Connect to the previous article
06: About heartworms
Heartworm, a parasite that spreads through mosquitoes, is also found in China! Many wild animals can be infected! Let's first look at how heartworms spread to cats.
Image from the web
Many mosquitoes can spread heartworms, when they bite the animal infected with heartworms, and then bite the cat, they will infect the heartworm, they will evolve in the cat's body, from the larvae to adult worms, killing our cats. Note: Indoor cats can also be infected with heartworms, there are statistics: 1/3 of cats infected with heartworms live only indoors. Compared with long-haired cats, short-haired cats are more likely to be bitten by mosquitoes and infected with heartworms.
About 100 days after the infection begins, the larvae begin to enter the blood vessels. They will first go to the lungs, mature, if there are many worms, some will go to the heart, central nervous system, eyes, posterior vena cava... Cause breathing difficulties, hindlimb disabilities, paresthesias, etc...
For cats, in fact, heartworms are not so easy to infect, much lower than the probability of infection in dogs. However, once a cat is infected with heartworms, it is difficult to diagnose (only by ultrasound examination of the right ventricle, pulmonary artery, etc.), cannot be treated, and is very prone to sudden death.
The problem of very easy sudden death is terrible, which makes it impossible to treat it by means of insecticide. Because cats are small and have thin blood vessels, even if there is only one adult worm, it is fatal to cats. After the worm dies naturally or is killed by drugs, it is easy to cause arterial embolism, which directly causes sudden death of the cat, so if it is found that there are adult heartworm worms in the cat, insecticidal treatment is generally not recommended.
Cats are not the main host of heartworms, and at the same time, the lifespan of heartworms in cats is very short, almost only 4-5 months, so it is possible that if you don't care about cats, cats will heal on their own.
If the worm is usually dewormed on time, it will hardly infect heartworms. However, if the insect is not repelled on time, there are problems such as breathing difficulties and shortness of breath, and it is necessary to check the heartworm.
Hospitals generally use ELISA antibody testing, with chest X-ray, electrocardiogram, ultrasonography, blood test, biochemical tests to confirm the diagnosis, sometimes also need a urine test, and a few months later to check again.
Heartworms can cause irreversible damage to the lungs and even the heart and brain of cats and dogs, and are difficult to find and treat, so prevention is almost the only thing we can do.
It takes about 5-6 months for heartworms to mature in the body, so it is recommended that you deworm cats once a month. If you feel that the financial pressure is too great, give cats and dogs a month to deworm after the emergence of mosquitoes (June to October), and in the southern region, you can start from April.
Many deworming drugs on the market can now prevent heartworms, such as ivermectin, serramectin, mebemycin oxime, moxyxiktin, pyrimethamine, etc.
For example, the main ingredient of Heartgard is ivermectin, the main ingredient of Revolution is xylamrin, and the main ingredient of Advocate is imidacloprid and moxyxidine, all of which can be selected.
The probability of human infection with heartworm is very, very low, and heartworm larvae will not grow and develop in the human body, so it will not cause major damage and will not be fatal, but this question, the veterinarian can not answer in detail, super-class.
There are very few cases and studies in this regard, so there is no definite help. Don't worry too much.
07: About Toxoplasma gondii
Image from Animal Internal Medicine
Toxoplasma gondii, also known as Gondii, is a protozoa parasite (a type of coccidiosis) that can infect almost all warm-blooded animals, of which cats are the only terminal host.
The causes of human infection with Toxoplasma gondii are divided into the following categories: 1, eating pigs, sheep, etc. infected with Toxoplasma gondii; 2, drinking water, fruits, etc. contaminated with cat feces; 3, blood transfusion or organ transplant infection; 4, from the mother through the placenta to the fetus.
But it is generally a latent infection, and the vast majority of people have no symptoms after infection. However, 10% to 20% of patients with acute infection may develop cervical lymphadenopathy and/or influenza-like illness. Clinical processes are usually benign and self-limiting, and symptoms disappear within a few weeks to a few months. In rare cases, ocular infections can occur with visual loss.
Adults with intact immune systems will experience temporary discomforts such as fever, muscle pain, sore throat, etc. after the first infection. But for people with weakened immune systems, such as fetuses, newborns, the elderly, or people with immune system diseases, the situation is more serious. There is usually a central nervous system disorder, but there may be retinal choroiditis, pneumonia, or other systemic disorders. In AIDS patients, Toxoplasma encephalitis is the most common cause of lesions of the brain mass.
