diseases conditions of small ruminants

1. Diseases / Conditions of Small Ruminants National Board Review 2005

3. Drugs approved for use in sheep Naxcel� (ceftiofur) Procaine pen G Micotil 300 Erythro--200

4. Disbudding ideal age less than 2 weeks 3-5 days for buck kids 5-7 days for doe kids electrothermal dehorning 200-watt dehorner copper tip

5. Thermal meningitis

6. Tail docking

7. Castration

8. Chronic weight loss in small ruminants malnutrition dental attrition / periodontal disease social order & feeder space AED lameness neoplasia Johne�s disease CL CAE OPP scrapie internal parasites

9. GI Parasites Haemonchus contortus - abomasum - anemia Trichostrongylus colubriformis - small intestine - diarrhea Eimeria E. arloingi E. ninakohlyakimovae

10. Haemonchus severe anemia check mucous membranes (conjunctiva) FAMACHA

11. Treatment for coccidiosis Sulfas: sulfadimethoxine sulfaquinoxaline sulfamethazine Antibiotics: amprolium � Corid� (overdose can cause polio) Ionophores: lasalocid monensin Quinolones decoquinate

12. Levamisole toxicity Salivation Muscle tremors Ataxia

13. Johne�s Disease chronic, granulomatous, mycobacterial infection of the intestinal tract age of onset similar to cattle clinical course shorter in small ruminants chronic weight loss diarrhea is not a typical clinical finding in small ruminants

14. Johne�s disease

15. Johne�s disease Ways in which Johne�s disease differs in small ruminants vs. cattle: no diarrhea adults can become infected and develop clinical signs fecal culture unreliable AGID fairly accurate & good screening test

16. Caseous lymphadenitis - CL Corynebacterium pseudotuberculosis Highly contagious, chronic Abscessation of lymph nodes and /or visceral organs Eradication difficult: Poor response to antimicrobials Persists in environment Lack of reliable tests

17. Caseous Lymphadenitis � CLspecies differences Sheep Visceral form more common Prescapular / prefemoral Abscesses caseated Goats Superficial form more common Lnn. of head & neck Exudate uniform, pasty, green

18. Caseous Lymphadenitis - CL

19. Caseous lymphadenitis

20. Caseous Lymphadenitis - CL Transmission � contamination of superficial wounds*, inhalation, ingestion Source of infection � animals with draining external abscesses or via pulmonary abscesses

21. Caseous Lymphadenitis - CL Many serologic tests available � usefulness controversial False positives False negatives Synergistic hemolysin inhibition test (SHIT) has been found to be fairly reliable Sensitivity 98% in goats, 96% in sheep

22. Caseous Lymphadenitis - CL Aggressive culling recommended Or, split herd/flock into infected and clean groups Kids/lambs from infected ewes/does should be raised on pasteurized colostrum/milk Vaccination

23. Caseous Lymphadenitis - CL Treatment Long term antibiotics � 4-6 weeks Remove entire, unopened abscess Lance, drain, flush abscesses � isolate animal Intra-abscess formalin injection

24. Caprine Arthritis Encephalitis lentivirus (retroviridae) arthritis, induration of udder, chronic interstitial pneumonia, chronic weight loss in adults and progressive rear limb paresis (leukoencephalomyelitis) in young (2-6 months) transmitted by infected colostrum/milk more prevalent in dairy goats (low in Angora breed) ELISA test more sensitive

25. CAE severe arthritis (DJD) in adults (esp. carpi)

26. CAE leukoencephalomalacia in kids posterior paresis/tetraparesis

27. CAE kids should be removed from infected dams immediately after birth and fed heat treated colostrum (132.8o F, 60 mins.) and pasteurized milk (165o F, 15 secs.) or colostrum/milk from negative does horizontal transmission also occurs no vaccine no treatment

