Trichomoniasis: an enigma in cats
Over the past two decades, the protozoan Tritrichomonas fetus has become a cause of chronic colitis in cats in many countries around the world. Today, trichomoniasis is considered one of the most common infectious causes of diarrhea of ââthe large intestine. Affected cats are generally young (median age 1 year) and maintain good health and body condition, but they exhibit increasing and decreasing diarrhea. Characteristically, feces have the consistency of “cow pie” and often contain mucus and / or blood. In many cats, diarrhea goes away on its own without treatment after several months, but in some cases it continues to grow and decrease for many years.
The guilty, T. fetus, flagellated in the shape of a very mobile tear, would be transmitted from cat to cat by the faecal-oral route; cats acquired in catteries and breeding shelters are at increased risk of infection, as dense housing conditions favor this route of transmission. T. fetus also infects cattle, in which it is sexually transmitted and a potential cause of abortion and infertility. The economic impact of the disease on the cattle industry around the world has given rise to a rapidly developing area of ââtrichomonas research. However, what is frustrating for vets is that the more you learn about trichomoniasis in cats, the more delicate it becomes.
Complications and controversies surrounding feline trichomoniasis are explored in a state-of-the-art review article published this month in the Journal of Feline Medicine and Surgery. The authors, Dr Jody Gookin and colleagues at the College of Veterinary Medicine, North Carolina State University explain that one of the most pressing challenges is that feline trichomoniasis is resistant to all commonly used antiprotozoa. Currently, the only drug proven to be effective in cats is ronidazole, but this agent has a narrow margin of safety and clinical resistance is increasingly recognized. A cat treated with the drug may indeed show complete or almost complete resolution of its diarrhea, but it can be very difficult to determine whether the treatment really eradicated the infection or simply masked the clinical signs. This, in turn, raises the specific question of the risk that a treated cat may present to other cats if, for example, it is reintroduced into a breeding cattery. More broadly, given these difficulties, and the spontaneous resolution of diarrhea seen in many cats, the controversial question has arisen: should vets even bother to treat the infection in cats?
The authors conclude that while research has gone a long way to advancing understanding of this infection, there remain many unanswered questions that are critical to future progress. Are felines and cattle T. fetus truly biologically distinct genotypes, residing in separate hosts, or is there potential for cross infection between cattle and cats? Should all cats in contact with an infected cat with the Tritrichomonas species also be treated? What is the long-term effect of infection with the Tritrichomonas species on feline gastrointestinal health, and can we identify safer and more effective drugs for the treatment of the infection?
* The riddle of feline trichomoniasis. The more we learn, the more “complicated” it becomes. J Feline Med Surg 2017; 19: 261-274.
The article is free to read here
Image: Appearance of a feline Tritrichomonas species at 100x magnification. These highly motile, teardrop-shaped flagellates lack many of their own biosynthetic pathways and depend on nutrient retrieval from their host for survival. Image courtesy of Jody Gookin
For more information: Margaret Melling, [email protected], +44 (0) 1747 871872
Notes to Editors:
About Journal of Feline Medicine and Surgery
The Journal of Feline Medicine and Surgery is the official journal of the International Society of Feline Medicine (ISFM) and the American Association of Feline Practitioners (AAFP), and is published by SAGE Publishing.
Journal of Feline Medicine and Surgery
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