Most seriously, pregnant women who are infected with Toxoplasma gondii for the first time can lead to congenital malformations, mental retardation, and even death. It should be noted here that if you have been infected with Toxoplasma gondii before pregnancy, it generally has no effect. Dangerously, people who are infected with Toxoplasma gondii for the first time after pregnancy. The incidence and severity of congenital toxoplasmosis varies with pregnancy. Since the mother's treatment can reduce the incidence of congenital infections in infants and reduce the occurrence of sequelae, timely and accurate diagnosis is crucial.
The same is true for cats, most cats will not have clinical symptoms after infection with Toxoplasma gondii. The lungs, eyes, and liver are the most commonly infected organs, and clinical symptoms can occur if they cause local necrosis of the organs. Clinical symptoms include: anorexia, fever, lethargy, pneumonia-related dyspnea, jaundice, muscle pain, pancreatitis and neurological symptoms, some cats will bleed in the eyes, retinal choroiditis and so on.
There are some scientific studies that suggest that infection with Toxoplasma gondii alters host behavior to increase the likelihood of transmission. Recent laboratory experiments have shown that rats infected with toxoplasma gondii for a long time lose their innate fear of cats, making them more likely to become prey. In humans, studies have been conducted since 1966 to prove the relationship between toxoplasmosis seropora and schizophrenia, suicide, and behavioral changes, but the jury has not yet been conclusive.
Diagnosis of Toxoplasma gondii
There are many ways to diagnose Toxoplasma gondii, mainly through basic tests such as hematology, biochemical and urinalysis, cytology and histopathology, radiological examination, etc. Toxoplasma gondii infection is determined, and serum antibody testing can also determine toxoplasmosis infection. Diagnosis of congenital infection can be achieved by detecting Toxoplasma dna in amniotic fluid by molecular methods, such as polymerase chain reaction (PCR) testing.
Serum antibody testing is the most important diagnostic method for Toxoplasma gondii infection. Usually by testing for Toxoplasma gondii-specific IgG, IgM, IgA, or IgE antibodies. Among them, IgM antibodies appear around 2 weeks of infection, and IgG antibodies appear in the fourth week after infection, usually for life, unless increased by 4 times in 3 weeks, otherwise only represent previous infections.
Theoretically, a positive IgM and a negative IgG indicate recent exposure, there should be a high suspicion of infection with Toxoplasma gondii and should be retested after two weeks;
Positive IgG and negative IgM indicate past exposure, but no presence of clinical disease;
The following is a reference to the results of a laboratory diagnosis of Toxoplasma gondii in humans:
However, it is worth noting that there are problems with both IgM and IgG antibody detection, that is, 20% of infected cats do not produce IgM, and high IgG titers cannot prove to be recently infected, and high IgG titers and chronic persistence only indicate the persistence of toxoplasmosis antigen after infection, and do not rule out the possibility of re-ovulation.
Therefore, antibody classification does not accurately predict the period of oocyst shedding, the likelihood of oocyst shedding, or the stage of infection. Once a cat is infected with Toxoplasma gondii, the toxoplasma tissue envelope will remain for life, which will stimulate a long-term humoral immune response in infected cats, and the seroprevalence rate increases with age.
Serological tests in immunosuppressed patients are sometimes unreliable. Because toxoplasma gondii cysts and antibodies persist in asymptomatic chronic latent infection, immunosuppressed people, whether positive polymerase chain reaction or serological results, should interpret their diagnostic test results associated with the clinical features of active infection. Negative PCR does not exclude active infection. Polymerase chain reaction can also be performed in sheep water, which helps to determine fetal infection after acute acquired infection in the mother.
Diagnosis can be made by direct observation of parasites in stained tissue sections, cerebrospinal fluid (CSF), or other biopsy material. Since these samples are difficult to obtain, the frequency of using these techniques is low. Parasites can also be isolated from blood or other body fluids, such as cerebrospinal fluid, but this process can be difficult and take quite a long time.
Eye diseases are diagnosed mainly by eye examination.
PCR testing is a better way to detect Toxoplasma gondii DNA in the blood, but a positive PCR result does not mean that there is a clinical disease, but if the pathogen is found in inflammatory tissue, the possibility of toxoplasmosis should be considered.
