November 3, 2020

 

US swine center's webinar gives specifics on lameness management, diagnosis

 

Lameness and arthritis management were the subject of a webinar sponsored by the Swine Health Information Center (SHIC) and American Association of Swine Veterinarians (AASV) on October 13.

 

In her presentation, Dr. Kathleen Wood of Christensen Farms, said, in her experience, lameness is the number one cause of mortality in mid to late finishing stage pigs.

 

Understanding the causes, costs and methods of managing can help address consequences of lameness and arthritis. Dr. Wood was joined by nutritionist Dr. Paul Cline of Christensen Farms, practitioner Dr. Michael Eisenmenger of Swine Vet Center and diagnosticians Dr. Michael Rahe of Iowa State University (ISU) and Dr. Stephanie Rossow of University of Minnesota.

 

The latest in a series of webinars addressing swine industry chatter, this event provided participants' experience, recommendations and direction for addressing these issues which have been on the rise, per submissions to veterinary diagnostic labs (VDLs). The webinar was conducted by ISU's Swine Medicine Education Center.

 

Dr. Eisenmenger and Dr. Wood said solving the issue of lameness requires veterinarians to be in barns, observing animals, as well as performing necropsies to define the cause of lameness. Dr. Eisenmenger recommended combining resources to examine flow, health, nutrition and operations as causes of lameness and working together to identify issues. He said the best chance for success is to work in a manner that increases the opportunity for answers when working with VDLs.

 

During her presentation, Dr. Wood said she had farms where 10 to 25% stiffness in grow-finish pigs grew to 25 to 40% this year. She attributed the increase to a variety of factors including infectious arthritis, injury or trauma, as well as leg conformation problems or defects. Additionally, she attributed some of the increase in incidence to increased awareness of stiffness after a return to closer observation as barn visits resumed after a lag due to the COVID-19 pandemic.

 

Dr. Wood believes anti-inflammatory injectables are an important treatment, relieving pain and related issues. However, their use is variable and may be difficult to manage with potential issues revolving around withdrawal times for grow-finish pigs. She also recommended looking upstream for possible origin of stiffness/lameness problems including sow nutrition, sow farm medications and pre-farrow vaccinations.

 

Critical to management is field communication. Dr. Wood believes continual training of staff to recognise and properly identify issues is essential and working from the premise lameness and stiffness are not part of "normal." She also recommended more practitioner field time, necropsies and pursuing diagnostics. In fact, she said: "Necropsy everything." And that would include popping open joints, snapping ribs and identifying broken bones during routine necropsies versus only in infection/abscess presence.

 

Dr. Wood's colleague at Christensen Farms, Dr. Paul Cline, shared a nutritionist's perspective during the webinar. He said the industry needs to do better at understanding the interactions between health and nutrition. One of the ways to deal with that is to nurture the agreement that veterinarians and nutritionists are working toward the same goal. He also believes a more robust standard reference resource for bone characteristics is necessary.

 

Dr. Cline talked about how the consequences of an out-of-feed event aren't truly understood in terms of how quickly bone ash changes. Another area in need of examination involves components that need to be measured to understand impact on bone. This includes boron levels in feed, impact of intake level on bone development, as well as seasonality.

 

For getting the best results when seeking results from submissions to VDLs, Dr. Michael Rahe of the ISU Veterinary Diagnostic Lab, offered these best practices:

 

- Submitters can call VDL ahead of time and discuss what is seen in impacted pigs and what tissues would be helpful to submit;

 

- Live pigs or limbs can be submitted;

 

- Specific tissues to submit for lameness workup: Evaluate joints to rule out infectious arthritis or submit limbs; serum - vitamin D (collect antemortem or shortly after euthanasia); second ribs (bone ash and density); fixed long rib(s) – 10th ribs (microscopic evaluation of physis (growth plate) and trabecular and cortical bone); fixed skeletal muscle from hamstrings, triceps and diaphragm; fresh and fixed liver (vitamin E and trace mineral panel); urine (calcium and phosphorus); fresh and fixed lung, kidney, spleen and brain to rule out systemic disease, meningitis, encephalitis, etc.

 

Dr. Rahe said acutely affected pigs are better than chronic pigs for sample submission and agent isolation. Sampled pigs should represent what is being observed in the herd. He also emphasised that findings/diagnosis in one pig could be an isolated case and not necessarily representative of the herd. Correspondingly, the same finding in multiple animals then adds confidence in a herd level diagnosis.

 

Dr. Stephanie Rossow of the University of Minnesota VDL began her presentation by emphasising that structure of the pig is directly tied to function, so addressing lameness concerns is essential.

 

She said abnormal structure equals abnormal function with related consequences affecting pig health and performance. Understanding of disease initiators versus promoters also helps develop effective prevention and treatment protocols.

 

Dr. Rossow emphasised the importance of using a diagnostic lab, saying VDLs have the people, time and tools for extensive investigation. Dr. Rossow shared many images from VDL investigation of lameness, describing the process and results of their work.

  

- SHIC