I'm glad to see that you guys are all egg production masters here. That's wonderful. Attending all these lectures. So, we're going to move on to parasites. Now, I'm going to start off with my favorite parasites, which are the mites, the ectoparasites. Mites here are most often transmitted bird to bird. So that doesn't just mean chicken to chicken, turkey to turkey, etc. That also means wild birds can bring in mites, which is pretty gross. That's another reason to keep your coops contained, keep that mesh up, make sure that your finches and songbirds aren't visiting. Heavy blood feeding infestations of certain types of mites can cause anemia. They can also obviously cause poor animal welfare and decreases in egg production and growth. So things to think about. These are probably the ones that will appear most often on the tests. So red fowl mites, northern fowl mites and scaly leg mites. Red fowl mites here are very rare in the U.S. and Canada. They are more common in the subtropical warmer areas of the world. They are night blood feeders. So this is a this is a exam question that comes up frequently. They will live in the nooks and crannies of your chicken coop, your chicken house and during the day. And then when your birds come in to roost at night, they will crawl up onto your broods and actually suck their blood then. And before the morning comes, they will return to their nooks and crannies, which means if you're going in the daylight and looking at these birds, and you're like, why I saw this happening? I can't see any mites on there. It's because they might be red fowl mites. So you might not see the mites themselves on the chicken, but you can check for dirty feathers and the occasional mist mite in the vent area. So dirty feathers you're going to see browning feathers, sort of like reddish brown stuff that's probably mite feces they've left. It's going to be around the vent, around the cloaca opening, and you can always check those nooks and crannies to see if you actually see mites with sticky tapes or other traps. Northern fowl mites are what we're going to see more frequently in the U.S. if we see mites. This is another exam question. In comparison to red fowl mites which live in the house and feed at night, the Northern fowl mites will spend their entire lifecycle on the bird. They live and blood feed on the birds. So if you pick up a chicken and you're like, Oh, there's mites on this chicken, most likely you're seeing northern fowl mites. You're again going to check for those dirty feathers and mites in the vent area. A big differential is going to be the color of mites, a brown versus more red. And also being able to see them on the bird versus being able to see them in the coop in the coop crannies. Scaly leg mites are my favorite type of mites. They are caused by Knemidocoptes mutans which is the same mite that can cause issues in the sear of parakeets. And so you often see those photos on exam prep as well. They are going to burrow under the scales on birds shanks and they're going to cause an inflammation and they're going to be like chewing and defecating and having their whole lifecycle there, which causes our shanks to thicken and our scales to raise and crust, which is why we get the name scaly leg mite. So this is a good photo of a up close and personal scaly leg infection on the foot of a chicken. You can see how these scales have risen. There's a gap right here between this scale and this next scale. There's a gap here between this scale and that scale. And all of these now look kind of like kernels of corn, more than just like a continuous, nice, scaly leg. So when you remember what a normal chicken shank should look like, it should be shiny, it should just be continuously smooth. You run your hand down it, it shouldn't feel bumpy at all. That's not the case in scaly leg mites. And this is what you're going to see, instead. All of these mites are going to cause bird irritation. So scaly legs will just be itchy, scratchy. Northern fowl mites and red fowl mites also itchy, scratchy. The red fowl mites more at night, which causes issues with the birds sleeping. So all of these are welfare concerns. 

To diagnose these, you're going to look at them based on lifestyle and appearance. So again, are they on the legs? Are they on the bird body? Where did we find them? Did we find them during the day? Did we find them only at night? And there's various options for control. The thing that I think is most easy for people in backyard situations are diatomaceous earth dusting pans so you can just get like a little like cat litter box and put diatomaceous earth in there and then birds will go ahead and engage in dusting behavior like this wild bird shown. That's a natural behavior. It's good enrichment and diatomaceous earth is full of tiny little particles of sort of glass like shards almost. They're so, so small. They cause tiny breaks in the cuticle of the ectoparasites, which causes them to dehydrate and die. So it's a very natural, non-chemical way to do this at home. Some people actually add sulfur dust as well to these pans. If you're having especially like a more refractory issue, you can try that, which is another thing that helps to kill off the mites. But there are some anti mite topicals available for use in poultry in the U.S. There are permethrins, there are dichlorvos products, but you should be using these judiciously under guidance from FARAD, and you should make sure that your clients know about proper handling as well because they are pesticides. 

