separation of a milk sample into a granular sediment and a greenish-yellow supernatant, there is a foul odor with this organism. Fibrosis is absent and treatment unsuccessful. Most are agalactic in both udder halves, but some goats have subclinical mastitis. Culture and cull.
4. Prevention of Mastitis
Good nutrition of adult so nursing lambs/kids not chewing on teats. Avoid other udder injuries.
Clean dry housing.
Clean dry udder at milking, single service paper towels.
Properly adjusted milking machine or gloved hands
Teat dip with 1% iodine, chlorhexidine, etc.
Milk infected animals or those with skin lesions last.
Infuse dry treatment into udder if previously infected or early weaned.
Cull animals with mastitis or poor udder conformation.
Do not buy from herds with Staph aureus, mycoplasma, CAE/MV, etc.
Staph vaccines decrease severity of mastitis but do not prevent infection.
5. Additional Udder Problems
a. Staphylococcal dermatitis
Pustules on udder or moist dermatitis between udder halves. Antibacterial ointment, milk last.
The contagious ecthyma (orf) virus can spread to the teats of a lactating ewe or doe from the lips of the infected lamb or kid if the mother is not yet immune. Secondary Staph infection of the scabs is to be expected and leads to mastitis if the teat orifice is damaged.
Saanen goats with white skin on the udder, living in sunny regions, can develop warts (papillomas) on the udder. The problem can spread through the herd after purchase of an infected animal. Some self-cure at the end of lactation, some do not regress or return the next year, and a few transform into squamous cell carcinomas. In Australia, selection for Saanens with pigmented skin has helped to prevent warts
d. Witch's Milk and Precocious Udder
Witch's milk is present in the udder at birth, because of in-utero hormone stimulation (and increased hormone receptors?). Also occurs in human babies. Do not express milk or try to treat.
Precocious udder (udder development without pregnancy) occurs commonly in young kids and in pet goats in the spring. Prolactin effect? Complicated by prolonged progesterone of false pregnancy? Infuse dry treatment and stop grain feeding if owner unwilling to milk goat. If milk daily until October, easier to dry off when prolactin levels low. Udder amputation may be necessary in pet goat with large udder. Ovariectomy might prevent this problem in pet goats (theory not tested).
Gynecomastia occasionally seen in male goats - some remain fertile. (This milk is valuable in some cultures as aphrodisiac.)
Differential for inappropriate udder development includes mastitis, self-sucking, and neoplasia.
e. Extra Teats and Fused Teats
Hereditary - more common in meat and fiber goats, where little selection applied.
Selection for more teats in sheep did not increase milk production
Lamb may starve because it sucks only on extra teat.
If small and completely separate from main teats, owner cuts off with clean scissors
If fused with main teat, do not try to correct surgically (if animal is to be bred, exhibited, or sold)
f. Ectopic Mammary Gland
The embryonic mammary line extends from the thorax to the vulva. Occasionally udder tissue is present in the vulva and enlarges at parturition due to secretion of milk. Pressure gradually causes regression in 2 to 3 months, but swelling recurs at next parturition.
Care of the Neonate
1. Normal Birth
Vaccinate dam 3 to 4 weeks before parturition against tetanus/enterotoxemia C&D. Shear or at least remove wool from perineum (crutch) before lambing. Mother licks neonate dry, lamb or kid is up to nurse in 15 - 30 minutes. "Clip, dip, strip, sip" refers to routine care of the umbilicus (cut if long, dip in tincture of iodine), verify that milk comes easily from the teats, and that neonate nurses. Check for malformations. Pen together for 1 day if single, 2 days if twins, 3 days if triplets before mixing in barn with other ewe/lamb groups. Record date, dam, identification of lambs/kids, any problems..
Adequate colostrum provides antibodies and energy to avoid hypoglycemia and starvation as well as fat soluble vitamins A & D. Sick or malnourished mother does not produce enough colostrum, twins and triplets may not get enough. Do not hesitate to tube feed colostrum to small or weak neonate immediately: 50 ml/kg every 8 hours for first day. Also feed any neonate with empty abdomen (hold up by front legs to evaluate). Rubber feeding tube (18 French) passed without speculum to level of last rib. Slowly inject colostrum with syringe. Tube feeding does not interfere with bonding or cause inhalation pneumonia. Avoid transmitting paratuberculosis or CAE/MV with colostrum. Artificial colostrum usually does not provide adequate antibody transfer.