In addition, because Toxoplasma gondii may cause tissue inflammation, it is necessary to determine whether there is tissue inflammation by blood routine, serum biochemical and urinalysis, radiological examination, etc., if there is leukocytosis, lymphopenia, and eosinophils. Increased AST of bilirubin, alanine aminotransferase ALT, and aspartate aminotransferase means liver or muscle necrosis. Elevated serum amylase means that pancreatitis may be caused. Radiation tests of the chest can detect pleural effusions, whether they cause inflammation in the lungs, etc.
Treatment of Toxoplasma gondii
First of all, I must tell you that there is no such thing as a toxoplasmosis vaccine in the world now, and what you see is to cheat money...
Currently recommended toxoplasmosis treatments target the rapid-breeding phase of the parasite and do not eradicate the capsular parasite in tissues. For humans, pimetoxamine is considered the most effective drug for the treatment of toxoplasmosis and is a standard component of treatment. Pirmetoxamine is a folate antagonist that causes dose-dependent bone marrow suppression, while administration of folic acid (leucovorin) reduces bone marrow suppression. Leucine protects the bone marrow from the toxic effects of pirmethoramine. A second drug, such as sulfadiazine or clindamycin (if the patient has an allergic reaction to sulfonamides) should also be included. The immobilized combination of trimethoprim and sulfamethoxazole has been used as an alternative drug, as well as other drugs, such as atovaquine, pirmexamine, and azithromycin, which have not been extensively studied.
Treatment of eye diseases should be based on a complete ophthalmic evaluation. The decision to treat eye diseases depends on many parameters, including the sharpness of the lesion, the degree of inflammation, vision, lesion size, location, and persistence. Cured lesions should not be treated. "Classic treatments" for toxoplasmosis of the eye include:
Adults: pirmexamine 100 mg, 1 day as a loading dose, 25-50 mg / day, plus sulfadiazine 2-4 g / day, 2 days, then 500 mg to 1 g / day, 4 times / day, plus folic acid (leucine) 5-25 mg / dose of pimetsamine;
Pediatric dose: 2 mg/kg of pimetsamine 1 mg/kg/day, sulfadiazine 50 mg/kg twice daily, folic acid (leucine) 7.5 mg/day).
Treatment should be continued for 4 to 6 weeks, followed by a re-evaluation of the patient's condition. (See: de-la-Torre A, Stanford M, Curi A, Jaffe GJ, Gomez-Marin JE. Therapy for ocular toxoplasmosis. Ocul Immunol Inflamm. 2011; 19:314-20.) In addition to antiparasitic drugs, corticosteroids are sometimes required.
If left untreated, toxoplasmosis in immunodeficient patients is often fatal. Treatment is recommended for at least 4 to 6 weeks, more than the resolution of all clinical signs and symptoms, but may take 6 months or more. Patients with AIDS are known to relapse, and maintenance therapy is recommended until antiretroviral therapy achieves significant immune improvement. Pirmexamine, folic acid (leucovorin), and sulfadiazine are the criteria of treatment for immunocompromised patients.
For cats, clindamycin is a first-line drug for toxoplasma gondii, and if toxoplasma gondii causes preveitis in cats, topical, oral, or injectable corticosteroids can be used at the same time. Note that to prevent possible esophagitis, clindamycin must be swallowed once after oral administration of food or water. If oral administration is not possible, subcutaneous injection may also be used. Generally, after 24 to 48 hours of taking the drug, it can relieve the systemic symptoms caused by Toxoplasma gondii, including fever, hyperesthesia, and sports disorders.
In addition, pyrimethamine, trimethoprim and sulfonamides, triazine compounds, and a combination of fluconazole and fluconazole are all drugs that can be used for toxoplasmosis treatment. If the cat is infected with Toxoplasma gondii, go to the hospital.
Prevention of Toxoplasma gondii
The only way to prevent a cat from contracting Toxoplasma gondii is to keep the cat indoors, make sure not to touch toxoplasma gondii egg sacs and carriers, and keep food and water clean and tidy. If raw meat and bones are to be fed, freezing meat at temperatures of -12 degrees Celsius or lower for at least three days before feeding can kill tissue oocysts. Be aware, however, that if the freezer temperature is not high enough, the oocyst can continue to survive.
Not eating undercooked meat (pork, beef, lamb) is the best way for humans to prevent toxoplasmosis disease, wash your hands thoroughly after touching raw meat, and prepare a special raw meat cutting board, which should be cleaned and disinfected after each use. Raw goat's milk, oysters, clams, mussels, etc. are not consumed. Fruits and vegetables should be washed or peeled. In addition, after gardening work, you should wash your hands after fiddling with flowers and plants.
