Diseases of Pigs Scott P. Terrell, DVM, Diplomate ACVP Veterinary Pathologist, Disney’s Animal Programs Instructor in Wildlife Pathology, UF CVM North American Veterinary Licensing Examination (NAVLE) 360 multiple choice questions 6 blocks of 60 questions Approx. 60 images (xrays, diagrams, photos, microscope images, etc) Total 7.5 hours 55-65% to pass (90% pass) North American Veterinary Licensing Examination (NAVLE) Blueprint by species Small animal • Canine 26% • Feline 22% • Pet bird 3% • Other (fish, lab, exotics) 3% Food animal • Bovine 15% • Pigs 7% • Sheep / goat 2% Horses 16% Public health, poultry 6% Gram positive or gram negative? SS BECLR DAMN (a ship) S - Staphylococcus sp. S - Streptoccoccus sp. B - Bacillus sp. E - Erysipelothrix rhusiopathiae C - Clostridium sp. L - Listeria monocytogenes R - Rhodococcus equi D - Dermatophilus congolensis A - Actinomyces (Arcanobacterium) pyogenes M - Mycobacterium sp. (acid fast) N - Nocardiasp. On to the pigs.... Ages of pigs are important Neonates 0-3 weeks <4 kg Weanlings/nursery 3-10 weeks 4-25 kg Growers/finisher 10-26 weeks 25-120 kg Breeders/adults >6-8 months >120 kg Pig management Backyard herds All in / all out SPF Segregrated early weaning Depop / repop Pig medicine Blood collection Jugular vein / anterior vena cava IV injection Auricular vein Rubberband Orderly thinking... Multisystemic Diseases Respiratory Diseases Gastrointestinal Diseases Neurologic Diseases Musculoskeletal Diseases Reproductive Diseases Dermatology Miscellaneous Multisystemic diseases Erysipelas (Erysipelothrix rhusiopathiae) Glasser’s disease (Haemophilus parasuis) Salmonella PRRS (arterivirus) PWMWS (circovirus) Pseudorabies virus (herpes virus) Vitamin E / selenium deficiency Erysipelas Erysipelothrix rhusiopathiae Gram positive rod Environmental contaminant most herds have carriers Septicemia diamond skin, arthritis, endocarditis, necrosis Diamond skin disease Valvular endocarditis Erysipelas cont... Treatment Penicillin Tetracyclins Prevention and control Sanitation Vaccinate at weaning and then q6 months Glasser’s disease (polyserositis) Haemophilus parasuis Gram negative coccobacillus Endemic, initiated by stress Polyserositis, septicemia (fibrinous) Pleuritis Pericarditis Peritonitis Meningitis!!! Glasser’s disease Glasser’s cont... Diagnosis Culture is difficult (but try it) Go with suspicion from gross lesions Treatment Penicillins Tetracyclins Prevention and control Reduce stress Vaccine at weaning then again 3-4 weeks later Salmonella sp. Salmonella cholerasuis Salmonella typhimurium Zoonotic Low-levelendemnicity, carriers Septicemia pyrexia, anorexia purple discoloration of the ears (infarction) Small or large intestinal diarrhea (button ulcers) Pneumonia Rectal strictures Salmonella Salmonella cont... Diagnosis Aerobic culture Treatment Neomycin in the feed/water for whole group Naxcel (ceftiofur) for individual Prevention and control Sanitation All in - all out operation Various vaccines (live avirulent) PRRS Porcine reproduction and respiratory syndrome Arterivirus Clinical signs - neonates anorexia, lethargy, fever cyanosis of the ears, respiratory distress secondary bacterial pneumonia delayed or abnormal estrus cycle with increased numbers of stillborns/mummies PRRS cont... Diagnosis serology, virus isolation IFA, IHC most common test used in the USA Treatment Supportive care, treat secondary bacteria Control closed herds change feed if contaminated by mycotoxins (*) RespPRRS vaccine Post weaning multisystemic wasting syndrome (PWMWS) Porcine circovirus -2 Relatively new disease Responsible for many of the clinical signs associated with “atypical PRRS virus”. PWMWS Clinical signs Wasting in weanling pigs Enlarged peripheral lymph nodes Evidence of pneumonia Diagnosis Necropsy- • Granulomatous lymphadenitis and pneumonia • Intracytoplasmic inclusions Serology, IFA PWMWS Treatment None Supportive care