Okay, moving on to lice. So poultry lice, they do have various species. They are all, however, chewing lice, so it makes it easier to figure out what they are if you see them under the microscope. These lice will also spend their entire lifecycle on the host. Most frequently you're going to see Menacanthus stramineus, which is the most common poultry louse, and that's the one that's pictured in this photo. To find these guys inspect the feather shafts. So when I say feather shaft, it's like that central beam down the middle of a feather, for lice feces. So like brown, dusty material. Nits, which are like white accumulations of both eggs and also like the sticky material that lice create to stick eggs onto the feather shafts. As well as these adult lice, which you can actually sometimes see creeping, crawling through the shafts of feathers. You're going to see from a distance, just maybe dirty brown feathers. So like areas of a white bird that just look kind of unthrifty, a little bit dirty, but there's no reason for it necessarily in the coop. You're going to look for those white nit masses as well. Look for your search around the vents around the cloacal opening, under the wings and around the crest or like the back of the neck area. Those are the areas that these were most likely to live in, but they're also areas that are harder for the birds to actually bathe and groom, so it makes it harder for them to get rid of them on their own. Control methods are going to be the same as control of mites. And again, you know, we want to really want to prevent introduction here. So as much as we can do to when we quarantine new bird additions, when we prevent bird to bird contact with wild birds as well, it's very important. 

Bedbugs are also a thing in poultry. I wish they weren't. They're very disgusting. Both poultry and humans species infest poultry flocks. This is a huge downer because it is a potential for bidirectional zoonotic infestation. Which means if you have bedbugs in your house and you have one on your pant leg and you go to visit chickens, you actually could give them bedbugs into that coop. And the reverse also goes, that if I go to that coop, I could pick up a bedbug and bring it home, and then I could have bedbugs in my own home. So that's an issue for both animal welfare for the same reasons that it is for people, because they're woken up at night, they're itchy, they're scratchy, they're losing blood. And then for people, you know, it's really concerning. They're very hard to eradicate from homes as well. So we want to make sure this doesn't happen. Bedbugs live in nooks and crannies. They feed on blood at night, so they have a more of a life cycle that's more similar to a red fowl mite. They're not going to be living on the bird permanently. You're going to be able to see larger masses of them, though, in the nooks and crannies then you would the red fowl mites. For an impact, you know, this feeding is going to disrupt bird sleep. We actually have really good videos of this from welfare studies where they wake up alot to like dust and itch in the middle of the night, which decreases their ability to have that full continuous night's sleep. You can also have anemia in heavy infestations if you're really just having a lot of blood sucked out of your birds. To diagnose these guys, we're going to try to collect some and look at insect morphology. So if you have a suspicion of mites and you can't find them on the birds a day and you're thinking maybe it's red fowl mites, also think, hmm, maybe it's bedbugs and you're going to go ahead and look in those nooks and crannies. You can look at them during the day and also check at night. Collect specimens from covered areas of the coop on tape. So just go ahead and bring in like regular old packing tape, any sort of nooks and crannies that's like under in a protected area stick tape on it, take it off, look to see what you got. If you can't identify them yourself, you can always send them to your local vet school and they have parasitology departments that can help. These are very difficult to eradicate. They're very difficult to eradicate from human houses. They're very difficult to eradicate from hen houses. I would advise you strongly to consult a pest management professional, see your local companies that deal with this sort of thing in human houses if you end up having this issue. 

Moving on to endoparasites, roundworms. The primary species of concern in chickens is Ascaridia galli So that's a common test question as well. This is a worm that is infrequently a primary cause of pathology, so it will actually be present at low levels fairly frequently. But we don't usually expect to have an impact unless it's a very heavy infestation. And then in those cases, that's primarily due to weight loss because the worm is actually eating the things that you need to survive and intestinal impaction. You can see so many worms proliferate that no feed can actually pass through and just have like a bolus of worms that are stuck in the intestines. To get these worms are going to have a direct life cycle. So you can just pick up an oocyste, or a sorry, a infectious worm egg out of feces and consume it, or you can have it be ingested by an insect first and then have your bird pick that up and eat it instead. A picture of one of these Ascarid species eggs from a fecal float, is there. A lot of these have similar morphology, so you'll  have seen them already in your parasitology courses. Clinical signs, you're going to see loss of body condition. You're going to see maybe some diarrhea, not super common, maybe depression if there's a large infestation. It's very rare to find one of these in a actual egg. So sometimes you will see a worm in an egg and it's either an extremely heavy infestation or it's a worm that somehow fell down into the cloaca and tried to crawl back up the intestine. This is the running hypothesis. In the cloaca, we know there are three entrances the cloaca. From the kidneys, from the oviduct, and from the GI. If it chooses the wrong tube, as it were, to go up, it can actually go up the oviduct to be incorporated into an egg. Very rare.  You can also see mortality if these birds are already otherwise compromised and if the birds are immunocompromised or very stressed, everything's going to get a little bit worse, just as with any other parasitism or disease. To diagnose these guys, you can do fecal flotation to identify their eggs. 

