Bacterial urinary tract infections

A very large US study revealed an increased risk for bacterial urinary tract infections in Abyssinian cats (Lekcharoensuk et al 2001). However, the nature of any heritability has still to be determined.

Lekcharoensuk C et al. (2001) Epidemiologic study of risk factors for lower urinary tract diseases in cats. JAVMA 218(9): 1429-1435

Immune response to Feline Coronavirus (FCoV) and the development of Feline Infectious Peritonitis (FIP)(*)

Many studies have shown that purebred cats are far more likely to develop FIP that non-pedigree cats. It also appears that there are significant differences in the way that the immune system of cats of particular breeds responds to FCoV infection: Higher antibody levels against FCoV are seen in some breeds, and some breeds and lines of cats appear to be predisposed to the development of FIP. In two Australian studies BSH, Cornish Rex, Burmese, Birman, Russian Blue and Ragdoll cats were shown to have higher anti-FCoV antibody levels than Siamese, Persian, Bengal, Devon Rex and DSH cats (Bell et al 2006a &b). Although there was no correlation between the level of the antibody response and the health of the cats, the three breeds with the highest antibody levels in one of these studies (BSH, Cornish Rex, and Burmese [(Bell et al 2006a]) were also shown to be most likely to develop FIP (at least in Australia) (Norris et al 2005).
Predisposition to the development of FIP does not result solely from hereditable factors; it also relates to different management factors. However, in one study, >50% of FIP susceptibility in purebred cats was found to be attributable to inherited differences between individuals (Foley & Pedersen 1996), with the mode of inheritance best modelled as a polygenic trait. It is sometimes possible to trace inheritance of FIP back to a particular ancestor, and cats that are first degree relatives of FIP-affected cats are significantly more likely to be affected by FIP than unrelated cats.
It is important to note that while a particular breed may appear to be predisposed in one country this does not mean that it will necessarily be predisposed in a different country as the genetic stock within different countries varies. This is exemplified by a contrasting study from the USA, where Abyssinian, Bengal, Himalayan (Colourpoint Persian), Rex, and in particular Birman and Ragdoll cats had a significantly increased risk of developing FIP, compared to Burmese, Exotic Shorthair, Manx, Persian, Russian Blue and Siamese (Peteanu-Somogyi et al 2006).
Bell et al (2006a) The relationship between the feline coronavirus antibody titre and the age, breed, gender and health status of Australian cats. Australian Vet Journal 84(1&2): 2-7
Bell et al (2006b) Seroprevalence study of feline coronavirus in owned and feral cats in Sydney, Australia. Australian Vet Journal 84(3): 74-81
Foley JE & Pedersen NC (1996) The inheritance of susceptibility to feline infectious peritonits in purebred catteries. Feline Practice 24, 14 – 22
Norris et al (2005) Clinicopathological findings associated with feline infectious peritonitis in Sydney, Australia: 42 cases (1990-2002). Australian Vet Journal 83(11): 666-673
Peteanu-Somogyi et al (2006) Prevalence of feline infectious peritonitis in specific cat breeds. Journal of Feline Medicine and Surgery 8, 1 – 6

Increased risk of deep fungal infections

Deep fungal infections are caused by various agents including Cryptococcus, Histoplasma, Coccidioides, Sporothrix, Blastomyces, Aspergillus and Candida. These organisms exist in the environment and are rarely cause disease. A link with infections (FIV, FeLV, FIP) and drugs (glucocorticoids) affecting the immune system has been suggested. In the paper cited below, which reviewed the literature around the subject, several breed predispositions were noted. C.neoformans in Siamese and Abyssinian, B.dermatitidis in Abyssinians, H. capsulatum in Persians and S.schenckii in Siamese. The conditions result in various clinical signs including nasal discharge, respiratory signs, pyrexia and lymphadenopathy, gastrointestinal and neurological signs. Treatment can be difficult but successful in many cases.

Davies, C. & Troy, G.C. (1996) Deep Mycotic Infections in Cats. J Am Anim Hosp Assoc 32:380-91
Discussed on Susan Little’s website www.catvet.homestead.com

Tritrichomonas  foetus infection

Tritrichomonas foetus is a protozoan parasite that has recently been identified as a cause of diarrhoea in domestic cats. Clinical signs can range from none to prolonged and intractable diarrhoea which typically presents with increased frequency of defecation, the passage of semi-formed to liquid often foul-smelling faeces, sometimes containing fresh blood and mucus; the cat’s anus may become inflamed, and faecal incontinence may occur. Most affected cats are otherwise well, and they rarely show significant weight loss.
Most reports of T. foetus infection have come from the USA. However, the infection has a much wider distribution; it hasbeen found in faeces from cats in the UK, Germany, Italy, and Spain, and studies from the early 1900’s indicated that the infection may have been present in Brazil, France, Yugoslavia, and China. While it has not been found in the faeces of feral cats or healthy indoor cats living in colonies that do not suffer from diarrhoea, it is frequently seen in households containing young pedigree cats, especially those where diarrhoea is common, in young cats from rescue centres, and in cats from other multi-cat households. One study found 31% of cats at a cat show in the USA were infected; while 15-20% of faecal samples from cats with diarrhoea in the UK are infected. Diarrhoea is seen most commonly in young cats and kittens, and the majority being <12 months of age. Studies suggest that certain cat breeds are more likely to have diarrhoea due to T. foetus infection, e.g. Siamese and Bengal cats. However, this may result from management practices rather than genetic factors. Management practices that are most likely to be associated with T. foetus infection and diarrhoea include keeping very large numbers of cats (high population density is the most important risk factor for this infection because it predisposes to high levels of faecal-oral spread) and, possibly, importing significant numbers of cats from the USA.
Diagnosis can be made by (i) looking for motile trophozoites in fresh faecal smears with saline dilution (ii) using the specific ‘In Pouchtm TF’ culture system or (iii) by detection of T. foetus ribosomal DNA using PCR. The long-term prognosis for infected cats is good, most cats will eventually overcome the infection but this can be a slow process, taking from 2 months to 3 years. Many potential treatments (including metronidazole and fenbendazole) are poorly effective, and although recent work has indicated that treatment with ronidazole may be successful, there is currently no licensed form of this product for cats, and its administration can result in adverse reactions (typically lethargy, ataxia, tremors and, occasionally, seizures).

Gookin JL, Stebbins ME, Hunt E, Bulone K, Fulton M, Hochel R, Talaat M, Poore M, Levy MG (2004) Prevalence and risk factors for feline Tritrichomonas foetus and Giardia infection.  Journal of Clinical Microbiology 42,2707-2710
Gunn-Moore DA, McCann TM, Simpson KE, Tennant B. (2007) Prevalence of Tritrichomonas foetus infection in cats with diarrhoea in the UK. JFMS. 9(3): 214-218
For more information about T. foetus infection in cats see www.fabcats.org/tritrichomonas
The PCR and ‘In Pouchtm TF’ tests are available in the UK from Capital Diagnostics in Edinburgh (0131
535 3145) and in the USA from North Caroline State University, USA,
www.cvm.ncsu.edu/mbs/gookin_jody.htm.