23. Non-infectious, infectious, & parasitic diseases of nervous system in respective pig categories

(Sunstroke, overheating, Congenital tremor, Adenovirus infection, Aujezsky’s disease, Teschen disease, Viral encephalomyocarditis, Japanese B encephalitis, Eastern encephalomyelitis of horses, Coronavirus encephalomyelitis in piglets, Nipah-virus disease, Blue eye disease, Rabies, Streptococcus meningitis, Listeriosis, Tetanus, Toxoplasmosis)

What are examples of non-infectious, infectious, and parasitic diseases of the nervous system?

1. Non-infectious

   1. Sunstroke/hyperthermia

   2. Congenital tremor

   3. Hydrocephalus, intoxications, iron toxicity, hypothermia, hypoglycaemia

2. Infectious

   1. Aujeszky’s

   2. Rabies

   3. Teschen disease

   4. Coronavirus encephalomyelitis

   5. Viral encephalomyocarditis

   6. Blue-eye disease

   7. Nipah

   8. Porcine meningitis

   9. Tetanus

3. Parasitic

   1. Toxoplasmosis

   2. Ascaris suum

What is the main cause of sunstroke and hyperthermia in swine?

Extreme temperatures and water shortages

What can sunstroke and hyperthermia in pigs lead to?

Weakness, diarrhoea, acute distress, and even death

What are common clinical signs of sunstroke and hyperthermia in swine?

Stress, tachypnoea, muscle tremor, weakness, vomiting, diarrhoea, pyrexia, convulsions, spasms

What is the treatment for sunstroke and hyperthermia in pigs?

Emergency fluids and electrolytes, cold water into the rectum, and cold water spray

What is congenital tremor in pigs?

A sporadic disease seen in newborn pigs, marked by tremors and shaking of the head and body

What are the causes of congenital tremor in pigs?

Circovirus, classical swine fever, genetic factors, teratogens, Aujeszky's disease, Japanese encephalomyelitis virus

What are the clinical signs of congenital tremor in pigs?

Tremor during waking moments, difficulties in walking and feeding, spontaneous recovery, exacerbation by cold and excitement

How can congenital tremor in pigs be managed?

Assisted feeding and immunisation of gilts

What other non-infectious conditions can affect pigs besides sunstroke and congenital tremor?

Hydrocephalus, intoxications, iron toxicity, hypothermia, hypoglycaemia

What is Aujeszky’s disease in pigs?

A highly contagious and economically significant disease caused by suid alphaherpesvirus 1, DNA

How is Aujeszky’s disease transmitted?

Mainly through respiratory or oral routes, but also venereal transmission is possible

What are the clinical signs of Aujeszky’s disease?

• Newborn: fever, depression, vomitus, tremor, ataxia, convulsions, mortality (100%)

• 3-4 weeks: nervous signs, pharyngeal lesions- voice change, mortality (50-70%),

• 4 weeks- 3 months: anorexia, mild fever, low mortality

• Adults: pyrexia, anorexia, cough, nasal discharge, rare CNS signs

• Sows: poor fertility, abortion, small litters

How is Aujeszky’s disease diagnosed?

Immunofluorescence, immunoperoxidase test, virus neutralisation, DNA dot-blot hybridization for latent virus, serological tests (VNT and ELISA)

What is rabies in swine?

A viral disease caused by the neurotropic rabies lyssavirus, leading to inflammation of the brain

What are the initial clinical signs of rabies in pigs?

Restlessness, anorexia, increased appetite, vomiting, slight fever

What are the advanced signs of rabies in pigs?

Twitching of the nose, pruritus at the bite site, excitement, aggression, convulsions, paralysis, excessive salivation, chewing motion, death within 48 hours

What is Teschen disease in pigs?

A disease caused by a porcine enterovirus, serotype 1 from the Picornaviridae family, affecting pigs of all ages

What is the difference between Teschen disease and Talfan disease?

Teschen disease is more severe, while Talfan disease is a mild form caused by less virulent strains of the virus

How does the Teschen virus spread in pigs?

The virus enters orally, replicates in the tonsils and intestines, spreads haematogenously to the central nervous system

What conditions must be present for the Teschen virus to damage the CNS?

Absence of specific circulating antibodies or when they are at insufficient levels

What are the general clinical signs of Teschen disease?

Anorexia, depression, irritability, paresis of the extremities

What are the severe clinical signs of Teschen disease?

Tremors, nystagmus, violent clonic convulsions, collapse, coma, sudden temperature drop, death within 3-4 days

How is Teschen disease diagnosed?

Clinical signs, ELISA, VNT, virus isolation

What is the treatment and prevention for Teschen disease?

No effective treatment; prevention through all-in, all-out management and vaccination

What is the cause of coronavirus encephalomyelitis in pigs?

Porcine haemagglutinating encephalomyelitis virus (PHEV), coronavirus, RNA

How is coronavirus encephalomyelitis transmitted?

Presumably through infectious nasal secretions or aerosol

What age group of pigs is most affected by coronavirus encephalomyelitis?

Pigs less than four weeks old

What are the clinical signs of coronavirus encephalomyelitis in pigs?

