Allergies to cats, and Toxoplasmosis: vet spot podcast from Newstalk’s Pat Kenny Show

This week, Pete reported on two cat-related stories. First, new science on how people can be helped if they are allergic to cats. And second, the truth about Toxoplasmosis, a common parasite that’s widely misunderstood. To listen to the podcast, click on the play button below.

Allergies to cats

Pete had just come back from a two-day symposium about the science of feline nutrition (organised by Purina, the pet food company). This was in Prague, and was an international event with speakers and delegates from across Europe and the world. Many topics were covered but the major point of interest was new discoveries about the science of humans being allergic to cats. This affects up to 20% of the population and is a major reason for people not keeping cats, and for cats having to be rehomed. The allergy in humans is caused by a protein produced in cat saliva (Fel D1), and spread across the cat’s body by grooming, then released into the home on dander and fur. Anyway, the new finding is that if cats are fed an antibody to this FelD1 antigen, the antigen is neutralised actually inside the cat’s mouth. This results in a significant drop in the amount of antigen produced by the cat ,and it is likely that it will allow people who are allergic to cats to live with them. This is brand new science, and has not yet translated into a product on the market place (e.g. a special diet or a powder to add to food) but it is likely that such products will become available during 2020.
The antibody to the FelD1 antigen is produced in eggs by exposing hens to FelD1, and then the egg yolks are formulated into an edible product for cats.

Toxoplasmosis

Toxoplasmosis is the most well known and publicised disease that humans can get from cats. However, there is a huge amount of misunderstanding about this disease and about the role in which the cat plays in causing human disease.

There are some key messages about this disease that are not widely known:

1. Toxoplasmosis is an invisible infection in most cases: most people never realize that they have had it.
2. In Ireland, USA and UK around 20-30% of people are infected at some point in their lives, whereas approximately 80% of people in France and Germany are infected. This is likely to be because they eat more undercooked meat in these countries i.e. nothing to do with cats
3. While 20-60% of cats will be infected with T gondii, very few of these show any signs of illness and hardly any of these cats will be shedding the parasite: this only happens when they are first infected (and only for up to two weeks). After this, they stop shedding the parasite so that they are no longer infectious to humans. By the time they test positive, most cats have already stopped shedding the organism. This aspect is the source of much confusion amongst patients and doctors.
4. There is no correlation between cat ownership and human disease caused by this parasite.

To find out more, listen to the podcast.

Questions from listeners

This week, the following questions were asked by listeners and answered by Pete on air.

• My dog has a continuous open sore on his knee joint. Can I strap it up and treat it myself?
• My Black Labrador has been scratching himself to the extent that his underside is blackened with thickened skin, and the area around his eyebrows has gone bald. What could this be?

You can find out the answers to these questions by listening to the podcast.

Pete also did a Facebook Live video session which you can watch here.