Euthanasia of affected animals Control Difficult at this time Carrier animals are important Pseudorabies Aujesky’s disease Herpes virus Dogs, cats, domestic ruminants Not humans! Pseudorabies cont... Baby piglets up to 100% mortality neurologic dz, vomiting, diarrhea Ulcers on oral cavity and esophagus Weanling/growers up to 60% mortality in weanlings, 0-15% in finishers pneumonia impt, neurologic dz, vomiting, extreme pyrexia Adults - often inapparent can cause stillbirth/abortion Pseudorabies cont... Reportable disease! Diagnosis Necropsy - • histologic lesions in brain, ulcers in gi tract Serum neutralization is standard test ELISA can be used as a screening test Treatment - none Prevention closed herd! quarantine! restrict wildlife vaccination Pseudorabies Pseudorabies Regulation use of vaccine regulated by states federal regulations for monitoring all animals over 6mo old must be tested 25% of herd tested q3months or... 10% of herd tested q1month White muscle disease / Mulberry heart disease Nursery or grower pigs Vitamin E / Selenium deficiency Propionic acid destroys Vit E / Sel Rancid fat can destroy Midwest U.S. is selenium deficient Clinical signs acute death (mulberry heart disease) muscle weakness (white muscle disease) Vit E / Selenium cont... Diagnosis Necropsy - hydropericardium, fibrinous epicarditis, myocardial hemorrhage Diffise hepatic necrosis - hepatosis dietetica Liver selenium < 0.5 ug/g Mulberry heart disease Cardiovascular disease Encephalomyocarditis virus Hog cholera African swine fever Erysipelas Vitamin E / selenium deficiency EMC virus Cardiovirus Clinical signs • neonates - sudden death • older pigs - subclinical chronic myocarditis Pathology • Epicardial hemorrhage often only lesion • May see white streaks or spots in myocardium • Heart may be enlarged, soft and pale • Hydropericardium, hydrothorax, pulmonary edema, etc. • Non-suppurative myocarditis, meningitis, encephalitis Pig EMC virus myocarditis Other cardiovascular conditions Hog cholera - FAD African swine fever - FAD Erysipelas - valvular endocarditis Vitamin E / selenium deficiency Mulberry heart disease Necrosis / degeneration of myocardium Respiratory diseases Atrophic rhinitis Swine influenza Mycoplasma pneumoniae Actinobacillus pleuropneumoniae Pasteurella Verminous pneumonia Atrophic rhinitis Bordatella bronchiseptica Pasteurella multocida High ammonia Clinical signs sneezing, sniffling twisted snouts excessive lacrimation epistaxis Atrophic rhinitis cont... Diagnosis Necropsy - cut snout at 2nd premolar Nasal culture for either organism Treatment tetracyclines in the feed LA200 to neonates Control and prevention all in all out, reduce stress, clean air vaccinate sows Atrophic rhinitis Swine influenza Influenza virus Zoonotic associated with movement or Outbreaks extreme weather changes up to 100% morbidity low mortality unless secondary bacterial infection complicates things Swine influenza cont... Diagnosis Necropsy - cranioventral pneumonia Fluorescent antibody test Treatment - supportive Prevention closed herd control secondary infections keep away from humans (no shows!) Mycoplasma hyopneumoniae Enzootic pneumonia Most common cause of chronic pneumonia Chronic, non-productive cough Low mortality Secondary bacterial complication Mycoplasma cont... Diagnosis Necropsy - “plum colored”or pale cranio-ventral pneumonia Culture to rule out secondary bacteria Fluorescent antibody test on lung Mycoplasma cont... Treatment - Lincomycin in feed Prevention - improve management Actinobacillus pleuropneumonia Intensive swine operations Inapparent carriers Peracute, acute, and chronic forms Clinical signs severe respiratory distress death Actinobacillus cont... Diagnosis necropsy - fibrinous pleuropneumonia often diaphragmatic lobes most severe culture is difficult complement fixation serology Treatment ceftiofur (Naxcel) and procaine penicillin Control vaccination of