In the right eye, we noted an acute, focal, centrally located white spot, 1.5mm in diameter, which we determined to be a healed corneal ulceration.
Potential causes of this are trauma (such as from fighting), a foreign body, or a viral infection.
If the lesion were to be attributed to a viral infection, we believe it would have been feline herpesvirus 1, as it primarily manifests in the respiratory tract and in the eyes as a corneal ulceration. This occurs when the virus lyses the cells of the corneal epithelium, which may be replaced by a conjunctival-like epithelium that is not completely transparent. It may effect one or both of the eyes.
Due to the lesions noted in various places across the face, we believe the ulceration was most likely caused by an injury sustained from fighting. However, due to the lack of testing to determine if an FHV-1 infection was present premortem, we cannot indefinitely rule out FHV-1 as a potential cause. Likewise, due to the healed nature of the lesion, we cannot rule out a foreign body as a potential cause.
The waxy exudate may have been caused by the ear mite Otodectescynotis,but due to the lack of inflammation we believe this was a normal findingChronic, bilateral exudate, potentially due to otitisexterna
Can be due to a wide variety of factors: parasites, foreign bodies, hypersensitivity, bacteria/yeasts, etc
Fighting is very common in the feral cat population, especially when they are not surgically altered. The lesions notedare most likely due to cat fights. The lesion on the left forelimb may have been acquired when the cat was prepped for his neuter. The symmetrically shaved region and premortem signs of inflammation suggest the placement of a catheter.
Acute, multifocal, mild skin abrasions
Shaved area (4x7cm), inside which is an acute, focal reddened area of inflammation which surrounds a centrally located focal puncture wound (1x3mm)
Over the surface of the skin there were red-black dirt-like specks ranging from the size of a pin head to approximately 0.5mm. The presence of this accumulate is consistent with a Ctenocephalides parasitic infection. Fleas! Flea dirt is mostly acquired through Ctenocephalidesfelis or Ctenocephalidescanis. It is a result of the the excreted blood that dries within minutes into reddish black fecal pellets or long tubular coils.
D. caninum is also known as the common tapeworm. It's intermediate hosts are the flea (Ctenocephalidesspp) and the louse (Trichodectescanis), which is where our flea dirt plays an important role. It can also be transmitted to humans making it a zoonosis. D. caninum has an indirect life cycle. This means once the segments of the adult tapeworm are passed, oncospheres that are contained in egg packets are released into the feces and the fur. The flea or the louse may serve as an intermediate host by ingesting the oncospheres. There, they travel into he abdominal cavity of their host and develop into infective cysticercoids. The final host is infected by ingestion of the flea or louse containing the cysticercoids. Clinical signs of this parasite include but are not limited to excessive grooming of the perineum , scooting, diarrhea and irritation of the intestinal mucosa. Catarrhal enteritis is brought on by irritation of the mucosal surface of the small intestine resulting in excess mucous production, disruption of vasculature and edema of intestinal segments containing the parasitic infection.Diagnosis of D. caninum infection is confirmed by taking Scotch tape and placing it in the perianal area. Then observe under a microscope for the eggs unique to this parasite. Treatment of choice is usually a cestocide such as praziquantal. Once the parasitic infection is removed from the system, the intestinal mucosa will re-establish itself with little to no lasting effects on the host.
On observation we noted that there were areas of dark red with pink throughout the entire right lung. The color changes were not present in the left lung and the tissue appeared normal pink coloration. We believe the color changes could have been due to either hypostatic congestion or hypostatic pneumonia. We also discovered a small thickened lesion on the apex of the right caudal lung lobe. The area measured 2cm by 1cm.
Hypostatic congestion is a post mortem finding that results from the pull of gravity and its effects on the settling of blood. The variation can range in any organ or tissue. Some of the main tissues affected by the pooling of blood are organs which are perfused by large amounts of blood. Examples include skin, lung, heart, kidneys and liver. We did not find any similar changes in the other organs mentioned. The areas affected when palpated felt spongy to the touch, which is normal. We believe this was most likely the cause of the observed change.
This is basically the same process as hypostatic congestion with the exception that it is a pre-mortem process affecting the lungs. It is caused by anything that slows the flow of blood through the lungs forcing it to move into the pulmonary spaces. Often the congestion can increase the risk for bacterial infections to occur. it is a secondary process to other diseases. Examples of diseases include congestive heart failure. Upon observation of the other organs we did not find anything to make us believe that the lung changes were secondary to any other diseases. The changes could have also been due to the fact that the cat was under anesthesia, since this consequently leads to a lowered respiration rate, and would result if there was a lack of repositioning to the animal while under. It would be difficult to say
The thickened area measured 2cm by 1cm and felt more dense then the surrounding lung tissue when palpated. The change could have been due to a number of reasons. One being the fact that the cat was FIV positive. The mechanisms for this will be mentioned in the next couple of slides. The change or scarring could have also been related to a past experience of pneumonia due to a bacterial or viral infections.