28. Scrapie A fatal , degenerative neurological disease of sheep & goats � a TSE Main clinical sign = chronic weight loss Takes years to develop disease, therefore a disease of adults Scrapie in the US prevents sale of stock, semen, embryos to many foreign countries

29. Scrapie Signs appear 2-5 years after infection Clinical course 1-6 months, death inevitable Pruritus, head pressing, disorientation, abnormal gait Scratching their back elicits nibbling, lip smacking Differentials OPP, listeriosis, pregnancy toxemia, rabies, polioencephalomalacia

30. Scrapie Australia & New Zealand are only scrapie free countries Usually affects Suffolk breed Etiologic agent unknown � possibly a prion � resistant to heat & sterilization Does not evoke an immune response Spread from infected ewes to lambs by contact with placenta & fetal fluids

31. Scrapie the affected animal and it�s family are destroyed (dam, sire, offspring, full & half sibs) if two or more family lines are affected, the entire flock is slaughtered codon 171 gene typing indicates susceptibility occurs most often in Suffolk breed occurs in goats but is rare eradication program currently underway

32. Scrapie Eradication program Identifying pre-clinical, infected sheep Slaughter surveillance Tracing of animals to flock/herd of origin Provision of indemnity, live animal testing, genetic testing

33. Scrapie Scrapie eradication program started in the US Due to inability to market stock, semen, embryos to foreign markets Because of the public attention received concerning TSEs

34. Scrapie Diagnosis Histopathology � vacuolated neurons in medulla oblongata Immunohistochemistry (PrP-Sc) Western immunoblot Immunohistochemistry of lymphoid tissue of 3rd eyelid, antemortem

35. OPP vs OPA OPP (maedi-visna) retrovirus, chronic progressive pneumonia (mastitis, arthritis), all affected animals die within a year of development of clinical signs, no treatment, no vaccine OPA (jaagziekte) retrovirus, contagious lung neoplasm, elevation of hindquarters results in copious amounts of mucus running from nose, no treatment, no serological tests available

36. OPA

37. AED of Suffolk sheep abomasal dilatation and mechanical transport failure etiology unknown elevated rumen chloride (>15 mEq/L) most affected animals die rumenotomy + metaclopramide (dopamine antagonist, stimulates abomasal emptying) used for treatment

38. Lameness ovine contagious footrot Dichelobacter nodosus and Fusobacterium necrophorum separation of affected and unaffected animals frequent trims footbaths ZnSO4 vaccination

39. Contagious ecthyma orf, sore mouth, contagious pustular dermatitis parapoxvirus morbidity near 100% mortality as high as 20% in young zoonotic live virus vaccine available sloughed scabs may remain infective for years carrier sheep & goats occur

40. Contagious ecthyma

41. Azalea toxicosis Rhododendron spp. toxic principle = grayanotoxin 0.1# or 1.6 oz /100# bwt. folage is toxic depression, salivation, abdominal cramps, regurgitation, fine m. tremors mineral oil, activated charcoal, fluids can test for toxin in feces or urine

42. Pregnancy toxemia occurs in over-conditioned ewes & does in last 2-4 weeks of gestation usually multiple fetuses anorexia, depression, weakness, neuro signs (star gazing, circling, tremors, teeth grinding, appear blind) negative energy balance d/t fetal demands ketonuria*, acidotic, hypocalcemic

43. Pregnancy toxemia pale, friable, fatty liver on necropsy treatment induce parturition dexamethasone (15-20 mg) in ewes dexamethasone (10 mg) or PGF2? (10?g) in does C-section IV dextrose (5-10%), rumen transfaunations, 15-30 ml propylene glycol P.O. q12h, calcium, lactated ringers, B12 , biotin prognosis guarded to poor

44. Pregnancy toxemia typical fatty liver

45. Pinkeye (keratoconjunctivitis) Mycoplasma conjuntivae in goats* and sheep (also responsible for respiratory disease) usually recover spontaneously in 10 days topical or parenteral tetracycline Chlamydia psittaci in sheep (also causes abortion & polyarthritis) follicular conjunctivitis, inclusions tetracycline (topical or parenteral)