young pigs Contagious pleuropneumonia Pasteurella multocida Most common bacterial isolate from pig lungs opportunistic pathogen mycoplasma, influenza, actinobacillus, stress clinical signs moist productive cough dyspnea some die Pasteurella cont... Diagnosis necropsy - suppurative cranio-ventral bronchopneumonia may be pleuritis similar to actinobacillus culture Treatment - penicillin, tetracyclines Control look for underlying disease medicate feed and water (tetracyclines) Pasteurella pneumonia Verminous pneumonia Ascarissuum - direct life cycle Metastrongylus elongatus - earthworm intermediate Problem with pasture pigs Clinical signs poor doer respiratory distress Secondary bacterial infection “Milk spots” liver, worms in the GI Levamisole, ivermectin Gastrointestinal diseases Stomach Ulcers Small intestine E. coli (piglets) TGE (piglets) Clostridium (piglets) Coccidiosis (>7 days) Rota virus (post weaning) Salmonella (any) Gastrointestinal disease cont... Large intestine Swine dysentery (grower/finishers) Proliferative enteropathy (grower/finishers) • Hemorrhagic bowel syndrome • Proliferative illeitis Whipworms (growers) Salmonella (any) Gastric ulcer disease Almost always the pars esophagea Non-specific lesions Can lead to “bleed-out” Predisposing factors... Finely ground feed Stress Vit E/Selenium def Melena,ulceration of squamous portion of stomach, anorexia “Bleed out” Colibacillosis E. coli Most impt cause of diarrhea in piglets <5 days old!!! Clinical signs clear watery to pasty brown feces dehydration and depression death losses higher in younger pigs Colibacillosis cont... Diagnosis ph of feces (>8) culture of organism (large number) necropsy - dilated gas filled small intestine Treatment Ampicillin, tetracyclin, gentamicin, fluids Control sanitation, vaccination of sow Colibacillosis TGE - transmissable gastroenteritis Coronavirus (similar to FIP) Epidemic form (all ages) Endemic form (1-8 weeks old) WINTER disease Clinical signs Neonates - diarrhea with undigested milk Growers, finishers - diarrhea recovers <7days and mortality high in pigs Morbidity <2weeks old TGE cont... Diagnosis ELISA, immunoflourescence of gut contents Necropsy • undigested milk in small intestine • thin walled, transparent small intestine Treatment - supportive Control isolate new additions for 2 weeks, keep dogs and bird away (carriers) Immunization of sows or piglets Grind up piglet guts and feed to pregnant sows TGE Clostridial enteritis Clostridium perfringens type C sudden death in 1-2 day old piglets Clinical signs BLOODY DIARRHEA Diagnosis Necropsy - blood in jejunum with flecks of mucosa, necrosis of small intestine Clinical signs Histopathology - large gram positive rods Clostridial enteritis Clostridial enteritis cont.... Treatment usually die too quickly type C antitoxin Control Sanitation Type C antitoxin within minutes of birth Vaccination of sow Prophylactic bacitracin or penicillin to piglets Coccidiosis Isospora suis piglets 5 days old to weaning Clinical signs diarrhea (7-10 days of age) no blood acidic feces (in contrast to E. coli) Dehydration Coccidiosis cont... Diagnosis Diarrheas in pigs <7days old are not Isospora! Necropsy - fibrinonecrotic enteritis Histopathology - oocysts, merozoites Fecal flotation can be falsely negative Treatment Adding coccidiostats to feed is ILLEGAL amprolium to piglets Control - disinfection of farrowing area Coccidiosis Rota virus Reovirus Almost all pigs are infected Diarrhea in post-weaned pigs Diagnosis - difficult Necropsy-thin walled small intestine Histopathology Flourescent antibody test Electron microscopy Rota virus cont... Treatment Glucose and fluids Antimicrobials for concurrent infections • E. coli • Isospora Control Wean pigs on good nutritional diet MLV vaccine at 7 and 21 days (in water) Dont forget Salmonella Salmonella typhimurium Salmonella cholerasuis Fibrinonecrotic enteritis or colitis at necropsy