It has been proven that contact with cats is not a common cause of toxoplasma gondii infection, because the oocyst sheds are short, the shedding is rarely repeated, and the cat loves to be clean, which can lead to the removal of feces and oocysts. But because dogs love to roll in the mud, they must wash their hands after touching the dogs to prevent infection. In addition, the garbage should be cleaned up in time, especially the cat litter box, which should be cleaned at least once a day.
08: About coccidiosis, trichomoniasis and giardia
Coccidioides, trichomoniasis, and giardia generally cause gastrointestinal symptoms in cats, such as diarrhea and blood in the stool.
Coccidiosis
The common coccidioides in dogs and cats are generally spores such as spores, generally ingested oocysts or sporopod infections (interested readers can see "Veterinary Parasitology"), the most common symptom of coccidiosis is chronic diarrhea, manifested by a large number of watery diarrhea that lasts for several weeks, and the treatment has basically no obvious effect.
Diagnosis requires identification of oocysts in the stool, history, and clinical symptoms, and sometimes severe, fatal coccidiosis occurs before the formation of the oocyst, so the presence of coccidiosis in the stool is not diagnostic of coccidiosis. However, if it is a kitten, puppy, or young child, and there is regular diarrhea in succession, coccidiosis should be considered first.
Coccidiosis is generally self-limiting and slowly improves with host immunity, but still excretes the oocyst with feces. The treatment and prevention of coccidiosis is more disturbing, because current conventional deworming drugs have no effect on coccidiosis, and there is currently no reliable disinfectant that can kill the source of infection in the environment. Advanced coccidiosis is generally supportive because no drugs have been used against host-infected coccidiosis. Sulfonamides are generally used to control the number of coccidiosis, and sometimes veterinarians also use triazines.
In addition, coccidioides such as Cryptosporidium, Toxoplasma gondii, Harmoncoccidia, Liver Clusterworm, Hemosporidium, and Malaria Parasite can also infect dogs and cats.
trichomonas
The trichomoniasis that infects cats is called Trichomonas fetalis, and it is an important cause of diarrhea in cats worldwide. Trichomonas fetalis predominantly parasitizes the vagina, uterus, macerated fetus, foreskin, penis, epididymis, and vas deferens. Trichomonas fetalis has 3-5 long flagella and a pronounced wavy membrane that is morphologically difficult to identify.
Trichomoniasis infection can be associated with chronic or recurrent large bowel diarrhea, characterized by increased mucus, foul-smelling, or semi-formed diarrhea with mucus and blood. Constipation, occasional blood in the stool, and increased stool frequency may also be possible. The median duration of diarrhea was 135 days, ranging from 1 day to 7.9 years. The anus is often red, swollen, and painful, and fecal incontinence is not uncommon. Most cats are usually intelligent, alert, responsive, in good physical condition, and have a normal appetite. Trichomoniasis can be isolated from the feces of asymptomatic cats, many of which do not have diarrhea. Infected cats are generally young, but the age of infection ranges from 3 months to 13 years (median is 9 months).
Diagnosis is by PCR testing (polymerase chain reaction) with Ronidazole, the drug of choice for the treatment of Trichomoniasis cats. It is important to accurately calculate the amount of ronidazole per cat based on the weight of each cat, and an overdose may increase the risk of neurotoxicity. Clinical symptoms of neurotoxicity include drowsiness, loss of appetite, ataxia, and seizures. This symptom usually goes away after stopping drug therapy, but can last for 1 to 2 weeks. If signs of neurotoxicity are found, ronidazole must be discontinued immediately.
In addition, the environmental control of Trichomoniasis fetalis is very fragile because it cannot form cysts. Drying, refrigeration, exposure to temperatures above 40.6 °C (105 °F) and prolonged exposure to oxygen kill organisms. During treatment, the litter should be replaced and the litter box disinfected to prevent the cat from re-infecting the trichomoniasis.
Giardia
Giardia infections are mainly caused by bodies of water contaminated with human or animal feces. There are 7 groups of Giardia, A and B mainly infect people, C and D mainly infect dogs, E groups are mainly infected with ungulates (such as cattle, sheep, pigs and horses), F group is mainly infected with cats, and group G is mainly infected with mice. For cats, in addition to the F group, they can also be infected by the D group, A group, C group, note that cats can be infected with giardia A group, which means that giardia has a risk of human-cat comorbidity, but transmission from cat to person is still relatively rare.
