Enhanced survival of rats concurrently infected with Trypanosoma brucei and Strongyloides ratti

The interaction between the blood protozoan parasite, Trypanosoma brucei and the gastrointestinal nematode parasite, Strongyloides ratti was studied in outbred white albino rats. Rats were grouped and given either single infection with T. brucei or S. ratti or concurrently infected with both parasites. Blood parasitaemia and packed cell volume, faecal egg/larva output, adult worm burden and survivability were monitored in order to assess the interactive effects of the infections. All trypanosome-infected rats became parasitaemic within 1 week of infection but surprisingly parasitaemia was higher in the single than concurrently infected group of rats. In addition all animals with single T. brucei infection had died by 14 days after the infection, whereas animals with concurrent infection were still alive by day 28 after the infection when the experiment was terminated. Concurrent infection resulted in significant increase in daily S. ratti egg/larval output in faeces (P < 0.01), but lesser number of adult worms were recovered from the intestine of sacrificed rats on day 8 post-infection. Taken together these results suggest that T. brucei and S. ratti interact in a manner that ameliorates their pathogenic effects resulting in a decrease in the level of parasitaemia and intestinal worm burden and in increased life span of the infected rats. These results differ from the classical immunosuppressive attributes of T. brucei and the results are discussed in the context of the possible immune responses that might have contributed to this outcome and the potential significance of the findings in alternative control method of trypanosomosis.     

The response of Nigerian West African Dwarf goats to experimental infections with Haemonchus contortus

One option for controlling haemonchosis in warm pastoral regions is improvement of resistance by selective breeding. Variation in acquired immunity to H. contortus and immunological correlates of infection were studied in West African Dwarf (WAD) goats. Following exposure to 5000 L3, 63 per cent of the inoculum established but 77 per cent of established worms were expelled by week 5. All infected animals were anaemic (day 14). When exposed to 2000L3, 36 per cent of the inoculum was still present (day 35) with no loss by day 49. Persisting primary infection worms survived a superimposed challenge (day 35), but their growth was slowed and resistance to challenge was significant. Most goats showed eosinophilia and parasite-specific IgG responses to primary infection, but only eosinophilia increased after challenge. No consistent associations were found between parasite burden and any immunological measures of infection, but parasite egg counts showed considerable variation. Overall, our results suggest that resistant genotypes exist among the WAD goat population.     

Rehabilitation of companion animals following orthopaedic surgery

ABSTRACT

Physical therapy and rehabilitation following orthopaedic surgery in companion animals have become more common and new advancements in this field have been made in recent years. Surgery alone may not return the animal to its previous physical activity or work-related tasks, whether due to concurrent soft tissue trauma, arthrogenic muscle inhibition or osteoarthritis. Rehabilitation therapies following surgery can restore function as well as strength, coordination and balance. Many simple techniques such as cryotherapy and passive range of motion exercises have been shown to improve outcomes following musculoskeletal procedures and may help restore function as well as reduce pain and facilitate healing. Some techniques are more useful during different stages in order to achieve optimum tissue healing and recovery of function. During the first 72 hours, rehabilitation should focus on reduction of inflammation and pain, maintaining joint nutrition and range of motion, and stimulating vascularisation and healing; and may include cryotherapy, passive range of motion exercises, massage and therapeutic exercises. Following the initial recovery period, the goals of rehabilitation also include restoring strength, balance and normal gait patterns, as well as recovery of function. During this period the focus of therapy may shift toward therapeutic exercises, aquatic therapy and increasing activity in the animal. Therapeutic modalities such as neuromuscular electrical stimulation, photobiomodulation (laser therapy), therapeutic ultrasound and extracorporeal shock wave therapy have been reported to reduce pain and inflammation, enhance healing and reduce recovery time in the early and late stages following orthopaedic surgery.