Rectal strictures Culture of organism Swine dysentery Serpulina hyodysenteriae Grower / finishers Mortality can be up to 30% Clinical signs diarrhea sometimes with blood eventually watery, bloody, mucoid most recover in 2 weeks but 30% may die Swine dysentery cont... Diagnosis Necropsy - mucohemorrhagic colitis histopathology Spiral shaped organism on dark field microscopy Culture is definitive Treatment Lincomycin in water Control medicated water, depopulation, close herd vaccine only reduces clinical signs Swine dysentery Swine dysentery Proliferative enteropathy Lawsonia intracellulare proliferative illeitis, hemorrhagic bowel syndrome Large intestine Weanlings and older Clinical signs intermittant diarrhea can be hemorrhagic diarrhea anemia (think gastric ulcer first) Proliferative enteropathy cont... Diagnosis Necropsy - “garden hose” ilium and colon – can be hemorrhagic or fibrinonecrotic Histopathology - intracellular, silver positive DNA probes Treatment and control No specific treatment Reduce stress Medicate feed - tetracyclines, carbadox Proliferative illeitis Whipworms Trichuris suis 2-6 months of age Large intestine Clinical signs diarrhea with mucus and blood anemia (2 DDX?) Diagnosis - fecal float, fibrinnecrotic colitis Control - dichlorvos and fenbendazole Whipworms Don’t forget Salmonella! Salmonella typhimurium Salmonella cholersuis associated with rectal strictures? Can be large intestine Fibrinonecrotic colitis Rectal strictures Culture Parasites of pigs Trichuris suis - colon Ascaris suum - small intestine, milk spots Stephanurus edentatus - kidney Macrocanthorynchus hirudinaceous -small intestine Neurological diseases Hypoglycemia Streptococcus suis poisoning Salt Edema disease Hypoglycemia Newborn piglets Blood glucose <50 may develop signs Clinical signs convulsions shivering hypothermia gait abnormalities Hypoglycemia cont... Diagnosis Blood glucose Empty stomach Treatment 20ml/kg 5% glucosa, warm em up Control make sure the milk is flowing Streptococcus suis Streptococcal meningitis 3-12 weeks of age Clinical signs fever, anorexia, depression tremors, blindness, ataxia, convulsions Diagnosis Necropsy - suppurative meningitis Culture of CSF or meningeal swab Strep suis cont... Treatment penicillin, tetracyclines must be quick! Control minimize stress prophylactic antibiotics Can be zoonotic - meningitis, headaches Streptococcal meningitis Salt poisoning Usually due to water deprivation rather than too much Na Causes hyperosmalarity of CNS resulting in swelling and edema Clinical signs thirst, constipation depression, blindness, convulsions Salt poisoning cont... Diagnosis History Clinical pathology-eosinopenia, hypernatremia Histopathology - eosinophilic meningitis Treatment None Control provide free access to water reduce salt in diet Edema disease E. coli - toxin differs from GI form Shiga like toxin - vascular injury - edema 1-3 weeks post weaning Clinical signs sudden death ataxia, convulsions, palpebral edema Diagnosis palpebral edema, widespread edema in multiple sites Culture - pure culture from SI or colon Detection of toxin Edema disease Edema disease cont... Treatment ineffectual if clinical signs have developed Control Antibiotics in feed/water High fiber diets? Musculoskeletal diseases Arthritis S. suis, Erysipelothrix, A. pyogenes Mycoplasma hyosynoviae Myodegenerative disease Malignant hyperthermia (PSE) White muscle disease Rickets Fibrocartilagenous infarcts Osteochondrosis Suppurative arthritis Streptococcus suis Erysipelothrix rhusiopathiae Actinomyces pyogenes May see loss of cartilage Due to fighting, surgical contamination Distended joints, abscesses Penicillin - treatment often no good Suppurative arthritis Mycoplasmal arthritis Mycoplasma hyosynoviae 4-12 weeks of age acute or chronic lameness non-suppurative arthritis/synovitis edema of synovial tissue Lincomysin to treat Mycoplasmal arthritis Malignant