To treat them, we do have an on label treatment, which is very exciting. It's labeled for use in chickens. It has a zero day meat or egg withdrawal, which means if it's used on label, you can go ahead and give it and you can start eating the eggs just right away. I would not recommend you use piperazine because it does not kill parasites. It paralyzes them with the hope that they will be expelled from the body by the time that they become unparalyzed, as it were. We actually saw an increased rate of eggs with ascerids contained in them when piperazine was a more frequent treatment in the industry. So I suspect some of those worms are actually falling down and waking up and going up the wrong tube more frequently back then. So for control here, just minimize contact with feces, really. You don't want to help reinfestation occur. You going to top dress litter with new shavings when it's soiled. Just put more over the top. If you're pasturing, you're going to want to rotate your pastures, just as you would to control ascerid issues in your horses and cows. Periodic deworming is going to be really helpful. Usually it's every six months or maybe as needed to control burden. And you can check that based on fecal flotation. You can use your fecal flotations in your clinical settings to inform frequency because that might not be the right frequency for everyone. Some folks may have more. Some folks might have less. It's always good to collect that data so you know how to use your dewormers judiciously. 

Tapeworms are also present in poultry, but they are rare for a primary health concern, except in very severe infestations. Usually these are transmitted through insects as paratenic hosts, most commonly flies in that poop setting. So to diagnoses go ahead and do a fecal flotation. Look for tape eggs. Fecal proglottids are pretty rare, except if you have a very, very heavy infestations. I wouldn't rely on just visual inspection of feces for these guys. To control them, your primary means is going to be limit insect ingestion. This can be difficult if you have birds going out and foraging on pasture. But you know, you can do things that are just very manageable, like putting up fly tapes or traps. That minimizes a lot because we know that flies are specifically attracted to feces and then birds like things that are zipping past their face to eat. So if we control flies, we're just controlled a huge step in that lifecycle. Go ahead and muck up a coop frequently to decrease the amount of feces available for the flies and top dress the litter to keep it clean. We don't have a labeled treatment for tapeworms in poultry. We have some anecdotal evidence off label, but you should consult FARAD. And again, it's unlikely that you would actually need to treat them. Typically, it's just a light infestation every once in a while, if that. 

Coccidia is probably the parasitic disease of most importance, both for commercial poultry and backyard poultry around the world. It is ubiquitous, so commercial flocks have it. Small flocks have it. Folks are always talking about it online. They are caused, Coccidia is caused by myriad species. They're protozoans. Most of them are specific to a single host species. And there are various species within Eimeria that cause disease at different levels of the intestine. They complete both the asexual and sexual reproduction cycle in the intestinal mucosa, and that's what causes the damage and causes the clinical signs we see associated with it is them breaking down the cells they need to reproduce. Transmission is fecal oral. So again, to become infective, these oocysts must sporulate in the presence of moisture, oxygen and warmth. This is something you've heard before if you've been to my previous major diseases of poultry talks. It's so important, though. We're going to go over it again. 

Primarily this is a disease of young poultry, because if these birds are regularly exposed to low levels, as they would be in a typical sort of wild environment with their mama bird and around her droppings, they would develop an immunity because it would be sort of like trickle dosed immunity. Regular doses of a low level in early life will allow immunity without overt disease. But if these birds are exposed and they've been completely naive and they're adults now, they can have a pretty severe reaction and disease later in life, too. But most of the time I think about it as an early disease if you have a typical flock. Clinical signs are going to vary a lot by the eimeria species. There's a lot written about this. There's a lot in these good textbooks I'm going to recommend at the end. But the typical things you might think about and look for are going to be lost condition. So, weight loss, lack of growth, depression, dehydration. You're going to see wet litter, diarrhea, sometimes diuresis as well. Loose droppings in general. Bloody droppings is a big red flag for Coccidiosis. And then you can actually have mortality with the more virulent species. Inapparent or subclinical infections do occur. And in turkeys, turkeys behave a little differently. They like to be different. The top clinical signs are going to be dehydration and increased vocalization. So if you have a young turkey flock and they are much louder than they were just a couple of days ago, you might look into coccidiosis. 

Okay. Gross lesions. Check out the Zuku review tune up top Poultry Diseases part two for more information there. Because there's a lot of different types, but often these lesions are fully diagnostic without other forms of testing, which is super helpful. Which means if you had an episode of mortality and you open those birds, if you know what to look for, you can say, Hey, this is coccidiosis. It's probably this species of Eimeria. And you can go about controlling it. To manage this disease, you're going to minimize environmental parasite load by controlling litter, moisture, cleaning out regularly, ensuring good drainage and airflow in that moisture because again, they can't become infective unless they are moist, warm and have oxygen. So they get rid as much of the pieces as possible and keep it dry, that's our best chance of keeping these parasites from overpopulating our houses. We're going to decrease our bird access to feces again, top dress your litter regularly, muck out whenever you can, don't mix bird ages whenever possible, because what we worry about is having a large dose of parasites all of a sudden coming on to a naive young chick with no immunity and having them have actual disease. You can also feed anticoccidial chemicals. These are labeled chemicals for use and it's like a medicated feed. So you might go to a feed store and you'll see a chick starter that's like medicated chick starter on the label. That's what they mean is they're medicating against coccidiosis. And that helps just to sort of cut the top off the amount of clinical signs, the amount of protozoa that are actually replicating in the gut and allows them to more efficiently generate immunity without having disease form.