Protozoa

PROTOZOA (Coccidia, Giardia and Toxoplasma)

Protozoa are MICROSCOPIC single-celled organisms that can sometimes cause disease in us and in our pets. The list of protozoal infections in dogs and cats is long, but the most common infections are those caused by Giardia, Coccidia and Toxoplasma.

Some protozoal infections seen in pets can be passed to people and cause serious illness so it is important to be aware of the symptoms, and to diagnose and treat infections early.

Protozoal infections are NOT covered by routine parasite prevention treatments.

COCCIDIA

There are several species of coccidia that can infect dogs and cats in the UK. This Coccidia infection occurs when the microscopic parasites invade the lining of the intestines, leading to DIARRHOEA, VOMITING and DEHYDRATION. Infection is usually passed on through the POO of an infected dog or cat.

Although extremely common, coccidiosis does not often cause severe disease and most pets will clear the infection on their own. However, in very young puppies and kittens, or animals with a weak immune system, Coccidia infection can become more severe.

Cocidial infections can be diagnosed using a microscope to check a sample of your pet’s poo. Coccidial infections can be treated with a course of a specific type of ANTIBIOTIC. There is no routine preventative treatment for coccidiosis but good hygiene and correct disposal of our pets’ poo can help to minimise our pets’ exposure.

GIARDIA

Giardia infections are one of the most common causes of persistent diarrhoea in our pets, especially Giardia in dogs which is a frequent concern for many pet owners. Unlike Coccidial infections, most Giardia infections will not get better without treatment.

The Giardia parasites invade the lining of the intestines causing DIARRHOEA and sometimes vomiting. Infected pets will shed Giardia in their poo which can then infect other pets… or people! Pets can get Giardia from WATER or SOIL that has been contaminated with another animal’s POO.

Giardia can be diagnosed from a sample of your pet’s poo. Giardia cysts may be seen using a microscope, or it may be detected even at low levels using a special type of test.

Most routine antibiotics and parasite treatments are not effective against Giardia, so diagnosis is important for your vet to be able to prescribe the correct treatment to clear the infection before it causes severe illness in your pet, or in you or your family.

Giardia infections can be pretty stubborn, sometimes taking several courses of treatment to clear up. Also, your pet can get Giardia again and again, sometimes even reinfecting themselves from their own garden.

Infections that are allowed to persist without treatment will continue to cause diarrhoea and sickness, and may cause long term damage to your pet’s intestines… another reason why early detection is so important!

Some tips for dealing with a Giardia infection in your pet and protecting your family:

EARLY DETECTION is key- if your pet has had diarrhoea for more than a few days then speak to your vet and arrange for a poo sample to be tested.

• Always practice STRICT HYGIENE when it comes to handling and disposing of your pet’s poo- in the house, garden, and out on walks, whether you know they have an infection or not.
  
• Giardia cysts can contaminate the fur around your pet’s bottom causing re- infection. So, if your pet has been diagnosed with Giardia and he has especially long or fluffy fur, then it can help to cut his hair short and bath him regularly while he is on treatment.
  
• Always finish the course of treatment provided by your vet.

TOXOPLASMA

This is a protozoal parasite that commonly affects cats, often referred to as Toxoplasma in cats, and can sometimes infect people as well. In fact, Toxoplasma can infect most warm-blooded animals.

Toxoplasma has a complicated life cycle with several stages:

• Cats become infected when they eat infected PREY such as rodents or birds. Toxoplasma invades the lining of the intestines and the cat will start to shed Toxoplasma eggs (called oocysts) in it’s poo within about ten days.
  
• Once passed in the poo the Toxoplasma oocysts take several days to mature, after which point they can infect another animal. Mature oocysts can stay in the soil for over a year, ready to infect their next HOST.
  
• If that host is a mouse or a bird then a cat can become infected when hunting, and the cycle begins again.
  
• If a PERSON is infected with the Toxoplasma oocysts (either from contact with cat poo or in contaminated soil) then it usually causes MILD flu-like symptoms which resolve on their own. However, if that person has a weak immune system it can cause serious illness. If a woman is infected for the first time during pregnancy then Toxoplasma can cause miscarriage, or disease in the baby before or after birth.
  
• If the Toxoplasma oocysts are eaten by an animal such as a sheep, cow or pig, then the infection can be passed on to people or by eating UNDERCOOKED MEAT.

Most cats infected with Toxoplasma will show no signs of illness. In fact, most UK cats that go outdoors have been exposed to Toxoplasma, recovered, and are probably immune to reinfection. In young cats, or cats that have weak immune systems, Toxoplasma infection can make them very poorly. When Toxoplasma causes disease it is called TOXOPLASMOSIS. Symptoms can include fever, loss of appetite, pneumonia, eye disease, seizures, incoordination and personality changes.

If your vet thinks your cat may have Toxoplasmosis then BLOOD TESTS may help with the diagnosis. Sometimes multiple blood tests a couple of weeks apart are necessary. Toxoplasmosis can be treated but not all cats will recover.

The risk of Toxoplasmosis in people is the reason that pregnant women and immunosuppressed people have traditionally been advised to avoid all contact with cat litter or areas where cats toilet. However, more recent advice acknowledges that, with GOOD HYGIENE such as cleaning cat litter daily and wearing gloves during contact with soil or sand outdoors, the risk of getting Toxoplasma from your cat is minimal (although never zero!).

Key Points to know about Toxoplasma:

• Toxoplasma exposure is very common in the UK.
  
• Toxoplasma does not often cause severe illness in our pets or in us.
  
• Practicing good hygiene makes the risk of Toxoplasma low in people (but not zero!).
  
• Toxoplasmosis is most common in immunosuppressed individuals.

SO there you have it: a round up of (most) of the parasites that we see in our pets. Whether your pet is a couch potato or wanders far and wide, whether he shares your bed or has a kennel outside, they are all exposed to parasites and so are we.

Although it’s pretty scary to think of all the creatures that can be hiding in and on our pets, and the ways they can make us both ill, it’s also important to remember that you CAN protect your pet and your family. The vast majority of these infections are preventable or treatable with good veterinary care: use regular good quality
parasite prevention and, if your pet is poorly then see your vet. If you any questions then get in touch with your veterinary surgery they will be more than happy to help