3. Hypothermia - Rewarming
If neonate is not licked dry or is born in a wet/windy place or does not consume colostrum immediately, it will develop hypothermia, especially if small (triplet, premature, mother malnourished). If kid is hunched or shivering or has a cool mouth and extremities and is not suckling, check rectal temperature. Normal 38.5 - 40 or 40.5. Dry with towel, tube feed if 37.8 - 38.5. Rewarm with heat lamp in addition to giving colostrum if 36.7 - 37.8. If still colder, hot water bath or warming box better. If must remove one of twins from mother for rewarming, Remove them both, or else she will not accept the treated one when it is returned. A wool sock over the body is safer than a heat lamp. A plastic coat protects lambs from rain.
4. Hypoglycemia - Intraperitoneal Glucose
If more than 5 hours old and can`t hold head up, brown fat (non-shivering heat source) will be used up.
Do not rewarm until a glucose source is given. Intraperitoneal injection of 20% glucose (25 ml small lamb, 35 ml medium lamb, 50 ml large lamb) with needle 2.5 cm to side and 2.5 cm below umbilicus prevents
convulsions during rewarming. Give systemic antibiotics. Do not use this technique if lamb has enteritis.
5. Grafting Lambs
An experienced mother will accept a newborn covered with birth fluids immediately after delivering her own lambs. If orphan is older, may help to tie its legs together so it appears helpless. The skin of a dead lamb can be put on an orphan until the milk from the adopting mother passes through it, but don't do this if first lamb died of starvation! A wooden stanchion to hold the ewe in place while the orphan nurses may result in adoption in 7-10 days. Short lambing periods, as with use of a vasectomized teaser ram before the breeding season, encourage the shepherd to work harder to save lambs.
6. Septicemia, Omphalophlebitis
Swollen umbilicus, swollen joints, lameness, meningitis suggest neonatal septicemia. Give systemic antibiotics for 5-7 days and improved colostrum program, treat umbilicus of each neonate with iodine. May also be septicemic from abortion disease (treat with oxytetracycline) or Listeria excreted in the milk of a mother fed silage.
7. Watery Mouth
Weak, drooling lamb. Appears to be an E. coli septicemia/toxemia in first few days, especially if inadequate colostrum. Improve colostrum program and delay castration and tail docking until 2nd day.
8. Nutrition, Creep Feed
Provide creep feed, preferably with coccidiostat, by 1 to 2 weeks of age. Permits more rapid growth and earlier weaning, especially of twins. Vitamin E/selenium supplementation necessary in some herds.
Common cause of squinting or tearing in young lamb or kid. Replace manually several times a day or inject 1 ml penicillin into eyelid or use wound clips to tighten skin. Some crush fold of skin with hemostats. Hereditary tendency - raise for meat, not breeding.
Most commonly cranioventral, Mannheimia haemolytica. Improve ventilation in stall, colostrum feeding, vitamin E/selenium (to prevent white muscle disease). Avoid bottle feeding weak lamb/kid. oxytetracyline, ceftiofur. Do not use tilmycosin in goats.
11. Cryptococcosis and Coccidiosis - see lecture of 4.7.00
12. Floppy Kid Syndrome - see lecture of 5.7.00
13. Fracture Repair
Fractures very common in indoor housed flocks and in bottle reared lambs. Almost all can be repaired with a light splint and a little white tape. Two tooth brushes for fractures low on limb, split plastic tubing or rolled paper splints for higher fractures. Tape hind limb up in sling if femur fractured. Three (-4 if older) weeks adequate for repair.
Bostedt, H., Dedié, K.: Schaf- und Ziegenkrankheiten, 2. Auflage
Behrens, H.: Lehrbuch der Schafkrankheiten
Smith, M.C.: Goat Medicine
Linklater, K., Smith, M.C.: Color Atlas of Diseases and Disorders of the Sheep and Goat
Martin, W.B.and Aitken, I.D.: Diseases of Sheep 2nd edition.
Zettl, K., Brömel, J.: Handbuch Schafkrankheiten