Some examples of parasites are Filaroides and Aelurostrongylus . Virus examples: Adenoviruses, Parainfluenza viruses, Lentiviruses
Tuberculouspnemonia is caused by Mycobacterium tuberculosis which has been reported to infect both cats and dogs. The bacterium is aerobic, so inhabiting the respiratory tract is ideal for survival. The bacteria is taken up by the alveolar macrophages but the animal is unable to phagocytose it and so the bacteria end up residing and multiplying within the cells of the respiratory tract. Although Mycobacterium tubercolosisappears to be an uncommon finding in cats it can be listed as a cause of pneumoia in this case.In Addition to this, Streptococcus pneumoniaeis a bacteria that can be part of the transient flora within the respiratory tract. This can be a contributing factor to an animal developing pneumonia (especially lobular pneumonia). This bacteria is also associated with other infectious diseases such as conjunctivitis, septicemia, otitis media and urinary tract infections. This could be an explanation for the corneal lesion on the right eye that is present along with brown waxy material found in both ears. Samples were sent to the lab but we do not have a definitive Dx for these findings at this time.Chlamydiae is another bacteria that can be found in cats. However, pneumonia may occur as a rare sequela of chlamydial conjunctivitis and rhinitis.
A case reported that in postmortem bronchoalveolar lavage examination of several FIV infected cats there appeared to be a lymphoid interstitial pneumonitis process occurring. After histological examination of the lungs alveolitis was confirmed, along with other inflammatory processes such as parenchymatous lymphoplasmacytic infiltration and myomatosis.
The Feline Immunodeficiency virus is a lentivirus from the family Retroviridae. Viruses of this nature are characterized by their chronic presentation in hosts' cells and also by their variability in antigenicity due to a high mutation rate. There are currently 5 sub types described (A,B,C,D, and E) with subtypes A and B being the most prevalent in North America. While there has been some experimental evidence to show cross protection among the subtypes via modified vaccines, Veterinarians are still skeptical about the efficacy of the vaccines themselves.
FIV is transmitted mainly through the saliva of infected cats to non-infected ones, most commonly as bite wounds. Therefore, it is more common to have intact, feral male cats present with this infection due to their higher incidence of fighting among each other for mates and territory. It has also been demonstrated that transmission may occur vertically via in utero or through the colostrum of the queen to her offspring.
The pathogenesis we see with FIV is mainly an attack on the T-lymphocytes of the infected cat's immune system; though the virus does have a tropism for other cells such as macrophages, CNS, and salivary gland cells. The T-lymphocytes that are mainly targeted are the CD4+. The virus invades the T-cell via surface fusion after attaching to the CD4 receptor and a co-receptor. This allows the release of 2 strands of viral RNA and enzymes such as reverse transcriptase, integrase, and protease from the capsid into the host cells cytoplasm. The RT begins transcribing a single viral RNA strand into a RNA-DNA double helix via RNA-dependent DNA polymerase. The RNA portion of the double helix is then seperated from the DNA portion. The viral single strand DNA is then transcribed by the RT, this time forming a DNA double helix. This newly formed viral DNA is then edited by the viral integrase on both of its 3' ends so that it may be integrated into host DNA later. The integrase then facilitates the movement of the new proviral DNA into the host cell's nucleus. Here it is then incorporated into the endogenous host DNA. Once the host cell initiates transcription, the proviral DNA is then made into mRNA. It then migrates into the cell's cytoplasm and undergoes translation via host ribosomes. These newly synthesized viral proteins are then edited by the viral protease so as to make the proteins better able to assemble. Once all the components of viral assembly are complete, the virus then exits the host cell through the membrane, incorporating host membrane components into its own viral envelope. This virus is now capable of infecting other host cells. This process occurs continuously which eventually compromises the integrity of the host cell in form and function, leading to death of the T-cell.
The acute phase Maybe completely asymptomatic or sporadically clinical in nature. The clinical signs are flu like in nature and comprised of fever, malaise, lymphadenopathy and diarrhea. During the acute phase Ab’s are present but ineffective in clearing the virus from the body.
The latent phaseThis will follow the the Acute phase (which might go completely unnoticed) The latent phase will last from months too years. During this time that host will be asymptomatic and lead a normal life. Once the immunosuppression is great enough (CD4 cell numbers have dropped sufficiently) opportunistic infections will take hold and the terminal phase has started.
