Coccidiosis: cryptosporidium, cystoisospora, and other coccidia
Coccidia are single-cell parasites that can cause short-term diarrhea, especially in young animals. The diarrhea usually passes within a few weeks, but the eggs can remain in the environment for years and infect other animals.
Most of the coccidia have, besides being an end-host (that is the animal with intestinal complaints), also an intermediate host. At the intermediate host, the parasite can cause inflammation in the muscles, organs or brain
Unborn animals and individuals with poor resistance can become seriously ill.
Animals can become infected by eating the eggs (oocysts) and / or by eating raw meat from intermediate hosts.
The best known Coccidia are Toxoplasma, Neospora, Cryptosporidium and Cystoisospora.
Toxoplasmosis is caused by Toxoplasma gondii. This parasite is very common.
The parasite is best known because it can lead to abortion, death of the baby just after birth, permanent brain or eye damage.
This is the reason that pregnant women are not allowed to eat red meat.
The parasite can also cause problems in people, dogs and cats with reduced resistance.
The parasite is spread through the stool of the cat (the end-host). It is almost always a young cat. The cat may have diarrhea, but that is not necessary. The cat spreads millions of eggs in 2-3 weeks and then (almost at life time) is immune. The oocysts are infectious after 2-3 days and can remain for several years.
The between-host (man, dog) usually infects indirectly: through the garden, raw vegetables and raw meat.
Can cause serious illness in dogs, but is especially notorious among farmers. Healthy dogs can transfer the parasites to cows, who can reject them (get a miscarriage). Dogs become infected by eating the rejected fruit or by eating raw meat.
1 in 10 dogs has antibodies against Neospora.
Only a small proportion of these dogs become ill, or transfer the parasite to the offspring.
Healthy adult dogs and cats are usually not sick of this parasite. Kittens and, less often, pups can get watery sometimes stinking diarrhea due to this parasite. Diarrhea can persist for days to weeks and is accompanied by abdominal pain, vomiting and fever.
The parasite is directly transferable from animal to animal and from animal to human. There are no intermediate hosts.
In most people, Cryptosporidium gives a few weeks of diarrhea that heals automatically. People with poor resistance can become seriously ill.
Cystoisospora is one of the most commonly found coccidia in the young dog and cat (<4 months, peak in 3 to 8 week old animals). They usually give very little disease symptoms.
The parasite is directly transferable between dogs and cats, but not from dog to cat and not from cat to dog. The parasite is also transferable via raw meat.
In case of severe intestinal infections, other symptoms can occur in addition to diarrhea. These are fever, poor appetite, weight loss, dehydration and, in rare cases, mortality. In this type of serious infections, several causes (worms, viruses, bacteria, dietary change) probably play a role.
Cystoisospora is very animal-specific. A person can not get sick from a sick dog or cat.
The following varieties are most common in the dog: Cystoisospora canis, Cystoisospora ohioensis, Cystoisospora neorivolta and Cystoisospora burrowsi (often referred to by the old name Isospora).
Probably this parasite is not clinically important for the dog and the cat. A dog or cat can only get the parasite through raw meat.
This parasite does not cause clinical symptoms at the end- and between-host.
This parasite is only transferable via an intermediate host (so only by eating raw meat)
This is a parasite for poultry, but is sometimes (as a passant) found in the feces of dogs and cats.
Diagnosis of coccidiosis
We usually make the diagnosis of coccidiosis with faecal examinations. The eggs (oocysts) are much smaller than worm eggs and inexperienced researchers can miss them.