Presentation on theme: "“Suis-cide” Disease and Nursery Production Kevin J. Vilaca, B.Sc., M.Sc., DVM Maitland Swine Services Ontario, Canada."— Presentation transcript:
“Suis-cide” Disease and Nursery Production Kevin J. Vilaca, B.Sc., M.Sc., DVM Maitland Swine Services Ontario, Canada
Main Areas The diseases –Strep, H and A Suis Mini case study Treatment/control Prevention
Stockmanship This is an old word that is not used as much as it used to be but is vital to pig production. Simply put, it is your intimate knowledge and understanding of pigs. It is obtained by two ways –Knowledge (learned or acquired from hands on) –Experience (time put in and hands on) Everyone who will work with pigs will need to have or develop it. –Protocols are important and necessary but stockmanship is vital to working successfully with pigs.
Fear the Silver Bullet There is no such thing as a silver bullet. Diseases on farm are complex and multifactorial. Require you to have an assorted arsenal to solve the problems. Any one that depends on only one method or one approach for every situation (a silver bullet) is dangerous. As a student, do not fall in to the silver bullet trap. Approach each situation systematically and with an open mind.
The Bacteria Streptococcus suis Haemophilus parasuis (Glassers Disease) Actinobacillus suis Great amount of virulence and strain variation Colonization of animals occurs early in life Can be a primary or secondary disease –Always look for an underlining primary disease
Clinical Picture Neurological signs (staggering, paddling) Respiratory distress (thumping, puffing) Joint infection (lameness, stiffness) Poor performance (growth, feed intake, etc.) Increase in morbidity and mortality (dead pigs) Post Mortem – polyserocytis with fibrin on surface of internal organs (Thorax, Pericardium, Abdomen)
Fibrin adhesions on thoracic surface and pericardium
Sample Selection Minimum Information –Histology = Lung, liver, Spleen, Kidney (Heart, Lymph nodes, Tonsils, Brain) –Culture: Pluck (Lung+Heart etc.) with intact pericardium Can also choose to swab other organs/tissues Brain Swab (I like this)
Sample Interpretation Histology : –Lets you know what is going on at a cellular level –Gives you indications if there is an underlining viral component – PRRS, SIV, PCV2 (lots of times there is) Bacteriology (culture) –Most important Questions - Is it significant? –Some bacteria can be present in the respiratory tract and not be significant –How do you know?
* Indicates Swabs collected on Farm SiteCultureSerotype HeartStrep. suisS. suis 7 PericardiumStrep. suisS. suis 7 LungStrep. suis, H parasuis, P. multocida S. suis 7+24, H. parasuis 5 *Brain SwabStrep. suisS. suis 7 *Pleural Swab Mixed Growth including Proteus
Culture Interpretation Culture was able to grow 5 “Bugs” –Strep suis 7 + 24, H. parasuis, P. multocida and Proteus. Big question is which ones if any are important? This is vital for treatment decisions, as well as for decision making for possible autogenous vaccines.
P. multocida This bacteria is a normal inhabitant of the respiratory tract. Predominantly is an opportunistic bacteria that multiplies when defense mechanisms are down/damaged. In this case, it was unlikely responsible for the disease since it was only isolated from the lung
H. Parasuis This bacteria is known to cause disease and the clinical signs we are seeing. It can be cultured from the lungs without causing disease. In this case it was only cultured from the lungs. Less likely to be the pathogen responsible for disease.
Strep. suis Strep. suis can be found in the respiratory tract of pigs and not cause disease. Strep. should not be cultured from tissues that are otherwise sterile –Strep. 7 was found in all tissues except the pleural swab –Strep. 24 was only found in the lung culture –Since Strep. 7 was found in tissues that for all intents and purposes are sterile, this is significant –The pathogen has clearly entered the blood stream and established itself in other tissue (Heart, Brain, Pericardium)
Proteus Fast growing and very easily overgrows culture plates (drowns other bacteria out) Presence usually indicates the quality of the sample collection (contamination) In this case it shows that the vet really needs to learn to be more careful and collect better samples when on farm!
Treatment (antibiotics) Ideally treatment should be based on culture and sensitivity (perfect world) However, many times you have to make a call to start treating on farm (pigs are dying) So how do you make your decision? NOTE: Always collect your samples. You may need them if there is no response to treatment, and once you have treated your ability to isolate the bacteria may be diminished or biased.
Antibiotic selection Route of Administration Feed –Pro: low cost, ease of administration –Con: delayed timing (ordering, delivering, feed already in bins), Sick pigs may not eat. Water –Pro: ease and speed of administration, sick pigs will still drink –Con: moderate cost Injectable –Pro: accurate dosing of acute cases, –Con: labour intensive, higher cost Often a combination of two of the above
Antibiotic Selection Factors to consider Clinical picture – how aggressive is the disease (mortality/production) Post mortem finding – what is the most likely bacteria involved Past experience – in similar cases, what has worked Response to previous treatments – have they treated the pig with no response already (ASK) Susceptibility/Resistance – what was the sensitivity pattern? (there is a difference between in vitro results and in vivo results) Pharmacology – mode of action, absorption, distribution
Control/prevention Stress is a killer: reduce them –Transport, pig movement/handling Nursery environment –Sanitation, temperature, ventilation, Management –All in/ All out, stocking density, mixing of pigs, mixing of ages/parity. In feed medication (preventative, pulse) Vaccination – Especially if resistance is an issue Education of barn staff – If they know why it is important to do it they are more likely to get it done
Temperature Pigs above are too cold (pilled) Pigs below are just right (spread out)
Autogenous vaccines A non-commercial herd specific vaccine that is composed of bacteria isolated from the farm which the vaccine is to be used on. Sample (pathogen) selection is vital to vaccine success. Multiple animals cultured over a 2 or 3 sample periods Due to cost and efficacy only the bacteria responsible should be included. (can be more than one involved) Like the treatment example, you need to know which bacteria is responsible.
In this case I would be starting off with a vaccine that only contained S. suis 7 SiteCultureSerotype HeartStrep. suisS. suis 7 PericardiumStrep. suisS. suis 7 LungStrep. suis, H parasuis, P. multocida S. suis 7+24, H. parasuis 5 *Brain SwabStrep. suisS. suis 7 *Pleural Swab Mixed Growth including Proteus
Importance of Viruses Always look for Primary Viral involvement –PRRS – acts as an immunosuppressant to allow bacteria to establish a foot hold –Swine Influenza (SIV) – damages the lungs defense mechanisms (bronchial cilia) and prevent bacterial clearance (establishment) –Circo Virus – leads to immunosuppressant and allow bacteria to establish. Plays a greater role than previously thought. –Mycoplasma – a bacteria that acts by coating the lining of the bronchiols preventing ciliary action
No such thing as a “Silly” Question Thank You! AASV Maitland Swine Services Any Questions?