The Terminal phase is lastIt is characterized by opportunistic infections by bacteria (both commensal and infective, fungus, protozoa and other viruses.Clinical presentation will vary depending on the co-infecting pathogen. In General they will include any and/or all of the following. (Please not this is not an exhaustive list) 1) Chronic Respiratory Disease 2) Chronic Diarrhea and wasting 3) Chronic stomatitis and gingivitis 4) Dermatitis 5) Neurological signsMycotic infections are very common and easily become deep rooted superinfections which consequently drain what little immune system is functional and leave the host open to more opportunistic infections. A higher incidence of co-infection will be seen in those pathogens that are endemic to the hosts home range as well as overgrowth of normal host fauna and flora. Some of the most common are Toxoplasmosis, FIP and FeLV
After initial infection, antibodies will begin to appear in 2-4 weeks. Methods available for testing for antibodies include immunofluorescence assays (IFAs), Enzyme-Linked Immunosorbent Assay (ELISAs), and Western Blots.When using the presence of antibodies to determine if an animal has been infected with FIV, false positive and false negative test results are possible.Animals can be infected with the virus test negative if antibody concentrations are not great enough. This could occur in an animal that was recently infected. To avoid false negatives, its best to retest animals for FIV at least 60 days after their most recent possible exposure to the virus.Young kittens can test positive even though they haven’t been infected, because they can acquire maternal antibodies through colostrum. However, it should be noted that while less common, kittens can become infected with FIV during their passage through the birth canal or during nursing. As a result, any kitten that tests positive for FIV should be retested after 12 weeks of age. Any antibodies detected at this time would have been formed by kitten’s own immune system.False-negative test results are also possible in animals with later stage infections of FIV. Their immune systems are no longer able to function properly and as a result cannot continue to produce antibodies to the virus.Another method of testing is Polymerase chain reactions, or PCRs. They are designed to directly detect short sequences of a virus’s genetic code. These tests would prove to be very useful for determining if a kitten’s AB’s are maternal in origin or if the animal has been infected by the virus. Because the sequences of FIV viruses are so variable and a PCR requires the use of a specific probe to detect the virus, these tests can yield false-negative results (sensitivity 41–93%, specificity 44–100%). Image sources: http://www.kruuse.com/nn-NO/ecom/Laboratorium/Forbrug_laboratorium/Test/SNAP_test_IDEXX/prod_290727.aspx
As seen in the presenting case, feral cats that test positive for FIV in catch and release programs are typically euthanized because of the high horizontal transmission rates between fighting feral cats, particularly intact toms. The best method of control owners can practice is prevention. Keep your pets away from feral cats to prevent exposure to FIV-infected animals.Vaccines are available, but their benefits are questionable. There are many different strains and subtypes of FIV, and a vaccine designed off of one strain may not offer protection from another.It should be noted an animal that has been vaccinated against FIV will test positive for the disease when using AB-based tests.
A few years back, a study headed by Dr. Patrick Kelly was conducted to quantify the prevelance of FIV on our island of St. Kitts. The study occurred between the years 2006-2007 and in 2009. Of the 99 cats sampled in the 2006/7 study, 15% were found to be FIV(+), 12 males and 3 females. In 2009, 72 were sampled with a FIV incidence of 14% (+), 9 males and 1 female.
FooFoo was brought in as a part of the feral cat program. He was an intact, domestic short hair male approximately 12 months old. He tested positive for FIV and was euthanized. FIV is a virus that disrupts the normal immune function of the animal leaving it susceptible to various opportunistic infections from bacteria, fungi and other viruses. It is very common in free roaming cats, such as this one, and is transmitted through bites of infected animals. This is the most probable cause for how FooFoo acquired the disease. The gross findings in this case showed few definitive diagnoses for FIV. It can therefore be presumed that the disease was in its earlier stages. There were numerous facial lesions along with a healed corneal ulcer that were most likely caused by cat fights. Diffuse bilateral otitisexterna was also observed. The most probable cause coming from an ectoparisite like Otodectescynotis. A single firm area was found on the apical portion of the right caudal lung lobe. Most likely related to a prior incidence of pneumonia. The pneumonia was probably contracted from a secondary bacterial, viral or fungal infection that typically occurs in the immunosuppressed state of FIV. Five white helminths were also observed in the jejunum. Due to the site of infection, gross appearance and the findings of what appeared to be flea dirt throughout the fur the parasite was presumed to be Diplidyumcaninum.