hyperthermia Porcine stress syndrome, Pale soft edudative pork Autosomal recessive gene Stress predisposes Fighting, movement, handling Halothane anesthesia Clinical signs muscle tremors, dyspnea, red areas of skin, increased body temperature, muscle rigidity Malignant hyperthermia Treatment Remove stress Cool Dantrolene Control genetic selection - DNA probe avoid stress Malignant hyperthermia White muscle disease / Mulberry heart disease Nursery or grower pigs Vitamin E / Selenium deficiency Propionic acid destroys Vit E / Sel Rancid fat can destroy Midwest U.S. is selenium deficient Clinical signs acute death (mulberry heart disease) muscle weakness (white muscle disease) Vit E / Selenium cont... Diagnosis Necropsy - hydropericardium, fibrinous epicarditis, myocardial hemorrhage hepatic necrosis - hepatosis dietetica Liver selenium < 0.5 ug/g Treatment and control Vit E or selenium injection feed supplements Mulberry heart disease Rickets Ca/P imbalance or Vit D deficiency Decreased mineralization of bone 3-5 months of age Pathologic fractures Distorted bones Adjust diet Osteochondrosis Grower pigs Rapid growth Usually involves humero-radial joint Stifle less common Fibrocartilagenous infarcts Heavily muscled lean pigs Usually present down in hindlimbs Evidence of discospondylitis Rupture of nucleus pulposus Embolism of nucleus pulposus with subsequent infarction of spinal cord Reproductive disease Parvovirus Leptospirosis PRRS Cystitis/ pyelonephritis Brucellosis Porcine parvovirus 100% prevalence Signs depend on time of infection <30days - embryo resorbed 30-70days - mummy >70days - dead or weak, survive normally no other signs of illness SMEDI - stillbirth, mummy, embryonic death, infertility Diagnosis - detection of virus in mummy by immunofluorescence or by rising titer Parvo - SMEDI Porcine parvovirus cont... Control Natural infection of gilts before breeding Commingle gilts with sows Grind up mummies and feed to gilts Vaccination! • may still get some losses Leptospirosis Leptospira interrogans serovar pomona - most common serovar bratislava Clinical signs Pyrexia, last trimester abortion, stillbirths Diagnosis Culture difficult Dark field microscopy of fetal fluids, urine Serology (<1:800) Leptospirosis cont... Treatment Chlortetracycline in feed Control Vaccination Gilts twice before first breeding Sows before every breeding PRRS Porcine reproductive/respiratory syndrome Premature farrowing Small weak piglets or stillborns increased numbers of mummies Delayed or abnormal estrus Serology to diagnose Vaccination for prevention Cystitis / Pyelonephritis Eubacterium suis Clinical signs pyrexia, blood or pus in urine high urine pH Diagnosis necropsy - hemorrhagic cystitis Culture difficult - anaerobic Treatment - penicillin Brucellosis Brucella suis Clinical signs abortion at any time in gestation infertility - many sows coming back into heat infected sows recover and deliver normally Lesions mild endometritis arthritis orchitis Brucellosis Brucellosis cont... Diagnosis Serology - card test Culture Treatment and control Test and slaughter Zoonotic Abortions/stillbirths Parvo virus PRRS Pseudorabies Lepto Dermatologic diseases Mange Greasy pig disease Swine pox Erysipelas Pityriasis rosea (JPPD) PRRS associated vasculitis/glomerulonephritis Mange Sarcoptes scabei var suis Young nursery or grower pigs Clinical signs intense pruritis, thickened skin poor production susceptible to other diseases Diagnosis- clinical signs, skin scrape Treatment and control acaricide (amitraz) topically, ivermectin injection Mangy piglet Mangy piglet Sarcoptes scabei Histopath Greasy pig disease Exudative dermatitis Staphylococcus hyicus Affects late preweaning pigs Clinical signs exfoliation of skin, excess sebaceous secretion pruritis not a feature unless complicated my mange Diagnosis - clinical signs and culture Greasy pigs Greasy pig disease cont... Treatment