Vomiting & wasting syndrome: Sneezing & coughing, vomiting of milk & retching.

Encephalomyelitis syndrome: Initial signs are similar to those above. Later, a variety of signs of encephalomyelitis appear- stilted gait, muscle tremors, nystagmus, blindness, opisthotonus, convulsions, & progressive paresis leading to recumbency w/ paddling of the legs.

What treatment is available for coronavirus encephalomyelitis in pigs?

No treatment; prevention is through injection of hyper-immune serum at birth or exposing gilts to faeces of older sows

What is the causative agent of viral encephalomyocarditis in swine?

Members of the genus Cardiovirus, family Picornaviridae, RNA

How is viral encephalomyocarditis (EMC) transmitted?

Through rodent excretions and via nasal secretions and faeces of pigs

What are the clinical signs of viral encephalomyocarditis in pigs?

Sudden death, fever, anorexia, listlessness, trembling, staggering, dyspnea, and paralysis

What age group of pigs is most affected by viral encephalomyocarditis?

Suckling swine, with mortality approaching 100%

What virus causes blue eye disease in pigs?

Porcine rubulavirus (PoRV), Paramyxoviridae, an enveloped RNA virus

How is blue eye disease transmitted in pigs?

Through direct contact (nose-to-nose)

What are the clinical signs of blue eye disease in piglets?

Blindness, nystagmus, dilated pupils, anterior uveitis, conjunctivitis, swollen eyelids with exudate, and corneal opacity

What are the reproductive effects of blue eye disease in sows and boars?

Irregular return to oestrus, stillbirth, mummification, orchitis, epididymitis, testicular atrophy, decreased spermatozoon concentration and motility

What methods are used to diagnose blue eye disease in pigs?

Culturing in pig kidney cell lines, direct immunofluorescence, RT-PCR, hemagglutination inhibition, virus neutralisation, and ELISA

What is the most common cause of meningitis in pigs?

Streptococcus suis infection

What other conditions can Streptococcus suis cause in pigs?

Septicaemia, arthritis, endocarditis, myocarditis, and abortion

How is Streptococcus suis transmitted in pigs?

Clinically healthy pigs can carry the organism in their tonsils, nasal mucosa, and vagina for many months; transmission may occur through ingestion, inhalation, or nose-to-nose contact

What is the pathogenesis of porcine meningitis?

Oral/respiratory infection → tonsils → mandibular lymph nodes → septicaemia → phagocytes → CSF (brain, meninges), joints, lungs, reproductive system

What are the clinical signs of meningitis in pigs?

Sudden death, fever, anorexia, depression, tremors, ataxia, convulsions, and blindness; lameness and swelling if arthritis is present

How is porcine meningitis diagnosed?

Clinical signs, necropsy, & isolation of organism from CSF, brain, lungs, synovial fluid or heart

What is the causative agent of tetanus in pigs?

Clostridium tetani

How does Clostridium tetani enter the body?

Through a break in the skin, such as a cut or puncture wound from a contaminated object

What is the pathogenesis of tetanus?

C. tetanus produces toxins which interfere with muscle contractions

What are the clinical signs of tetanus in pigs?

Spasms starting in the jaw and progressing to the rest of the body, potentially severe enough to cause bone fractures

How is tetanus treated?

Amoxicillin is early enough. Kills bacteria, not toxins

What species causes Toxoplasma infection in pigs?

Toxoplasma gondii

What are the common clinical signs of Toxoplasma infection in pigs?

Mild or asymptomatic, laboured breathing, CNS signs, foetal losses, abortion in early pregnancy, stillbirths, and mummification in later gestation

What are examples of other agents causing neurological disease?

1. Porcine adenovirus

2. Nipah virus

3. CSF, ASF

4. Eastern equine encephalitis

5. Japanese encephalitis

6. Listeria monocytogenes

What neurological symptoms can be caused by porcine adenovirus?

Dullness, depression, lethargy, listlessness, and tremors, often secondary to dehydration

What are the body systems affected by Nipah virus??

Brain (encephalitis; convulsions) and respiratory system

What are the effects of classical swine fever and African swine fever?

Discoloration of skin, high fever, haemorrhages, acute staggering, incoordination, and paresis

What disease is caused by the Eastern equine encephalitis (EEE) virus?

A zoonotic alphavirus and arbovirus that affects horses and other mammals, causing brain damage and neurological signs

Abnormal gait, aimless wandering, circling, dyspnoea, drowsiness, head pressing, hyperactivity paralysis, restlessness, sensitivity to sound, & death

What is the main transmission vector for Japanese encephalitis virus?

The Culex mosquito

What are the primary clinical signs of Japanese encephalitis in pigs?

Reproductive losses (testes) and potential CNS effects

What animal species is most commonly affected by listeriosis caused by Listeria monocytogenes?

Ruminants, especially sheep, though a variety of animal species can be infected

What are the clinical signs of the encephalitic form of listeriosis?

Stiff gait, paralysis of face and limbs, and opisthotonus

What is the aetiological agent of glassers disease?

Glaesserella parasuis