46. Pinkeye advanced lesion � cornea opaque

47. Mastitis in goats most common isolate from subclinical mastitis in does = Staph (coag. neg.) does have higher somatic cell count than cows Mycoplasma mycoides can cause mastitis in does / pneumonia & arthritis in neonates CAE can cause severe agalactiae & fibrosis, called �hard bag�

48. Mastitis in sheep causes of gangrenous mastitis (blue bag) in ewes: Mannheimia hemolytica Staph aureus �hard bag� caused by OPP (fibrosis of udder)

49. Gangrenous mastitis

50. Skin diseases Staph dermatitis - udder impetigo - nodules, pustules, scabs common on teats, udder, perineum, underside of tail in dairy goats lumpy wool disease = Dermatophilus orf

51. Skin diseases sheep keds Melophagus ovinus wingless fly, resemble ticks fly feces stain wool causes skin irritation, pruritis, wool damage, blood loss more prevalent in fall/winter

52. Dentistry dental formula for sheep and goats: 2 X (I 0/4; C 0/0; P3/3; M 3/3) = 32 eruption of permanent incisors: I1 1 year I2 2 years I3 3 years I4 4 years

53. Dentition

54. Copper toxicity fatal hemolytic crisis (mainly sheep) anemia, hemoglobinuria, icterus sources - incorrect rations, trace mineralized salts, chicken litter, copper sulfate footbaths �gun-metal gray� kidneys treat with D-penicillamine (chelator) & ammonium molybdate

55. Copper toxicity icterus

56. Copper toxicity gun metal gray kidneys

57. Goat Reproduction - Does does are seasonally polyestrus, cycle with decreasing daylight estrous cycle length = 21 days short cycles (5-7 days) occur & are normal at beginning and end of season (transition periods) standing heat lasts 24 hrs. ovulation occurs near end of standing estrus & 24 hrs. after peak LH estrus can be induced by intro of a buck or �buck jar�, this first ovulation is accompanied by estrus and is fertile, in contrast to ewe*

58. Goat Reproduction - Does anestrous breeding: melatonin progestin + PMS sudden intro of a buck decrease light exposure (artificially lengthen then shorten day) PGF2? doesn�t work, no CL weaning kids doesn�t cause them to cycle

59. Goat Reproduction - Does gestation 145-150 days CL supplies progesterone to support pregnancy therefore, drug of choice to induce parturition (or abortion) after day 5 = PGF2? elevated urinary estrone sulfate concs. 50 days post-breeding is an accurate indication of pregnancy transabdominal US for pregnancy diagnosis is most accurate from 45-100 days of gestation lochia may be discharged for up to 3 wks. post-partum

60. Goat Reproduction - Does pseudopregnancy or false pregnancy common in goats - some develop w/o exposure to buck assoc. w/ retained CL and prolonged elevations in progesterone appears as hydrometra on US (no fetus) may resolve spontaneously early in course with evidence of bloody vulvar discharge may resolve late as �cloudburst� of fluid treatment with prostaglandin

61. Pseudopregnancy

62. Sheep reproduction - ewes show few signs of estrus unless a male is present, almost no homosexual interaction (same is true of does) estrous cycle = 17 days, estrus avgs. 36 hrs., ovulation spontaneous 24 hrs. after onset of estrus placenta maintains pregnancy after it�s established (>50 days), therefore, PGF2? will not be effective to abort or induce (use dexamethasone, late) introduction of a ram (or teaser) causes ewes to ovulate (no estrus), subsequent estrus 17 days later is ovulatory & fertile = �ram effect�

63. Polled intersex goats affected animals are genetic females (XX) may display male, female, or mixed characteristics phenotypic females enlarged clitoris, decreased ano-genital distance, odor, atretic vagina phenotypic males testes scrotal (hypoplastic), inguinal, abdominal, hypospadias, shortened penis, no sperm

