CASE NOTES
SARCOPTES SCABEI VAR SUIS
Kylie Greentree, DV Cumberland Livestock Health and Pest Authority
Posted Flock & Herd July 2012
History
An Agricultural High School on the Central Coast called the Cumberland Livestock Health and Pest Authority in Maitland as their seven piglets that were five weeks of age had very thickened skin, alopecia, severe rubbing and shaking ears. The piglets had multiple scabs mostly over head and forequarters. The sow had had the same clinical signs around farrowing time but had been given only one dose of Ivermectin as treatment which appeared to clear the clinical signs up.
Clinical Signs
The piglets presented with hyperkeratosis (Figure 1), large amount of scale in the external ear canals (Figure 2), alopecia and severe pruritus.
Figure 1. Piglets with severe pruritus and hyperkeratosis
Figure 2. Scale in external ear canals showing active infection in the ear of a pig
Diagnosis
Several deep skin scrapings were taken from the edge of lesions on the skin and thick swaps were taken from the external ear canal (note: a teaspoon is ideal for taking a scaping from external ear canal, spread material on black paper and wait 10 minutes to see if you can see mange mites. The mange mites are rounded and 0.5mm just visible to the naked eye). I was unable to see any mites under the schools microscope but was pretty convinced that Sarcoptes was what we had so I recommended treatment with Ivermectin injection (two injections 10 days apart) while we waited for the lab results to come back.
Differential diagnosis
Differential diagnoses include the following. Hyperkeratinisation (Figure 5) is normal dead flaky skin that can be rubbed off leaving normal skin underneath. Greasy Pig Disease (Figure 6) is caused by a bacterium Staphylococcus hyicus. Swine Pox (Figure 7) is a viral disease that is characterized by the acute appearance of round to oval cutaneous lesions that heal in three to four weeks. Sun Burn (Figure 8), caused by exposure to ultraviolet light, is not possible in this case as the piglets were housed in an indoor pen.
Figure 5: Hyperkeratinisation
Figure 6: Greasy Pig Disease
Figure 7: Swine Pox
Figure 8: Sunburn
LABORATORY RESULTS
Insect / Mite Specialist ID (Figure 9):
Genus Sarcoptes
Species scabiei
Author (Linnaeus)
Order Acari
Family Sarcoptidae
Common name sarcoptic mange mite
Figure 9. Sarcoptes scabiei var suis under magnification, the cause of
Sarcoptic mange in pigs
FINAL DIAGNOSIS
Sarcoptic Mange
Treatment
All the piglets had been weaned from the sow one week before visiting the High School; they were given Ivermectin injections (300ug/kg s/c) 14 days apart. The sow was also treated even though she appeared to have recovered; she was only given one dose of Ivermectin at the time she showed clinical signs of Sarcoptic Mange so this ensured that she was free from infection.
Discussion
This parasite like many others will lead to a decrease in weight gain in weaner piglets and if the sows are affected it will lead to her being more restless and hence more piglet mortalities.
'Prevention is better than cure', as all treatments add up to take out a good chunk of the producer's profit, especially in this case when multiple treatments are required. Ways to maintain a Mange free herd include
- Examine carefully any introductions into the herd
- Insist on Veterinary declaration of disease free status
- Isolate new pigs and take skin scrapings from any suspect lesions. If in doubt treat with Ivermectin/doramectin® or related compounds 10 days apart which should eliminate any mites
- The sows and boars are the permanent reservoirs for infection as they are the constants in the herd. It is recommended to treat the sow seven days prior to farrowing to prevent the sow infecting her piglets. Also treat sows every six months
- Cull pigs with chronic lesions if you can't get on top of these with treatment
- Treat boars regularly every three months
- The mite will only live away from the pigs for around five days. Wash down pens that have had infected pigs in them with a wash that will kill mites and leave them pig-free for five days.
References
- Google images
- Averbeck GA, Stromberg MS, Stromberg BE. Sarcoptic Mange in Swine