Giardia in adult cats is usually subclinical, and in the early stages of infection, there will be a temporary softening of stools, but for kittens, if infected with Giardia, there will be acute diarrhea, and the stool will be pale and accompanied by foul odor and mucus.
Diagnosis is mainly by ELISA (enzyme-linked immunosorbent test) or zinc sulfate fecal float test, which should be distinguished from Trichomoniasis fetalis. Trichomonas fetalis should also be distinguished from Giardia, which has a concave abdominal disc, binucleus, and movements similar to that of deciduous tumbling. In contrast, Trichomoniasis fetalis is spindle-shaped, mononuclear, with a wavy membrane that runs through the entire body, moving in a more irregular and rapid manner.
Treatment is with metronidazole, albendazole, fenbendazole and other drugs can be used. In addition to drug treatment, it is also necessary to control giardia infection and minimize the infection in the treated animals by the following methods:
1. Purify the environment: purify the environment, improve the therapeutic effect, and eliminate the Giardia brachia sac from the cat's living environment as much as possible. Contaminated feces are removed as many times a day as possible, the cat litter basin is rinsed with water, then covered with a layer of disinfectant, and after 10-20 minutes, rinsed with clean water and dried.
2, bathing, you can remove the bag on the hair.
3. Prevent re-infection, keep drinking water clean and clean, and never touch polluted water sources again.
note:
If the cat has persistent diarrhea, it is necessary to first determine the possible causes of diarrhea and exclude them one by one, first to rule out whether there are underlying diseases, such as various inflammations, and if there are coccidiosis, giardia and trichomonas fetal, then symptomatic treatment.
In addition, Feline Disease recommends that cats infected with Giardia should be screened for feline leukemia virus FeLV and feline HIV FIV.
09: About trematodes
Trematodes have always been parasites that make us smell discolored, and the adults of trematodes are generally parasitic in the bile ducts, and the eggs first enter the intestinal cavity with bile, and then excrete through feces. After the eggs fall into the water, they begin to develop slowly, looking for a host, in the aquatic plants (such as riverside grass, watercress, etc.), fish, shrimp, crab snails, frogs, snakes, rats into infectious cysticers, if the animals (including humans) eat these cysticer infected animals, Ou ... It is infected with liver flukes. There are also some flukes that are infected by burrowing into the skin.
Image from Veterinary Parasitology
Of course, we still look at the geographical distribution, there are seven main species of flukes distributed in Asia, Bucholas ginger flukes, homotopy and colonis, posterior testicles, mycodchidism, Man's schistosomiasis, Japanese schistosomiasis, bird genus, mainly infected cattle, sheep, pigs and people, dogs and cats occasionally infected, most of the diseases caused by intestinal damage and lesions, hepatitis, liver fibrosis, dermatitis, etc., which lead to death when serious. The way to pay attention is not to give the cat raw fish, raw shrimp, salmon do not eat raw, crayfish do not give the cat to eat.
Let's take a look at the problem of parasites infected with raw salmon and trout.
The main reason is that salmon (salmon) and trout may have salmon pygmy trematodes in them, and common salmon poisoning manifests as lymphadenopathy, hemorrhagic enteritis, requiring stool testing and broad-spectrum antibiotic treatment after finding eggs.
The treatment of trematodes requires the determination of what trematodes are infected, and the common crepetual trematozoma in the United States can be used with praziquantel (23 mg/kg body weight, three times a day for three consecutive days), fenbendazole (50 mg/kg body weight, 10-14 days) or albendazole (25 mg/kg body weight, twice a day, for 14 days). Posterior testosteria can also be treated with praziquantel, the dosage is 100 mg/kg body weight. Trematode infections in the intestine can be treated with praziquantel. Japanese schistosomiasis, etc. infected by the skin can be treated with praziquantel, fenbendazole, and ezetyl.
10: Other
Parasites and anthelmintics associated with cats
Diagnostic Parasitology for Vetäs
Bibliography and Literature:
1、[美] Dwight D. Bowman, 《Georgis' Parasitology for Veterinarians》
2. "Pfizer Parasite Color Atlas"
3、Anne M. Zajac et al, 《Veterinary Clinical Parasitology》
4、Dennis Jacobs et al, 《Principles of Veterinary Parasitology》
5、Charles M Hendrix,《Diagnostic Parasitology for Veterinary Technicians》
6、Hany M Elsheikha et al,《Veterinary Parasitology: Self Assessment》