N059 06 17-2011
GROUP 9NECROPSY PRESENTATION07-04-2011 Byrnes, Heather Childress, Will Bovino, Robert Cloonan, Brendan Cameron- Blake, Ninian Cologgi, Kristen Cantrell, Margaret Concepcion, Anaelys Carril, Valerie Cowan, Shane Cerulli, Katherine
Necropsy Case Number: N059:06-17-2011 Date of necropsy: 6-17-2011 Time of necropsy: 11:00 am Animal Euthanized: 6-14-2011 Name of attending pathologist: Dr. Fernanda Castillo Client Number: 11599
History Came to Ross as a part of the Feline spay and neuter program. Presented for castration Was given IM injection in cervical epaxials for sedation. Jugular venipuncture Tested FIV positive, euthanized
Healed corneal ulceration Acute, focal, healed corneal ulceration of the right eye 1.5mm in diameter
Corneal ulceration FHV-1 Primary infection manifests in respiratory tract and eyes Damage during active infection due to lysis of cells of the corneal epithelium May be replaced by conjunctival-like epithelium that is not completely transparent One or both eyes may be affected
Corneal ulceration Most likely cause of the trauma is fighting Due to presence of other facial lesions
Auditory System Bilateral dark brown to black waxy exudate No signs of external trauma or inflammation in ear canal Potentially otitis externa Likely just normal secretions and dirt (common finding in feral cats)
Auditory system: Otitis externa Acute or chronic inflammation of the epithelium of the external ear canal Characterized by erythema, edema, increased sebum or exudate, and desquamation of the epithelium Most common disease of the ear canal in cats Can be due to a wide variety of factors
Integument: Skin lesions Facial lesions (10) Likelybite wounds (fighting) Located around eyes, muzzle, chin, ears, and top of head Ranged from 1-3mm in length Left foreleg Hairless area (4cm x 7cm) surrounding inflamed tissue (2cm x 5cm) Puncture wound (3mm) in inflamed tissue Likely from premortem venipuncture
Integument: Flea Dirt Red-black dirt-like specks size of a pin head to approximately 0.5mm The presence of this accumulate is consistent with a Ctenocephalides spp. parasitic infection: fleas!
Internal Findings: SmallIntestine Dipylidium caninum Clinical signs The segments range Excessive grooming in size: of the perineum 180mm x 3-5mm x Scooting 1mm 125mm x 3-5mm x Diarrhea 1mm 54mm x 3-5mm x 1mm 65mm x 3-5mm x 1mm Morphologic Dx? Catarrhal enteritis
Respiratory System Dark red coloration of the right lung Left lung appears to be unaffected Potential causes: 1. Hypostatic Congestion 2. Hypostatic Pneumonia Small thickened area present on apex of the right caudal lung lobe
Hypostatic Congestion Results from the pull of gravity and its effects on the settling of blood Post-mortem process Normal finding often due to the positioning of the body after death
Hypostatic Pneumonia Anything that slows the flow of blood through the lungs causing it to move into the pulmonary spaces Pre-mortem Secondary process to other diseases e.g. congestive heart failure Anesthesia
Thickening of Lung Related to FIV Scarring from past lung infection or pneumonia Bacterial or viral infections
What is Pneumonia? It’s the acute or chronic inflammation of the lungs and bronchi causing irregular respiration and hypoxemia. Pneumonia can be caused by several factors; parasites, viruses, bacteria, some chemical agents and direct injury to the lung.
Pneumonia Some bacteria that cause Pneumonia are Mycobacterium tuberculosis Streptococcus pneumoniae Chlamydiae (but this is rare)
Pneumonia Although bacterial infections play a role in the progression of FIV in terms of lung damage, it has been reported that FIV can lead to lung disease without the presence of bacterial infections.
FIV Lentivirus Chronic disease High Antigenic Variation 5 subtypes A, B, C, D, E
Diagnosis Testing for antibodies: ELISA (snap test), IFA, or Western Blot Both false negative and false positive results are possible Kittens < 12 weeks must be retested after 12 weeks of age to make sure antibodies detected were not maternally derived Testing for the virus: Proviral DNA PCR Found in peripheral blood leukocytes of infected cats
Control As in the presenting case, feral cats that test positive for FIV in catch and release programs may be euthanized as transmission between fighting feral cats is very high. House pets should be kept away from feral cats. Vaccines are available Will the vaccine protect against all serotypes? Efficacy is still in question as well it has been associated with Vaccine Associated Sarcoma Zoonosis Virus is species specific and no transmission to date has been recorded in humans
FIV: in St. Kitts Study conducted through RUSVM 2006-2007 99 feral cats sampled 51 males and 48 females 15% FIV (+) 12 males and 3 females 2009 72 feral cats sampled 41 males and 31 females 14% FIV (+) 9 males and 1 female
Summary Foo Foo intact male approximately 12 months old Part of the feral cat program Tested positive for FIV and euthanized No gross findings Numerous skin lesions Healed corneal ulceration Diffuse bilateral otitis externa Single firm area on the caudal right lung lobe Five white helminths observed in the jejunum
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Any Questions? P.S. This is NOT appropriate dress code for lab!