Diseases Affecting 4H Sheep and Goats Dr. Chad Frank DVM, MS, DACVP CSU Veterinary Diagnostic Laboratory 1 Clostridial Diseases C. perfringens type D (Enterotoxemia) Usually sudden changes in diet Sheep- Acute, subacute or chronic neurologic disease Sudden death Goats- Acute form- young, unvaccinated animals Similar to sheep Subacute form- Adults Hemorrhagic diarrhea, neurologic signs Chronic form- Adults Watery diarrhea with blood and mucus, weakness, anorexia 2 Clostridial Diseases Lesions (epsilon toxin) Sheep-bicavitary effusion, petechiation, pulmonary edema, focal symmetrical encephalomalacia Goats- Acute form-similar to sheep Chronic form- fibrinohemorrhagic colitis +/- distal enteritis Subacute- combination of acute and chronic Diagnosis 3
Clostridial Diseases C. perfringens type C Hemorrhagic enteritis Suckling lambs and kids Abdominal pain and distension, dysentery, death Ileum and jejunum-hemorrhagic wall and blood or blood cast in lumen Hemorrhagic and necrotizing enteritis Eccymoses in multiple tissues Struck Adult sheep and goats 4 Clostridial Diseases Clostridium septicum and perfringens type A Abomasitis in sheep Clostridium novyi type A or C Big head Clostridium novyi type B and C. haemolyticum Necrotic hepatitis and bacillary haemoglobinuria Related to liver flukes 5 Coccidiosis Eimeria Lambs <6 months Kids 2-3 weeks after weaning Sheep E. ovinoidalis, E. ahsata, E. bakuensis Goats E. ninakohlyakimovae, E. christenseni, E. arloingi Watery diarrhea Dehydration, weight loss, poor growth Lesions Small intestine Yellow to white plaques on mucosa, hemorrhage, ulcerations 6
Ruminal acidosis Ingestion of excess carbohydrates-> decreased rumen PH (volatile fatty acids)- >altered rumen flora->lactic acid production- >further decrease in PH->rumen atony, dehydration, circulatory collapse, metabolic acidosis, damaged mucosa, +/-bacterial or fungal infection Gross lesions 7 Rumen fluid ph Smear Laboratory findings Rumen Acidosis 8 Bloat Primary tympany (frothy bloat) Legumes or high-concentrate rations Foam prevents free gas cap and eructation Secondary tympany (Free gas bloat) Physical or functional defect in eructation of gas Physical Internal or external obstruction of esophagus, interference with contraction of the forestomachs Functional Toxins, vagal nerve damage 9
Vagal Indigestion Type I Failure of eructation->free gas bloat Vagal damage Type II Failure of omasal transport (rumen distended with feed (not gas)) Functional or mechanical outflow disturbances Type III Abomasal impaction (primary or secondary) Primary-dry, course feed with inadequate water Secondary-altered abomasal motility or pyloric outflow obstruction 10 Type IV Vagal Indigesion Partial forestomach obstruction during late pregnancy 11 Bloat Clinical signs Distended abdomen (dorsal left paralumbar fossa), signs of colic, anxiety, vocalization, respiratory distress, recumbency, sudden death Cause of death? Postmortem findings Sawhorse stance, dark blood that clots poorly, hemorrhage, congestion and edema of head and neck, bloat line, foam (first few hours) Treatment Orogastric tube, trocar rumen, rumenotomy, antifoaming agents (e.g. poloxalene, dioctyl sodium sulfosuccinate, mineral oil) 12
Caseous Lymphadenitis Corynebacterium pseudotuberculosis Carrier animals, contaminated equipment, shearing wounds Wound infection->lymph node +/-internal viscera via lymphatic or vasculature Sheep-visceral form more common Goats-superficial form more common Chronic weight loss and poor production or subclinical 13 Caseous Lymphadenitis Lymph node-caseous necrosis and suppurative inflammation Visceral lesions Differential diagnosis Culture SHI 14 Nutritional Myopathy Vitamin E or selenium deficiency-oxidative injury Rapidly growing animals (usually >1 year) Cardiac form Death (within 24 hours), rapid onset of depression and respiratory distress Skeletal form Slower onset-weakness, stiffness, recumbent, dysphagia 15
Nutritional Myopathy Clinical pathology Increased CK, AST, and LDH Necropsy findings Pale and dry muscle, white streaks Measure levels in blood or tissue biopsy Differential diagnosis 16 Lentiviruses Caprine arthritis and encephalitis virus (CAE) Transmission Colostrum and milk Arthritis Adults, acute or chronic lameness Neurologic disease 2-4-month-old animals Ataxia and weakness Pneumonia Mastitis 17 Lentiviruses Ovine progressive pneumonia (Maedi-visna virus) Spread to lambs at birth Generally >2-years-old Signs Progressive weight loss with good appetite, exercise intolerance, arthritis, mastitis Gross lesions No effective treatment 18
Urolithiasis Intact and castrated males (increased prevalence in young) Struvite and calcium phosphate high concentrate and low roughage High phosphorus levels Calcium carbonate Silica Urethral process and sigmoid flexure Diagnostic tests 19 Complications Urolithiasis Acute urethral obstruction Urethral rupture Urinary bladder rupture (water belly) Hydronephrosis and hydroureter 20