64. Intersex goats intersex can be prevented by making sure at least one parent is horned not reported in Nubian and Angora (these breeds have different horn inheritance)

65. Goat Reproduction - Bucks & Rams scrotal circumference is highly related to semen producing capacity - sexually mature rams should have a scrotal circumference of at least 30 cm - bucks have a smaller scrotal circumference than rams (quite variable with breed) semen check before breeding season important common cause of sterility in bucks is sperm granuloma

66. Causes of abortions in sheep & goats Toxoplasmosis* Chlamydia* Campylobacter Bluetongue Q fever (Coxiella burnetii) Border disease Listeria Brucellosis *most common causes of abortion in goats in U.S.

67. Chlamydia psittaci common cause of abortion in sheep & goats also called enzootic abortion of ewes (EAE) 4th or 5th month abortion placentitis - cotyledonary and intercotyledonary necrosis transmission by ingestion tetracycline treatment of choice vaccine available

68. Campylobacter C. fetus, spp. fetus common cause of abortion in sheep, less common in goats transmitted by ingestion abortion in last 6 weeks of pregnancy foci of necrosis in fetal liver highly suggestive of campylobacter vaccine available

69. Toxoplasmosis common abortifacient in sheep & goats small white foci of mineralization on cotyledons cats serve to spread disease (ingestion of oocytes from feed or grass contaminated with cat feces) zoonotic disease diagnosed by detection of antibodies in body fluids or presuckling serum of fetus abortion at any stage

70. Toxoplasmosis focal necrosis of the cotyledons

71. Bluetongue orbivirus any stage abortion Border disease ovine pestivirus any stage abortion �hairy shaker� lambs Q fever Coxiella burnetii, zoonosis** abortion near term, tetracycline Listeriosis late term, tetracycline

72. Border disease �Hairy Shakers�

73. Nutritional myodegeneration(white muscle disease) vitamin E / Se deficiency young rapidly growing lambs / kids two syndromes cardiac form - sudden onset, sudden death skeletal form - slower onset, muscle weakness, stiffness ? recumbency ? death ? CPK, ? AST, ? LDH skeletal muscle degeneration, pale discoloration, white streaks in muscle bundles treat with vitamin E / SE

74. Veratrum californicum teratogen = cyclopamine if ingested by ewe on day 14 of gestation, lambs lack pituitary or have deformed hypothalamic stalk & 2o adrenal hypoplasia leading to prolonged gestation cyclopian lambs born

75. Oestrus ovis nasal bots of sheep & sometimes goats adult flies deposit larvae around nostrils adult flies annoy sheep, cause sneezing, nose rubbing, feet stamping and lost grazing time ivermectin (200 mcg/kg) effective

76. Pneumonia in sheep and goats Mannheimia hemolytica Pasteurella multocida Haemophilus spp. Mycoplasma mycoides ssp. mycoides Salmonella PI3, RSV, adenovirus

77. Mycoplasma mycoides ssp. mycoides (Mmm) usually affects kids high fever, polyarthritis, pneumonia CNS signs in kids, mastitis in does necropsy: fibrinopurulent polyarthritis treatment: tylosin or tetracycline - not very effective carriers may develop so culling of kids with swollen joints and does with positive milk cultures is important

78. Bluetongue clinical disease mostly restricted to sheep orbivirus (cross reacts with epizootic hemorrhagic disease, EHD, of deer) Culicoides transmission clinical signs: edema of face, salivation, hyperemia of oral mucosa, cyanotic tongue, lameness, stiffness (coronitis, myopathy), breaks in wool, abortion, teratogenic affects

79. Cl. perfringens, type C necrotic enteritis of neonatal lambs (calves & pigs, too) ?-toxin responsible (trypsin inhibitors in colostrum prevent breakdown of toxin by proteolytic enzymes) rapid death, treatment usually unsuccessful, antitoxin vaccinate dam with toxoid before lambing