Injectible penicllin, oxytetracyline Tetracyclines in feed Control Sanitation Control external parasites Good nutrition Swine pox Swine pox virus Only pigs less than 4months old Clinical signs papules 1-6 mm in diameter pustules, crusts clear spontaenously Diagnosis - clinical signs, biopsy intracytoplasmic inclusion bodies Treatment - not necessary Swine pox Erysipelas Erysipelothrix rhusiopathiae Diamond skin disease pigs 3months - 3years old Clinical signs widespread ecchymotic hemorrhages due to microthrombi arthritis, endocarditis Diagnosis Diamond skin lesions pathognomonic Culture of blood, joints, lung, liver Diamond skin disease Erysipelas cont... Treatment Penicillin is the drug of choice Control General sanitation Bacterins or attenuated live vaccines Pityriasis rosea Juvenillepustular psoriaform dermatitis Pseudo-ringworm Spontaneous regression PRRS associated Vasculitis/glomerulonephritis Newly described condition associated with PRRS virus infection Type III hypersensitivity reaction Causing vasculitis Dermal and cutaneous infarction Large red sloughing skin lesions usually over rear and legs Commonly associated renal disease PRRS vasculitis/glomerulonephritis Miscellaneous diseases Swine lice Baby piglet anemia Eperythrozoonosis Swine lice Haematopinus suis Indicator of poor management Clinical signs pruritis (mild), anemia, poor growing Diagnosis visible to naked eye Treatment - same as for mange Baby pig anemia Iron deficiency Piglets iron demand is greater than the sows milk Clinical signs anemia within 2-3 days of birth dyspnea, edema, pale skin, lethargy Diagnosis - clinical signs, CBC Treatment - 200mg iron dextran at 1-3 days of age Eperythrozoonosis Eperythrozoan suis Obligate intracellular parasite of RBC’s Clinical signs pyrexia, icterus, anemia intravascular hemolysis necropsy - large spleen Diagnosis - Giemsa stained blood smear Serology - 1:80 considered positive Eperythrozoonosis cont... Treatment Oxytetracycline injected or in feed Control Control lice and fomite transmission Surgical instruments, needles, etc... Pigweed Amaranthus retroflexus Common in southeast Severe perirenal edema Fumonensin Fusarium moniliforme Hypertension Arteriolar medial proliferation Hemorrhagic pleural and pulmonary edema* Foreign diseases Hog cholera pestivirus - splenic infarction is pathognomonic African swine fever iridovirus - hemorrhage in multiple areas Vesicular diseases of swine Foot and mouth disease - apthavirus* Swine vesicular disease - enterovirus Vesicular exanthema - calicivirus Vesicular stomatitis - rhabdovirus Case #1 Signalment: 10 weanling pigs History: dead and dying Necropsy findings: yellow fibrin covering lungs yellow fibrin covering abdominal organs meninges are reddened DDX? Case #2 Signalment: several growers History: poor doers, chronic cough Clinical signs: non-productive cough harsh lung sounds Euthanize and necropsy: cranioventral pneumonia, plum-red color DDX? Case #3 Signalment: 2 grower pig females History: diarrhea, weak Clinical signs: pale mucous membranes perineum stained with feces One dies - necropsy findings: Large intestine markedly thickened and contains small amount of blood DDX Case #4 Signalment: 1 piglet just weaned History: sudden death Clinical signs: dead! Necropsy findings: subQ expanded by fluid, eyelids swollen mesentery and omentum expanded by fluid Diagnosis? How do you confirm? Case #5 Signalment: breeding sows History: decreased fertility litters have contained dried up small fetuses Clinical signs: none in the sows DDX? How do you confirm your top differential? Case #6 Signalment: many weanlings History: lameness Clinical signs swollen painful hocks fever, one has pulmonary edema on xrays Aspiration of joint reveals pus DDX? Case #7 Signalment: young nursery pigs History: very itchy, bad skin Clinical signs: dermatitis, pustules intense pruritis, self trauma DDX? Diagnostic tests? THE END!!!