80. Cl. perfringens, type D enterotoxemia, overeating disease, pulpy kidney disease more prevalent in sheep, usually feedlot lambs (well-fed, fast growing animals) sudden death epsilon toxin glucosuria**, hallmark of disease sublethal doses cause CNS disease - FSE, focal symmetric encephalomalacia vaccinate with toxoid

81. Cl perfringens, type D

82. Ulcerative posthitis Corynebacterium renale pizzle rot, sheep & goats high protein diet, high level of urinary urea, alkaline urine, C. renale hydrolyzes urea to ammonia, ammonia cytotoxic, causes ulcerations on prepuce treat with CuSO4, antibiotics, shear prepuce internal posthitis can cause urinary obstruction

83. Copper deficiency low dietary copper (1?) or alteration in absorption or metabolism (2?) hypocuprosis diarrhea, ? weight gain, ill thrift, poor wool quality (stringy or kinky), anemia, spontaneous fractures, epiphysitis, demyelinization (enzootic ataxia or swayback of lambs/kids)

84. Obstructive urolithiasis due to rations high in grain (phosphorous = phosphate calculi) alkaline urine urethral process, small urethral diameter prevention: no grain or balance ration so Ca:P is 2-2.5:1, urinary acidifiers (ammonium chloride or sulfate), salt

85. Differentials for neurologic disease in small ruminants polioencephalomalacia tetanus FSE lead toxicity thermal meningitis bacterial meningitis Listeriosis CAE swayback rabies pseudorabies hepatoencephalopathy water deprivation scrapie Parelaphostrongylus tenuuis (meningeal worm)

86. Polioencephalomalacia thiamine (B1) deficiency may be 2? to grain overload any ration change can initiate polio as can certain drugs (ace, TBZ, levamisole, amprolium, sulfates) thiaminase (I & II) producing bacteria causes laminar necrosis in cortical gray matter

87. Polioencephalomalacia clinical signs: star gazing, ataxia, opisthotonus, dorsomedial strabismus, blindness diagnosis based on clinical signs, response to treatment, ? erythrocyte transketolase treat aggressively with thiamine HCl brain may fluoresce with UV lamp (ceroid lipofuscin pigment)

88. Polioencephalomalacia

89. Polioencephalomalacia

90. Listeria monocytogenes neurologic dz, abortion, septicemia usually individual animal disease source of organism ? rotting vegetation droopy ear, eyelid, lip (unilateral), circling, xs salivation (may lead to metabolic acidosis) mononuclear cell meningoencephalitis (resembles GME)

91. Listeriosis

92. Tetanus Clostridium tetani, anerobe, wound or incision contaminant small ruminants very susceptible, always vaccinate (Cl. perfringens C & D and tetanus - CD-T) muscle rigidity progressing to respiratory arrest �sawhorse stance�, erect ears & tail, flashing of 3rd eyelid, hyperesthesia

93. Tetanus toxins: tetanospasmin, tetanolysin, nonspasmogenic toxin treatment: quiet, tranquilize, antitoxin, penicillin, wound debridement no characteristic post mortem lesions

94. Tetanus

95. Spider lamb syndrome chondrodysplasia, lethal autosomal recessive, Suffolk, Suffolk X, Hampshire breeds kyphosis, scoliosis, angular limb deformities, roman nose (deformed maxilla) radiographs diagnostic: wide, irregular growth plates with retained islands of cartilage in olecranon, sternum, spine, long bones

96. Spider lamb syndrome

97. Vaginal prolapse

98. Rectal prolapse in sheep Factors predisposing to development of rectal prolapse short tail docking (tails should not be docked shorter than the distal end of the caudal tail fold) coughing overconditioning straining urolithiasis diarrhea dystocia

99. Rectal prolapse

100. Rectal prolapse repair

101. Rectal prolapse repair